Using android.os.Handler
/*
* Copyright (C) 2007 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 app.test;
import java.io.ByteArrayOutputStream;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.BitmapFactory.Options;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Picture;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;
/**
* PurgeableBitmap demonstrates the effects of setting Bitmaps as being
* purgeable.
*
* In the NonPurgeable case, an encoded bitstream is decoded to a different
* Bitmap over and over again up to 200 times until out-of-memory occurs. In
* contrast, the Purgeable case shows that the system can complete decoding the
* encoded bitstream 200 times without hitting the out-of-memory case.
*/
public class Test extends GraphicsActivity {
private PurgeableBitmapView mView;
private final RefreshHandler mRedrawHandler = new RefreshHandler();
class RefreshHandler extends Handler {
@Override
public void handleMessage(Message msg) {
int index = mView.update(this);
if (index > 0) {
showAlertDialog(getDialogMessage(true, index));
} else if (index < 0) {
mView.invalidate();
showAlertDialog(getDialogMessage(false, -index));
} else {
mView.invalidate();
}
}
public void sleep(long delayMillis) {
this.removeMessages(0);
sendMessageDelayed(obtainMessage(0), delayMillis);
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mView = new PurgeableBitmapView(this, detectIfPurgeableRequest());
mRedrawHandler.sleep(0);
setContentView(mView);
}
private boolean detectIfPurgeableRequest() {
PackageManager pm = getPackageManager();
CharSequence labelSeq = null;
try {
ActivityInfo info = pm.getActivityInfo(this.getComponentName(),
PackageManager.GET_META_DATA);
labelSeq = info.loadLabel(pm);
} catch (NameNotFoundException e) {
e.printStackTrace();
return false;
}
String[] components = labelSeq.toString().split("/");
if (components[components.length - 1].equals("Purgeable")) {
return true;
} else {
return false;
}
}
private String getDialogMessage(boolean isOutOfMemory, int index) {
StringBuilder sb = new StringBuilder();
if (isOutOfMemory) {
sb.append("Out of memery occurs when the ");
sb.append(index);
sb.append("th Bitmap is decoded.");
} else {
sb.append("Complete decoding ").append(index)
.append(" bitmaps without running out of memory.");
}
return sb.toString();
}
private void showAlertDialog(String message) {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage(message)
.setCancelable(false)
.setPositiveButton("Yes",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
}
});
AlertDialog alert = builder.create();
alert.show();
}
}
/**
* 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.
*/
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(Test.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();
}
}
class GraphicsActivity extends Activity {
// set to true to test Picture
private static final boolean TEST_PICTURE = false;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public void setContentView(View view) {
if (TEST_PICTURE) {
ViewGroup vg = new PictureLayout(this);
vg.addView(view);
view = vg;
}
super.setContentView(view);
}
}
class PictureLayout extends ViewGroup {
private final Picture mPicture = new Picture();
public PictureLayout(Context context) {
super(context);
}
public PictureLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public void addView(View child) {
if (getChildCount() > 1) {
throw new IllegalStateException(
"PictureLayout can host only one direct child");
}
super.addView(child);
}
@Override
public void addView(View child, int index) {
if (getChildCount() > 1) {
throw new IllegalStateException(
"PictureLayout can host only one direct child");
}
super.addView(child, index);
}
@Override
public void addView(View child, LayoutParams params) {
if (getChildCount() > 1) {
throw new IllegalStateException(
"PictureLayout can host only one direct child");
}
super.addView(child, params);
}
@Override
public void addView(View child, int index, LayoutParams params) {
if (getChildCount() > 1) {
throw new IllegalStateException(
"PictureLayout can host only one direct child");
}
super.addView(child, index, params);
}
@Override
protected LayoutParams generateDefaultLayoutParams() {
return new LayoutParams(LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
final int count = getChildCount();
int maxHeight = 0;
int maxWidth = 0;
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (child.getVisibility() != GONE) {
measureChild(child, widthMeasureSpec, heightMeasureSpec);
}
}
maxWidth += getPaddingLeft() + getPaddingRight();
maxHeight += getPaddingTop() + getPaddingBottom();
Drawable drawable = getBackground();
if (drawable != null) {
maxHeight = Math.max(maxHeight, drawable.getMinimumHeight());
maxWidth = Math.max(maxWidth, drawable.getMinimumWidth());
}
setMeasuredDimension(resolveSize(maxWidth, widthMeasureSpec),
resolveSize(maxHeight, heightMeasureSpec));
}
private void drawPict(Canvas canvas, int x, int y, int w, int h, float sx,
float sy) {
canvas.save();
canvas.translate(x, y);
canvas.clipRect(0, 0, w, h);
canvas.scale(0.5f, 0.5f);
canvas.scale(sx, sy, w, h);
canvas.drawPicture(mPicture);
canvas.restore();
}
@Override
protected void dispatchDraw(Canvas canvas) {
super.dispatchDraw(mPicture.beginRecording(getWidth(), getHeight()));
mPicture.endRecording();
int x = getWidth() / 2;
int y = getHeight() / 2;
if (false) {
canvas.drawPicture(mPicture);
} else {
drawPict(canvas, 0, 0, x, y, 1, 1);
drawPict(canvas, x, 0, x, y, -1, 1);
drawPict(canvas, 0, y, x, y, 1, -1);
drawPict(canvas, x, y, x, y, -1, -1);
}
}
@Override
public ViewParent invalidateChildInParent(int[] location, Rect dirty) {
location[0] = getLeft();
location[1] = getTop();
dirty.set(0, 0, getWidth(), getHeight());
return getParent();
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
final int count = super.getChildCount();
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (child.getVisibility() != GONE) {
final int childLeft = getPaddingLeft();
final int childTop = getPaddingTop();
child.layout(childLeft, childTop,
childLeft + child.getMeasuredWidth(),
childTop + child.getMeasuredHeight());
}
}
}
}
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