Android Open Source - Sketcher History Helper

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Back to project page Sketcher.

License

The source code is released under:

Apache License

If you think the Android project Sketcher listed in this page is inappropriate, such as containing malicious code/tools or violating the copyright, please email info at java2s dot com, thanks.

Java Source Code

package org.sketcher;
//from ww  w .ja  v  a  2 s  .c  om
import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.util.HashMap;

import org.sketcher.style.StylesFactory;

import android.graphics.Bitmap;

public class HistoryHelper {
  private final Surface mSurface;

  private State mUndoState = new State();
  private State mRedoState = new State();

  private boolean isSwaped = false;

  public HistoryHelper(Surface surface) {
    mSurface = surface;
  }

  public void undo() {
    if (mRedoState.mBuffer == null || mUndoState.mBuffer == null) {
      return;
    }
    restoreState(mSurface.getBitmap(), isSwaped ? mRedoState : mUndoState);
    isSwaped = !isSwaped;
  }

  private void restoreState(Bitmap bitmap, State state) {
    Buffer byteBuffer = ByteBuffer.wrap(state.mBuffer);
    bitmap.copyPixelsFromBuffer(byteBuffer);
    StylesFactory.restoreState(state.stylesState);
  }

  public void saveState() {
    saveState(mSurface.getBitmap(), isSwaped ? mRedoState : mUndoState);
    isSwaped = !isSwaped;
  }

  private void saveState(Bitmap bitmap, State state) {
    state.mBuffer = new byte[bitmap.getRowBytes() * bitmap.getHeight()];
    Buffer byteBuffer = ByteBuffer.wrap(state.mBuffer);
    bitmap.copyPixelsToBuffer(byteBuffer);
    StylesFactory.saveState(state.stylesState);
  }

  private static class State {
    byte[] mBuffer = null;
    final HashMap<Integer, Object> stylesState = new HashMap<Integer, Object>();
  }
}

Java Source Code List