/* * Copyright (C) 2012 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.android.server.accessibility; import android.animation.ObjectAnimator; import android.animation.TypeEvaluator; import android.animation.ValueAnimator; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.graphics.Rect; import android.graphics.Region; import android.os.AsyncTask; import android.os.Binder; import android.os.Handler; import android.os.Message; import android.os.RemoteException; import android.os.ServiceManager; import android.os.SystemClock; import android.provider.Settings; import android.text.TextUtils; import android.util.Property; import android.util.Slog; import android.view.GestureDetector; import android.view.GestureDetector.SimpleOnGestureListener; import android.view.IMagnificationCallbacks; import android.view.IWindowManager; import android.view.MagnificationSpec; import android.view.MotionEvent; import android.view.MotionEvent.PointerCoords; import android.view.MotionEvent.PointerProperties; import android.view.ScaleGestureDetector; import android.view.ScaleGestureDetector.OnScaleGestureListener; import android.view.View; import android.view.ViewConfiguration; import android.view.accessibility.AccessibilityEvent; import android.view.animation.DecelerateInterpolator; import com.android.internal.os.SomeArgs; import java.util.Locale; /** * This class handles the screen magnification when accessibility is enabled. * The behavior is as follows: * * 1. Triple tap toggles permanent screen magnification which is magnifying * the area around the location of the triple tap. One can think of the * location of the triple tap as the center of the magnified viewport. * For example, a triple tap when not magnified would magnify the screen * and leave it in a magnified state. A triple tapping when magnified would * clear magnification and leave the screen in a not magnified state. * * 2. Triple tap and hold would magnify the screen if not magnified and enable * viewport dragging mode until the finger goes up. One can think of this * mode as a way to move the magnified viewport since the area around the * moving finger will be magnified to fit the screen. For example, if the * screen was not magnified and the user triple taps and holds the screen * would magnify and the viewport will follow the user's finger. When the * finger goes up the screen will zoom out. If the same user interaction * is performed when the screen is magnified, the viewport movement will * be the same but when the finger goes up the screen will stay magnified. * In other words, the initial magnified state is sticky. * * 3. Pinching with any number of additional fingers when viewport dragging * is enabled, i.e. the user triple tapped and holds, would adjust the * magnification scale which will become the current default magnification * scale. The next time the user magnifies the same magnification scale * would be used. * * 4. When in a permanent magnified state the user can use two or more fingers * to pan the viewport. Note that in this mode the content is panned as * opposed to the viewport dragging mode in which the viewport is moved. * * 5. When in a permanent magnified state the user can use two or more * fingers to change the magnification scale which will become the current * default magnification scale. The next time the user magnifies the same * magnification scale would be used. * * 6. The magnification scale will be persisted in settings and in the cloud. */ public final class ScreenMagnifier extends IMagnificationCallbacks.Stub implements EventStreamTransformation { private static final String LOG_TAG = ScreenMagnifier.class.getSimpleName(); private static final boolean DEBUG_STATE_TRANSITIONS = false; private static final boolean DEBUG_DETECTING = false; private static final boolean DEBUG_SET_MAGNIFICATION_SPEC = false; private static final boolean DEBUG_PANNING = false; private static final boolean DEBUG_SCALING = false; private static final boolean DEBUG_MAGNIFICATION_CONTROLLER = false; private static final int STATE_DELEGATING = 1; private static final int STATE_DETECTING = 2; private static final int STATE_VIEWPORT_DRAGGING = 3; private static final int STATE_MAGNIFIED_INTERACTION = 4; private static final float DEFAULT_MAGNIFICATION_SCALE = 2.0f; private static final int MULTI_TAP_TIME_SLOP_ADJUSTMENT = 50; private static final int MESSAGE_ON_MAGNIFIED_BOUNDS_CHANGED = 1; private static final int MESSAGE_ON_RECTANGLE_ON_SCREEN_REQUESTED = 2; private static final int MESSAGE_ON_USER_CONTEXT_CHANGED = 3; private static final int MESSAGE_ON_ROTATION_CHANGED = 4; private static final int DEFAULT_SCREEN_MAGNIFICATION_AUTO_UPDATE = 1; private static final int MY_PID = android.os.Process.myPid(); private final Rect mTempRect = new Rect(); private final Rect mTempRect1 = new Rect(); private final Context mContext; private final IWindowManager mWindowManager; private final MagnificationController mMagnificationController; private final ScreenStateObserver mScreenStateObserver; private final DetectingStateHandler mDetectingStateHandler; private final MagnifiedContentInteractonStateHandler mMagnifiedContentInteractonStateHandler; private final StateViewportDraggingHandler mStateViewportDraggingHandler; private final AccessibilityManagerService mAms; private final int mTapTimeSlop = ViewConfiguration.getTapTimeout(); private final int mMultiTapTimeSlop = ViewConfiguration.getDoubleTapTimeout() - MULTI_TAP_TIME_SLOP_ADJUSTMENT; private final int mTapDistanceSlop; private final int mMultiTapDistanceSlop; private final long mLongAnimationDuration; private final Region mMagnifiedBounds = new Region(); private EventStreamTransformation mNext; private int mCurrentState; private int mPreviousState; private boolean mTranslationEnabledBeforePan; private PointerCoords[] mTempPointerCoords; private PointerProperties[] mTempPointerProperties; private long mDelegatingStateDownTime; private boolean mUpdateMagnificationSpecOnNextBoundsChange; private final Handler mHandler = new Handler() { @Override public void handleMessage(Message message) { switch (message.what) { case MESSAGE_ON_MAGNIFIED_BOUNDS_CHANGED: { Region bounds = (Region) message.obj; handleOnMagnifiedBoundsChanged(bounds); bounds.recycle(); } break; case MESSAGE_ON_RECTANGLE_ON_SCREEN_REQUESTED: { SomeArgs args = (SomeArgs) message.obj; final int left = args.argi1; final int top = args.argi2; final int right = args.argi3; final int bottom = args.argi4; handleOnRectangleOnScreenRequested(left, top, right, bottom); args.recycle(); } break; case MESSAGE_ON_USER_CONTEXT_CHANGED: { handleOnUserContextChanged(); } break; case MESSAGE_ON_ROTATION_CHANGED: { final int rotation = message.arg1; handleOnRotationChanged(rotation); } break; } } }; public ScreenMagnifier(Context context, int displayId, AccessibilityManagerService service) { mContext = context; mWindowManager = IWindowManager.Stub.asInterface( ServiceManager.getService("window")); mAms = service; mLongAnimationDuration = context.getResources().getInteger( com.android.internal.R.integer.config_longAnimTime); mTapDistanceSlop = ViewConfiguration.get(context).getScaledTouchSlop(); mMultiTapDistanceSlop = ViewConfiguration.get(context).getScaledDoubleTapSlop(); mDetectingStateHandler = new DetectingStateHandler(); mStateViewportDraggingHandler = new StateViewportDraggingHandler(); mMagnifiedContentInteractonStateHandler = new MagnifiedContentInteractonStateHandler( context); mMagnificationController = new MagnificationController(mLongAnimationDuration); mScreenStateObserver = new ScreenStateObserver(context, mMagnificationController); try { mWindowManager.setMagnificationCallbacks(this); } catch (RemoteException re) { /* ignore */ } transitionToState(STATE_DETECTING); } @Override public void onMagnifedBoundsChanged(Region bounds) { Region newBounds = Region.obtain(bounds); mHandler.obtainMessage(MESSAGE_ON_MAGNIFIED_BOUNDS_CHANGED, newBounds).sendToTarget(); if (MY_PID != Binder.getCallingPid()) { bounds.recycle(); } } private void handleOnMagnifiedBoundsChanged(Region bounds) { // If there was a rotation we have to update the center of the magnified // region since the old offset X/Y may be out of its acceptable range for // the new display width and height. if (mUpdateMagnificationSpecOnNextBoundsChange) { mUpdateMagnificationSpecOnNextBoundsChange = false; MagnificationSpec spec = mMagnificationController.getMagnificationSpec(); Rect magnifiedFrame = mTempRect; mMagnifiedBounds.getBounds(magnifiedFrame); final float scale = spec.scale; final float centerX = (-spec.offsetX + magnifiedFrame.width() / 2) / scale; final float centerY = (-spec.offsetY + magnifiedFrame.height() / 2) / scale; mMagnificationController.setScaleAndMagnifiedRegionCenter(scale, centerX, centerY, false); } mMagnifiedBounds.set(bounds); mAms.onMagnificationStateChanged(); } @Override public void onRectangleOnScreenRequested(int left, int top, int right, int bottom) { SomeArgs args = SomeArgs.obtain(); args.argi1 = left; args.argi2 = top; args.argi3 = right; args.argi4 = bottom; mHandler.obtainMessage(MESSAGE_ON_RECTANGLE_ON_SCREEN_REQUESTED, args).sendToTarget(); } private void handleOnRectangleOnScreenRequested(int left, int top, int right, int bottom) { Rect magnifiedFrame = mTempRect; mMagnifiedBounds.getBounds(magnifiedFrame); if (!magnifiedFrame.intersects(left, top, right, bottom)) { return; } Rect magnifFrameInScreenCoords = mTempRect1; getMagnifiedFrameInContentCoords(magnifFrameInScreenCoords); final float scrollX; final float scrollY; if (right - left > magnifFrameInScreenCoords.width()) { final int direction = TextUtils.getLayoutDirectionFromLocale(Locale.getDefault()); if (direction == View.LAYOUT_DIRECTION_LTR) { scrollX = left - magnifFrameInScreenCoords.left; } else { scrollX = right - magnifFrameInScreenCoords.right; } } else if (left < magnifFrameInScreenCoords.left) { scrollX = left - magnifFrameInScreenCoords.left; } else if (right > magnifFrameInScreenCoords.right) { scrollX = right - magnifFrameInScreenCoords.right; } else { scrollX = 0; } if (bottom - top > magnifFrameInScreenCoords.height()) { scrollY = top - magnifFrameInScreenCoords.top; } else if (top < magnifFrameInScreenCoords.top) { scrollY = top - magnifFrameInScreenCoords.top; } else if (bottom > magnifFrameInScreenCoords.bottom) { scrollY = bottom - magnifFrameInScreenCoords.bottom; } else { scrollY = 0; } final float scale = mMagnificationController.getScale(); mMagnificationController.offsetMagnifiedRegionCenter(scrollX * scale, scrollY * scale); } @Override public void onRotationChanged(int rotation) { mHandler.obtainMessage(MESSAGE_ON_ROTATION_CHANGED, rotation, 0).sendToTarget(); } private void handleOnRotationChanged(int rotation) { resetMagnificationIfNeeded(); if (mMagnificationController.isMagnifying()) { mUpdateMagnificationSpecOnNextBoundsChange = true; } } @Override public void onUserContextChanged() { mHandler.sendEmptyMessage(MESSAGE_ON_USER_CONTEXT_CHANGED); } private void handleOnUserContextChanged() { resetMagnificationIfNeeded(); } private void getMagnifiedFrameInContentCoords(Rect rect) { MagnificationSpec spec = mMagnificationController.getMagnificationSpec(); mMagnifiedBounds.getBounds(rect); rect.offset((int) -spec.offsetX, (int) -spec.offsetY); rect.scale(1.0f / spec.scale); } private void resetMagnificationIfNeeded() { if (mMagnificationController.isMagnifying() && isScreenMagnificationAutoUpdateEnabled(mContext)) { mMagnificationController.reset(true); } } @Override public void onMotionEvent(MotionEvent event, MotionEvent rawEvent, int policyFlags) { mMagnifiedContentInteractonStateHandler.onMotionEvent(event); switch (mCurrentState) { case STATE_DELEGATING: { handleMotionEventStateDelegating(event, rawEvent, policyFlags); } break; case STATE_DETECTING: { mDetectingStateHandler.onMotionEvent(event, rawEvent, policyFlags); } break; case STATE_VIEWPORT_DRAGGING: { mStateViewportDraggingHandler.onMotionEvent(event, policyFlags); } break; case STATE_MAGNIFIED_INTERACTION: { // mMagnifiedContentInteractonStateHandler handles events only // if this is the current state since it uses ScaleGestureDetecotr // and a GestureDetector which need well formed event stream. } break; default: { throw new IllegalStateException("Unknown state: " + mCurrentState); } } } @Override public void onAccessibilityEvent(AccessibilityEvent event) { if (mNext != null) { mNext.onAccessibilityEvent(event); } } @Override public void setNext(EventStreamTransformation next) { mNext = next; } @Override public void clear() { mCurrentState = STATE_DETECTING; mDetectingStateHandler.clear(); mStateViewportDraggingHandler.clear(); mMagnifiedContentInteractonStateHandler.clear(); if (mNext != null) { mNext.clear(); } } @Override public void onDestroy() { mScreenStateObserver.destroy(); try { mWindowManager.setMagnificationCallbacks(null); } catch (RemoteException re) { /* ignore */ } } private void handleMotionEventStateDelegating(MotionEvent event, MotionEvent rawEvent, int policyFlags) { switch (event.getActionMasked()) { case MotionEvent.ACTION_DOWN: { mDelegatingStateDownTime = event.getDownTime(); } break; case MotionEvent.ACTION_UP: { if (mDetectingStateHandler.mDelayedEventQueue == null) { transitionToState(STATE_DETECTING); } } break; } if (mNext != null) { // If the event is within the magnified portion of the screen we have // to change its location to be where the user thinks he is poking the // UI which may have been magnified and panned. final float eventX = event.getX(); final float eventY = event.getY(); if (mMagnificationController.isMagnifying() && mMagnifiedBounds.contains((int) eventX, (int) eventY)) { final float scale = mMagnificationController.getScale(); final float scaledOffsetX = mMagnificationController.getOffsetX(); final float scaledOffsetY = mMagnificationController.getOffsetY(); final int pointerCount = event.getPointerCount(); PointerCoords[] coords = getTempPointerCoordsWithMinSize(pointerCount); PointerProperties[] properties = getTempPointerPropertiesWithMinSize(pointerCount); for (int i = 0; i < pointerCount; i++) { event.getPointerCoords(i, coords[i]); coords[i].x = (coords[i].x - scaledOffsetX) / scale; coords[i].y = (coords[i].y - scaledOffsetY) / scale; event.getPointerProperties(i, properties[i]); } event = MotionEvent.obtain(event.getDownTime(), event.getEventTime(), event.getAction(), pointerCount, properties, coords, 0, 0, 1.0f, 1.0f, event.getDeviceId(), 0, event.getSource(), event.getFlags()); } // We cache some events to see if the user wants to trigger magnification. // If no magnification is triggered we inject these events with adjusted // time and down time to prevent subsequent transformations being confused // by stale events. After the cached events, which always have a down, are // injected we need to also update the down time of all subsequent non cached // events. All delegated events cached and non-cached are delivered here. event.setDownTime(mDelegatingStateDownTime); mNext.onMotionEvent(event, rawEvent, policyFlags); } } private PointerCoords[] getTempPointerCoordsWithMinSize(int size) { final int oldSize = (mTempPointerCoords != null) ? mTempPointerCoords.length : 0; if (oldSize < size) { PointerCoords[] oldTempPointerCoords = mTempPointerCoords; mTempPointerCoords = new PointerCoords[size]; if (oldTempPointerCoords != null) { System.arraycopy(oldTempPointerCoords, 0, mTempPointerCoords, 0, oldSize); } } for (int i = oldSize; i < size; i++) { mTempPointerCoords[i] = new PointerCoords(); } return mTempPointerCoords; } private PointerProperties[] getTempPointerPropertiesWithMinSize(int size) { final int oldSize = (mTempPointerProperties != null) ? mTempPointerProperties.length : 0; if (oldSize < size) { PointerProperties[] oldTempPointerProperties = mTempPointerProperties; mTempPointerProperties = new PointerProperties[size]; if (oldTempPointerProperties != null) { System.arraycopy(oldTempPointerProperties, 0, mTempPointerProperties, 0, oldSize); } } for (int i = oldSize; i < size; i++) { mTempPointerProperties[i] = new PointerProperties(); } return mTempPointerProperties; } private void transitionToState(int state) { if (DEBUG_STATE_TRANSITIONS) { switch (state) { case STATE_DELEGATING: { Slog.i(LOG_TAG, "mCurrentState: STATE_DELEGATING"); } break; case STATE_DETECTING: { Slog.i(LOG_TAG, "mCurrentState: STATE_DETECTING"); } break; case STATE_VIEWPORT_DRAGGING: { Slog.i(LOG_TAG, "mCurrentState: STATE_VIEWPORT_DRAGGING"); } break; case STATE_MAGNIFIED_INTERACTION: { Slog.i(LOG_TAG, "mCurrentState: STATE_MAGNIFIED_INTERACTION"); } break; default: { throw new IllegalArgumentException("Unknown state: " + state); } } } mPreviousState = mCurrentState; mCurrentState = state; } private final class MagnifiedContentInteractonStateHandler extends SimpleOnGestureListener implements OnScaleGestureListener { private static final float MIN_SCALE = 1.3f; private static final float MAX_SCALE = 5.0f; private static final float SCALING_THRESHOLD = 0.3f; private final ScaleGestureDetector mScaleGestureDetector; private final GestureDetector mGestureDetector; private float mInitialScaleFactor = -1; private boolean mScaling; public MagnifiedContentInteractonStateHandler(Context context) { mScaleGestureDetector = new ScaleGestureDetector(context, this); mGestureDetector = new GestureDetector(context, this); } public void onMotionEvent(MotionEvent event) { mScaleGestureDetector.onTouchEvent(event); mGestureDetector.onTouchEvent(event); if (mCurrentState != STATE_MAGNIFIED_INTERACTION) { return; } if (event.getActionMasked() == MotionEvent.ACTION_UP) { clear(); final float scale = Math.min(Math.max(mMagnificationController.getScale(), MIN_SCALE), MAX_SCALE); if (scale != getPersistedScale()) { persistScale(scale); } if (mPreviousState == STATE_VIEWPORT_DRAGGING) { transitionToState(STATE_VIEWPORT_DRAGGING); } else { transitionToState(STATE_DETECTING); } } } @Override public boolean onScroll(MotionEvent first, MotionEvent second, float distanceX, float distanceY) { if (mCurrentState != STATE_MAGNIFIED_INTERACTION) { return true; } if (DEBUG_PANNING) { Slog.i(LOG_TAG, "Panned content by scrollX: " + distanceX + " scrollY: " + distanceY); } mMagnificationController.offsetMagnifiedRegionCenter(distanceX, distanceY); return true; } @Override public boolean onScale(ScaleGestureDetector detector) { if (!mScaling) { if (mInitialScaleFactor < 0) { mInitialScaleFactor = detector.getScaleFactor(); } else { final float deltaScale = detector.getScaleFactor() - mInitialScaleFactor; if (Math.abs(deltaScale) > SCALING_THRESHOLD) { mScaling = true; return true; } } return false; } final float newScale = mMagnificationController.getScale() * detector.getScaleFactor(); final float normalizedNewScale = Math.min(Math.max(newScale, MIN_SCALE), MAX_SCALE); if (DEBUG_SCALING) { Slog.i(LOG_TAG, "normalizedNewScale: " + normalizedNewScale); } mMagnificationController.setScale(normalizedNewScale, detector.getFocusX(), detector.getFocusY(), false); return true; } @Override public boolean onScaleBegin(ScaleGestureDetector detector) { return (mCurrentState == STATE_MAGNIFIED_INTERACTION); } @Override public void onScaleEnd(ScaleGestureDetector detector) { clear(); } private void clear() { mInitialScaleFactor = -1; mScaling = false; } } private final class StateViewportDraggingHandler { private boolean mLastMoveOutsideMagnifiedRegion; private void onMotionEvent(MotionEvent event, int policyFlags) { final int action = event.getActionMasked(); switch (action) { case MotionEvent.ACTION_DOWN: { throw new IllegalArgumentException("Unexpected event type: ACTION_DOWN"); } case MotionEvent.ACTION_POINTER_DOWN: { clear(); transitionToState(STATE_MAGNIFIED_INTERACTION); } break; case MotionEvent.ACTION_MOVE: { if (event.getPointerCount() != 1) { throw new IllegalStateException("Should have one pointer down."); } final float eventX = event.getX(); final float eventY = event.getY(); if (mMagnifiedBounds.contains((int) eventX, (int) eventY)) { if (mLastMoveOutsideMagnifiedRegion) { mLastMoveOutsideMagnifiedRegion = false; mMagnificationController.setMagnifiedRegionCenter(eventX, eventY, true); } else { mMagnificationController.setMagnifiedRegionCenter(eventX, eventY, false); } } else { mLastMoveOutsideMagnifiedRegion = true; } } break; case MotionEvent.ACTION_UP: { if (!mTranslationEnabledBeforePan) { mMagnificationController.reset(true); } clear(); transitionToState(STATE_DETECTING); } break; case MotionEvent.ACTION_POINTER_UP: { throw new IllegalArgumentException("Unexpected event type: ACTION_POINTER_UP"); } } } public void clear() { mLastMoveOutsideMagnifiedRegion = false; } } private final class DetectingStateHandler { private static final int MESSAGE_ON_ACTION_TAP_AND_HOLD = 1; private static final int MESSAGE_TRANSITION_TO_DELEGATING_STATE = 2; private static final int ACTION_TAP_COUNT = 3; private MotionEventInfo mDelayedEventQueue; private MotionEvent mLastDownEvent; private MotionEvent mLastTapUpEvent; private int mTapCount; private final Handler mHandler = new Handler() { @Override public void handleMessage(Message message) { final int type = message.what; switch (type) { case MESSAGE_ON_ACTION_TAP_AND_HOLD: { MotionEvent event = (MotionEvent) message.obj; final int policyFlags = message.arg1; onActionTapAndHold(event, policyFlags); } break; case MESSAGE_TRANSITION_TO_DELEGATING_STATE: { transitionToState(STATE_DELEGATING); sendDelayedMotionEvents(); clear(); } break; default: { throw new IllegalArgumentException("Unknown message type: " + type); } } } }; public void onMotionEvent(MotionEvent event, MotionEvent rawEvent, int policyFlags) { cacheDelayedMotionEvent(event, rawEvent, policyFlags); final int action = event.getActionMasked(); switch (action) { case MotionEvent.ACTION_DOWN: { mHandler.removeMessages(MESSAGE_TRANSITION_TO_DELEGATING_STATE); if (!mMagnifiedBounds.contains((int) event.getX(), (int) event.getY())) { transitionToDelegatingStateAndClear(); return; } if (mTapCount == ACTION_TAP_COUNT - 1 && mLastDownEvent != null && GestureUtils.isMultiTap(mLastDownEvent, event, mMultiTapTimeSlop, mMultiTapDistanceSlop, 0)) { Message message = mHandler.obtainMessage(MESSAGE_ON_ACTION_TAP_AND_HOLD, policyFlags, 0, event); mHandler.sendMessageDelayed(message, ViewConfiguration.getLongPressTimeout()); } else if (mTapCount < ACTION_TAP_COUNT) { Message message = mHandler.obtainMessage( MESSAGE_TRANSITION_TO_DELEGATING_STATE); mHandler.sendMessageDelayed(message, mMultiTapTimeSlop); } clearLastDownEvent(); mLastDownEvent = MotionEvent.obtain(event); } break; case MotionEvent.ACTION_POINTER_DOWN: { if (mMagnificationController.isMagnifying()) { transitionToState(STATE_MAGNIFIED_INTERACTION); clear(); } else { transitionToDelegatingStateAndClear(); } } break; case MotionEvent.ACTION_MOVE: { if (mLastDownEvent != null && mTapCount < ACTION_TAP_COUNT - 1) { final double distance = GestureUtils.computeDistance(mLastDownEvent, event, 0); if (Math.abs(distance) > mTapDistanceSlop) { transitionToDelegatingStateAndClear(); } } } break; case MotionEvent.ACTION_UP: { if (mLastDownEvent == null) { return; } mHandler.removeMessages(MESSAGE_ON_ACTION_TAP_AND_HOLD); if (!mMagnifiedBounds.contains((int) event.getX(), (int) event.getY())) { transitionToDelegatingStateAndClear(); return; } if (!GestureUtils.isTap(mLastDownEvent, event, mTapTimeSlop, mTapDistanceSlop, 0)) { transitionToDelegatingStateAndClear(); return; } if (mLastTapUpEvent != null && !GestureUtils.isMultiTap(mLastTapUpEvent, event, mMultiTapTimeSlop, mMultiTapDistanceSlop, 0)) { transitionToDelegatingStateAndClear(); return; } mTapCount++; if (DEBUG_DETECTING) { Slog.i(LOG_TAG, "Tap count:" + mTapCount); } if (mTapCount == ACTION_TAP_COUNT) { clear(); onActionTap(event, policyFlags); return; } clearLastTapUpEvent(); mLastTapUpEvent = MotionEvent.obtain(event); } break; case MotionEvent.ACTION_POINTER_UP: { /* do nothing */ } break; } } public void clear() { mHandler.removeMessages(MESSAGE_ON_ACTION_TAP_AND_HOLD); mHandler.removeMessages(MESSAGE_TRANSITION_TO_DELEGATING_STATE); clearTapDetectionState(); clearDelayedMotionEvents(); } private void clearTapDetectionState() { mTapCount = 0; clearLastTapUpEvent(); clearLastDownEvent(); } private void clearLastTapUpEvent() { if (mLastTapUpEvent != null) { mLastTapUpEvent.recycle(); mLastTapUpEvent = null; } } private void clearLastDownEvent() { if (mLastDownEvent != null) { mLastDownEvent.recycle(); mLastDownEvent = null; } } private void cacheDelayedMotionEvent(MotionEvent event, MotionEvent rawEvent, int policyFlags) { MotionEventInfo info = MotionEventInfo.obtain(event, rawEvent, policyFlags); if (mDelayedEventQueue == null) { mDelayedEventQueue = info; } else { MotionEventInfo tail = mDelayedEventQueue; while (tail.mNext != null) { tail = tail.mNext; } tail.mNext = info; } } private void sendDelayedMotionEvents() { while (mDelayedEventQueue != null) { MotionEventInfo info = mDelayedEventQueue; mDelayedEventQueue = info.mNext; final long offset = SystemClock.uptimeMillis() - info.mCachedTimeMillis; MotionEvent event = obtainEventWithOffsetTimeAndDownTime(info.mEvent, offset); MotionEvent rawEvent = obtainEventWithOffsetTimeAndDownTime(info.mRawEvent, offset); ScreenMagnifier.this.onMotionEvent(event, rawEvent, info.mPolicyFlags); event.recycle(); rawEvent.recycle(); info.recycle(); } } private MotionEvent obtainEventWithOffsetTimeAndDownTime(MotionEvent event, long offset) { final int pointerCount = event.getPointerCount(); PointerCoords[] coords = getTempPointerCoordsWithMinSize(pointerCount); PointerProperties[] properties = getTempPointerPropertiesWithMinSize(pointerCount); for (int i = 0; i < pointerCount; i++) { event.getPointerCoords(i, coords[i]); event.getPointerProperties(i, properties[i]); } final long downTime = event.getDownTime() + offset; final long eventTime = event.getEventTime() + offset; return MotionEvent.obtain(downTime, eventTime, event.getAction(), pointerCount, properties, coords, event.getMetaState(), event.getButtonState(), 1.0f, 1.0f, event.getDeviceId(), event.getEdgeFlags(), event.getSource(), event.getFlags()); } private void clearDelayedMotionEvents() { while (mDelayedEventQueue != null) { MotionEventInfo info = mDelayedEventQueue; mDelayedEventQueue = info.mNext; info.recycle(); } } private void transitionToDelegatingStateAndClear() { transitionToState(STATE_DELEGATING); sendDelayedMotionEvents(); clear(); } private void onActionTap(MotionEvent up, int policyFlags) { if (DEBUG_DETECTING) { Slog.i(LOG_TAG, "onActionTap()"); } if (!mMagnificationController.isMagnifying()) { mMagnificationController.setScaleAndMagnifiedRegionCenter(getPersistedScale(), up.getX(), up.getY(), true); } else { mMagnificationController.reset(true); } } private void onActionTapAndHold(MotionEvent down, int policyFlags) { if (DEBUG_DETECTING) { Slog.i(LOG_TAG, "onActionTapAndHold()"); } clear(); mTranslationEnabledBeforePan = mMagnificationController.isMagnifying(); mMagnificationController.setScaleAndMagnifiedRegionCenter(getPersistedScale(), down.getX(), down.getY(), true); transitionToState(STATE_VIEWPORT_DRAGGING); } } private void persistScale(final float scale) { new AsyncTask() { @Override protected Void doInBackground(Void... params) { Settings.Secure.putFloat(mContext.getContentResolver(), Settings.Secure.ACCESSIBILITY_DISPLAY_MAGNIFICATION_SCALE, scale); return null; } }.execute(); } private float getPersistedScale() { return Settings.Secure.getFloat(mContext.getContentResolver(), Settings.Secure.ACCESSIBILITY_DISPLAY_MAGNIFICATION_SCALE, DEFAULT_MAGNIFICATION_SCALE); } private static boolean isScreenMagnificationAutoUpdateEnabled(Context context) { return (Settings.Secure.getInt(context.getContentResolver(), Settings.Secure.ACCESSIBILITY_DISPLAY_MAGNIFICATION_AUTO_UPDATE, DEFAULT_SCREEN_MAGNIFICATION_AUTO_UPDATE) == 1); } private static final class MotionEventInfo { private static final int MAX_POOL_SIZE = 10; private static final Object sLock = new Object(); private static MotionEventInfo sPool; private static int sPoolSize; private MotionEventInfo mNext; private boolean mInPool; public MotionEvent mEvent; public MotionEvent mRawEvent; public int mPolicyFlags; public long mCachedTimeMillis; public static MotionEventInfo obtain(MotionEvent event, MotionEvent rawEvent, int policyFlags) { synchronized (sLock) { MotionEventInfo info; if (sPoolSize > 0) { sPoolSize--; info = sPool; sPool = info.mNext; info.mNext = null; info.mInPool = false; } else { info = new MotionEventInfo(); } info.initialize(event, rawEvent, policyFlags); return info; } } private void initialize(MotionEvent event, MotionEvent rawEvent, int policyFlags) { mEvent = MotionEvent.obtain(event); mRawEvent = MotionEvent.obtain(rawEvent); mPolicyFlags = policyFlags; mCachedTimeMillis = SystemClock.uptimeMillis(); } public void recycle() { synchronized (sLock) { if (mInPool) { throw new IllegalStateException("Already recycled."); } clear(); if (sPoolSize < MAX_POOL_SIZE) { sPoolSize++; mNext = sPool; sPool = this; mInPool = true; } } } private void clear() { mEvent.recycle(); mEvent = null; mRawEvent.recycle(); mRawEvent = null; mPolicyFlags = 0; mCachedTimeMillis = 0; } } private final class MagnificationController { private static final String PROPERTY_NAME_MAGNIFICATION_SPEC = "magnificationSpec"; private final MagnificationSpec mSentMagnificationSpec = MagnificationSpec.obtain(); private final MagnificationSpec mCurrentMagnificationSpec = MagnificationSpec.obtain(); private final Rect mTempRect = new Rect(); private final ValueAnimator mTransformationAnimator; public MagnificationController(long animationDuration) { Property property = Property.of(MagnificationController.class, MagnificationSpec.class, PROPERTY_NAME_MAGNIFICATION_SPEC); TypeEvaluator evaluator = new TypeEvaluator() { private final MagnificationSpec mTempTransformationSpec = MagnificationSpec.obtain(); @Override public MagnificationSpec evaluate(float fraction, MagnificationSpec fromSpec, MagnificationSpec toSpec) { MagnificationSpec result = mTempTransformationSpec; result.scale = fromSpec.scale + (toSpec.scale - fromSpec.scale) * fraction; result.offsetX = fromSpec.offsetX + (toSpec.offsetX - fromSpec.offsetX) * fraction; result.offsetY = fromSpec.offsetY + (toSpec.offsetY - fromSpec.offsetY) * fraction; return result; } }; mTransformationAnimator = ObjectAnimator.ofObject(this, property, evaluator, mSentMagnificationSpec, mCurrentMagnificationSpec); mTransformationAnimator.setDuration((long) (animationDuration)); mTransformationAnimator.setInterpolator(new DecelerateInterpolator(2.5f)); } public boolean isMagnifying() { return mCurrentMagnificationSpec.scale > 1.0f; } public void reset(boolean animate) { if (mTransformationAnimator.isRunning()) { mTransformationAnimator.cancel(); } mCurrentMagnificationSpec.clear(); if (animate) { animateMangificationSpec(mSentMagnificationSpec, mCurrentMagnificationSpec); } else { setMagnificationSpec(mCurrentMagnificationSpec); } Rect bounds = mTempRect; bounds.setEmpty(); mAms.onMagnificationStateChanged(); } public float getScale() { return mCurrentMagnificationSpec.scale; } public float getOffsetX() { return mCurrentMagnificationSpec.offsetX; } public float getOffsetY() { return mCurrentMagnificationSpec.offsetY; } public void setScale(float scale, float pivotX, float pivotY, boolean animate) { Rect magnifiedFrame = mTempRect; mMagnifiedBounds.getBounds(magnifiedFrame); MagnificationSpec spec = mCurrentMagnificationSpec; final float oldScale = spec.scale; final float oldCenterX = (-spec.offsetX + magnifiedFrame.width() / 2) / oldScale; final float oldCenterY = (-spec.offsetY + magnifiedFrame.height() / 2) / oldScale; final float normPivotX = (-spec.offsetX + pivotX) / oldScale; final float normPivotY = (-spec.offsetY + pivotY) / oldScale; final float offsetX = (oldCenterX - normPivotX) * (oldScale / scale); final float offsetY = (oldCenterY - normPivotY) * (oldScale / scale); final float centerX = normPivotX + offsetX; final float centerY = normPivotY + offsetY; setScaleAndMagnifiedRegionCenter(scale, centerX, centerY, animate); } public void setMagnifiedRegionCenter(float centerX, float centerY, boolean animate) { setScaleAndMagnifiedRegionCenter(mCurrentMagnificationSpec.scale, centerX, centerY, animate); } public void offsetMagnifiedRegionCenter(float offsetX, float offsetY) { final float nonNormOffsetX = mCurrentMagnificationSpec.offsetX - offsetX; mCurrentMagnificationSpec.offsetX = Math.min(Math.max(nonNormOffsetX, getMinOffsetX()), 0); final float nonNormOffsetY = mCurrentMagnificationSpec.offsetY - offsetY; mCurrentMagnificationSpec.offsetY = Math.min(Math.max(nonNormOffsetY, getMinOffsetY()), 0); setMagnificationSpec(mCurrentMagnificationSpec); } public void setScaleAndMagnifiedRegionCenter(float scale, float centerX, float centerY, boolean animate) { if (Float.compare(mCurrentMagnificationSpec.scale, scale) == 0 && Float.compare(mCurrentMagnificationSpec.offsetX, centerX) == 0 && Float.compare(mCurrentMagnificationSpec.offsetY, centerY) == 0) { return; } if (mTransformationAnimator.isRunning()) { mTransformationAnimator.cancel(); } if (DEBUG_MAGNIFICATION_CONTROLLER) { Slog.i(LOG_TAG, "scale: " + scale + " offsetX: " + centerX + " offsetY: " + centerY); } updateMagnificationSpec(scale, centerX, centerY); if (animate) { animateMangificationSpec(mSentMagnificationSpec, mCurrentMagnificationSpec); } else { setMagnificationSpec(mCurrentMagnificationSpec); } mAms.onMagnificationStateChanged(); } public void updateMagnificationSpec(float scale, float magnifiedCenterX, float magnifiedCenterY) { Rect magnifiedFrame = mTempRect; mMagnifiedBounds.getBounds(magnifiedFrame); mCurrentMagnificationSpec.scale = scale; final int viewportWidth = magnifiedFrame.width(); final float nonNormOffsetX = viewportWidth / 2 - magnifiedCenterX * scale; mCurrentMagnificationSpec.offsetX = Math.min(Math.max(nonNormOffsetX, getMinOffsetX()), 0); final int viewportHeight = magnifiedFrame.height(); final float nonNormOffsetY = viewportHeight / 2 - magnifiedCenterY * scale; mCurrentMagnificationSpec.offsetY = Math.min(Math.max(nonNormOffsetY, getMinOffsetY()), 0); } private float getMinOffsetX() { Rect magnifiedFrame = mTempRect; mMagnifiedBounds.getBounds(magnifiedFrame); final float viewportWidth = magnifiedFrame.width(); return viewportWidth - viewportWidth * mCurrentMagnificationSpec.scale; } private float getMinOffsetY() { Rect magnifiedFrame = mTempRect; mMagnifiedBounds.getBounds(magnifiedFrame); final float viewportHeight = magnifiedFrame.height(); return viewportHeight - viewportHeight * mCurrentMagnificationSpec.scale; } private void animateMangificationSpec(MagnificationSpec fromSpec, MagnificationSpec toSpec) { mTransformationAnimator.setObjectValues(fromSpec, toSpec); mTransformationAnimator.start(); } public MagnificationSpec getMagnificationSpec() { return mSentMagnificationSpec; } public void setMagnificationSpec(MagnificationSpec spec) { if (DEBUG_SET_MAGNIFICATION_SPEC) { Slog.i(LOG_TAG, "Sending: " + spec); } try { mSentMagnificationSpec.scale = spec.scale; mSentMagnificationSpec.offsetX = spec.offsetX; mSentMagnificationSpec.offsetY = spec.offsetY; mWindowManager.setMagnificationSpec( MagnificationSpec.obtain(spec)); } catch (RemoteException re) { /* ignore */ } } } private final class ScreenStateObserver extends BroadcastReceiver { private static final int MESSAGE_ON_SCREEN_STATE_CHANGE = 1; private final Context mContext; private final MagnificationController mMagnificationController; private final Handler mHandler = new Handler() { @Override public void handleMessage(Message message) { switch (message.what) { case MESSAGE_ON_SCREEN_STATE_CHANGE: { String action = (String) message.obj; handleOnScreenStateChange(action); } break; } } }; public ScreenStateObserver(Context context, MagnificationController magnificationController) { mContext = context; mMagnificationController = magnificationController; mContext.registerReceiver(this, new IntentFilter(Intent.ACTION_SCREEN_OFF)); } public void destroy() { mContext.unregisterReceiver(this); } @Override public void onReceive(Context context, Intent intent) { mHandler.obtainMessage(MESSAGE_ON_SCREEN_STATE_CHANGE, intent.getAction()).sendToTarget(); } private void handleOnScreenStateChange(String action) { if (mMagnificationController.isMagnifying() && isScreenMagnificationAutoUpdateEnabled(mContext)) { mMagnificationController.reset(false); } } } }