gecko-dev/mobile/android/base/gfx/LayerRenderer.java

736 lines
28 KiB
Java

/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.gecko.gfx;
import org.mozilla.gecko.GeckoAppShell;
import org.mozilla.gecko.R;
import org.mozilla.gecko.Tab;
import org.mozilla.gecko.Tabs;
import org.mozilla.gecko.gfx.Layer.RenderContext;
import org.mozilla.gecko.gfx.RenderTask;
import org.mozilla.gecko.mozglue.DirectBufferAllocator;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.graphics.Rect;
import android.graphics.RectF;
import android.opengl.GLES20;
import android.os.SystemClock;
import android.util.Log;
import org.mozilla.gecko.mozglue.JNITarget;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;
import java.util.concurrent.CopyOnWriteArrayList;
import javax.microedition.khronos.egl.EGLConfig;
/**
* The layer renderer implements the rendering logic for a layer view.
*/
public class LayerRenderer implements Tabs.OnTabsChangedListener {
private static final String LOGTAG = "GeckoLayerRenderer";
private static final String PROFTAG = "GeckoLayerRendererProf";
/*
* The amount of time a frame is allowed to take to render before we declare it a dropped
* frame.
*/
private static final int MAX_FRAME_TIME = 16; /* 1000 ms / 60 FPS */
private static final int FRAME_RATE_METER_WIDTH = 128;
private static final int FRAME_RATE_METER_HEIGHT = 32;
private static final long NANOS_PER_MS = 1000000;
private static final int NANOS_PER_SECOND = 1000000000;
private final LayerView mView;
private TextLayer mFrameRateLayer;
private final ScrollbarLayer mHorizScrollLayer;
private final ScrollbarLayer mVertScrollLayer;
private final FadeRunnable mFadeRunnable;
private ByteBuffer mCoordByteBuffer;
private FloatBuffer mCoordBuffer;
private RenderContext mLastPageContext;
private int mMaxTextureSize;
private int mBackgroundColor;
private int mOverscrollColor;
private long mLastFrameTime;
private final CopyOnWriteArrayList<RenderTask> mTasks;
private CopyOnWriteArrayList<Layer> mExtraLayers = new CopyOnWriteArrayList<Layer>();
// Dropped frames display
private int[] mFrameTimings;
private int mCurrentFrame, mFrameTimingsSum, mDroppedFrames;
// Render profiling output
private int mFramesRendered;
private float mCompleteFramesRendered;
private boolean mProfileRender;
private long mProfileOutputTime;
private IntBuffer mPixelBuffer;
// Used by GLES 2.0
private int mProgram;
private int mPositionHandle;
private int mTextureHandle;
private int mSampleHandle;
private int mTMatrixHandle;
// column-major matrix applied to each vertex to shift the viewport from
// one ranging from (-1, -1),(1,1) to (0,0),(1,1) and to scale all sizes by
// a factor of 2 to fill up the screen
public static final float[] DEFAULT_TEXTURE_MATRIX = {
2.0f, 0.0f, 0.0f, 0.0f,
0.0f, 2.0f, 0.0f, 0.0f,
0.0f, 0.0f, 2.0f, 0.0f,
-1.0f, -1.0f, 0.0f, 1.0f
};
private static final int COORD_BUFFER_SIZE = 20;
// The shaders run on the GPU directly, the vertex shader is only applying the
// matrix transform detailed above
// Note we flip the y-coordinate in the vertex shader from a
// coordinate system with (0,0) in the top left to one with (0,0) in
// the bottom left.
public static final String DEFAULT_VERTEX_SHADER =
"uniform mat4 uTMatrix;\n" +
"attribute vec4 vPosition;\n" +
"attribute vec2 aTexCoord;\n" +
"varying vec2 vTexCoord;\n" +
"void main() {\n" +
" gl_Position = uTMatrix * vPosition;\n" +
" vTexCoord.x = aTexCoord.x;\n" +
" vTexCoord.y = 1.0 - aTexCoord.y;\n" +
"}\n";
// We use highp because the screenshot textures
// we use are large and we stretch them alot
// so we need all the precision we can get.
// Unfortunately, highp is not required by ES 2.0
// so on GPU's like Mali we end up getting mediump
public static final String DEFAULT_FRAGMENT_SHADER =
"precision highp float;\n" +
"varying vec2 vTexCoord;\n" +
"uniform sampler2D sTexture;\n" +
"void main() {\n" +
" gl_FragColor = texture2D(sTexture, vTexCoord);\n" +
"}\n";
public LayerRenderer(LayerView view) {
mView = view;
setOverscrollColor(R.color.background_normal);
Bitmap scrollbarImage = view.getScrollbarImage();
IntSize size = new IntSize(scrollbarImage.getWidth(), scrollbarImage.getHeight());
scrollbarImage = expandCanvasToPowerOfTwo(scrollbarImage, size);
mTasks = new CopyOnWriteArrayList<RenderTask>();
mLastFrameTime = System.nanoTime();
mVertScrollLayer = new ScrollbarLayer(this, scrollbarImage, size, true);
mHorizScrollLayer = new ScrollbarLayer(this, diagonalFlip(scrollbarImage), new IntSize(size.height, size.width), false);
mFadeRunnable = new FadeRunnable();
mFrameTimings = new int[60];
mCurrentFrame = mFrameTimingsSum = mDroppedFrames = 0;
// Initialize the FloatBuffer that will be used to store all vertices and texture
// coordinates in draw() commands.
mCoordByteBuffer = DirectBufferAllocator.allocate(COORD_BUFFER_SIZE * 4);
mCoordByteBuffer.order(ByteOrder.nativeOrder());
mCoordBuffer = mCoordByteBuffer.asFloatBuffer();
Tabs.registerOnTabsChangedListener(this);
}
private Bitmap expandCanvasToPowerOfTwo(Bitmap image, IntSize size) {
IntSize potSize = size.nextPowerOfTwo();
if (size.equals(potSize)) {
return image;
}
// make the bitmap size a power-of-two in both dimensions if it's not already.
Bitmap potImage = Bitmap.createBitmap(potSize.width, potSize.height, image.getConfig());
new Canvas(potImage).drawBitmap(image, new Matrix(), null);
return potImage;
}
private Bitmap diagonalFlip(Bitmap image) {
Matrix rotation = new Matrix();
rotation.setValues(new float[] { 0, 1, 0, 1, 0, 0, 0, 0, 1 }); // transform (x,y) into (y,x)
Bitmap rotated = Bitmap.createBitmap(image, 0, 0, image.getWidth(), image.getHeight(), rotation, true);
return rotated;
}
public void destroy() {
DirectBufferAllocator.free(mCoordByteBuffer);
mCoordByteBuffer = null;
mCoordBuffer = null;
mHorizScrollLayer.destroy();
mVertScrollLayer.destroy();
if (mFrameRateLayer != null) {
mFrameRateLayer.destroy();
}
Tabs.unregisterOnTabsChangedListener(this);
}
void onSurfaceCreated(EGLConfig config) {
checkMonitoringEnabled();
createDefaultProgram();
activateDefaultProgram();
}
void setOverscrollColor(int colorId) {
try {
mOverscrollColor = mView.getContext().getResources().getColor(colorId);
} catch (Resources.NotFoundException nfe) { mOverscrollColor = Color.BLACK; }
}
public void createDefaultProgram() {
int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, DEFAULT_VERTEX_SHADER);
int fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER, DEFAULT_FRAGMENT_SHADER);
mProgram = GLES20.glCreateProgram();
GLES20.glAttachShader(mProgram, vertexShader); // add the vertex shader to program
GLES20.glAttachShader(mProgram, fragmentShader); // add the fragment shader to program
GLES20.glLinkProgram(mProgram); // creates OpenGL program executables
// Get handles to the vertex shader's vPosition, aTexCoord, sTexture, and uTMatrix members.
mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
mTextureHandle = GLES20.glGetAttribLocation(mProgram, "aTexCoord");
mSampleHandle = GLES20.glGetUniformLocation(mProgram, "sTexture");
mTMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uTMatrix");
int maxTextureSizeResult[] = new int[1];
GLES20.glGetIntegerv(GLES20.GL_MAX_TEXTURE_SIZE, maxTextureSizeResult, 0);
mMaxTextureSize = maxTextureSizeResult[0];
}
// Activates the shader program.
public void activateDefaultProgram() {
// Add the program to the OpenGL environment
GLES20.glUseProgram(mProgram);
// Set the transformation matrix
GLES20.glUniformMatrix4fv(mTMatrixHandle, 1, false, DEFAULT_TEXTURE_MATRIX, 0);
// Enable the arrays from which we get the vertex and texture coordinates
GLES20.glEnableVertexAttribArray(mPositionHandle);
GLES20.glEnableVertexAttribArray(mTextureHandle);
GLES20.glUniform1i(mSampleHandle, 0);
// TODO: Move these calls into a separate deactivate() call that is called after the
// underlay and overlay are rendered.
}
// Deactivates the shader program. This must be done to avoid crashes after returning to the
// Gecko C++ compositor from Java.
public void deactivateDefaultProgram() {
GLES20.glDisableVertexAttribArray(mTextureHandle);
GLES20.glDisableVertexAttribArray(mPositionHandle);
GLES20.glUseProgram(0);
}
public int getMaxTextureSize() {
return mMaxTextureSize;
}
public void postRenderTask(RenderTask aTask) {
mTasks.add(aTask);
mView.requestRender();
}
public void removeRenderTask(RenderTask aTask) {
mTasks.remove(aTask);
}
private void runRenderTasks(CopyOnWriteArrayList<RenderTask> tasks, boolean after, long frameStartTime) {
for (RenderTask task : tasks) {
if (task.runAfter != after) {
continue;
}
boolean stillRunning = task.run(frameStartTime - mLastFrameTime, frameStartTime);
// Remove the task from the list if its finished
if (!stillRunning) {
tasks.remove(task);
}
}
}
public void addLayer(Layer layer) {
synchronized (mExtraLayers) {
if (mExtraLayers.contains(layer)) {
mExtraLayers.remove(layer);
}
mExtraLayers.add(layer);
}
}
public void removeLayer(Layer layer) {
synchronized (mExtraLayers) {
mExtraLayers.remove(layer);
}
}
private void printCheckerboardStats() {
Log.d(PROFTAG, "Frames rendered over last 1000ms: " + mCompleteFramesRendered + "/" + mFramesRendered);
mFramesRendered = 0;
mCompleteFramesRendered = 0;
}
/** Used by robocop for testing purposes. Not for production use! */
IntBuffer getPixels() {
IntBuffer pixelBuffer = IntBuffer.allocate(mView.getWidth() * mView.getHeight());
synchronized (pixelBuffer) {
mPixelBuffer = pixelBuffer;
mView.requestRender();
try {
pixelBuffer.wait();
} catch (InterruptedException ie) {
}
mPixelBuffer = null;
}
return pixelBuffer;
}
private RenderContext createScreenContext(ImmutableViewportMetrics metrics, PointF offset) {
RectF viewport = new RectF(0.0f, 0.0f, metrics.getWidth(), metrics.getHeight());
RectF pageRect = metrics.getPageRect();
return createContext(viewport, pageRect, 1.0f, offset);
}
private RenderContext createPageContext(ImmutableViewportMetrics metrics, PointF offset) {
RectF viewport = metrics.getViewport();
RectF pageRect = metrics.getPageRect();
float zoomFactor = metrics.zoomFactor;
return createContext(new RectF(RectUtils.round(viewport)), pageRect, zoomFactor, offset);
}
private RenderContext createContext(RectF viewport, RectF pageRect, float zoomFactor, PointF offset) {
if (mCoordBuffer == null) {
throw new IllegalStateException();
}
return new RenderContext(viewport, pageRect, zoomFactor, offset, mPositionHandle, mTextureHandle,
mCoordBuffer);
}
private void updateDroppedFrames(long frameStartTime) {
int frameElapsedTime = (int)((System.nanoTime() - frameStartTime) / NANOS_PER_MS);
/* Update the running statistics. */
mFrameTimingsSum -= mFrameTimings[mCurrentFrame];
mFrameTimingsSum += frameElapsedTime;
mDroppedFrames -= (mFrameTimings[mCurrentFrame] + 1) / MAX_FRAME_TIME;
mDroppedFrames += (frameElapsedTime + 1) / MAX_FRAME_TIME;
mFrameTimings[mCurrentFrame] = frameElapsedTime;
mCurrentFrame = (mCurrentFrame + 1) % mFrameTimings.length;
int averageTime = mFrameTimingsSum / mFrameTimings.length;
mFrameRateLayer.beginTransaction(); // called on compositor thread
try {
mFrameRateLayer.setText(averageTime + " ms/" + mDroppedFrames);
} finally {
mFrameRateLayer.endTransaction();
}
}
/* Given the new dimensions for the surface, moves the frame rate layer appropriately. */
private void moveFrameRateLayer(int width, int height) {
mFrameRateLayer.beginTransaction(); // called on compositor thread
try {
Rect position = new Rect(width - FRAME_RATE_METER_WIDTH - 8,
height - FRAME_RATE_METER_HEIGHT + 8,
width - 8,
height + 8);
mFrameRateLayer.setPosition(position);
} finally {
mFrameRateLayer.endTransaction();
}
}
void checkMonitoringEnabled() {
/* Do this I/O off the main thread to minimize its impact on startup time. */
new Thread(new Runnable() {
@Override
public void run() {
Context context = mView.getContext();
SharedPreferences preferences = context.getSharedPreferences("GeckoApp", 0);
if (preferences.getBoolean("showFrameRate", false)) {
IntSize frameRateLayerSize = new IntSize(FRAME_RATE_METER_WIDTH, FRAME_RATE_METER_HEIGHT);
mFrameRateLayer = TextLayer.create(frameRateLayerSize, "-- ms/--");
moveFrameRateLayer(mView.getWidth(), mView.getHeight());
}
mProfileRender = Log.isLoggable(PROFTAG, Log.DEBUG);
}
}).start();
}
/*
* create a vertex shader type (GLES20.GL_VERTEX_SHADER)
* or a fragment shader type (GLES20.GL_FRAGMENT_SHADER)
*/
public static int loadShader(int type, String shaderCode) {
int shader = GLES20.glCreateShader(type);
GLES20.glShaderSource(shader, shaderCode);
GLES20.glCompileShader(shader);
return shader;
}
public Frame createFrame(ImmutableViewportMetrics metrics) {
return new Frame(metrics);
}
class FadeRunnable implements Runnable {
private boolean mStarted;
private long mRunAt;
void scheduleStartFade(long delay) {
mRunAt = SystemClock.elapsedRealtime() + delay;
if (!mStarted) {
mView.postDelayed(this, delay);
mStarted = true;
}
}
void scheduleNextFadeFrame() {
if (mStarted) {
Log.e(LOGTAG, "scheduleNextFadeFrame() called while scheduled for starting fade");
}
mView.postDelayed(this, 1000L / 60L); // request another frame at 60fps
}
boolean timeToFade() {
return !mStarted;
}
@Override
public void run() {
long timeDelta = mRunAt - SystemClock.elapsedRealtime();
if (timeDelta > 0) {
// the run-at time was pushed back, so reschedule
mView.postDelayed(this, timeDelta);
} else {
// reached the run-at time, execute
mStarted = false;
mView.requestRender();
}
}
}
public class Frame {
// The timestamp recording the start of this frame.
private long mFrameStartTime;
// A fixed snapshot of the viewport metrics that this frame is using to render content.
private ImmutableViewportMetrics mFrameMetrics;
// A rendering context for page-positioned layers, and one for screen-positioned layers.
private RenderContext mPageContext, mScreenContext;
// Whether a layer was updated.
private boolean mUpdated;
private final Rect mPageRect;
private final Rect mAbsolutePageRect;
private final PointF mRenderOffset;
public Frame(ImmutableViewportMetrics metrics) {
mFrameMetrics = metrics;
// Work out the offset due to margins
Layer rootLayer = mView.getLayerClient().getRoot();
mRenderOffset = mFrameMetrics.getMarginOffset();
mPageContext = createPageContext(metrics, mRenderOffset);
mScreenContext = createScreenContext(metrics, mRenderOffset);
RectF pageRect = mFrameMetrics.getPageRect();
mAbsolutePageRect = RectUtils.round(pageRect);
PointF origin = mFrameMetrics.getOrigin();
pageRect.offset(-origin.x, -origin.y);
mPageRect = RectUtils.round(pageRect);
}
private void setScissorRect() {
Rect scissorRect = transformToScissorRect(mPageRect);
GLES20.glEnable(GLES20.GL_SCISSOR_TEST);
GLES20.glScissor(scissorRect.left, scissorRect.top,
scissorRect.width(), scissorRect.height());
}
private Rect transformToScissorRect(Rect rect) {
IntSize screenSize = new IntSize(mFrameMetrics.getSize());
int left = Math.max(0, rect.left);
int top = Math.max(0, rect.top);
int right = Math.min(screenSize.width, rect.right);
int bottom = Math.min(screenSize.height, rect.bottom);
Rect scissorRect = new Rect(left, screenSize.height - bottom, right,
(screenSize.height - bottom) + (bottom - top));
scissorRect.offset(Math.round(-mRenderOffset.x), Math.round(-mRenderOffset.y));
return scissorRect;
}
/** This function is invoked via JNI; be careful when modifying signature. */
@JNITarget
public void beginDrawing() {
mFrameStartTime = System.nanoTime();
TextureReaper.get().reap();
TextureGenerator.get().fill();
mUpdated = true;
Layer rootLayer = mView.getLayerClient().getRoot();
// Run through pre-render tasks
runRenderTasks(mTasks, false, mFrameStartTime);
boolean hideScrollbars = (mView.getFullScreenState() == FullScreenState.NON_ROOT_ELEMENT);
if (!mPageContext.fuzzyEquals(mLastPageContext) && !hideScrollbars) {
// The viewport or page changed, so show the scrollbars again
// as per UX decision. Don't do this if we're disabling scrolling due to
// full-screen mode though.
mVertScrollLayer.unfade();
mHorizScrollLayer.unfade();
mFadeRunnable.scheduleStartFade(ScrollbarLayer.FADE_DELAY);
} else if (mFadeRunnable.timeToFade()) {
boolean stillFading = mVertScrollLayer.fade() | mHorizScrollLayer.fade();
if (stillFading) {
mFadeRunnable.scheduleNextFadeFrame();
}
}
mLastPageContext = mPageContext;
/* Update layers. */
if (rootLayer != null) {
// Called on compositor thread.
mUpdated &= rootLayer.update(mPageContext);
}
if (mFrameRateLayer != null) {
// Called on compositor thread.
mUpdated &= mFrameRateLayer.update(mScreenContext);
}
mUpdated &= mVertScrollLayer.update(mPageContext); // called on compositor thread
mUpdated &= mHorizScrollLayer.update(mPageContext); // called on compositor thread
for (Layer layer : mExtraLayers) {
mUpdated &= layer.update(mPageContext); // called on compositor thread
}
}
/** Retrieves the bounds for the layer, rounded in such a way that it
* can be used as a mask for something that will render underneath it.
* This will round the bounds inwards, but stretch the mask towards any
* near page edge, where near is considered to be 'within 2 pixels'.
* Returns null if the given layer is null.
*/
private Rect getMaskForLayer(Layer layer) {
if (layer == null) {
return null;
}
RectF bounds = RectUtils.contract(layer.getBounds(mPageContext), 1.0f, 1.0f);
Rect mask = RectUtils.roundIn(bounds);
// If the mask is within two pixels of any page edge, stretch it over
// that edge. This is to avoid drawing thin slivers when masking
// layers.
if (mask.top <= 2) {
mask.top = -1;
}
if (mask.left <= 2) {
mask.left = -1;
}
// Because we're drawing relative to the page-rect, we only need to
// take into account its width and height (and not its origin)
int pageRight = mPageRect.width();
int pageBottom = mPageRect.height();
if (mask.right >= pageRight - 2) {
mask.right = pageRight + 1;
}
if (mask.bottom >= pageBottom - 2) {
mask.bottom = pageBottom + 1;
}
return mask;
}
private void clear(int color) {
GLES20.glClearColor(((color >> 16) & 0xFF) / 255.0f,
((color >> 8) & 0xFF) / 255.0f,
(color & 0xFF) / 255.0f,
0.0f);
// The bits set here need to match up with those used
// in gfx/layers/opengl/LayerManagerOGL.cpp.
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT |
GLES20.GL_DEPTH_BUFFER_BIT);
}
/** This function is invoked via JNI; be careful when modifying signature. */
@JNITarget
public void drawBackground() {
// Any GL state which is changed here must be restored in
// CompositorOGL::RestoreState
GLES20.glDisable(GLES20.GL_SCISSOR_TEST);
// Draw the overscroll background area as a solid color
clear(mOverscrollColor);
// Update background color.
mBackgroundColor = mView.getBackgroundColor();
// Clear the page area to the page background colour.
setScissorRect();
clear(mBackgroundColor);
GLES20.glDisable(GLES20.GL_SCISSOR_TEST);
}
// Draws the layer the client added to us.
void drawRootLayer() {
Layer rootLayer = mView.getLayerClient().getRoot();
if (rootLayer == null) {
return;
}
rootLayer.draw(mPageContext);
}
@JNITarget
public void drawForeground() {
// Any GL state which is changed here must be restored in
// CompositorOGL::RestoreState
/* Draw any extra layers that were added (likely plugins) */
if (mExtraLayers.size() > 0) {
for (Layer layer : mExtraLayers) {
layer.draw(mPageContext);
}
}
/* Draw the vertical scrollbar. */
if (mPageRect.height() > mFrameMetrics.getHeight())
mVertScrollLayer.draw(mPageContext);
/* Draw the horizontal scrollbar. */
if (mPageRect.width() > mFrameMetrics.getWidth())
mHorizScrollLayer.draw(mPageContext);
/* Measure how much of the screen is checkerboarding */
Layer rootLayer = mView.getLayerClient().getRoot();
if ((rootLayer != null) &&
(mProfileRender || PanningPerfAPI.isRecordingCheckerboard())) {
// Calculate the incompletely rendered area of the page
float checkerboard = 1.0f - GeckoAppShell.computeRenderIntegrity();
PanningPerfAPI.recordCheckerboard(checkerboard);
if (checkerboard < 0.0f || checkerboard > 1.0f) {
Log.e(LOGTAG, "Checkerboard value out of bounds: " + checkerboard);
}
mCompleteFramesRendered += 1.0f - checkerboard;
mFramesRendered ++;
if (mFrameStartTime - mProfileOutputTime > NANOS_PER_SECOND) {
mProfileOutputTime = mFrameStartTime;
printCheckerboardStats();
}
}
runRenderTasks(mTasks, true, mFrameStartTime);
/* Draw the FPS. */
if (mFrameRateLayer != null) {
updateDroppedFrames(mFrameStartTime);
GLES20.glEnable(GLES20.GL_BLEND);
GLES20.glBlendFunc(GLES20.GL_SRC_ALPHA, GLES20.GL_ONE_MINUS_SRC_ALPHA);
mFrameRateLayer.draw(mScreenContext);
}
}
/** This function is invoked via JNI; be careful when modifying signature. */
@JNITarget
public void endDrawing() {
// If a layer update requires further work, schedule another redraw
if (!mUpdated)
mView.requestRender();
PanningPerfAPI.recordFrameTime();
/* Used by robocop for testing purposes */
IntBuffer pixelBuffer = mPixelBuffer;
if (mUpdated && pixelBuffer != null) {
synchronized (pixelBuffer) {
pixelBuffer.position(0);
GLES20.glReadPixels(0, 0, (int)mScreenContext.viewport.width(),
(int)mScreenContext.viewport.height(), GLES20.GL_RGBA,
GLES20.GL_UNSIGNED_BYTE, pixelBuffer);
pixelBuffer.notify();
}
}
// Remove background color once we've painted. GeckoLayerClient is
// responsible for setting this flag before current document is
// composited.
if (mView.getPaintState() == LayerView.PAINT_BEFORE_FIRST) {
mView.post(new Runnable() {
@Override
public void run() {
mView.getChildAt(0).setBackgroundColor(Color.TRANSPARENT);
}
});
mView.setPaintState(LayerView.PAINT_AFTER_FIRST);
}
mLastFrameTime = mFrameStartTime;
}
}
@Override
public void onTabChanged(final Tab tab, Tabs.TabEvents msg, Object data) {
// Sets the background of the newly selected tab. This background color
// gets cleared in endDrawing(). This function runs on the UI thread,
// but other code that touches the paint state is run on the compositor
// thread, so this may need to be changed if any problems appear.
if (msg == Tabs.TabEvents.SELECTED) {
if (mView != null) {
final int overscrollColor =
(tab.isPrivate() ? R.color.background_private : R.color.background_normal);
setOverscrollColor(overscrollColor);
if (mView.getChildAt(0) != null) {
mView.getChildAt(0).setBackgroundColor(tab.getBackgroundColor());
}
mView.setPaintState(LayerView.PAINT_START);
}
}
}
}