CircularRevealHelper.java 文件源码

public void buildCircularRevealCache() {
  if (STRATEGY == BITMAP_SHADER) {
    buildingCircularRevealCache = true;
    hasCircularRevealCache = false;

    view.buildDrawingCache();
    Bitmap bitmap = view.getDrawingCache();

    if (bitmap == null && view.getWidth() != 0 && view.getHeight() != 0) {
      bitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(), Config.ARGB_8888);
      Canvas canvas = new Canvas(bitmap);
      view.draw(canvas);
    }

    if (bitmap != null) {
      revealPaint.setShader(new BitmapShader(bitmap, TileMode.CLAMP, TileMode.CLAMP));
    }

    buildingCircularRevealCache = false;
    hasCircularRevealCache = true;
  }
}