* The actual bitmap decode work is handled by {@link DecodeTask}. */ public class ExtendedBitmapDrawable extends BasicBitmapDrawable implements Runnable, Parallaxable, DecodeAggregator.Callback { public static final int LOAD_STATE_UNINITIALIZED = 0; public static final int LOAD_STATE_NOT_YET_LOADED = 1; public static final int LOAD_STATE_LOADING = 2; public static final int LOAD_STATE_LOADED = 3; public static final int LOAD_STATE_FAILED = 4; public static final boolean DEBUG = false; private static final String TAG = ExtendedBitmapDrawable.class.getSimpleName(); private final Resources mResources; private final ExtendedOptions mOpts; // Parallax. private float mParallaxFraction = 1f / 2; // State changes. private int mLoadState = LOAD_STATE_UNINITIALIZED; private Placeholder mPlaceholder; private Progress mProgress; private int mProgressDelayMs; private final Handler mHandler = new Handler(); public ExtendedBitmapDrawable(final Resources res, final BitmapCache cache, final boolean limitDensity, ExtendedOptions opts) { super(res, cache, limitDensity); mResources = res; if (opts == null) { opts = new ExtendedOptions(0); } mOpts = opts; onOptsChanged(); } /** * Called after a field is changed in an {@link ExtendedOptions}, if that field requests this * method to be called. */ public void onOptsChanged() { mOpts.validate(); // Placeholder and progress. if ((mOpts.features & ExtendedOptions.FEATURE_STATE_CHANGES) != 0) { final int fadeOutDurationMs = mResources.getInteger(R.integer.bitmap_fade_animation_duration); mProgressDelayMs = mResources.getInteger(R.integer.bitmap_progress_animation_delay); // Placeholder is not optional because backgroundColor is part of it. Drawable placeholder = null; int placeholderWidth = mResources.getDimensionPixelSize(R.dimen.placeholder_size); int placeholderHeight = mResources.getDimensionPixelSize(R.dimen.placeholder_size); if (mOpts.placeholder != null) { ConstantState constantState = mOpts.placeholder.getConstantState(); if (constantState != null) { placeholder = constantState.newDrawable(mResources); } else { placeholder = mOpts.placeholder; } Rect bounds = mOpts.placeholder.getBounds(); if (bounds.width() != 0) { placeholderWidth = bounds.width(); } else if (placeholder.getIntrinsicWidth() != -1) { placeholderWidth = placeholder.getIntrinsicWidth(); } if (bounds.height() != 0) { placeholderHeight = bounds.height(); } else if (placeholder.getIntrinsicHeight() != -1) { placeholderHeight = placeholder.getIntrinsicHeight(); } } mPlaceholder = new Placeholder(placeholder, mResources, placeholderWidth, placeholderHeight, fadeOutDurationMs, mOpts); mPlaceholder.setCallback(this); mPlaceholder.setBounds(getBounds()); // Progress bar is optional. if (mOpts.progressBar != null) { int progressBarSize = mResources.getDimensionPixelSize(R.dimen.progress_bar_size); mProgress = new Progress(mOpts.progressBar.getConstantState().newDrawable(mResources), mResources, progressBarSize, progressBarSize, fadeOutDurationMs, mOpts); mProgress.setCallback(this); mProgress.setBounds(getBounds()); } else { mProgress = null; } } setLoadState(mLoadState); } @Override public void setParallaxFraction(float fraction) { mParallaxFraction = fraction; invalidateSelf(); } /** * Get the ExtendedOptions used to instantiate this ExtendedBitmapDrawable. Any changes made to * the parameters inside the options will take effect immediately. */ public ExtendedOptions getExtendedOptions() { return mOpts; } /** * This sets the drawable to the failed state, which remove all animations from the placeholder. * This is different from unbinding to the uninitialized state, where we expect animations. */ public void showStaticPlaceholder() { setLoadState(LOAD_STATE_FAILED); } /** * Directly sets the decode width and height. The given height should already have had the * parallaxSpeedMultiplier applied to it. */ public void setExactDecodeDimensions(int width, int height) { super.setDecodeDimensions(width, height); } /** * {@inheritDoc} * * The given height should not have had the parallaxSpeedMultiplier applied to it. */ @Override public void setDecodeDimensions(int width, int height) { super.setDecodeDimensions(width, (int) (height * mOpts.parallaxSpeedMultiplier)); } @Override protected void setImage(final RequestKey key) { if (mCurrKey != null && getDecodeAggregator() != null) { getDecodeAggregator().forget(mCurrKey); } mHandler.removeCallbacks(this); // start from a clean slate on every bind // this allows the initial transition to be specially instantaneous, so e.g. a cache hit // doesn't unnecessarily trigger a fade-in setLoadState(LOAD_STATE_UNINITIALIZED); super.setImage(key); if (key == null) { showStaticPlaceholder(); } } @Override protected void setBitmap(ReusableBitmap bmp) { if (bmp != null) { setLoadState(LOAD_STATE_LOADED); } else { onDecodeFailed(); } super.setBitmap(bmp); } @Override protected void loadFileDescriptorFactory() { boolean executeStateChange = shouldExecuteStateChange(); if (mCurrKey == null || mDecodeWidth == 0 || mDecodeHeight == 0) { return; } if (executeStateChange) { setLoadState(LOAD_STATE_NOT_YET_LOADED); } super.loadFileDescriptorFactory(); } @Override protected void onDecodeFailed() { super.onDecodeFailed(); setLoadState(LOAD_STATE_FAILED); } protected boolean shouldExecuteStateChange() { // TODO: AttachmentDrawable should override this method to match prev and curr request keys. return /* opts.stateChanges */ true; } @Override public float getDrawVerticalCenter() { return mParallaxFraction; } @Override protected final float getDrawVerticalOffsetMultiplier() { return mOpts.parallaxSpeedMultiplier; } @Override protected float getDecodeHorizontalCenter() { return mOpts.decodeHorizontalCenter; } @Override protected float getDecodeVerticalCenter() { return mOpts.decodeVerticalCenter; } private DecodeAggregator getDecodeAggregator() { return mOpts.decodeAggregator; } /** * Instead of overriding this method, subclasses should override {@link #onDraw(Canvas)}. * * The reason for this is that we need the placeholder and progress bar to be drawn over our * content. Those two drawables fade out, giving the impression that our content is fading in. * * Only override this method for custom drawings on top of all the drawable layers. */ @Override public void draw(final Canvas canvas) { final Rect bounds = getBounds(); if (bounds.isEmpty()) { return; } onDraw(canvas); // Draw the two possible overlay layers in reverse-priority order. // (each layer will no-op the draw when appropriate) // This ordering means cross-fade transitions are just fade-outs of each layer. if (mProgress != null) onDrawPlaceholderOrProgress(canvas, mProgress); if (mPlaceholder != null) onDrawPlaceholderOrProgress(canvas, mPlaceholder); } /** * Overriding this method to add your own custom drawing. */ protected void onDraw(final Canvas canvas) { super.draw(canvas); } /** * Overriding this method to add your own custom placeholder or progress drawing. */ protected void onDrawPlaceholderOrProgress(final Canvas canvas, final TileDrawable drawable) { drawable.draw(canvas); } @Override public void setAlpha(int alpha) { final int old = mPaint.getAlpha(); super.setAlpha(alpha); if (mPlaceholder != null) mPlaceholder.setAlpha(alpha); if (mProgress != null) mProgress.setAlpha(alpha); if (alpha != old) { invalidateSelf(); } } @Override public void setColorFilter(ColorFilter cf) { super.setColorFilter(cf); if (mPlaceholder != null) mPlaceholder.setColorFilter(cf); if (mProgress != null) mProgress.setColorFilter(cf); invalidateSelf(); } @Override protected void onBoundsChange(Rect bounds) { super.onBoundsChange(bounds); if (mPlaceholder != null) mPlaceholder.setBounds(bounds); if (mProgress != null) mProgress.setBounds(bounds); } @Override public void onDecodeBegin(final RequestKey key) { if (getDecodeAggregator() != null) { getDecodeAggregator().expect(key, this); } else { onBecomeFirstExpected(key); } super.onDecodeBegin(key); } @Override public void onBecomeFirstExpected(final RequestKey key) { if (!key.equals(mCurrKey)) { return; } // normally, we'd transition to the LOADING state now, but we want to delay that a bit // to minimize excess occurrences of the rotating spinner mHandler.postDelayed(this, mProgressDelayMs); } @Override public void run() { if (mLoadState == LOAD_STATE_NOT_YET_LOADED) { setLoadState(LOAD_STATE_LOADING); } } @Override public void onDecodeComplete(final RequestKey key, final ReusableBitmap result) { if (getDecodeAggregator() != null) { getDecodeAggregator().execute(key, new Runnable() { @Override public void run() { ExtendedBitmapDrawable.super.onDecodeComplete(key, result); } @Override public String toString() { return "DONE"; } }); } else { super.onDecodeComplete(key, result); } } @Override public void onDecodeCancel(final RequestKey key) { if (getDecodeAggregator() != null) { getDecodeAggregator().forget(key); } super.onDecodeCancel(key); } /** * Get the load state of this drawable. Return one of the LOAD_STATE constants. */ public int getLoadState() { return mLoadState; } /** * Each attachment gets its own placeholder and progress indicator, to be shown, hidden, * and animated based on Drawable#setVisible() changes, which are in turn driven by * setLoadState(). */ private void setLoadState(int loadState) { if (DEBUG) { Log.v(TAG, String.format("IN setLoadState. old=%s new=%s key=%s this=%s", mLoadState, loadState, mCurrKey, this)); } Trace.beginSection("set load state"); switch (loadState) { // This state differs from LOADED in that the subsequent state transition away from // UNINITIALIZED will not have a fancy transition. This allows list item binds to // cached data to take immediate effect without unnecessary whizzery. case LOAD_STATE_UNINITIALIZED: if (mPlaceholder != null) mPlaceholder.reset(); if (mProgress != null) mProgress.reset(); break; case LOAD_STATE_NOT_YET_LOADED: if (mPlaceholder != null) { mPlaceholder.setPulseEnabled(true); mPlaceholder.setVisible(true); } if (mProgress != null) mProgress.setVisible(false); break; case LOAD_STATE_LOADING: if (mProgress == null) { // Stay in same visual state as LOAD_STATE_NOT_YET_LOADED. break; } if (mPlaceholder != null) mPlaceholder.setVisible(false); if (mProgress != null) mProgress.setVisible(true); break; case LOAD_STATE_LOADED: if (mPlaceholder != null) mPlaceholder.setVisible(false); if (mProgress != null) mProgress.setVisible(false); break; case LOAD_STATE_FAILED: if (mPlaceholder != null) { mPlaceholder.setPulseEnabled(false); mPlaceholder.setVisible(true); } if (mProgress != null) mProgress.setVisible(false); break; } Trace.endSection(); mLoadState = loadState; boolean placeholderVisible = mPlaceholder != null && mPlaceholder.isVisible(); boolean progressVisible = mProgress != null && mProgress.isVisible(); if (DEBUG) { Log.v(TAG, String.format("OUT stateful setLoadState. new=%s placeholder=%s progress=%s", loadState, placeholderVisible, progressVisible)); } } private static class Placeholder extends TileDrawable { private final ValueAnimator mPulseAnimator; private boolean mPulseEnabled = true; private float mPulseAlphaFraction = 1f; public Placeholder(Drawable placeholder, Resources res, int placeholderWidth, int placeholderHeight, int fadeOutDurationMs, ExtendedOptions opts) { super(placeholder, placeholderWidth, placeholderHeight, fadeOutDurationMs, opts); if (opts.placeholderAnimationDuration == -1) { mPulseAnimator = null; } else { final long pulseDuration; if (opts.placeholderAnimationDuration == 0) { pulseDuration = res.getInteger(R.integer.bitmap_placeholder_animation_duration); } else { pulseDuration = opts.placeholderAnimationDuration; } mPulseAnimator = ValueAnimator.ofInt(55, 255).setDuration(pulseDuration); mPulseAnimator.setRepeatCount(ValueAnimator.INFINITE); mPulseAnimator.setRepeatMode(ValueAnimator.REVERSE); mPulseAnimator.addUpdateListener(new AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { mPulseAlphaFraction = ((Integer) animation.getAnimatedValue()) / 255f; setInnerAlpha(getCurrentAlpha()); } }); } mFadeOutAnimator.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationEnd(Animator animation) { stopPulsing(); } }); } @Override public void setInnerAlpha(final int alpha) { super.setInnerAlpha((int) (alpha * mPulseAlphaFraction)); } public void setPulseEnabled(boolean enabled) { mPulseEnabled = enabled; if (!mPulseEnabled) { stopPulsing(); } else { startPulsing(); } } private void stopPulsing() { if (mPulseAnimator != null) { mPulseAnimator.cancel(); mPulseAlphaFraction = 1f; setInnerAlpha(getCurrentAlpha()); } } private void startPulsing() { if (mPulseAnimator != null && !mPulseAnimator.isStarted()) { mPulseAnimator.start(); } } @Override public boolean setVisible(boolean visible) { final boolean changed = super.setVisible(visible); if (changed) { if (isVisible()) { // start if (mPulseAnimator != null && mPulseEnabled && !mPulseAnimator.isStarted()) { mPulseAnimator.start(); } } else { // can't cancel the pulsing yet-- wait for the fade-out animation to end // one exception: if alpha is already zero, there is no fade-out, so stop now if (getCurrentAlpha() == 0) { stopPulsing(); } } } return changed; } } private static class Progress extends TileDrawable { private final ValueAnimator mRotateAnimator; public Progress(Drawable progress, Resources res, int progressBarWidth, int progressBarHeight, int fadeOutDurationMs, ExtendedOptions opts) { super(progress, progressBarWidth, progressBarHeight, fadeOutDurationMs, opts); mRotateAnimator = ValueAnimator.ofInt(0, 10000) .setDuration(res.getInteger(R.integer.bitmap_progress_animation_duration)); mRotateAnimator.setInterpolator(new LinearInterpolator()); mRotateAnimator.setRepeatCount(ValueAnimator.INFINITE); mRotateAnimator.addUpdateListener(new AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { setLevel((Integer) animation.getAnimatedValue()); } }); mFadeOutAnimator.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationEnd(Animator animation) { if (mRotateAnimator != null) { mRotateAnimator.cancel(); } } }); } @Override public boolean setVisible(boolean visible) { final boolean changed = super.setVisible(visible); if (changed) { if (isVisible()) { if (mRotateAnimator != null) { mRotateAnimator.start(); } } else { // can't cancel the rotate yet-- wait for the fade-out animation to end // one exception: if alpha is already zero, there is no fade-out, so stop now if (getCurrentAlpha() == 0 && mRotateAnimator != null) { mRotateAnimator.cancel(); } } } return changed; } } /** * This class contains the features a client can specify, and arguments to those features. * Clients can later retrieve the ExtendedOptions from an ExtendedBitmapDrawable and change the * parameters, which will be reflected immediately. */ public static class ExtendedOptions { /** * Summary: * This feature enables you to draw decoded bitmap in order on the screen, to give the * visual effect of a single decode thread. * *
* Explanation: * Since DecodeTasks are asynchronous, multiple tasks may finish decoding at different * times. To have a smooth user experience, provide a shared {@link DecodeAggregator} to all * the ExtendedBitmapDrawables, and the decode aggregator will hold finished decodes so they * come back in order. * * * Pros: * Visual consistency. Images are not popping up randomly all over the place. * * * Cons: * Artificial delay. Images are not drawn as soon as they are decoded. They must wait * for their turn. * * * Requirements: * Set {@link #decodeAggregator} to a shared {@link DecodeAggregator}. */ public static final int FEATURE_ORDERED_DISPLAY = 1; /** * Summary: * This feature enables the image to move in parallax as the user scrolls, to give visual * flair to your images. * * * Explanation: * When the user scrolls D pixels in the vertical direction, this ExtendedBitmapDrawable * shifts its Bitmap f(D) pixels in the vertical direction before drawing to the screen. * Depending on the function f, the parallax effect can give varying interesting results. * * * Pros: * Visual pop and playfulness. Feeling of movement. Pleasantly surprise your users. * * * Cons: * Some users report motion sickness with certain speed multiplier values. Decode height * must be greater than visual bounds to account for the parallax. This uses more memory and * decoding time. * * * Requirements: * Set {@link #parallaxSpeedMultiplier} to the ratio between the decoded height and the * visual bound height. Call {@link ExtendedBitmapDrawable#setDecodeDimensions(int, int)} * with the height multiplied by {@link #parallaxSpeedMultiplier}. * Call {@link ExtendedBitmapDrawable#setParallaxFraction(float)} when the user scrolls. */ public static final int FEATURE_PARALLAX = 1 << 1; /** * Summary: * This feature enables fading in between multiple decode states, to give smooth transitions * to and from the placeholder, progress bars, and decoded image. * * * Explanation: * The states are: {@link ExtendedBitmapDrawable#LOAD_STATE_UNINITIALIZED}, * {@link ExtendedBitmapDrawable#LOAD_STATE_NOT_YET_LOADED}, * {@link ExtendedBitmapDrawable#LOAD_STATE_LOADING}, * {@link ExtendedBitmapDrawable#LOAD_STATE_LOADED}, and * {@link ExtendedBitmapDrawable#LOAD_STATE_FAILED}. These states affect whether the * placeholder and/or the progress bar is showing and animating. We first show the * pulsating placeholder when an image begins decoding. After 2 seconds, we fade in a * spinning progress bar. When the decode completes, we fade in the image. * * * Pros: * Smooth, beautiful transitions avoid perceived jank. Progress indicator informs users that * work is being done and the app is not stalled. * * * Cons: * Very fast decodes' short decode time would be eclipsed by the animation duration. Static * placeholder could be accomplished by {@link BasicBitmapDrawable} without the added * complexity of states. * * * Requirements: * Set {@link #backgroundColor} to the color used for the background of the placeholder and * progress bar. Use the alternative constructor to populate {@link #placeholder} and * {@link #progressBar}. Optionally set {@link #placeholderAnimationDuration}. */ public static final int FEATURE_STATE_CHANGES = 1 << 2; /** * Non-changeable bit field describing the features you want the * {@link ExtendedBitmapDrawable} to support. * * * Example: *
* opts.features = FEATURE_ORDERED_DISPLAY | FEATURE_PARALLAX | FEATURE_STATE_CHANGES;
*
*/
public final int features;
/**
* Optional field for general decoding.
*
* This field determines which section of the source image to decode from. A value of 0
* indicates a preference for the far left of the source, while a value of 1 indicates a
* preference for the far right of the source. A value of .5 will result in the center
* of the source being decoded.
*/
public float decodeHorizontalCenter = 1f / 2;
/**
* Optional field for general decoding.
*
* This field determines which section of the source image to decode from. A value of 0
* indicates a preference for the very top of the source, while a value of 1 indicates a
* preference for the very bottom of the source. A value of .5 will result in the center
* of the source being decoded.
*
* This should not be confused with {@link #setParallaxFraction(float)}. This field
* determines the general section for decode. The parallax fraction then determines the
* slice from within that section for display.
*/
public float decodeVerticalCenter = 1f / 2;
/**
* Required field if {@link #FEATURE_ORDERED_DISPLAY} is supported.
*/
public DecodeAggregator decodeAggregator = null;
/**
* Required field if {@link #FEATURE_PARALLAX} is supported.
*
* A value of 1.5f gives a subtle parallax, and is a good value to
* start with. 2.0f gives a more obvious parallax, arguably exaggerated. Some users report
* motion sickness with 2.0f. A value of 1.0f is synonymous with no parallax. Be careful not
* to set too high a value, since we will start cropping the widths if the image's height is
* not sufficient.
*/
public float parallaxSpeedMultiplier = 1;
/**
* Optional field if {@link #FEATURE_STATE_CHANGES} is supported. Must be an opaque color.
*
* See {@link android.graphics.Color}.
*/
public int backgroundColor = 0;
/**
* Optional field if {@link #FEATURE_STATE_CHANGES} is supported.
*
* If you modify this field you must call
* {@link ExtendedBitmapDrawable#onOptsChanged(Resources, ExtendedOptions)} on the
* appropriate ExtendedBitmapDrawable.
*/
public Drawable placeholder;
/**
* Optional field if {@link #FEATURE_STATE_CHANGES} is supported.
*
* Special value 0 means default animation duration. Special value -1 means disable the
* animation (placeholder will be at maximum alpha always). Any value > 0 defines the
* duration in milliseconds.
*/
public int placeholderAnimationDuration = 0;
/**
* Optional field if {@link #FEATURE_STATE_CHANGES} is supported.
*
* If you modify this field you must call
* {@link ExtendedBitmapDrawable#onOptsChanged(Resources, ExtendedOptions)} on the
* appropriate ExtendedBitmapDrawable.
*/
public Drawable progressBar;
/**
* Use this constructor when all the feature parameters are changeable.
*/
public ExtendedOptions(final int features) {
this(features, null, null);
}
/**
* Use this constructor when you have to specify non-changeable feature parameters.
*/
public ExtendedOptions(final int features, final Drawable placeholder,
final Drawable progressBar) {
this.features = features;
this.placeholder = placeholder;
this.progressBar = progressBar;
}
/**
* Validate this ExtendedOptions instance to make sure that all the required fields are set
* for the requested features.
*
* This will throw an IllegalStateException if validation fails.
*/
private void validate()
throws IllegalStateException {
if (decodeHorizontalCenter < 0 || decodeHorizontalCenter > 1) {
throw new IllegalStateException(
"ExtendedOptions: decodeHorizontalCenter must be within 0 and 1, " +
"inclusive");
}
if (decodeVerticalCenter < 0 || decodeVerticalCenter > 1) {
throw new IllegalStateException(
"ExtendedOptions: decodeVerticalCenter must be within 0 and 1, inclusive");
}
if ((features & FEATURE_ORDERED_DISPLAY) != 0 && decodeAggregator == null) {
throw new IllegalStateException(
"ExtendedOptions: To support FEATURE_ORDERED_DISPLAY, "
+ "decodeAggregator must be set.");
}
if ((features & FEATURE_PARALLAX) != 0 && parallaxSpeedMultiplier <= 1) {
throw new IllegalStateException(
"ExtendedOptions: To support FEATURE_PARALLAX, "
+ "parallaxSpeedMultiplier must be greater than 1.");
}
if ((features & FEATURE_STATE_CHANGES) != 0) {
if (backgroundColor == 0
&& placeholder == null) {
throw new IllegalStateException(
"ExtendedOptions: To support FEATURE_STATE_CHANGES, "
+ "either backgroundColor or placeholder must be set.");
}
if (placeholderAnimationDuration < -1) {
throw new IllegalStateException(
"ExtendedOptions: To support FEATURE_STATE_CHANGES, "
+ "placeholderAnimationDuration must be set correctly.");
}
if (backgroundColor != 0 && Color.alpha(backgroundColor) != 255) {
throw new IllegalStateException(
"ExtendedOptions: To support FEATURE_STATE_CHANGES, "
+ "backgroundColor must be set to an opaque color.");
}
}
}
}
}