Source code
Revision control
Copy as Markdown
Other Tools
/* 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
package org.mozilla.gecko;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
/**
* A {@link android.view.SurfaceView} which allows a {@link android.widget.Magnifier} widget to
* magnify a custom {@link android.view.Surface} rather than the SurfaceView's default Surface.
*/
public class MagnifiableSurfaceView extends SurfaceView {
private static final String LOGTAG = "MagnifiableSurfaceView";
private SurfaceHolderWrapper mHolder;
public MagnifiableSurfaceView(final Context context) {
super(context);
}
@Override
public SurfaceHolder getHolder() {
if (mHolder != null) {
// Only return our custom holder if we are being called from the Magnifier class.
// Throwable.getStackTrace() is faster than Thread.getStackTrace(), but still has a cost,
// hence why we only check the caller if we have set an override Surface.
final StackTraceElement[] stackTrace = new Throwable().getStackTrace();
if (stackTrace.length >= 2
&& stackTrace[1].getClassName().equals("android.widget.Magnifier")) {
return mHolder;
}
}
return super.getHolder();
}
/**
* Sets the Surface that should be magnified by a Magnifier widget.
*
* <p>This should be set immediately before calling {@link android.widget.Magnifier#show()} or
* {@link android.widget.Magnifier#update()}, and unset immediately afterwards.
*
* @param surface The Surface to be magnified. If null, the SurfaceView's default Surface will be
* used.
*/
public void setMagnifierSurface(final Surface surface) {
if (surface != null) {
mHolder = new SurfaceHolderWrapper(getHolder(), surface);
} else {
mHolder = null;
}
}
/**
* A {@link android.view.SurfaceHolder} implementation that simply forwards all methods to a
* provided SurfaceHolder instance, except for getSurface() which returns a custom Surface.
*/
private class SurfaceHolderWrapper implements SurfaceHolder {
private final SurfaceHolder mHolder;
private final Surface mSurface;
public SurfaceHolderWrapper(final SurfaceHolder holder, final Surface surface) {
mHolder = holder;
mSurface = surface;
}
@Override
public void addCallback(final Callback callback) {
mHolder.addCallback(callback);
}
@Override
public void removeCallback(final Callback callback) {
mHolder.removeCallback(callback);
}
@Override
public boolean isCreating() {
return mHolder.isCreating();
}
@Override
public void setType(final int type) {
mHolder.setType(type);
}
@Override
public void setFixedSize(final int width, final int height) {
mHolder.setFixedSize(width, height);
}
@Override
public void setSizeFromLayout() {
mHolder.setSizeFromLayout();
}
@Override
public void setFormat(final int format) {
mHolder.setFormat(format);
}
@Override
public void setKeepScreenOn(final boolean screenOn) {
mHolder.setKeepScreenOn(screenOn);
}
@Override
public Canvas lockCanvas() {
return mHolder.lockCanvas();
}
@Override
public Canvas lockCanvas(final Rect dirty) {
return mHolder.lockCanvas(dirty);
}
@Override
public void unlockCanvasAndPost(final Canvas canvas) {
mHolder.unlockCanvasAndPost(canvas);
}
@Override
public Rect getSurfaceFrame() {
return mHolder.getSurfaceFrame();
}
@Override
public Surface getSurface() {
return mSurface;
}
}
}