Android Open Source - Sketcher Surface

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Back to project page Sketcher.
License

The source code is released under:
Apache License
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Java Source Code

package org.sketcher;
/*from w w  w.  j ava2 s . co m*/
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;

public final class Surface extends SurfaceView implements Callback {
  public final class DrawThread extends Thread {
    private boolean mRun = true;
    private boolean mPause = false;

    @Override
    public void run() {
      waitForBitmap();

      final SurfaceHolder surfaceHolder = getHolder();
      Canvas canvas = null;

      while (mRun) {
        try {
          while (mRun && mPause) {
            Thread.sleep(100);
          }

          canvas = surfaceHolder.lockCanvas();
          if (canvas == null) {
            break;
          }

          synchronized (surfaceHolder) {
            controller.draw();
            canvas.drawBitmap(bitmap, 0, 0, null);
          }

          Thread.sleep(10);
        } catch (InterruptedException e) {
        } finally {
          if (canvas != null) {
            surfaceHolder.unlockCanvasAndPost(canvas);
          }
        }
      }
    }

    private void waitForBitmap() {
      while (bitmap == null) {
        try {
          Thread.sleep(100);
        } catch (InterruptedException e) {
          e.printStackTrace();
        }
      }
    }

    public void stopDrawing() {
      mRun = false;
    }

    public void pauseDrawing() {
      mPause = true;
    }

    public void resumeDrawing() {
      mPause = false;
    }
  }

  private DrawThread drawThread;
  private final Canvas drawCanvas = new Canvas();
  private final Controller controller = new Controller(drawCanvas);
  private Bitmap initialBitmap;
  private Bitmap bitmap;
  private final HistoryHelper mHistoryHelper = new HistoryHelper(this);

  // FIXME shouldn't be that complex for drawing thread lifecycle
  private boolean isSurfaceCreated = false;

  public Surface(Context context, AttributeSet attributes) {
    super(context, attributes);

    getHolder().addCallback(this);
    setFocusable(true);
  }

  @Override
  public boolean onTouchEvent(MotionEvent event) {
    switch (event.getAction()) {
    case MotionEvent.ACTION_UP:
      mHistoryHelper.saveState();
      break;
    }
    return controller.onTouch(this, event);
  }

  public void setStyle(Style style) {
    controller.setStyle(style);
  }

  public DrawThread getDrawThread() {
    if (drawThread == null) {
      drawThread = new DrawThread();
      if (isSurfaceCreated)
        // it starts only if canvas is created. It means the thread was
        // destroyed and should be started again
        drawThread.start();
    }
    return drawThread;
  }

  @Override
  public void surfaceChanged(SurfaceHolder holder, int format, int width,
      int height) {
    bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    bitmap.eraseColor(Color.WHITE);

    drawCanvas.setBitmap(bitmap);

    if (initialBitmap != null) {
      drawCanvas.drawBitmap(initialBitmap, 0, 0, null);
    }
    mHistoryHelper.saveState();
  }

  @Override
  public void surfaceCreated(SurfaceHolder holder) {
    getDrawThread().start();
    isSurfaceCreated = true;
  }

  @Override
  public void surfaceDestroyed(SurfaceHolder holder) {
    isSurfaceCreated = false;
    getDrawThread().stopDrawing();
    while (true) {
      try {
        getDrawThread().join();
        break;
      } catch (InterruptedException e) {
      }
    }
    drawThread = null;
  }

  public void clearBitmap() {
    bitmap.eraseColor(Color.WHITE);
    controller.clear();
    mHistoryHelper.saveState();
  }

  public void setPaintColor(Paint color) {
    controller.setPaintColor(color);
  }

  public Paint getPaintColor() {
    return controller.getPaintColor();
  }

  public void setInitialBitmap(Bitmap initialBitmap) {
    this.initialBitmap = initialBitmap;
  }

  public Bitmap getBitmap() {
    return bitmap;
  }

  public void undo() {
    mHistoryHelper.undo();
  }
}
Java Source Code List
