* A ViewGroup is a special view that can contain other views
* (called children.) The view group is the base class for layouts and views
* containers. This class also defines the
* {@link android.view.ViewGroup.LayoutParams} class which serves as the base
* class for layouts parameters.
*
* Also see {@link LayoutParams} for layout attributes. *
* *For more information about creating user interface layouts, read the * XML Layouts developer * guide.
* If an {@link android.view.View.AccessibilityDelegate} has been specified via calling * {@link android.view.View#setAccessibilityDelegate(android.view.View.AccessibilityDelegate)} its * {@link android.view.View.AccessibilityDelegate#onRequestSendAccessibilityEvent(ViewGroup, View, AccessibilityEvent)} * is responsible for handling this call. *
* * @param child The child which requests sending the event. * @param event The event to be sent. * @return True if the event should be sent. * * @see #requestSendAccessibilityEvent(View, AccessibilityEvent) */ public boolean onRequestSendAccessibilityEvent(View child, AccessibilityEvent event) { if (mAccessibilityDelegate != null) { return mAccessibilityDelegate.onRequestSendAccessibilityEvent(this, child, event); } else { return onRequestSendAccessibilityEventInternal(child, event); } } /** * @see #onRequestSendAccessibilityEvent(View, AccessibilityEvent) * * Note: Called from the default {@link View.AccessibilityDelegate}. */ boolean onRequestSendAccessibilityEventInternal(View child, AccessibilityEvent event) { return true; } /** * Called when a child view has changed whether or not it is tracking transient state. * * @hide */ public void childHasTransientStateChanged(View child, boolean childHasTransientState) { final boolean oldHasTransientState = hasTransientState(); if (childHasTransientState) { mChildCountWithTransientState++; } else { mChildCountWithTransientState--; } final boolean newHasTransientState = hasTransientState(); if (mParent != null && oldHasTransientState != newHasTransientState) { try { mParent.childHasTransientStateChanged(this, newHasTransientState); } catch (AbstractMethodError e) { Log.e(TAG, mParent.getClass().getSimpleName() + " does not fully implement ViewParent", e); } } } /** * @hide */ @Override public boolean hasTransientState() { return mChildCountWithTransientState > 0 || super.hasTransientState(); } /** * {@inheritDoc} */ @Override public boolean dispatchUnhandledMove(View focused, int direction) { return mFocused != null && mFocused.dispatchUnhandledMove(focused, direction); } /** * {@inheritDoc} */ public void clearChildFocus(View child) { if (DBG) { System.out.println(this + " clearChildFocus()"); } mFocused = null; if (mParent != null) { mParent.clearChildFocus(this); } } /** * {@inheritDoc} */ @Override public void clearFocus() { if (DBG) { System.out.println(this + " clearFocus()"); } if (mFocused == null) { super.clearFocus(); } else { View focused = mFocused; mFocused = null; focused.clearFocus(); } } /** * {@inheritDoc} */ @Override void unFocus() { if (DBG) { System.out.println(this + " unFocus()"); } if (mFocused == null) { super.unFocus(); } else { mFocused.unFocus(); mFocused = null; } } /** * Returns the focused child of this view, if any. The child may have focus * or contain focus. * * @return the focused child or null. */ public View getFocusedChild() { return mFocused; } /** * Returns true if this view has or contains focus * * @return true if this view has or contains focus */ @Override public boolean hasFocus() { return (mPrivateFlags & PFLAG_FOCUSED) != 0 || mFocused != null; } /* * (non-Javadoc) * * @see android.view.View#findFocus() */ @Override public View findFocus() { if (DBG) { System.out.println("Find focus in " + this + ": flags=" + isFocused() + ", child=" + mFocused); } if (isFocused()) { return this; } if (mFocused != null) { return mFocused.findFocus(); } return null; } /** * {@inheritDoc} */ @Override public boolean hasFocusable() { if ((mViewFlags & VISIBILITY_MASK) != VISIBLE) { return false; } if (isFocusable()) { return true; } final int descendantFocusability = getDescendantFocusability(); if (descendantFocusability != FOCUS_BLOCK_DESCENDANTS) { final int count = mChildrenCount; final View[] children = mChildren; for (int i = 0; i < count; i++) { final View child = children[i]; if (child.hasFocusable()) { return true; } } } return false; } /** * {@inheritDoc} */ @Override public void addFocusables(ArrayList* This method is called before dispatching a hover event to a child of * the view group or to the view group's own {@link #onHoverEvent} to allow * the view group a chance to intercept the hover event. * This method can also be used to watch all pointer motions that occur within * the bounds of the view group even when the pointer is hovering over * a child of the view group rather than over the view group itself. *
* The view group can prevent its children from receiving hover events by
* implementing this method and returning true to indicate
* that it would like to intercept hover events. The view group must
* continuously return true from {@link #onInterceptHoverEvent}
* for as long as it wishes to continue intercepting hover events from
* its children.
*
* Interception preserves the invariant that at most one view can be * hovered at a time by transferring hover focus from the currently hovered * child to the view group or vice-versa as needed. *
* If this method returns true and a child is already hovered, then the
* child view will first receive a hover exit event and then the view group
* itself will receive a hover enter event in {@link #onHoverEvent}.
* Likewise, if this method had previously returned true to intercept hover
* events and instead returns false while the pointer is hovering
* within the bounds of one of a child, then the view group will first receive a
* hover exit event in {@link #onHoverEvent} and then the hovered child will
* receive a hover enter event.
*
* The default implementation always returns false. *
* * @param event The motion event that describes the hover. * @return True if the view group would like to intercept the hover event * and prevent its children from receiving it. */ public boolean onInterceptHoverEvent(MotionEvent event) { return false; } private static MotionEvent obtainMotionEventNoHistoryOrSelf(MotionEvent event) { if (event.getHistorySize() == 0) { return event; } return MotionEvent.obtainNoHistory(event); } /** * {@inheritDoc} */ @Override protected boolean dispatchGenericPointerEvent(MotionEvent event) { // Send the event to the child under the pointer. final int childrenCount = mChildrenCount; if (childrenCount != 0) { final View[] children = mChildren; final float x = event.getX(); final float y = event.getY(); final boolean customOrder = isChildrenDrawingOrderEnabled(); for (int i = childrenCount - 1; i >= 0; i--) { final int childIndex = customOrder ? getChildDrawingOrder(childrenCount, i) : i; final View child = children[childIndex]; if (!canViewReceivePointerEvents(child) || !isTransformedTouchPointInView(x, y, child, null)) { continue; } if (dispatchTransformedGenericPointerEvent(event, child)) { return true; } } } // No child handled the event. Send it to this view group. return super.dispatchGenericPointerEvent(event); } /** * {@inheritDoc} */ @Override protected boolean dispatchGenericFocusedEvent(MotionEvent event) { // Send the event to the focused child or to this view group if it has focus. if ((mPrivateFlags & (PFLAG_FOCUSED | PFLAG_HAS_BOUNDS)) == (PFLAG_FOCUSED | PFLAG_HAS_BOUNDS)) { return super.dispatchGenericFocusedEvent(event); } else if (mFocused != null && (mFocused.mPrivateFlags & PFLAG_HAS_BOUNDS) == PFLAG_HAS_BOUNDS) { return mFocused.dispatchGenericMotionEvent(event); } return false; } /** * Dispatches a generic pointer event to a child, taking into account * transformations that apply to the child. * * @param event The event to send. * @param child The view to send the event to. * @return {@code true} if the child handled the event. */ private boolean dispatchTransformedGenericPointerEvent(MotionEvent event, View child) { final float offsetX = mScrollX - child.mLeft; final float offsetY = mScrollY - child.mTop; boolean handled; if (!child.hasIdentityMatrix()) { MotionEvent transformedEvent = MotionEvent.obtain(event); transformedEvent.offsetLocation(offsetX, offsetY); transformedEvent.transform(child.getInverseMatrix()); handled = child.dispatchGenericMotionEvent(transformedEvent); transformedEvent.recycle(); } else { event.offsetLocation(offsetX, offsetY); handled = child.dispatchGenericMotionEvent(event); event.offsetLocation(-offsetX, -offsetY); } return handled; } /** * {@inheritDoc} */ @Override public boolean dispatchTouchEvent(MotionEvent ev) { if (mInputEventConsistencyVerifier != null) { mInputEventConsistencyVerifier.onTouchEvent(ev, 1); } boolean handled = false; if (onFilterTouchEventForSecurity(ev)) { final int action = ev.getAction(); final int actionMasked = action & MotionEvent.ACTION_MASK; // Handle an initial down. if (actionMasked == MotionEvent.ACTION_DOWN) { // Throw away all previous state when starting a new touch gesture. // The framework may have dropped the up or cancel event for the previous gesture // due to an app switch, ANR, or some other state change. cancelAndClearTouchTargets(ev); resetTouchState(); } // Check for interception. final boolean intercepted; if (actionMasked == MotionEvent.ACTION_DOWN || mFirstTouchTarget != null) { final boolean disallowIntercept = (mGroupFlags & FLAG_DISALLOW_INTERCEPT) != 0; if (!disallowIntercept) { intercepted = onInterceptTouchEvent(ev); ev.setAction(action); // restore action in case it was changed } else { intercepted = false; } } else { // There are no touch targets and this action is not an initial down // so this view group continues to intercept touches. intercepted = true; } // Check for cancelation. final boolean canceled = resetCancelNextUpFlag(this) || actionMasked == MotionEvent.ACTION_CANCEL; // Update list of touch targets for pointer down, if needed. final boolean split = (mGroupFlags & FLAG_SPLIT_MOTION_EVENTS) != 0; TouchTarget newTouchTarget = null; boolean alreadyDispatchedToNewTouchTarget = false; if (!canceled && !intercepted) { if (actionMasked == MotionEvent.ACTION_DOWN || (split && actionMasked == MotionEvent.ACTION_POINTER_DOWN) || actionMasked == MotionEvent.ACTION_HOVER_MOVE) { final int actionIndex = ev.getActionIndex(); // always 0 for down final int idBitsToAssign = split ? 1 << ev.getPointerId(actionIndex) : TouchTarget.ALL_POINTER_IDS; // Clean up earlier touch targets for this pointer id in case they // have become out of sync. removePointersFromTouchTargets(idBitsToAssign); final int childrenCount = mChildrenCount; if (childrenCount != 0) { // Find a child that can receive the event. // Scan children from front to back. final View[] children = mChildren; final float x = ev.getX(actionIndex); final float y = ev.getY(actionIndex); final boolean customOrder = isChildrenDrawingOrderEnabled(); for (int i = childrenCount - 1; i >= 0; i--) { final int childIndex = customOrder ? getChildDrawingOrder(childrenCount, i) : i; final View child = children[childIndex]; if (!canViewReceivePointerEvents(child) || !isTransformedTouchPointInView(x, y, child, null)) { continue; } newTouchTarget = getTouchTarget(child); if (newTouchTarget != null) { // Child is already receiving touch within its bounds. // Give it the new pointer in addition to the ones it is handling. newTouchTarget.pointerIdBits |= idBitsToAssign; break; } resetCancelNextUpFlag(child); if (dispatchTransformedTouchEvent(ev, false, child, idBitsToAssign)) { // Child wants to receive touch within its bounds. mLastTouchDownTime = ev.getDownTime(); mLastTouchDownIndex = childIndex; mLastTouchDownX = ev.getX(); mLastTouchDownY = ev.getY(); newTouchTarget = addTouchTarget(child, idBitsToAssign); alreadyDispatchedToNewTouchTarget = true; break; } } } if (newTouchTarget == null && mFirstTouchTarget != null) { // Did not find a child to receive the event. // Assign the pointer to the least recently added target. newTouchTarget = mFirstTouchTarget; while (newTouchTarget.next != null) { newTouchTarget = newTouchTarget.next; } newTouchTarget.pointerIdBits |= idBitsToAssign; } } } // Dispatch to touch targets. if (mFirstTouchTarget == null) { // No touch targets so treat this as an ordinary view. handled = dispatchTransformedTouchEvent(ev, canceled, null, TouchTarget.ALL_POINTER_IDS); } else { // Dispatch to touch targets, excluding the new touch target if we already // dispatched to it. Cancel touch targets if necessary. TouchTarget predecessor = null; TouchTarget target = mFirstTouchTarget; while (target != null) { final TouchTarget next = target.next; if (alreadyDispatchedToNewTouchTarget && target == newTouchTarget) { handled = true; } else { final boolean cancelChild = resetCancelNextUpFlag(target.child) || intercepted; if (dispatchTransformedTouchEvent(ev, cancelChild, target.child, target.pointerIdBits)) { handled = true; } if (cancelChild) { if (predecessor == null) { mFirstTouchTarget = next; } else { predecessor.next = next; } target.recycle(); target = next; continue; } } predecessor = target; target = next; } } // Update list of touch targets for pointer up or cancel, if needed. if (canceled || actionMasked == MotionEvent.ACTION_UP || actionMasked == MotionEvent.ACTION_HOVER_MOVE) { resetTouchState(); } else if (split && actionMasked == MotionEvent.ACTION_POINTER_UP) { final int actionIndex = ev.getActionIndex(); final int idBitsToRemove = 1 << ev.getPointerId(actionIndex); removePointersFromTouchTargets(idBitsToRemove); } } if (!handled && mInputEventConsistencyVerifier != null) { mInputEventConsistencyVerifier.onUnhandledEvent(ev, 1); } return handled; } /** * Resets all touch state in preparation for a new cycle. */ private void resetTouchState() { clearTouchTargets(); resetCancelNextUpFlag(this); mGroupFlags &= ~FLAG_DISALLOW_INTERCEPT; } /** * Resets the cancel next up flag. * Returns true if the flag was previously set. */ private static boolean resetCancelNextUpFlag(View view) { if ((view.mPrivateFlags & PFLAG_CANCEL_NEXT_UP_EVENT) != 0) { view.mPrivateFlags &= ~PFLAG_CANCEL_NEXT_UP_EVENT; return true; } return false; } /** * Clears all touch targets. */ private void clearTouchTargets() { TouchTarget target = mFirstTouchTarget; if (target != null) { do { TouchTarget next = target.next; target.recycle(); target = next; } while (target != null); mFirstTouchTarget = null; } } /** * Cancels and clears all touch targets. */ private void cancelAndClearTouchTargets(MotionEvent event) { if (mFirstTouchTarget != null) { boolean syntheticEvent = false; if (event == null) { final long now = SystemClock.uptimeMillis(); event = MotionEvent.obtain(now, now, MotionEvent.ACTION_CANCEL, 0.0f, 0.0f, 0); event.setSource(InputDevice.SOURCE_TOUCHSCREEN); syntheticEvent = true; } for (TouchTarget target = mFirstTouchTarget; target != null; target = target.next) { resetCancelNextUpFlag(target.child); dispatchTransformedTouchEvent(event, true, target.child, target.pointerIdBits); } clearTouchTargets(); if (syntheticEvent) { event.recycle(); } } } /** * Gets the touch target for specified child view. * Returns null if not found. */ private TouchTarget getTouchTarget(View child) { for (TouchTarget target = mFirstTouchTarget; target != null; target = target.next) { if (target.child == child) { return target; } } return null; } /** * Adds a touch target for specified child to the beginning of the list. * Assumes the target child is not already present. */ private TouchTarget addTouchTarget(View child, int pointerIdBits) { TouchTarget target = TouchTarget.obtain(child, pointerIdBits); target.next = mFirstTouchTarget; mFirstTouchTarget = target; return target; } /** * Removes the pointer ids from consideration. */ private void removePointersFromTouchTargets(int pointerIdBits) { TouchTarget predecessor = null; TouchTarget target = mFirstTouchTarget; while (target != null) { final TouchTarget next = target.next; if ((target.pointerIdBits & pointerIdBits) != 0) { target.pointerIdBits &= ~pointerIdBits; if (target.pointerIdBits == 0) { if (predecessor == null) { mFirstTouchTarget = next; } else { predecessor.next = next; } target.recycle(); target = next; continue; } } predecessor = target; target = next; } } private void cancelTouchTarget(View view) { TouchTarget predecessor = null; TouchTarget target = mFirstTouchTarget; while (target != null) { final TouchTarget next = target.next; if (target.child == view) { if (predecessor == null) { mFirstTouchTarget = next; } else { predecessor.next = next; } target.recycle(); final long now = SystemClock.uptimeMillis(); MotionEvent event = MotionEvent.obtain(now, now, MotionEvent.ACTION_CANCEL, 0.0f, 0.0f, 0); event.setSource(InputDevice.SOURCE_TOUCHSCREEN); view.dispatchTouchEvent(event); event.recycle(); return; } predecessor = target; target = next; } } /** * Returns true if a child view can receive pointer events. * @hide */ private static boolean canViewReceivePointerEvents(View child) { return (child.mViewFlags & VISIBILITY_MASK) == VISIBLE || child.getAnimation() != null; } /** * Returns true if a child view contains the specified point when transformed * into its coordinate space. * Child must not be null. * @hide */ protected boolean isTransformedTouchPointInView(float x, float y, View child, PointF outLocalPoint) { float localX = x + mScrollX - child.mLeft; float localY = y + mScrollY - child.mTop; if (! child.hasIdentityMatrix() && mAttachInfo != null) { final float[] localXY = mAttachInfo.mTmpTransformLocation; localXY[0] = localX; localXY[1] = localY; child.getInverseMatrix().mapPoints(localXY); localX = localXY[0]; localY = localXY[1]; } final boolean isInView = child.pointInView(localX, localY); if (isInView && outLocalPoint != null) { outLocalPoint.set(localX, localY); } return isInView; } /** * Transforms a motion event into the coordinate space of a particular child view, * filters out irrelevant pointer ids, and overrides its action if necessary. * If child is null, assumes the MotionEvent will be sent to this ViewGroup instead. */ private boolean dispatchTransformedTouchEvent(MotionEvent event, boolean cancel, View child, int desiredPointerIdBits) { final boolean handled; // Canceling motions is a special case. We don't need to perform any transformations // or filtering. The important part is the action, not the contents. final int oldAction = event.getAction(); if (cancel || oldAction == MotionEvent.ACTION_CANCEL) { event.setAction(MotionEvent.ACTION_CANCEL); if (child == null) { handled = super.dispatchTouchEvent(event); } else { handled = child.dispatchTouchEvent(event); } event.setAction(oldAction); return handled; } // Calculate the number of pointers to deliver. final int oldPointerIdBits = event.getPointerIdBits(); final int newPointerIdBits = oldPointerIdBits & desiredPointerIdBits; // If for some reason we ended up in an inconsistent state where it looks like we // might produce a motion event with no pointers in it, then drop the event. if (newPointerIdBits == 0) { return false; } // If the number of pointers is the same and we don't need to perform any fancy // irreversible transformations, then we can reuse the motion event for this // dispatch as long as we are careful to revert any changes we make. // Otherwise we need to make a copy. final MotionEvent transformedEvent; if (newPointerIdBits == oldPointerIdBits) { if (child == null || child.hasIdentityMatrix()) { if (child == null) { handled = super.dispatchTouchEvent(event); } else { final float offsetX = mScrollX - child.mLeft; final float offsetY = mScrollY - child.mTop; event.offsetLocation(offsetX, offsetY); handled = child.dispatchTouchEvent(event); event.offsetLocation(-offsetX, -offsetY); } return handled; } transformedEvent = MotionEvent.obtain(event); } else { transformedEvent = event.split(newPointerIdBits); } // Perform any necessary transformations and dispatch. if (child == null) { handled = super.dispatchTouchEvent(transformedEvent); } else { final float offsetX = mScrollX - child.mLeft; final float offsetY = mScrollY - child.mTop; transformedEvent.offsetLocation(offsetX, offsetY); if (! child.hasIdentityMatrix()) { transformedEvent.transform(child.getInverseMatrix()); } handled = child.dispatchTouchEvent(transformedEvent); } // Done. transformedEvent.recycle(); return handled; } /** * Enable or disable the splitting of MotionEvents to multiple children during touch event * dispatch. This behavior is enabled by default for applications that target an * SDK version of {@link Build.VERSION_CODES#HONEYCOMB} or newer. * *When this option is enabled MotionEvents may be split and dispatched to different child
* views depending on where each pointer initially went down. This allows for user interactions
* such as scrolling two panes of content independently, chording of buttons, and performing
* independent gestures on different pieces of content.
*
* @param split true to allow MotionEvents to be split and dispatched to multiple
* child views. false to only allow one child view to be the target of
* any MotionEvent received by this ViewGroup.
*/
public void setMotionEventSplittingEnabled(boolean split) {
// TODO Applications really shouldn't change this setting mid-touch event,
// but perhaps this should handle that case and send ACTION_CANCELs to any child views
// with gestures in progress when this is changed.
if (split) {
mGroupFlags |= FLAG_SPLIT_MOTION_EVENTS;
} else {
mGroupFlags &= ~FLAG_SPLIT_MOTION_EVENTS;
}
}
/**
* Returns true if MotionEvents dispatched to this ViewGroup can be split to multiple children.
* @return true if MotionEvents dispatched to this ViewGroup can be split to multiple children.
*/
public boolean isMotionEventSplittingEnabled() {
return (mGroupFlags & FLAG_SPLIT_MOTION_EVENTS) == FLAG_SPLIT_MOTION_EVENTS;
}
/**
* {@inheritDoc}
*/
public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) {
if (disallowIntercept == ((mGroupFlags & FLAG_DISALLOW_INTERCEPT) != 0)) {
// We're already in this state, assume our ancestors are too
return;
}
if (disallowIntercept) {
mGroupFlags |= FLAG_DISALLOW_INTERCEPT;
} else {
mGroupFlags &= ~FLAG_DISALLOW_INTERCEPT;
}
// Pass it up to our parent
if (mParent != null) {
mParent.requestDisallowInterceptTouchEvent(disallowIntercept);
}
}
/**
* Implement this method to intercept all touch screen motion events. This
* allows you to watch events as they are dispatched to your children, and
* take ownership of the current gesture at any point.
*
*
Using this function takes some care, as it has a fairly complicated * interaction with {@link View#onTouchEvent(MotionEvent) * View.onTouchEvent(MotionEvent)}, and using it requires implementing * that method as well as this one in the correct way. Events will be * received in the following order: * *
* NOTE: In order for this method to be called, you must enable child ordering
* first by calling {@link #setChildrenDrawingOrderEnabled(boolean)}.
*
* @param i The current iteration.
* @return The index of the child to draw this iteration.
*
* @see #setChildrenDrawingOrderEnabled(boolean)
* @see #isChildrenDrawingOrderEnabled()
*/
protected int getChildDrawingOrder(int childCount, int i) {
return i;
}
private void notifyAnimationListener() {
mGroupFlags &= ~FLAG_NOTIFY_ANIMATION_LISTENER;
mGroupFlags |= FLAG_ANIMATION_DONE;
if (mAnimationListener != null) {
final Runnable end = new Runnable() {
public void run() {
mAnimationListener.onAnimationEnd(mLayoutAnimationController.getAnimation());
}
};
post(end);
}
if ((mGroupFlags & FLAG_ANIMATION_CACHE) == FLAG_ANIMATION_CACHE) {
mGroupFlags &= ~FLAG_CHILDREN_DRAWN_WITH_CACHE;
if ((mPersistentDrawingCache & PERSISTENT_ANIMATION_CACHE) == 0) {
setChildrenDrawingCacheEnabled(false);
}
}
invalidate(true);
}
/**
* This method is used to cause children of this ViewGroup to restore or recreate their
* display lists. It is called by getDisplayList() when the parent ViewGroup does not need
* to recreate its own display list, which would happen if it went through the normal
* draw/dispatchDraw mechanisms.
*
* @hide
*/
@Override
protected void dispatchGetDisplayList() {
final int count = mChildrenCount;
final View[] children = mChildren;
for (int i = 0; i < count; i++) {
final View child = children[i];
if (((child.mViewFlags & VISIBILITY_MASK) == VISIBLE || child.getAnimation() != null) &&
child.hasStaticLayer()) {
child.mRecreateDisplayList = (child.mPrivateFlags & PFLAG_INVALIDATED)
== PFLAG_INVALIDATED;
child.mPrivateFlags &= ~PFLAG_INVALIDATED;
child.getDisplayList();
child.mRecreateDisplayList = false;
}
}
}
/**
* Draw one child of this View Group. This method is responsible for getting
* the canvas in the right state. This includes clipping, translating so
* that the child's scrolled origin is at 0, 0, and applying any animation
* transformations.
*
* @param canvas The canvas on which to draw the child
* @param child Who to draw
* @param drawingTime The time at which draw is occurring
* @return True if an invalidate() was issued
*/
protected boolean drawChild(Canvas canvas, View child, long drawingTime) {
return child.draw(canvas, this, drawingTime);
}
/**
* By default, children are clipped to their bounds before drawing. This
* allows view groups to override this behavior for animations, etc.
*
* @param clipChildren true to clip children to their bounds,
* false otherwise
* @attr ref android.R.styleable#ViewGroup_clipChildren
*/
public void setClipChildren(boolean clipChildren) {
boolean previousValue = (mGroupFlags & FLAG_CLIP_CHILDREN) == FLAG_CLIP_CHILDREN;
if (clipChildren != previousValue) {
setBooleanFlag(FLAG_CLIP_CHILDREN, clipChildren);
for (int i = 0; i < mChildrenCount; ++i) {
View child = getChildAt(i);
if (child.mDisplayList != null) {
child.mDisplayList.setClipChildren(clipChildren);
}
}
}
}
/**
* By default, children are clipped to the padding of the ViewGroup. This
* allows view groups to override this behavior
*
* @param clipToPadding true to clip children to the padding of the
* group, false otherwise
* @attr ref android.R.styleable#ViewGroup_clipToPadding
*/
public void setClipToPadding(boolean clipToPadding) {
setBooleanFlag(FLAG_CLIP_TO_PADDING, clipToPadding);
}
/**
* {@inheritDoc}
*/
@Override
public void dispatchSetSelected(boolean selected) {
final View[] children = mChildren;
final int count = mChildrenCount;
for (int i = 0; i < count; i++) {
children[i].setSelected(selected);
}
}
/**
* {@inheritDoc}
*/
@Override
public void dispatchSetActivated(boolean activated) {
final View[] children = mChildren;
final int count = mChildrenCount;
for (int i = 0; i < count; i++) {
children[i].setActivated(activated);
}
}
@Override
protected void dispatchSetPressed(boolean pressed) {
final View[] children = mChildren;
final int count = mChildrenCount;
for (int i = 0; i < count; i++) {
final View child = children[i];
// Children that are clickable on their own should not
// show a pressed state when their parent view does.
// Clearing a pressed state always propagates.
if (!pressed || (!child.isClickable() && !child.isLongClickable())) {
child.setPressed(pressed);
}
}
}
/**
* When this property is set to true, this ViewGroup supports static transformations on
* children; this causes
* {@link #getChildStaticTransformation(View, android.view.animation.Transformation)} to be
* invoked when a child is drawn.
*
* Any subclass overriding
* {@link #getChildStaticTransformation(View, android.view.animation.Transformation)} should
* set this property to true.
*
* @param enabled True to enable static transformations on children, false otherwise.
*
* @see #getChildStaticTransformation(View, android.view.animation.Transformation)
*/
protected void setStaticTransformationsEnabled(boolean enabled) {
setBooleanFlag(FLAG_SUPPORT_STATIC_TRANSFORMATIONS, enabled);
}
/**
* Sets Adds a child view. If no layout parameters are already set on the child, the
* default parameters for this ViewGroup are set on the child. Note: do not invoke this method from
* {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
* {@link #dispatchDraw(android.graphics.Canvas)} or any related method. Note: do not invoke this method from
* {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
* {@link #dispatchDraw(android.graphics.Canvas)} or any related method. Note: do not invoke this method from
* {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
* {@link #dispatchDraw(android.graphics.Canvas)} or any related method. Note: do not invoke this method from
* {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
* {@link #dispatchDraw(android.graphics.Canvas)} or any related method. Note: do not invoke this method from
* {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
* {@link #dispatchDraw(android.graphics.Canvas)} or any related method. Note: do not invoke this method from
* {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
* {@link #dispatchDraw(android.graphics.Canvas)} or any related method. Note: do not invoke this method from
* {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
* {@link #dispatchDraw(android.graphics.Canvas)} or any related method. Note: do not invoke this method from
* {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
* {@link #dispatchDraw(android.graphics.Canvas)} or any related method. Note: do not invoke this method from
* {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
* {@link #dispatchDraw(android.graphics.Canvas)} or any related method. Note: do not invoke this method from
* {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
* {@link #dispatchDraw(android.graphics.Canvas)} or any related method. Note: do not invoke this method from
* {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
* {@link #dispatchDraw(android.graphics.Canvas)} or any related method. Note: do not invoke this method from
* {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
* {@link #dispatchDraw(android.graphics.Canvas)} or any related method.
* This method is intended to be lightweight and makes no assumptions about whether the
* parent or child should be redrawn. Proper use of this method will include also making
* any appropriate {@link #requestLayout()} or {@link #invalidate()} calls.
* For example, callers can {@link #post(Runnable) post} a {@link Runnable}
* which performs a {@link #requestLayout()} on the next frame, after all detach/remove
* calls are finished, causing layout to be run prior to redrawing the view hierarchy.
*
* @param child the child to be definitely removed from the view hierarchy
* @param animate if true and the view has an animation, the view is placed in the
* disappearing views list, otherwise, it is detached from the window
*
* @see #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)
* @see #detachAllViewsFromParent()
* @see #detachViewFromParent(View)
* @see #detachViewFromParent(int)
*/
protected void removeDetachedView(View child, boolean animate) {
if (mTransition != null) {
mTransition.removeChild(this, child);
}
if (child == mFocused) {
child.clearFocus();
}
child.clearAccessibilityFocus();
cancelTouchTarget(child);
cancelHoverTarget(child);
if ((animate && child.getAnimation() != null) ||
(mTransitioningViews != null && mTransitioningViews.contains(child))) {
addDisappearingView(child);
} else if (child.mAttachInfo != null) {
child.dispatchDetachedFromWindow();
}
if (child.hasTransientState()) {
childHasTransientStateChanged(child, false);
}
onViewRemoved(child);
}
/**
* Attaches a view to this view group. Attaching a view assigns this group as the parent,
* sets the layout parameters and puts the view in the list of children so that
* it can be retrieved by calling {@link #getChildAt(int)}.
*
* This method is intended to be lightweight and makes no assumptions about whether the
* parent or child should be redrawn. Proper use of this method will include also making
* any appropriate {@link #requestLayout()} or {@link #invalidate()} calls.
* For example, callers can {@link #post(Runnable) post} a {@link Runnable}
* which performs a {@link #requestLayout()} on the next frame, after all detach/attach
* calls are finished, causing layout to be run prior to redrawing the view hierarchy.
*
* This method should be called only for views which were detached from their parent.
*
* @param child the child to attach
* @param index the index at which the child should be attached
* @param params the layout parameters of the child
*
* @see #removeDetachedView(View, boolean)
* @see #detachAllViewsFromParent()
* @see #detachViewFromParent(View)
* @see #detachViewFromParent(int)
*/
protected void attachViewToParent(View child, int index, LayoutParams params) {
child.mLayoutParams = params;
if (index < 0) {
index = mChildrenCount;
}
addInArray(child, index);
child.mParent = this;
child.mPrivateFlags = (child.mPrivateFlags & ~PFLAG_DIRTY_MASK
& ~PFLAG_DRAWING_CACHE_VALID)
| PFLAG_DRAWN | PFLAG_INVALIDATED;
this.mPrivateFlags |= PFLAG_INVALIDATED;
if (child.hasFocus()) {
requestChildFocus(child, child.findFocus());
}
}
/**
* Detaches a view from its parent. Detaching a view should be followed
* either by a call to
* {@link #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)}
* or a call to {@link #removeDetachedView(View, boolean)}. Detachment should only be
* temporary; reattachment or removal should happen within the same drawing cycle as
* detachment. When a view is detached, its parent is null and cannot be retrieved by a
* call to {@link #getChildAt(int)}.
*
* @param child the child to detach
*
* @see #detachViewFromParent(int)
* @see #detachViewsFromParent(int, int)
* @see #detachAllViewsFromParent()
* @see #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)
* @see #removeDetachedView(View, boolean)
*/
protected void detachViewFromParent(View child) {
removeFromArray(indexOfChild(child));
}
/**
* Detaches a view from its parent. Detaching a view should be followed
* either by a call to
* {@link #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)}
* or a call to {@link #removeDetachedView(View, boolean)}. Detachment should only be
* temporary; reattachment or removal should happen within the same drawing cycle as
* detachment. When a view is detached, its parent is null and cannot be retrieved by a
* call to {@link #getChildAt(int)}.
*
* @param index the index of the child to detach
*
* @see #detachViewFromParent(View)
* @see #detachAllViewsFromParent()
* @see #detachViewsFromParent(int, int)
* @see #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)
* @see #removeDetachedView(View, boolean)
*/
protected void detachViewFromParent(int index) {
removeFromArray(index);
}
/**
* Detaches a range of views from their parents. Detaching a view should be followed
* either by a call to
* {@link #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)}
* or a call to {@link #removeDetachedView(View, boolean)}. Detachment should only be
* temporary; reattachment or removal should happen within the same drawing cycle as
* detachment. When a view is detached, its parent is null and cannot be retrieved by a
* call to {@link #getChildAt(int)}.
*
* @param start the first index of the childrend range to detach
* @param count the number of children to detach
*
* @see #detachViewFromParent(View)
* @see #detachViewFromParent(int)
* @see #detachAllViewsFromParent()
* @see #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)
* @see #removeDetachedView(View, boolean)
*/
protected void detachViewsFromParent(int start, int count) {
removeFromArray(start, count);
}
/**
* Detaches all views from the parent. Detaching a view should be followed
* either by a call to
* {@link #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)}
* or a call to {@link #removeDetachedView(View, boolean)}. Detachment should only be
* temporary; reattachment or removal should happen within the same drawing cycle as
* detachment. When a view is detached, its parent is null and cannot be retrieved by a
* call to {@link #getChildAt(int)}.
*
* @see #detachViewFromParent(View)
* @see #detachViewFromParent(int)
* @see #detachViewsFromParent(int, int)
* @see #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)
* @see #removeDetachedView(View, boolean)
*/
protected void detachAllViewsFromParent() {
final int count = mChildrenCount;
if (count <= 0) {
return;
}
final View[] children = mChildren;
mChildrenCount = 0;
for (int i = count - 1; i >= 0; i--) {
children[i].mParent = null;
children[i] = null;
}
}
/**
* Don't call or override this method. It is used for the implementation of
* the view hierarchy.
*/
public final void invalidateChild(View child, final Rect dirty) {
ViewParent parent = this;
final AttachInfo attachInfo = mAttachInfo;
if (attachInfo != null) {
// If the child is drawing an animation, we want to copy this flag onto
// ourselves and the parent to make sure the invalidate request goes
// through
final boolean drawAnimation = (child.mPrivateFlags & PFLAG_DRAW_ANIMATION)
== PFLAG_DRAW_ANIMATION;
// Check whether the child that requests the invalidate is fully opaque
// Views being animated or transformed are not considered opaque because we may
// be invalidating their old position and need the parent to paint behind them.
Matrix childMatrix = child.getMatrix();
final boolean isOpaque = child.isOpaque() && !drawAnimation &&
child.getAnimation() == null && childMatrix.isIdentity();
// Mark the child as dirty, using the appropriate flag
// Make sure we do not set both flags at the same time
int opaqueFlag = isOpaque ? PFLAG_DIRTY_OPAQUE : PFLAG_DIRTY;
if (child.mLayerType != LAYER_TYPE_NONE) {
mPrivateFlags |= PFLAG_INVALIDATED;
mPrivateFlags &= ~PFLAG_DRAWING_CACHE_VALID;
child.mLocalDirtyRect.union(dirty);
}
final int[] location = attachInfo.mInvalidateChildLocation;
location[CHILD_LEFT_INDEX] = child.mLeft;
location[CHILD_TOP_INDEX] = child.mTop;
if (!childMatrix.isIdentity() ||
(mGroupFlags & ViewGroup.FLAG_SUPPORT_STATIC_TRANSFORMATIONS) != 0) {
RectF boundingRect = attachInfo.mTmpTransformRect;
boundingRect.set(dirty);
Matrix transformMatrix;
if ((mGroupFlags & ViewGroup.FLAG_SUPPORT_STATIC_TRANSFORMATIONS) != 0) {
Transformation t = attachInfo.mTmpTransformation;
boolean transformed = getChildStaticTransformation(child, t);
if (transformed) {
transformMatrix = attachInfo.mTmpMatrix;
transformMatrix.set(t.getMatrix());
if (!childMatrix.isIdentity()) {
transformMatrix.preConcat(childMatrix);
}
} else {
transformMatrix = childMatrix;
}
} else {
transformMatrix = childMatrix;
}
transformMatrix.mapRect(boundingRect);
dirty.set((int) (boundingRect.left - 0.5f),
(int) (boundingRect.top - 0.5f),
(int) (boundingRect.right + 0.5f),
(int) (boundingRect.bottom + 0.5f));
}
do {
View view = null;
if (parent instanceof View) {
view = (View) parent;
}
if (drawAnimation) {
if (view != null) {
view.mPrivateFlags |= PFLAG_DRAW_ANIMATION;
} else if (parent instanceof ViewRootImpl) {
((ViewRootImpl) parent).mIsAnimating = true;
}
}
// If the parent is dirty opaque or not dirty, mark it dirty with the opaque
// flag coming from the child that initiated the invalidate
if (view != null) {
if ((view.mViewFlags & FADING_EDGE_MASK) != 0 &&
view.getSolidColor() == 0) {
opaqueFlag = PFLAG_DIRTY;
}
if ((view.mPrivateFlags & PFLAG_DIRTY_MASK) != PFLAG_DIRTY) {
view.mPrivateFlags = (view.mPrivateFlags & ~PFLAG_DIRTY_MASK) | opaqueFlag;
}
}
parent = parent.invalidateChildInParent(location, dirty);
if (view != null) {
// Account for transform on current parent
Matrix m = view.getMatrix();
if (!m.isIdentity()) {
RectF boundingRect = attachInfo.mTmpTransformRect;
boundingRect.set(dirty);
m.mapRect(boundingRect);
dirty.set((int) (boundingRect.left - 0.5f),
(int) (boundingRect.top - 0.5f),
(int) (boundingRect.right + 0.5f),
(int) (boundingRect.bottom + 0.5f));
}
}
} while (parent != null);
}
}
/**
* Don't call or override this method. It is used for the implementation of
* the view hierarchy.
*
* This implementation returns null if this ViewGroup does not have a parent,
* if this ViewGroup is already fully invalidated or if the dirty rectangle
* does not intersect with this ViewGroup's bounds.
*/
public ViewParent invalidateChildInParent(final int[] location, final Rect dirty) {
if ((mPrivateFlags & PFLAG_DRAWN) == PFLAG_DRAWN ||
(mPrivateFlags & PFLAG_DRAWING_CACHE_VALID) == PFLAG_DRAWING_CACHE_VALID) {
if ((mGroupFlags & (FLAG_OPTIMIZE_INVALIDATE | FLAG_ANIMATION_DONE)) !=
FLAG_OPTIMIZE_INVALIDATE) {
dirty.offset(location[CHILD_LEFT_INDEX] - mScrollX,
location[CHILD_TOP_INDEX] - mScrollY);
final int left = mLeft;
final int top = mTop;
if ((mGroupFlags & FLAG_CLIP_CHILDREN) == FLAG_CLIP_CHILDREN) {
if (!dirty.intersect(0, 0, mRight - left, mBottom - top)) {
dirty.setEmpty();
}
}
mPrivateFlags &= ~PFLAG_DRAWING_CACHE_VALID;
location[CHILD_LEFT_INDEX] = left;
location[CHILD_TOP_INDEX] = top;
if (mLayerType != LAYER_TYPE_NONE) {
mPrivateFlags |= PFLAG_INVALIDATED;
mLocalDirtyRect.union(dirty);
}
return mParent;
} else {
mPrivateFlags &= ~PFLAG_DRAWN & ~PFLAG_DRAWING_CACHE_VALID;
location[CHILD_LEFT_INDEX] = mLeft;
location[CHILD_TOP_INDEX] = mTop;
if ((mGroupFlags & FLAG_CLIP_CHILDREN) == FLAG_CLIP_CHILDREN) {
dirty.set(0, 0, mRight - mLeft, mBottom - mTop);
} else {
// in case the dirty rect extends outside the bounds of this container
dirty.union(0, 0, mRight - mLeft, mBottom - mTop);
}
if (mLayerType != LAYER_TYPE_NONE) {
mPrivateFlags |= PFLAG_INVALIDATED;
mLocalDirtyRect.union(dirty);
}
return mParent;
}
}
return null;
}
/**
* Quick invalidation method called by View.invalidateViewProperty. This doesn't set the
* DRAWN flags and doesn't handle the Animation logic that the default invalidation methods
* do; all we want to do here is schedule a traversal with the appropriate dirty rect.
*
* @hide
*/
public void invalidateChildFast(View child, final Rect dirty) {
ViewParent parent = this;
final AttachInfo attachInfo = mAttachInfo;
if (attachInfo != null) {
if (child.mLayerType != LAYER_TYPE_NONE) {
child.mLocalDirtyRect.union(dirty);
}
int left = child.mLeft;
int top = child.mTop;
if (!child.getMatrix().isIdentity()) {
child.transformRect(dirty);
}
do {
if (parent instanceof ViewGroup) {
ViewGroup parentVG = (ViewGroup) parent;
if (parentVG.mLayerType != LAYER_TYPE_NONE) {
// Layered parents should be recreated, not just re-issued
parentVG.invalidate();
parent = null;
} else {
parent = parentVG.invalidateChildInParentFast(left, top, dirty);
left = parentVG.mLeft;
top = parentVG.mTop;
}
} else {
// Reached the top; this calls into the usual invalidate method in
// ViewRootImpl, which schedules a traversal
final int[] location = attachInfo.mInvalidateChildLocation;
location[0] = left;
location[1] = top;
parent = parent.invalidateChildInParent(location, dirty);
}
} while (parent != null);
}
}
/**
* Quick invalidation method that simply transforms the dirty rect into the parent's
* coordinate system, pruning the invalidation if the parent has already been invalidated.
*/
private ViewParent invalidateChildInParentFast(int left, int top, final Rect dirty) {
if ((mPrivateFlags & PFLAG_DRAWN) == PFLAG_DRAWN ||
(mPrivateFlags & PFLAG_DRAWING_CACHE_VALID) == PFLAG_DRAWING_CACHE_VALID) {
dirty.offset(left - mScrollX, top - mScrollY);
if ((mGroupFlags & FLAG_CLIP_CHILDREN) == 0 ||
dirty.intersect(0, 0, mRight - mLeft, mBottom - mTop)) {
if (mLayerType != LAYER_TYPE_NONE) {
mLocalDirtyRect.union(dirty);
}
if (!getMatrix().isIdentity()) {
transformRect(dirty);
}
return mParent;
}
}
return null;
}
/**
* Offset a rectangle that is in a descendant's coordinate
* space into our coordinate space.
* @param descendant A descendant of this view
* @param rect A rectangle defined in descendant's coordinate space.
*/
public final void offsetDescendantRectToMyCoords(View descendant, Rect rect) {
offsetRectBetweenParentAndChild(descendant, rect, true, false);
}
/**
* Offset a rectangle that is in our coordinate space into an ancestor's
* coordinate space.
* @param descendant A descendant of this view
* @param rect A rectangle defined in descendant's coordinate space.
*/
public final void offsetRectIntoDescendantCoords(View descendant, Rect rect) {
offsetRectBetweenParentAndChild(descendant, rect, false, false);
}
/**
* Helper method that offsets a rect either from parent to descendant or
* descendant to parent.
*/
void offsetRectBetweenParentAndChild(View descendant, Rect rect,
boolean offsetFromChildToParent, boolean clipToBounds) {
// already in the same coord system :)
if (descendant == this) {
return;
}
ViewParent theParent = descendant.mParent;
// search and offset up to the parent
while ((theParent != null)
&& (theParent instanceof View)
&& (theParent != this)) {
if (offsetFromChildToParent) {
rect.offset(descendant.mLeft - descendant.mScrollX,
descendant.mTop - descendant.mScrollY);
if (clipToBounds) {
View p = (View) theParent;
rect.intersect(0, 0, p.mRight - p.mLeft, p.mBottom - p.mTop);
}
} else {
if (clipToBounds) {
View p = (View) theParent;
rect.intersect(0, 0, p.mRight - p.mLeft, p.mBottom - p.mTop);
}
rect.offset(descendant.mScrollX - descendant.mLeft,
descendant.mScrollY - descendant.mTop);
}
descendant = (View) theParent;
theParent = descendant.mParent;
}
// now that we are up to this view, need to offset one more time
// to get into our coordinate space
if (theParent == this) {
if (offsetFromChildToParent) {
rect.offset(descendant.mLeft - descendant.mScrollX,
descendant.mTop - descendant.mScrollY);
} else {
rect.offset(descendant.mScrollX - descendant.mLeft,
descendant.mScrollY - descendant.mTop);
}
} else {
throw new IllegalArgumentException("parameter must be a descendant of this view");
}
}
/**
* Offset the vertical location of all children of this view by the specified number of pixels.
*
* @param offset the number of pixels to offset
*
* @hide
*/
public void offsetChildrenTopAndBottom(int offset) {
final int count = mChildrenCount;
final View[] children = mChildren;
for (int i = 0; i < count; i++) {
final View v = children[i];
v.mTop += offset;
v.mBottom += offset;
if (v.mDisplayList != null) {
v.mDisplayList.offsetTopBottom(offset);
invalidateViewProperty(false, false);
}
}
}
/**
* {@inheritDoc}
*/
public boolean getChildVisibleRect(View child, Rect r, android.graphics.Point offset) {
// It doesn't make a whole lot of sense to call this on a view that isn't attached,
// but for some simple tests it can be useful. If we don't have attach info this
// will allocate memory.
final RectF rect = mAttachInfo != null ? mAttachInfo.mTmpTransformRect : new RectF();
rect.set(r);
if (!child.hasIdentityMatrix()) {
child.getMatrix().mapRect(rect);
}
int dx = child.mLeft - mScrollX;
int dy = child.mTop - mScrollY;
rect.offset(dx, dy);
if (offset != null) {
if (!child.hasIdentityMatrix()) {
float[] position = mAttachInfo != null ? mAttachInfo.mTmpTransformLocation
: new float[2];
position[0] = offset.x;
position[1] = offset.y;
child.getMatrix().mapPoints(position);
offset.x = (int) (position[0] + 0.5f);
offset.y = (int) (position[1] + 0.5f);
}
offset.x += dx;
offset.y += dy;
}
if (rect.intersect(0, 0, mRight - mLeft, mBottom - mTop)) {
if (mParent == null) return true;
r.set((int) (rect.left + 0.5f), (int) (rect.top + 0.5f),
(int) (rect.right + 0.5f), (int) (rect.bottom + 0.5f));
return mParent.getChildVisibleRect(this, r, offset);
}
return false;
}
/**
* {@inheritDoc}
*/
@Override
public final void layout(int l, int t, int r, int b) {
if (mTransition == null || !mTransition.isChangingLayout()) {
if (mTransition != null) {
mTransition.layoutChange(this);
}
super.layout(l, t, r, b);
} else {
// record the fact that we noop'd it; request layout when transition finishes
mLayoutSuppressed = true;
}
}
/**
* {@inheritDoc}
*/
@Override
protected abstract void onLayout(boolean changed,
int l, int t, int r, int b);
/**
* Indicates whether the view group has the ability to animate its children
* after the first layout.
*
* @return true if the children can be animated, false otherwise
*/
protected boolean canAnimate() {
return mLayoutAnimationController != null;
}
/**
* Runs the layout animation. Calling this method triggers a relayout of
* this view group.
*/
public void startLayoutAnimation() {
if (mLayoutAnimationController != null) {
mGroupFlags |= FLAG_RUN_ANIMATION;
requestLayout();
}
}
/**
* Schedules the layout animation to be played after the next layout pass
* of this view group. This can be used to restart the layout animation
* when the content of the view group changes or when the activity is
* paused and resumed.
*/
public void scheduleLayoutAnimation() {
mGroupFlags |= FLAG_RUN_ANIMATION;
}
/**
* Sets the layout animation controller used to animate the group's
* children after the first layout.
*
* @param controller the animation controller
*/
public void setLayoutAnimation(LayoutAnimationController controller) {
mLayoutAnimationController = controller;
if (mLayoutAnimationController != null) {
mGroupFlags |= FLAG_RUN_ANIMATION;
}
}
/**
* Returns the layout animation controller used to animate the group's
* children.
*
* @return the current animation controller
*/
public LayoutAnimationController getLayoutAnimation() {
return mLayoutAnimationController;
}
/**
* Indicates whether the children's drawing cache is used during a layout
* animation. By default, the drawing cache is enabled but this will prevent
* nested layout animations from working. To nest animations, you must disable
* the cache.
*
* @return true if the animation cache is enabled, false otherwise
*
* @see #setAnimationCacheEnabled(boolean)
* @see View#setDrawingCacheEnabled(boolean)
*/
@ViewDebug.ExportedProperty
public boolean isAnimationCacheEnabled() {
return (mGroupFlags & FLAG_ANIMATION_CACHE) == FLAG_ANIMATION_CACHE;
}
/**
* Enables or disables the children's drawing cache during a layout animation.
* By default, the drawing cache is enabled but this will prevent nested
* layout animations from working. To nest animations, you must disable the
* cache.
*
* @param enabled true to enable the animation cache, false otherwise
*
* @see #isAnimationCacheEnabled()
* @see View#setDrawingCacheEnabled(boolean)
*/
public void setAnimationCacheEnabled(boolean enabled) {
setBooleanFlag(FLAG_ANIMATION_CACHE, enabled);
}
/**
* Indicates whether this ViewGroup will always try to draw its children using their
* drawing cache. By default this property is enabled.
*
* @return true if the animation cache is enabled, false otherwise
*
* @see #setAlwaysDrawnWithCacheEnabled(boolean)
* @see #setChildrenDrawnWithCacheEnabled(boolean)
* @see View#setDrawingCacheEnabled(boolean)
*/
@ViewDebug.ExportedProperty(category = "drawing")
public boolean isAlwaysDrawnWithCacheEnabled() {
return (mGroupFlags & FLAG_ALWAYS_DRAWN_WITH_CACHE) == FLAG_ALWAYS_DRAWN_WITH_CACHE;
}
/**
* Indicates whether this ViewGroup will always try to draw its children using their
* drawing cache. This property can be set to true when the cache rendering is
* slightly different from the children's normal rendering. Renderings can be different,
* for instance, when the cache's quality is set to low.
*
* When this property is disabled, the ViewGroup will use the drawing cache of its
* children only when asked to. It's usually the task of subclasses to tell ViewGroup
* when to start using the drawing cache and when to stop using it.
*
* @param always true to always draw with the drawing cache, false otherwise
*
* @see #isAlwaysDrawnWithCacheEnabled()
* @see #setChildrenDrawnWithCacheEnabled(boolean)
* @see View#setDrawingCacheEnabled(boolean)
* @see View#setDrawingCacheQuality(int)
*/
public void setAlwaysDrawnWithCacheEnabled(boolean always) {
setBooleanFlag(FLAG_ALWAYS_DRAWN_WITH_CACHE, always);
}
/**
* Indicates whether the ViewGroup is currently drawing its children using
* their drawing cache.
*
* @return true if children should be drawn with their cache, false otherwise
*
* @see #setAlwaysDrawnWithCacheEnabled(boolean)
* @see #setChildrenDrawnWithCacheEnabled(boolean)
*/
@ViewDebug.ExportedProperty(category = "drawing")
protected boolean isChildrenDrawnWithCacheEnabled() {
return (mGroupFlags & FLAG_CHILDREN_DRAWN_WITH_CACHE) == FLAG_CHILDREN_DRAWN_WITH_CACHE;
}
/**
* Tells the ViewGroup to draw its children using their drawing cache. This property
* is ignored when {@link #isAlwaysDrawnWithCacheEnabled()} is true. A child's drawing cache
* will be used only if it has been enabled.
*
* Subclasses should call this method to start and stop using the drawing cache when
* they perform performance sensitive operations, like scrolling or animating.
*
* @param enabled true if children should be drawn with their cache, false otherwise
*
* @see #setAlwaysDrawnWithCacheEnabled(boolean)
* @see #isChildrenDrawnWithCacheEnabled()
*/
protected void setChildrenDrawnWithCacheEnabled(boolean enabled) {
setBooleanFlag(FLAG_CHILDREN_DRAWN_WITH_CACHE, enabled);
}
/**
* Indicates whether the ViewGroup is drawing its children in the order defined by
* {@link #getChildDrawingOrder(int, int)}.
*
* @return true if children drawing order is defined by {@link #getChildDrawingOrder(int, int)},
* false otherwise
*
* @see #setChildrenDrawingOrderEnabled(boolean)
* @see #getChildDrawingOrder(int, int)
*/
@ViewDebug.ExportedProperty(category = "drawing")
protected boolean isChildrenDrawingOrderEnabled() {
return (mGroupFlags & FLAG_USE_CHILD_DRAWING_ORDER) == FLAG_USE_CHILD_DRAWING_ORDER;
}
/**
* Tells the ViewGroup whether to draw its children in the order defined by the method
* {@link #getChildDrawingOrder(int, int)}.
*
* @param enabled true if the order of the children when drawing is determined by
* {@link #getChildDrawingOrder(int, int)}, false otherwise
*
* @see #isChildrenDrawingOrderEnabled()
* @see #getChildDrawingOrder(int, int)
*/
protected void setChildrenDrawingOrderEnabled(boolean enabled) {
setBooleanFlag(FLAG_USE_CHILD_DRAWING_ORDER, enabled);
}
private void setBooleanFlag(int flag, boolean value) {
if (value) {
mGroupFlags |= flag;
} else {
mGroupFlags &= ~flag;
}
}
/**
* Returns an integer indicating what types of drawing caches are kept in memory.
*
* @see #setPersistentDrawingCache(int)
* @see #setAnimationCacheEnabled(boolean)
*
* @return one or a combination of {@link #PERSISTENT_NO_CACHE},
* {@link #PERSISTENT_ANIMATION_CACHE}, {@link #PERSISTENT_SCROLLING_CACHE}
* and {@link #PERSISTENT_ALL_CACHES}
*/
@ViewDebug.ExportedProperty(category = "drawing", mapping = {
@ViewDebug.IntToString(from = PERSISTENT_NO_CACHE, to = "NONE"),
@ViewDebug.IntToString(from = PERSISTENT_ANIMATION_CACHE, to = "ANIMATION"),
@ViewDebug.IntToString(from = PERSISTENT_SCROLLING_CACHE, to = "SCROLLING"),
@ViewDebug.IntToString(from = PERSISTENT_ALL_CACHES, to = "ALL")
})
public int getPersistentDrawingCache() {
return mPersistentDrawingCache;
}
/**
* Indicates what types of drawing caches should be kept in memory after
* they have been created.
*
* @see #getPersistentDrawingCache()
* @see #setAnimationCacheEnabled(boolean)
*
* @param drawingCacheToKeep one or a combination of {@link #PERSISTENT_NO_CACHE},
* {@link #PERSISTENT_ANIMATION_CACHE}, {@link #PERSISTENT_SCROLLING_CACHE}
* and {@link #PERSISTENT_ALL_CACHES}
*/
public void setPersistentDrawingCache(int drawingCacheToKeep) {
mPersistentDrawingCache = drawingCacheToKeep & PERSISTENT_ALL_CACHES;
}
/**
* Returns the basis of alignment during layout operations on this view group:
* either {@link #CLIP_BOUNDS} or {@link #OPTICAL_BOUNDS}.
*
* @return the layout mode to use during layout operations
*
* @see #setLayoutMode(int)
*
* @hide
*/
public int getLayoutMode() {
return mLayoutMode;
}
/**
* Sets the basis of alignment during the layout of this view group.
* Valid values are either {@link #CLIP_BOUNDS} or {@link #OPTICAL_BOUNDS}.
*
* The default is {@link #CLIP_BOUNDS}.
*
* @param layoutMode the layout mode to use during layout operations
*
* @see #getLayoutMode()
*
* @hide
*/
public void setLayoutMode(int layoutMode) {
if (mLayoutMode != layoutMode) {
mLayoutMode = layoutMode;
requestLayout();
}
}
/**
* Returns a new set of layout parameters based on the supplied attributes set.
*
* @param attrs the attributes to build the layout parameters from
*
* @return an instance of {@link android.view.ViewGroup.LayoutParams} or one
* of its descendants
*/
public LayoutParams generateLayoutParams(AttributeSet attrs) {
return new LayoutParams(getContext(), attrs);
}
/**
* Returns a safe set of layout parameters based on the supplied layout params.
* When a ViewGroup is passed a View whose layout params do not pass the test of
* {@link #checkLayoutParams(android.view.ViewGroup.LayoutParams)}, this method
* is invoked. This method should return a new set of layout params suitable for
* this ViewGroup, possibly by copying the appropriate attributes from the
* specified set of layout params.
*
* @param p The layout parameters to convert into a suitable set of layout parameters
* for this ViewGroup.
*
* @return an instance of {@link android.view.ViewGroup.LayoutParams} or one
* of its descendants
*/
protected LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
return p;
}
/**
* Returns a set of default layout parameters. These parameters are requested
* when the View passed to {@link #addView(View)} has no layout parameters
* already set. If null is returned, an exception is thrown from addView.
*
* @return a set of default layout parameters or null
*/
protected LayoutParams generateDefaultLayoutParams() {
return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
}
/**
* {@inheritDoc}
*/
@Override
protected void debug(int depth) {
super.debug(depth);
String output;
if (mFocused != null) {
output = debugIndent(depth);
output += "mFocused";
Log.d(VIEW_LOG_TAG, output);
}
if (mChildrenCount != 0) {
output = debugIndent(depth);
output += "{";
Log.d(VIEW_LOG_TAG, output);
}
int count = mChildrenCount;
for (int i = 0; i < count; i++) {
View child = mChildren[i];
child.debug(depth + 1);
}
if (mChildrenCount != 0) {
output = debugIndent(depth);
output += "}";
Log.d(VIEW_LOG_TAG, output);
}
}
/**
* Returns the position in the group of the specified child view.
*
* @param child the view for which to get the position
* @return a positive integer representing the position of the view in the
* group, or -1 if the view does not exist in the group
*/
public int indexOfChild(View child) {
final int count = mChildrenCount;
final View[] children = mChildren;
for (int i = 0; i < count; i++) {
if (children[i] == child) {
return i;
}
}
return -1;
}
/**
* Returns the number of children in the group.
*
* @return a positive integer representing the number of children in
* the group
*/
public int getChildCount() {
return mChildrenCount;
}
/**
* Returns the view at the specified position in the group.
*
* @param index the position at which to get the view from
* @return the view at the specified position or null if the position
* does not exist within the group
*/
public View getChildAt(int index) {
if (index < 0 || index >= mChildrenCount) {
return null;
}
return mChildren[index];
}
/**
* Ask all of the children of this view to measure themselves, taking into
* account both the MeasureSpec requirements for this view and its padding.
* We skip children that are in the GONE state The heavy lifting is done in
* getChildMeasureSpec.
*
* @param widthMeasureSpec The width requirements for this view
* @param heightMeasureSpec The height requirements for this view
*/
protected void measureChildren(int widthMeasureSpec, int heightMeasureSpec) {
final int size = mChildrenCount;
final View[] children = mChildren;
for (int i = 0; i < size; ++i) {
final View child = children[i];
if ((child.mViewFlags & VISIBILITY_MASK) != GONE) {
measureChild(child, widthMeasureSpec, heightMeasureSpec);
}
}
}
/**
* Ask one of the children of this view to measure itself, taking into
* account both the MeasureSpec requirements for this view and its padding.
* The heavy lifting is done in getChildMeasureSpec.
*
* @param child The child to measure
* @param parentWidthMeasureSpec The width requirements for this view
* @param parentHeightMeasureSpec The height requirements for this view
*/
protected void measureChild(View child, int parentWidthMeasureSpec,
int parentHeightMeasureSpec) {
final LayoutParams lp = child.getLayoutParams();
final int childWidthMeasureSpec = getChildMeasureSpec(parentWidthMeasureSpec,
mPaddingLeft + mPaddingRight, lp.width);
final int childHeightMeasureSpec = getChildMeasureSpec(parentHeightMeasureSpec,
mPaddingTop + mPaddingBottom, lp.height);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
/**
* Ask one of the children of this view to measure itself, taking into
* account both the MeasureSpec requirements for this view and its padding
* and margins. The child must have MarginLayoutParams The heavy lifting is
* done in getChildMeasureSpec.
*
* @param child The child to measure
* @param parentWidthMeasureSpec The width requirements for this view
* @param widthUsed Extra space that has been used up by the parent
* horizontally (possibly by other children of the parent)
* @param parentHeightMeasureSpec The height requirements for this view
* @param heightUsed Extra space that has been used up by the parent
* vertically (possibly by other children of the parent)
*/
protected void measureChildWithMargins(View child,
int parentWidthMeasureSpec, int widthUsed,
int parentHeightMeasureSpec, int heightUsed) {
final MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();
final int childWidthMeasureSpec = getChildMeasureSpec(parentWidthMeasureSpec,
mPaddingLeft + mPaddingRight + lp.leftMargin + lp.rightMargin
+ widthUsed, lp.width);
final int childHeightMeasureSpec = getChildMeasureSpec(parentHeightMeasureSpec,
mPaddingTop + mPaddingBottom + lp.topMargin + lp.bottomMargin
+ heightUsed, lp.height);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
/**
* Does the hard part of measureChildren: figuring out the MeasureSpec to
* pass to a particular child. This method figures out the right MeasureSpec
* for one dimension (height or width) of one child view.
*
* The goal is to combine information from our MeasureSpec with the
* LayoutParams of the child to get the best possible results. For example,
* if the this view knows its size (because its MeasureSpec has a mode of
* EXACTLY), and the child has indicated in its LayoutParams that it wants
* to be the same size as the parent, the parent should ask the child to
* layout given an exact size.
*
* @param spec The requirements for this view
* @param padding The padding of this view for the current dimension and
* margins, if applicable
* @param childDimension How big the child wants to be in the current
* dimension
* @return a MeasureSpec integer for the child
*/
public static int getChildMeasureSpec(int spec, int padding, int childDimension) {
int specMode = MeasureSpec.getMode(spec);
int specSize = MeasureSpec.getSize(spec);
int size = Math.max(0, specSize - padding);
int resultSize = 0;
int resultMode = 0;
switch (specMode) {
// Parent has imposed an exact size on us
case MeasureSpec.EXACTLY:
if (childDimension >= 0) {
resultSize = childDimension;
resultMode = MeasureSpec.EXACTLY;
} else if (childDimension == LayoutParams.MATCH_PARENT) {
// Child wants to be our size. So be it.
resultSize = size;
resultMode = MeasureSpec.EXACTLY;
} else if (childDimension == LayoutParams.WRAP_CONTENT) {
// Child wants to determine its own size. It can't be
// bigger than us.
resultSize = size;
resultMode = MeasureSpec.AT_MOST;
}
break;
// Parent has imposed a maximum size on us
case MeasureSpec.AT_MOST:
if (childDimension >= 0) {
// Child wants a specific size... so be it
resultSize = childDimension;
resultMode = MeasureSpec.EXACTLY;
} else if (childDimension == LayoutParams.MATCH_PARENT) {
// Child wants to be our size, but our size is not fixed.
// Constrain child to not be bigger than us.
resultSize = size;
resultMode = MeasureSpec.AT_MOST;
} else if (childDimension == LayoutParams.WRAP_CONTENT) {
// Child wants to determine its own size. It can't be
// bigger than us.
resultSize = size;
resultMode = MeasureSpec.AT_MOST;
}
break;
// Parent asked to see how big we want to be
case MeasureSpec.UNSPECIFIED:
if (childDimension >= 0) {
// Child wants a specific size... let him have it
resultSize = childDimension;
resultMode = MeasureSpec.EXACTLY;
} else if (childDimension == LayoutParams.MATCH_PARENT) {
// Child wants to be our size... find out how big it should
// be
resultSize = 0;
resultMode = MeasureSpec.UNSPECIFIED;
} else if (childDimension == LayoutParams.WRAP_CONTENT) {
// Child wants to determine its own size.... find out how
// big it should be
resultSize = 0;
resultMode = MeasureSpec.UNSPECIFIED;
}
break;
}
return MeasureSpec.makeMeasureSpec(resultSize, resultMode);
}
/**
* Removes any pending animations for views that have been removed. Call
* this if you don't want animations for exiting views to stack up.
*/
public void clearDisappearingChildren() {
if (mDisappearingChildren != null) {
mDisappearingChildren.clear();
invalidate();
}
}
/**
* Add a view which is removed from mChildren but still needs animation
*
* @param v View to add
*/
private void addDisappearingView(View v) {
ArrayList
* The base LayoutParams class just describes how big the view wants to be
* for both width and height. For each dimension, it can specify one of:
* For more information about creating user interface layouts, read the
* XML Layouts developer
* guide.t to be the static transformation of the child, if set, returning a
* boolean to indicate whether a static transform was set. The default implementation
* simply returns false; subclasses may override this method for different
* behavior. {@link #setStaticTransformationsEnabled(boolean)} must be set to true
* for this method to be called.
*
* @param child The child view whose static transform is being requested
* @param t The Transformation which will hold the result
* @return true if the transformation was set, false otherwise
* @see #setStaticTransformationsEnabled(boolean)
*/
protected boolean getChildStaticTransformation(View child, Transformation t) {
return false;
}
/**
* {@hide}
*/
@Override
protected View findViewTraversal(int id) {
if (id == mID) {
return this;
}
final View[] where = mChildren;
final int len = mChildrenCount;
for (int i = 0; i < len; i++) {
View v = where[i];
if ((v.mPrivateFlags & PFLAG_IS_ROOT_NAMESPACE) == 0) {
v = v.findViewById(id);
if (v != null) {
return v;
}
}
}
return null;
}
/**
* {@hide}
*/
@Override
protected View findViewWithTagTraversal(Object tag) {
if (tag != null && tag.equals(mTag)) {
return this;
}
final View[] where = mChildren;
final int len = mChildrenCount;
for (int i = 0; i < len; i++) {
View v = where[i];
if ((v.mPrivateFlags & PFLAG_IS_ROOT_NAMESPACE) == 0) {
v = v.findViewWithTag(tag);
if (v != null) {
return v;
}
}
}
return null;
}
/**
* {@hide}
*/
@Override
protected View findViewByPredicateTraversal(Predicatenull means no transition will run on layout changes.
* @attr ref android.R.styleable#ViewGroup_animateLayoutChanges
*/
public void setLayoutTransition(LayoutTransition transition) {
if (mTransition != null) {
mTransition.removeTransitionListener(mLayoutTransitionListener);
}
mTransition = transition;
if (mTransition != null) {
mTransition.addTransitionListener(mLayoutTransitionListener);
}
}
/**
* Gets the LayoutTransition object for this ViewGroup. If the LayoutTransition object is
* not null, changes in layout which occur because of children being added to or removed from
* the ViewGroup will be animated according to the animations defined in that LayoutTransition
* object. By default, the transition object is null (so layout changes are not animated).
*
* @return LayoutTranstion The LayoutTransition object that will animated changes in layout.
* A value of null means no transition will run on layout changes.
*/
public LayoutTransition getLayoutTransition() {
return mTransition;
}
private void removeViewsInternal(int start, int count) {
final View focused = mFocused;
final boolean detach = mAttachInfo != null;
View clearChildFocus = null;
final View[] children = mChildren;
final int end = start + count;
for (int i = start; i < end; i++) {
final View view = children[i];
if (mTransition != null) {
mTransition.removeChild(this, view);
}
if (view == focused) {
view.unFocus();
clearChildFocus = view;
}
view.clearAccessibilityFocus();
cancelTouchTarget(view);
cancelHoverTarget(view);
if (view.getAnimation() != null ||
(mTransitioningViews != null && mTransitioningViews.contains(view))) {
addDisappearingView(view);
} else if (detach) {
view.dispatchDetachedFromWindow();
}
if (view.hasTransientState()) {
childHasTransientStateChanged(view, false);
}
needGlobalAttributesUpdate(false);
onViewRemoved(view);
}
removeFromArray(start, count);
if (clearChildFocus != null) {
clearChildFocus(clearChildFocus);
ensureInputFocusOnFirstFocusable();
}
}
/**
* Call this method to remove all child views from the
* ViewGroup.
*
*
*
* There are subclasses of LayoutParams for different subclasses of
* ViewGroup. For example, AbsoluteLayout has its own subclass of
* LayoutParams which adds an X and Y value.Developer Guides
*
*
*
* @param c the application environment
* @param attrs the set of attributes from which to extract the layout
* parameters' values
*/
public LayoutParams(Context c, AttributeSet attrs) {
TypedArray a = c.obtainStyledAttributes(attrs, R.styleable.ViewGroup_Layout);
setBaseAttributes(a,
R.styleable.ViewGroup_Layout_layout_width,
R.styleable.ViewGroup_Layout_layout_height);
a.recycle();
}
/**
* Creates a new set of layout parameters with the specified width
* and height.
*
* @param width the width, either {@link #WRAP_CONTENT},
* {@link #FILL_PARENT} (replaced by {@link #MATCH_PARENT} in
* API Level 8), or a fixed size in pixels
* @param height the height, either {@link #WRAP_CONTENT},
* {@link #FILL_PARENT} (replaced by {@link #MATCH_PARENT} in
* API Level 8), or a fixed size in pixels
*/
public LayoutParams(int width, int height) {
this.width = width;
this.height = height;
}
/**
* Copy constructor. Clones the width and height values of the source.
*
* @param source The layout params to copy from.
*/
public LayoutParams(LayoutParams source) {
this.width = source.width;
this.height = source.height;
}
/**
* Used internally by MarginLayoutParams.
* @hide
*/
LayoutParams() {
}
/**
* Extracts the layout parameters from the supplied attributes.
*
* @param a the style attributes to extract the parameters from
* @param widthAttr the identifier of the width attribute
* @param heightAttr the identifier of the height attribute
*/
protected void setBaseAttributes(TypedArray a, int widthAttr, int heightAttr) {
width = a.getLayoutDimension(widthAttr, "layout_width");
height = a.getLayoutDimension(heightAttr, "layout_height");
}
/**
* Resolve layout parameters depending on the layout direction. Subclasses that care about
* layoutDirection changes should override this method. The default implementation does
* nothing.
*
* @param layoutDirection the direction of the layout
*
* {@link View#LAYOUT_DIRECTION_LTR}
* {@link View#LAYOUT_DIRECTION_RTL}
*/
public void resolveLayoutDirection(int layoutDirection) {
}
/**
* Returns a String representation of this set of layout parameters.
*
* @param output the String to prepend to the internal representation
* @return a String with the following format: output +
* "ViewGroup.LayoutParams={ width=WIDTH, height=HEIGHT }"
*
* @hide
*/
public String debug(String output) {
return output + "ViewGroup.LayoutParams={ width="
+ sizeToString(width) + ", height=" + sizeToString(height) + " }";
}
/**
* Use {@code canvas} to draw suitable debugging annotations for these LayoutParameters.
*
* @param view the view that contains these layout parameters
* @param canvas the canvas on which to draw
*
* @hide
*/
public void onDebugDraw(View view, Canvas canvas) {
}
/**
* Converts the specified size to a readable String.
*
* @param size the size to convert
* @return a String instance representing the supplied size
*
* @hide
*/
protected static String sizeToString(int size) {
if (size == WRAP_CONTENT) {
return "wrap-content";
}
if (size == MATCH_PARENT) {
return "match-parent";
}
return String.valueOf(size);
}
}
/**
* Per-child layout information for layouts that support margins.
* See
* {@link android.R.styleable#ViewGroup_MarginLayout ViewGroup Margin Layout Attributes}
* for a list of all child view attributes that this class supports.
*/
public static class MarginLayoutParams extends ViewGroup.LayoutParams {
/**
* The left margin in pixels of the child.
* Call {@link ViewGroup#setLayoutParams(LayoutParams)} after reassigning a new value
* to this field.
*/
@ViewDebug.ExportedProperty(category = "layout")
public int leftMargin;
/**
* The top margin in pixels of the child.
* Call {@link ViewGroup#setLayoutParams(LayoutParams)} after reassigning a new value
* to this field.
*/
@ViewDebug.ExportedProperty(category = "layout")
public int topMargin;
/**
* The right margin in pixels of the child.
* Call {@link ViewGroup#setLayoutParams(LayoutParams)} after reassigning a new value
* to this field.
*/
@ViewDebug.ExportedProperty(category = "layout")
public int rightMargin;
/**
* The bottom margin in pixels of the child.
* Call {@link ViewGroup#setLayoutParams(LayoutParams)} after reassigning a new value
* to this field.
*/
@ViewDebug.ExportedProperty(category = "layout")
public int bottomMargin;
/**
* The start margin in pixels of the child.
* Call {@link ViewGroup#setLayoutParams(LayoutParams)} after reassigning a new value
* to this field.
*/
@ViewDebug.ExportedProperty(category = "layout")
private int startMargin = DEFAULT_RELATIVE;
/**
* The end margin in pixels of the child.
* Call {@link ViewGroup#setLayoutParams(LayoutParams)} after reassigning a new value
* to this field.
*/
@ViewDebug.ExportedProperty(category = "layout")
private int endMargin = DEFAULT_RELATIVE;
/**
* The default start and end margin.
* @hide
*/
public static final int DEFAULT_RELATIVE = Integer.MIN_VALUE;
private int initialLeftMargin;
private int initialRightMargin;
private static int LAYOUT_DIRECTION_UNDEFINED = -1;
// Layout direction undefined by default
private int layoutDirection = LAYOUT_DIRECTION_UNDEFINED;
/**
* Creates a new set of layout parameters. The values are extracted from
* the supplied attributes set and context.
*
* @param c the application environment
* @param attrs the set of attributes from which to extract the layout
* parameters' values
*/
public MarginLayoutParams(Context c, AttributeSet attrs) {
super();
TypedArray a = c.obtainStyledAttributes(attrs, R.styleable.ViewGroup_MarginLayout);
setBaseAttributes(a,
R.styleable.ViewGroup_MarginLayout_layout_width,
R.styleable.ViewGroup_MarginLayout_layout_height);
int margin = a.getDimensionPixelSize(
com.android.internal.R.styleable.ViewGroup_MarginLayout_layout_margin, -1);
if (margin >= 0) {
leftMargin = margin;
topMargin = margin;
rightMargin= margin;
bottomMargin = margin;
} else {
leftMargin = a.getDimensionPixelSize(
R.styleable.ViewGroup_MarginLayout_layout_marginLeft, 0);
topMargin = a.getDimensionPixelSize(
R.styleable.ViewGroup_MarginLayout_layout_marginTop, 0);
rightMargin = a.getDimensionPixelSize(
R.styleable.ViewGroup_MarginLayout_layout_marginRight, 0);
bottomMargin = a.getDimensionPixelSize(
R.styleable.ViewGroup_MarginLayout_layout_marginBottom, 0);
startMargin = a.getDimensionPixelSize(
R.styleable.ViewGroup_MarginLayout_layout_marginStart, DEFAULT_RELATIVE);
endMargin = a.getDimensionPixelSize(
R.styleable.ViewGroup_MarginLayout_layout_marginEnd, DEFAULT_RELATIVE);
}
initialLeftMargin = leftMargin;
initialRightMargin = rightMargin;
a.recycle();
}
/**
* {@inheritDoc}
*/
public MarginLayoutParams(int width, int height) {
super(width, height);
}
/**
* Copy constructor. Clones the width, height and margin values of the source.
*
* @param source The layout params to copy from.
*/
public MarginLayoutParams(MarginLayoutParams source) {
this.width = source.width;
this.height = source.height;
this.leftMargin = source.leftMargin;
this.topMargin = source.topMargin;
this.rightMargin = source.rightMargin;
this.bottomMargin = source.bottomMargin;
this.startMargin = source.startMargin;
this.endMargin = source.endMargin;
this.initialLeftMargin = source.leftMargin;
this.initialRightMargin = source.rightMargin;
setLayoutDirection(source.layoutDirection);
}
/**
* {@inheritDoc}
*/
public MarginLayoutParams(LayoutParams source) {
super(source);
}
/**
* Sets the margins, in pixels. A call to {@link android.view.View#requestLayout()} needs
* to be done so that the new margins are taken into account. Left and right margins may be
* overriden by {@link android.view.View#requestLayout()} depending on layout direction.
*
* @param left the left margin size
* @param top the top margin size
* @param right the right margin size
* @param bottom the bottom margin size
*
* @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginLeft
* @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginTop
* @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginRight
* @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginBottom
*/
public void setMargins(int left, int top, int right, int bottom) {
leftMargin = left;
topMargin = top;
rightMargin = right;
bottomMargin = bottom;
initialLeftMargin = left;
initialRightMargin = right;
}
/**
* Sets the relative margins, in pixels. A call to {@link android.view.View#requestLayout()}
* needs to be done so that the new relative margins are taken into account. Left and right
* margins may be overriden by {@link android.view.View#requestLayout()} depending on layout
* direction.
*
* @param start the start margin size
* @param top the top margin size
* @param end the right margin size
* @param bottom the bottom margin size
*
* @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginStart
* @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginTop
* @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginEnd
* @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginBottom
*
* @hide
*/
public void setMarginsRelative(int start, int top, int end, int bottom) {
startMargin = start;
topMargin = top;
endMargin = end;
bottomMargin = bottom;
initialLeftMargin = 0;
initialRightMargin = 0;
}
/**
* Sets the relative start margin.
*
* @param start the start margin size
*
* @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginStart
*/
public void setMarginStart(int start) {
startMargin = start;
}
/**
* Returns the start margin in pixels.
*
* @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginStart
*
* @return the start margin in pixels.
*/
public int getMarginStart() {
if (startMargin != DEFAULT_RELATIVE) return startMargin;
switch(layoutDirection) {
case View.LAYOUT_DIRECTION_RTL:
return rightMargin;
case View.LAYOUT_DIRECTION_LTR:
default:
return leftMargin;
}
}
/**
* Sets the relative end margin.
*
* @param end the end margin size
*
* @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginEnd
*/
public void setMarginEnd(int end) {
endMargin = end;
}
/**
* Returns the end margin in pixels.
*
* @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginEnd
*
* @return the end margin in pixels.
*/
public int getMarginEnd() {
if (endMargin != DEFAULT_RELATIVE) return endMargin;
switch(layoutDirection) {
case View.LAYOUT_DIRECTION_RTL:
return leftMargin;
case View.LAYOUT_DIRECTION_LTR:
default:
return rightMargin;
}
}
/**
* Check if margins are relative.
*
* @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginStart
* @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginEnd
*
* @return true if either marginStart or marginEnd has been set.
*/
public boolean isMarginRelative() {
return (startMargin != DEFAULT_RELATIVE) || (endMargin != DEFAULT_RELATIVE);
}
/**
* Set the layout direction
* @param layoutDirection the layout direction.
* Should be either {@link View#LAYOUT_DIRECTION_LTR}
* or {@link View#LAYOUT_DIRECTION_RTL}.
*/
public void setLayoutDirection(int layoutDirection) {
if (layoutDirection != View.LAYOUT_DIRECTION_LTR &&
layoutDirection != View.LAYOUT_DIRECTION_RTL) return;
this.layoutDirection = layoutDirection;
}
/**
* Retuns the layout direction. Can be either {@link View#LAYOUT_DIRECTION_LTR} or
* {@link View#LAYOUT_DIRECTION_RTL}.
*
* @return the layout direction.
*/
public int getLayoutDirection() {
return layoutDirection;
}
/**
* This will be called by {@link android.view.View#requestLayout()}. Left and Right margins
* may be overridden depending on layout direction.
*/
@Override
public void resolveLayoutDirection(int layoutDirection) {
setLayoutDirection(layoutDirection);
if (!isMarginRelative()) return;
switch(layoutDirection) {
case View.LAYOUT_DIRECTION_RTL:
leftMargin = (endMargin > DEFAULT_RELATIVE) ? endMargin : initialLeftMargin;
rightMargin = (startMargin > DEFAULT_RELATIVE) ? startMargin : initialRightMargin;
break;
case View.LAYOUT_DIRECTION_LTR:
default:
leftMargin = (startMargin > DEFAULT_RELATIVE) ? startMargin : initialLeftMargin;
rightMargin = (endMargin > DEFAULT_RELATIVE) ? endMargin : initialRightMargin;
break;
}
}
/**
* @hide
*/
public boolean isLayoutRtl() {
return (layoutDirection == View.LAYOUT_DIRECTION_RTL);
}
/**
* @hide
*/
@Override
public void onDebugDraw(View view, Canvas canvas) {
drawRect(canvas,
view.getLeft() - leftMargin,
view.getTop() - topMargin,
view.getRight() + rightMargin,
view.getBottom() + bottomMargin, Color.MAGENTA);
}
}
/* Describes a touched view and the ids of the pointers that it has captured.
*
* This code assumes that pointer ids are always in the range 0..31 such that
* it can use a bitfield to track which pointer ids are present.
* As it happens, the lower layers of the input dispatch pipeline also use the
* same trick so the assumption should be safe here...
*/
private static final class TouchTarget {
private static final int MAX_RECYCLED = 32;
private static final Object sRecycleLock = new Object();
private static TouchTarget sRecycleBin;
private static int sRecycledCount;
public static final int ALL_POINTER_IDS = -1; // all ones
// The touched child view.
public View child;
// The combined bit mask of pointer ids for all pointers captured by the target.
public int pointerIdBits;
// The next target in the target list.
public TouchTarget next;
private TouchTarget() {
}
public static TouchTarget obtain(View child, int pointerIdBits) {
final TouchTarget target;
synchronized (sRecycleLock) {
if (sRecycleBin == null) {
target = new TouchTarget();
} else {
target = sRecycleBin;
sRecycleBin = target.next;
sRecycledCount--;
target.next = null;
}
}
target.child = child;
target.pointerIdBits = pointerIdBits;
return target;
}
public void recycle() {
synchronized (sRecycleLock) {
if (sRecycledCount < MAX_RECYCLED) {
next = sRecycleBin;
sRecycleBin = this;
sRecycledCount += 1;
} else {
next = null;
}
child = null;
}
}
}
/* Describes a hovered view. */
private static final class HoverTarget {
private static final int MAX_RECYCLED = 32;
private static final Object sRecycleLock = new Object();
private static HoverTarget sRecycleBin;
private static int sRecycledCount;
// The hovered child view.
public View child;
// The next target in the target list.
public HoverTarget next;
private HoverTarget() {
}
public static HoverTarget obtain(View child) {
final HoverTarget target;
synchronized (sRecycleLock) {
if (sRecycleBin == null) {
target = new HoverTarget();
} else {
target = sRecycleBin;
sRecycleBin = target.next;
sRecycledCount--;
target.next = null;
}
}
target.child = child;
return target;
}
public void recycle() {
synchronized (sRecycleLock) {
if (sRecycledCount < MAX_RECYCLED) {
next = sRecycleBin;
sRecycleBin = this;
sRecycledCount += 1;
} else {
next = null;
}
child = null;
}
}
}
/**
* Pooled class that orderes the children of a ViewGroup from start
* to end based on how they are laid out and the layout direction.
*/
static class ChildListForAccessibility {
private static final int MAX_POOL_SIZE = 32;
private static final Object sPoolLock = new Object();
private static ChildListForAccessibility sPool;
private static int sPoolSize;
private boolean mIsPooled;
private ChildListForAccessibility mNext;
private final ArrayListlayout_width: the width, either an exact value,
* {@link #WRAP_CONTENT}, or {@link #FILL_PARENT} (replaced by
* {@link #MATCH_PARENT} in API Level 8)layout_height: the height, either an exact value,
* {@link #WRAP_CONTENT}, or {@link #FILL_PARENT} (replaced by
* {@link #MATCH_PARENT} in API Level 8)