tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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MagnifiableSurfaceView.java (3904B)

      1 /* This Source Code Form is subject to the terms of the Mozilla Public
      2 * License, v. 2.0. If a copy of the MPL was not distributed with this
      3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      4 
      5 package org.mozilla.gecko;
      6 
      7 import android.content.Context;
      8 import android.graphics.Canvas;
      9 import android.graphics.Rect;
     10 import android.view.Surface;
     11 import android.view.SurfaceHolder;
     12 import android.view.SurfaceView;
     13 
     14 /**
     15 * A {@link android.view.SurfaceView} which allows a {@link android.widget.Magnifier} widget to
     16 * magnify a custom {@link android.view.Surface} rather than the SurfaceView's default Surface.
     17 */
     18 public class MagnifiableSurfaceView extends SurfaceView {
     19  private static final String LOGTAG = "MagnifiableSurfaceView";
     20 
     21  private SurfaceHolderWrapper mHolder;
     22 
     23  public MagnifiableSurfaceView(final Context context) {
     24    super(context);
     25  }
     26 
     27  @Override
     28  public SurfaceHolder getHolder() {
     29    if (mHolder != null) {
     30      // Only return our custom holder if we are being called from the Magnifier class.
     31      // Throwable.getStackTrace() is faster than Thread.getStackTrace(), but still has a cost,
     32      // hence why we only check the caller if we have set an override Surface.
     33      final StackTraceElement[] stackTrace = new Throwable().getStackTrace();
     34      if (stackTrace.length >= 2
     35          && stackTrace[1].getClassName().equals("android.widget.Magnifier")) {
     36        return mHolder;
     37      }
     38    }
     39    return super.getHolder();
     40  }
     41 
     42  /**
     43   * Sets the Surface that should be magnified by a Magnifier widget.
     44   *
     45   * <p>This should be set immediately before calling {@link android.widget.Magnifier#show()} or
     46   * {@link android.widget.Magnifier#update()}, and unset immediately afterwards.
     47   *
     48   * @param surface The Surface to be magnified. If null, the SurfaceView's default Surface will be
     49   *     used.
     50   */
     51  public void setMagnifierSurface(final Surface surface) {
     52    if (surface != null) {
     53      mHolder = new SurfaceHolderWrapper(getHolder(), surface);
     54    } else {
     55      mHolder = null;
     56    }
     57  }
     58 
     59  /**
     60   * A {@link android.view.SurfaceHolder} implementation that simply forwards all methods to a
     61   * provided SurfaceHolder instance, except for getSurface() which returns a custom Surface.
     62   */
     63  private class SurfaceHolderWrapper implements SurfaceHolder {
     64    private final SurfaceHolder mHolder;
     65    private final Surface mSurface;
     66 
     67    public SurfaceHolderWrapper(final SurfaceHolder holder, final Surface surface) {
     68      mHolder = holder;
     69      mSurface = surface;
     70    }
     71 
     72    @Override
     73    public void addCallback(final Callback callback) {
     74      mHolder.addCallback(callback);
     75    }
     76 
     77    @Override
     78    public void removeCallback(final Callback callback) {
     79      mHolder.removeCallback(callback);
     80    }
     81 
     82    @Override
     83    public boolean isCreating() {
     84      return mHolder.isCreating();
     85    }
     86 
     87    @Override
     88    public void setType(final int type) {
     89      mHolder.setType(type);
     90    }
     91 
     92    @Override
     93    public void setFixedSize(final int width, final int height) {
     94      mHolder.setFixedSize(width, height);
     95    }
     96 
     97    @Override
     98    public void setSizeFromLayout() {
     99      mHolder.setSizeFromLayout();
    100    }
    101 
    102    @Override
    103    public void setFormat(final int format) {
    104      mHolder.setFormat(format);
    105    }
    106 
    107    @Override
    108    public void setKeepScreenOn(final boolean screenOn) {
    109      mHolder.setKeepScreenOn(screenOn);
    110    }
    111 
    112    @Override
    113    public Canvas lockCanvas() {
    114      return mHolder.lockCanvas();
    115    }
    116 
    117    @Override
    118    public Canvas lockCanvas(final Rect dirty) {
    119      return mHolder.lockCanvas(dirty);
    120    }
    121 
    122    @Override
    123    public void unlockCanvasAndPost(final Canvas canvas) {
    124      mHolder.unlockCanvasAndPost(canvas);
    125    }
    126 
    127    @Override
    128    public Rect getSurfaceFrame() {
    129      return mHolder.getSurfaceFrame();
    130    }
    131 
    132    @Override
    133    public Surface getSurface() {
    134      return mSurface;
    135    }
    136  }
    137 }