Java tutorial
/* * Copyright (C) 2010 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.fastergallery.ui; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Point; import android.graphics.Rect; import android.graphics.RectF; import android.support.v4.util.LongSparseArray; import android.util.DisplayMetrics; import android.util.FloatMath; import android.view.WindowManager; import com.android.fastergallery.app.GalleryContext; import com.android.fastergallery.common.Utils; import com.android.fastergallery.data.DecodeUtils; import com.android.fastergallery.glrenderer.GLCanvas; import com.android.fastergallery.glrenderer.UploadedTexture; import com.android.fastergallery.util.Future; import com.android.fastergallery.util.ThreadPool; import com.android.fastergallery.util.ThreadPool.CancelListener; import com.android.fastergallery.util.ThreadPool.JobContext; import com.android.fasterphotos.data.GalleryBitmapPool; import java.util.concurrent.atomic.AtomicBoolean; public class TileImageView extends GLView { public static final int SIZE_UNKNOWN = -1; @SuppressWarnings("unused") private static final String TAG = "TileImageView"; private static final int UPLOAD_LIMIT = 1; // TILE_SIZE must be 2^N private static int sTileSize; /* * This is the tile state in the CPU side. Life of a Tile: ACTIVATED * (initial state) --> IN_QUEUE - by queueForDecode() --> RECYCLED - by * recycleTile() IN_QUEUE --> DECODING - by decodeTile() --> RECYCLED - by * recycleTile) DECODING --> RECYCLING - by recycleTile() --> DECODED - by * decodeTile() --> DECODE_FAIL - by decodeTile() RECYCLING --> RECYCLED - * by decodeTile() DECODED --> ACTIVATED - (after the decoded bitmap is * uploaded) DECODED --> RECYCLED - by recycleTile() DECODE_FAIL -> RECYCLED * - by recycleTile() RECYCLED --> ACTIVATED - by obtainTile() */ private static final int STATE_ACTIVATED = 0x01; private static final int STATE_IN_QUEUE = 0x02; private static final int STATE_DECODING = 0x04; private static final int STATE_DECODED = 0x08; private static final int STATE_DECODE_FAIL = 0x10; private static final int STATE_RECYCLING = 0x20; private static final int STATE_RECYCLED = 0x40; private TileSource mModel; private ScreenNail mScreenNail; protected int mLevelCount; // cache the value of mScaledBitmaps.length // The mLevel variable indicates which level of bitmap we should use. // Level 0 means the original full-sized bitmap, and a larger value means // a smaller scaled bitmap (The width and height of each scaled bitmap is // half size of the previous one). If the value is in [0, mLevelCount), we // use the bitmap in mScaledBitmaps[mLevel] for display, otherwise the value // is mLevelCount, and that means we use mScreenNail for display. private int mLevel = 0; // The offsets of the (left, top) of the upper-left tile to the (left, top) // of the view. private int mOffsetX; private int mOffsetY; private int mUploadQuota; private boolean mRenderComplete; private final RectF mSourceRect = new RectF(); private final RectF mTargetRect = new RectF(); private final LongSparseArray<Tile> mActiveTiles = new LongSparseArray<Tile>(); // The following three queue is guarded by TileImageView.this private final TileQueue mRecycledQueue = new TileQueue(); private final TileQueue mUploadQueue = new TileQueue(); private final TileQueue mDecodeQueue = new TileQueue(); // The width and height of the full-sized bitmap protected int mImageWidth = SIZE_UNKNOWN; protected int mImageHeight = SIZE_UNKNOWN; protected int mCenterX; protected int mCenterY; protected float mScale; protected int mRotation; // Temp variables to avoid memory allocation private final Rect mTileRange = new Rect(); private final Rect mActiveRange[] = { new Rect(), new Rect() }; private final TileUploader mTileUploader = new TileUploader(); private boolean mIsTextureFreed; private Future<Void> mTileDecoder; private final ThreadPool mThreadPool; private boolean mBackgroundTileUploaded; public static interface TileSource { public int getLevelCount(); public ScreenNail getScreenNail(); public int getImageWidth(); public int getImageHeight(); // The tile returned by this method can be specified this way: Assuming // the image size is (width, height), first take the intersection of (0, // 0) - (width, height) and (x, y) - (x + tileSize, y + tileSize). If // in extending the region, we found some part of the region are outside // the image, those pixels are filled with black. // // If level > 0, it does the same operation on a down-scaled version of // the original image (down-scaled by a factor of 2^level), but (x, y) // still refers to the coordinate on the original image. // // The method would be called in another thread. public Bitmap getTile(int level, int x, int y, int tileSize); } public static boolean isHighResolution(Context context) { DisplayMetrics metrics = new DisplayMetrics(); WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE); wm.getDefaultDisplay().getMetrics(metrics); return metrics.heightPixels > 2048 || metrics.widthPixels > 2048; } public TileImageView(GalleryContext context) { mThreadPool = context.getThreadPool(); mTileDecoder = mThreadPool.submit(new TileDecoder()); if (sTileSize == 0) { if (isHighResolution(context.getAndroidContext())) { sTileSize = 512; } else { sTileSize = 256; } } } public void setModel(TileSource model) { mModel = model; if (model != null) notifyModelInvalidated(); } public void setScreenNail(ScreenNail s) { mScreenNail = s; } public void notifyModelInvalidated() { invalidateTiles(); if (mModel == null) { mScreenNail = null; mImageWidth = 0; mImageHeight = 0; mLevelCount = 0; } else { setScreenNail(mModel.getScreenNail()); mImageWidth = mModel.getImageWidth(); mImageHeight = mModel.getImageHeight(); mLevelCount = mModel.getLevelCount(); } layoutTiles(mCenterX, mCenterY, mScale, mRotation); invalidate(); } @Override protected void onLayout(boolean changeSize, int left, int top, int right, int bottom) { super.onLayout(changeSize, left, top, right, bottom); if (changeSize) layoutTiles(mCenterX, mCenterY, mScale, mRotation); } // Prepare the tiles we want to use for display. // // 1. Decide the tile level we want to use for display. // 2. Decide the tile levels we want to keep as texture (in addition to // the one we use for display). // 3. Recycle unused tiles. // 4. Activate the tiles we want. private void layoutTiles(int centerX, int centerY, float scale, int rotation) { // The width and height of this view. int width = getWidth(); int height = getHeight(); // The tile levels we want to keep as texture is in the range // [fromLevel, endLevel). int fromLevel; int endLevel; // We want to use a texture larger than or equal to the display size. mLevel = Utils.clamp(Utils.floorLog2(1f / scale), 0, mLevelCount); // We want to keep one more tile level as texture in addition to what // we use for display. So it can be faster when the scale moves to the // next level. We choose a level closer to the current scale. if (mLevel != mLevelCount) { Rect range = mTileRange; getRange(range, centerX, centerY, mLevel, scale, rotation); mOffsetX = Math.round(width / 2f + (range.left - centerX) * scale); mOffsetY = Math.round(height / 2f + (range.top - centerY) * scale); fromLevel = scale * (1 << mLevel) > 0.75f ? mLevel - 1 : mLevel; } else { // Activate the tiles of the smallest two levels. fromLevel = mLevel - 2; mOffsetX = Math.round(width / 2f - centerX * scale); mOffsetY = Math.round(height / 2f - centerY * scale); } fromLevel = Math.max(0, Math.min(fromLevel, mLevelCount - 2)); endLevel = Math.min(fromLevel + 2, mLevelCount); Rect range[] = mActiveRange; for (int i = fromLevel; i < endLevel; ++i) { getRange(range[i - fromLevel], centerX, centerY, i, rotation); } // If rotation is transient, don't update the tile. if (rotation % 90 != 0) return; synchronized (this) { mDecodeQueue.clean(); mUploadQueue.clean(); mBackgroundTileUploaded = false; // Recycle unused tiles: if the level of the active tile is outside // the // range [fromLevel, endLevel) or not in the visible range. int n = mActiveTiles.size(); for (int i = 0; i < n; i++) { Tile tile = mActiveTiles.valueAt(i); int level = tile.mTileLevel; if (level < fromLevel || level >= endLevel || !range[level - fromLevel].contains(tile.mX, tile.mY)) { mActiveTiles.removeAt(i); i--; n--; recycleTile(tile); } } } for (int i = fromLevel; i < endLevel; ++i) { int size = sTileSize << i; Rect r = range[i - fromLevel]; for (int y = r.top, bottom = r.bottom; y < bottom; y += size) { for (int x = r.left, right = r.right; x < right; x += size) { activateTile(x, y, i); } } } invalidate(); } protected synchronized void invalidateTiles() { mDecodeQueue.clean(); mUploadQueue.clean(); // TODO disable decoder int n = mActiveTiles.size(); for (int i = 0; i < n; i++) { Tile tile = mActiveTiles.valueAt(i); recycleTile(tile); } mActiveTiles.clear(); } private void getRange(Rect out, int cX, int cY, int level, int rotation) { getRange(out, cX, cY, level, 1f / (1 << (level + 1)), rotation); } // If the bitmap is scaled by the given factor "scale", return the // rectangle containing visible range. The left-top coordinate returned is // aligned to the tile boundary. // // (cX, cY) is the point on the original bitmap which will be put in the // center of the ImageViewer. private void getRange(Rect out, int cX, int cY, int level, float scale, int rotation) { double radians = Math.toRadians(-rotation); double w = getWidth(); double h = getHeight(); double cos = Math.cos(radians); double sin = Math.sin(radians); int width = (int) Math.ceil(Math.max(Math.abs(cos * w - sin * h), Math.abs(cos * w + sin * h))); int height = (int) Math.ceil(Math.max(Math.abs(sin * w + cos * h), Math.abs(sin * w - cos * h))); int left = (int) FloatMath.floor(cX - width / (2f * scale)); int top = (int) FloatMath.floor(cY - height / (2f * scale)); int right = (int) FloatMath.ceil(left + width / scale); int bottom = (int) FloatMath.ceil(top + height / scale); // align the rectangle to tile boundary int size = sTileSize << level; left = Math.max(0, size * (left / size)); top = Math.max(0, size * (top / size)); right = Math.min(mImageWidth, right); bottom = Math.min(mImageHeight, bottom); out.set(left, top, right, bottom); } // Calculate where the center of the image is, in the view coordinates. public void getImageCenter(Point center) { // The width and height of this view. int viewW = getWidth(); int viewH = getHeight(); // The distance between the center of the view to the center of the // bitmap, in bitmap units. (mCenterX and mCenterY are the bitmap // coordinates correspond to the center of view) int distW, distH; if (mRotation % 180 == 0) { distW = mImageWidth / 2 - mCenterX; distH = mImageHeight / 2 - mCenterY; } else { distW = mImageHeight / 2 - mCenterY; distH = mImageWidth / 2 - mCenterX; } // Convert to view coordinates. mScale translates from bitmap units to // view units. center.x = Math.round(viewW / 2f + distW * mScale); center.y = Math.round(viewH / 2f + distH * mScale); } public boolean setPosition(int centerX, int centerY, float scale, int rotation) { if (mCenterX == centerX && mCenterY == centerY && mScale == scale && mRotation == rotation) return false; mCenterX = centerX; mCenterY = centerY; mScale = scale; mRotation = rotation; layoutTiles(centerX, centerY, scale, rotation); invalidate(); return true; } public void freeTextures() { mIsTextureFreed = true; if (mTileDecoder != null) { mTileDecoder.cancel(); mTileDecoder.get(); mTileDecoder = null; } int n = mActiveTiles.size(); for (int i = 0; i < n; i++) { Tile texture = mActiveTiles.valueAt(i); texture.recycle(); } mActiveTiles.clear(); mTileRange.set(0, 0, 0, 0); synchronized (this) { mUploadQueue.clean(); mDecodeQueue.clean(); Tile tile = mRecycledQueue.pop(); while (tile != null) { tile.recycle(); tile = mRecycledQueue.pop(); } } setScreenNail(null); } public void prepareTextures() { if (mTileDecoder == null) { mTileDecoder = mThreadPool.submit(new TileDecoder()); } if (mIsTextureFreed) { layoutTiles(mCenterX, mCenterY, mScale, mRotation); mIsTextureFreed = false; setScreenNail(mModel == null ? null : mModel.getScreenNail()); } } @Override protected void render(GLCanvas canvas) { mUploadQuota = UPLOAD_LIMIT; mRenderComplete = true; int level = mLevel; int rotation = mRotation; int flags = 0; if (rotation != 0) flags |= GLCanvas.SAVE_FLAG_MATRIX; if (flags != 0) { canvas.save(flags); if (rotation != 0) { int centerX = getWidth() / 2, centerY = getHeight() / 2; canvas.translate(centerX, centerY); canvas.rotate(rotation, 0, 0, 1); canvas.translate(-centerX, -centerY); } } try { if (level != mLevelCount && !isScreenNailAnimating()) { if (mScreenNail != null) { mScreenNail.noDraw(); } int size = (sTileSize << level); float length = size * mScale; Rect r = mTileRange; for (int ty = r.top, i = 0; ty < r.bottom; ty += size, i++) { float y = mOffsetY + i * length; for (int tx = r.left, j = 0; tx < r.right; tx += size, j++) { float x = mOffsetX + j * length; drawTile(canvas, tx, ty, level, x, y, length); } } } else if (mScreenNail != null) { mScreenNail.draw(canvas, mOffsetX, mOffsetY, Math.round(mImageWidth * mScale), Math.round(mImageHeight * mScale)); if (isScreenNailAnimating()) { invalidate(); } } } finally { if (flags != 0) canvas.restore(); } if (mRenderComplete) { if (!mBackgroundTileUploaded) uploadBackgroundTiles(canvas); } else { invalidate(); } } private boolean isScreenNailAnimating() { return (mScreenNail instanceof TiledScreenNail) && ((TiledScreenNail) mScreenNail).isAnimating(); } private void uploadBackgroundTiles(GLCanvas canvas) { mBackgroundTileUploaded = true; int n = mActiveTiles.size(); for (int i = 0; i < n; i++) { Tile tile = mActiveTiles.valueAt(i); if (!tile.isContentValid()) queueForDecode(tile); } } void queueForUpload(Tile tile) { synchronized (this) { mUploadQueue.push(tile); } if (mTileUploader.mActive.compareAndSet(false, true)) { getGLRoot().addOnGLIdleListener(mTileUploader); } } synchronized void queueForDecode(Tile tile) { if (tile.mTileState == STATE_ACTIVATED) { tile.mTileState = STATE_IN_QUEUE; if (mDecodeQueue.push(tile)) notifyAll(); } } boolean decodeTile(Tile tile) { synchronized (this) { if (tile.mTileState != STATE_IN_QUEUE) return false; tile.mTileState = STATE_DECODING; } boolean decodeComplete = tile.decode(); synchronized (this) { if (tile.mTileState == STATE_RECYCLING) { tile.mTileState = STATE_RECYCLED; if (tile.mDecodedTile != null) { GalleryBitmapPool.getInstance().put(tile.mDecodedTile); tile.mDecodedTile = null; } mRecycledQueue.push(tile); return false; } tile.mTileState = decodeComplete ? STATE_DECODED : STATE_DECODE_FAIL; return decodeComplete; } } private synchronized Tile obtainTile(int x, int y, int level) { Tile tile = mRecycledQueue.pop(); if (tile != null) { tile.mTileState = STATE_ACTIVATED; tile.update(x, y, level); return tile; } return new Tile(x, y, level); } synchronized void recycleTile(Tile tile) { if (tile.mTileState == STATE_DECODING) { tile.mTileState = STATE_RECYCLING; return; } tile.mTileState = STATE_RECYCLED; if (tile.mDecodedTile != null) { GalleryBitmapPool.getInstance().put(tile.mDecodedTile); tile.mDecodedTile = null; } mRecycledQueue.push(tile); } private void activateTile(int x, int y, int level) { long key = makeTileKey(x, y, level); Tile tile = mActiveTiles.get(key); if (tile != null) { if (tile.mTileState == STATE_IN_QUEUE) { tile.mTileState = STATE_ACTIVATED; } return; } tile = obtainTile(x, y, level); mActiveTiles.put(key, tile); } private Tile getTile(int x, int y, int level) { return mActiveTiles.get(makeTileKey(x, y, level)); } private static long makeTileKey(int x, int y, int level) { long result = x; result = (result << 16) | y; result = (result << 16) | level; return result; } private class TileUploader implements GLRoot.OnGLIdleListener { AtomicBoolean mActive = new AtomicBoolean(false); @Override public boolean onGLIdle(GLCanvas canvas, boolean renderRequested) { // Skips uploading if there is a pending rendering request. // Returns true to keep uploading in next rendering loop. if (renderRequested) return true; int quota = UPLOAD_LIMIT; Tile tile = null; while (quota > 0) { synchronized (TileImageView.this) { tile = mUploadQueue.pop(); } if (tile == null) break; if (!tile.isContentValid()) { boolean hasBeenLoaded = tile.isLoaded(); Utils.assertTrue(tile.mTileState == STATE_DECODED); tile.updateContent(canvas); if (!hasBeenLoaded) tile.draw(canvas, 0, 0); --quota; } } if (tile == null) mActive.set(false); return tile != null; } } // Draw the tile to a square at canvas that locates at (x, y) and // has a side length of length. public void drawTile(GLCanvas canvas, int tx, int ty, int level, float x, float y, float length) { RectF source = mSourceRect; RectF target = mTargetRect; target.set(x, y, x + length, y + length); source.set(0, 0, sTileSize, sTileSize); Tile tile = getTile(tx, ty, level); if (tile != null) { if (!tile.isContentValid()) { if (tile.mTileState == STATE_DECODED) { if (mUploadQuota > 0) { --mUploadQuota; tile.updateContent(canvas); } else { mRenderComplete = false; } } else if (tile.mTileState != STATE_DECODE_FAIL) { mRenderComplete = false; queueForDecode(tile); } } if (drawTile(tile, canvas, source, target)) return; } if (mScreenNail != null) { int size = sTileSize << level; float scaleX = (float) mScreenNail.getWidth() / mImageWidth; float scaleY = (float) mScreenNail.getHeight() / mImageHeight; source.set(tx * scaleX, ty * scaleY, (tx + size) * scaleX, (ty + size) * scaleY); mScreenNail.draw(canvas, source, target); } } static boolean drawTile(Tile tile, GLCanvas canvas, RectF source, RectF target) { while (true) { if (tile.isContentValid()) { canvas.drawTexture(tile, source, target); return true; } // Parent can be divided to four quads and tile is one of the four. Tile parent = tile.getParentTile(); if (parent == null) return false; if (tile.mX == parent.mX) { source.left /= 2f; source.right /= 2f; } else { source.left = (sTileSize + source.left) / 2f; source.right = (sTileSize + source.right) / 2f; } if (tile.mY == parent.mY) { source.top /= 2f; source.bottom /= 2f; } else { source.top = (sTileSize + source.top) / 2f; source.bottom = (sTileSize + source.bottom) / 2f; } tile = parent; } } private class Tile extends UploadedTexture { public int mX; public int mY; public int mTileLevel; public Tile mNext; public Bitmap mDecodedTile; public volatile int mTileState = STATE_ACTIVATED; public Tile(int x, int y, int level) { mX = x; mY = y; mTileLevel = level; } @Override protected void onFreeBitmap(Bitmap bitmap) { GalleryBitmapPool.getInstance().put(bitmap); } boolean decode() { // Get a tile from the original image. The tile is down-scaled // by (1 << mTilelevel) from a region in the original image. try { mDecodedTile = DecodeUtils.ensureGLCompatibleBitmap(mModel.getTile(mTileLevel, mX, mY, sTileSize)); } catch (Throwable t) { Log.w(TAG, "fail to decode tile", t); } return mDecodedTile != null; } @Override protected Bitmap onGetBitmap() { Utils.assertTrue(mTileState == STATE_DECODED); // We need to override the width and height, so that we won't // draw beyond the boundaries. int rightEdge = ((mImageWidth - mX) >> mTileLevel); int bottomEdge = ((mImageHeight - mY) >> mTileLevel); setSize(Math.min(sTileSize, rightEdge), Math.min(sTileSize, bottomEdge)); Bitmap bitmap = mDecodedTile; mDecodedTile = null; mTileState = STATE_ACTIVATED; return bitmap; } // We override getTextureWidth() and getTextureHeight() here, so the // texture can be re-used for different tiles regardless of the actual // size of the tile (which may be small because it is a tile at the // boundary). @Override public int getTextureWidth() { return sTileSize; } @Override public int getTextureHeight() { return sTileSize; } public void update(int x, int y, int level) { mX = x; mY = y; mTileLevel = level; invalidateContent(); } public Tile getParentTile() { if (mTileLevel + 1 == mLevelCount) return null; int size = sTileSize << (mTileLevel + 1); int x = size * (mX / size); int y = size * (mY / size); return getTile(x, y, mTileLevel + 1); } @Override public String toString() { return String.format("tile(%s, %s, %s / %s)", mX / sTileSize, mY / sTileSize, mLevel, mLevelCount); } } private static class TileQueue { private Tile mHead; public Tile pop() { Tile tile = mHead; if (tile != null) mHead = tile.mNext; return tile; } public boolean push(Tile tile) { boolean wasEmpty = mHead == null; tile.mNext = mHead; mHead = tile; return wasEmpty; } public void clean() { mHead = null; } } private class TileDecoder implements ThreadPool.Job<Void> { private CancelListener mNotifier = new CancelListener() { @Override public void onCancel() { synchronized (TileImageView.this) { TileImageView.this.notifyAll(); } } }; @Override public Void run(JobContext jc) { jc.setMode(ThreadPool.MODE_NONE); jc.setCancelListener(mNotifier); while (!jc.isCancelled()) { Tile tile = null; synchronized (TileImageView.this) { tile = mDecodeQueue.pop(); if (tile == null && !jc.isCancelled()) { Utils.waitWithoutInterrupt(TileImageView.this); } } if (tile == null) continue; if (decodeTile(tile)) queueForUpload(tile); } return null; } } }