| /* |
| * Copyright (C) 2009 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.example.android.apis.graphics; |
| |
| import android.content.Context; |
| import android.graphics.Bitmap; |
| import android.graphics.BitmapFactory; |
| import android.graphics.Canvas; |
| import android.graphics.Color; |
| import android.graphics.Paint; |
| import android.graphics.BitmapFactory.Options; |
| import android.view.View; |
| |
| import java.io.ByteArrayOutputStream; |
| |
| /** |
| * PurgeableBitmapView works with PurgeableBitmap to demonstrate the effects of setting |
| * Bitmaps as being purgeable. |
| * |
| * PurgeableBitmapView decodes an encoded bitstream to a Bitmap each time update() |
| * is invoked(), and its onDraw() draws the Bitmap and a number to screen. |
| * The number is used to indicate the number of Bitmaps that has been decoded. |
| */ |
| public class PurgeableBitmapView extends View { |
| private final byte[] bitstream; |
| |
| private Bitmap mBitmap; |
| private final int mArraySize = 200; |
| private final Bitmap[] mBitmapArray = new Bitmap [mArraySize]; |
| private final Options mOptions = new Options(); |
| private static final int WIDTH = 150; |
| private static final int HEIGHT = 450; |
| private static final int STRIDE = 320; // must be >= WIDTH |
| private int mDecodingCount = 0; |
| private final Paint mPaint = new Paint(); |
| private final int textSize = 32; |
| private static int delay = 100; |
| |
| public PurgeableBitmapView(Context context, boolean isPurgeable) { |
| super(context); |
| setFocusable(true); |
| mOptions.inPurgeable = isPurgeable; |
| |
| int[] colors = createColors(); |
| Bitmap src = Bitmap.createBitmap(colors, 0, STRIDE, WIDTH, HEIGHT, |
| Bitmap.Config.ARGB_8888); |
| bitstream = generateBitstream(src, Bitmap.CompressFormat.JPEG, 80); |
| |
| mPaint.setTextSize(textSize); |
| mPaint.setColor(Color.GRAY); |
| } |
| |
| private int[] createColors() { |
| int[] colors = new int[STRIDE * HEIGHT]; |
| for (int y = 0; y < HEIGHT; y++) { |
| for (int x = 0; x < WIDTH; x++) { |
| int r = x * 255 / (WIDTH - 1); |
| int g = y * 255 / (HEIGHT - 1); |
| int b = 255 - Math.min(r, g); |
| int a = Math.max(r, g); |
| colors[y * STRIDE + x] = (a << 24) | (r << 16) | (g << 8) | b; |
| } |
| } |
| return colors; |
| } |
| |
| public int update(PurgeableBitmap.RefreshHandler handler) { |
| try { |
| mBitmapArray[mDecodingCount] = BitmapFactory.decodeByteArray( |
| bitstream, 0, bitstream.length, mOptions); |
| mBitmap = mBitmapArray[mDecodingCount]; |
| mDecodingCount++; |
| if (mDecodingCount < mArraySize) { |
| handler.sleep(delay); |
| return 0; |
| } else { |
| return -mDecodingCount; |
| } |
| |
| } catch (OutOfMemoryError error) { |
| for (int i = 0; i < mDecodingCount; i++) { |
| mBitmapArray[i].recycle(); |
| } |
| return mDecodingCount + 1; |
| } |
| } |
| |
| @Override protected void onDraw(Canvas canvas) { |
| canvas.drawColor(Color.WHITE); |
| canvas.drawBitmap(mBitmap, 0, 0, null); |
| canvas.drawText(String.valueOf(mDecodingCount), WIDTH / 2 - 20, |
| HEIGHT / 2, mPaint); |
| } |
| |
| private byte[] generateBitstream(Bitmap src, Bitmap.CompressFormat format, |
| int quality) { |
| ByteArrayOutputStream os = new ByteArrayOutputStream(); |
| src.compress(format, quality, os); |
| return os.toByteArray(); |
| } |
| |
| } |