Java Code Examples for android.graphics.Canvas#CLIP_TO_LAYER_SAVE_FLAG

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    int LAYER_FLAGS = Canvas.MATRIX_SAVE_FLAG | Canvas.CLIP_SAVE_FLAG
            | Canvas.HAS_ALPHA_LAYER_SAVE_FLAG | Canvas.FULL_COLOR_LAYER_SAVE_FLAG
            | Canvas.CLIP_TO_LAYER_SAVE_FLAG;
    //通过Xfermode的DST_OUT来产生中间的透明裁剪区域，一定要另起一个Layer（层）
    canvas.saveLayer(0, 0, this.getWidth(), this.getHeight(), null, LAYER_FLAGS);
    //设置背景
    canvas.drawColor(Color.parseColor("#a8000000"));
    paint.setXfermode(xfermode);
    //绘制圆形裁剪框
    if (clipType == ClipType.CIRCLE) {
        //中间的透明的圆
        canvas.drawCircle(this.getWidth() / 2, this.getHeight() / 2, clipRadiusWidth, paint);
        //白色的圆边框
        canvas.drawCircle(this.getWidth() / 2, this.getHeight() / 2, clipRadiusWidth, borderPaint);
    } else if (clipType == ClipType.RECTANGLE) { //绘制矩形裁剪框
        //绘制中间的矩形
        canvas.drawRect(mHorizontalPadding, this.getHeight() / 2 - clipWidth / 2,
                this.getWidth() - mHorizontalPadding, this.getHeight() / 2 + clipWidth / 2, paint);
        //绘制白色的矩形边框
        canvas.drawRect(mHorizontalPadding, this.getHeight() / 2 - clipWidth / 2,
                this.getWidth() - mHorizontalPadding, this.getHeight() / 2 + clipWidth / 2, borderPaint);
    }
    //出栈，恢复到之前的图层，意味着新建的图层会被删除，新建图层上的内容会被绘制到canvas (or the previous layer)
    canvas.restore();
}
 

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    int flags = Canvas.MATRIX_SAVE_FLAG | Canvas.CLIP_SAVE_FLAG | Canvas.HAS_ALPHA_LAYER_SAVE_FLAG | Canvas.FULL_COLOR_LAYER_SAVE_FLAG | Canvas
            .CLIP_TO_LAYER_SAVE_FLAG;
    int sc = canvas.saveLayer(0, 0, getWidth(), getHeight(), null, flags);

    int wg = mItemWidth + mItemGap;
    int x = (getWidth() - mWidth) / 2;
    int y = (getHeight() - mItemHeight) / 2;

    mItemDrawable.setBounds(0, 0, mItemWidth, mItemHeight);
    mItemDrawableSelected.setBounds(0, 0, mItemWidth, mItemHeight);

    for (int i = 0; i < mItemCount; i++) {
        canvas.save();
        canvas.translate(x + i * wg, y);
        mItemDrawable.draw(canvas);
        canvas.restore();
    }

    canvas.save();
    canvas.translate(x + (mPosition + mPositionOffset) * wg, y);
    mItemDrawableSelected.draw(canvas);
    canvas.restore();

    canvas.restoreToCount(sc);
}
 

/**
 * draw Rounded Rectangle
 *
 * @param canvas
 * @param bitmap
 */
private void drawDrawable(Canvas canvas, Bitmap bitmap) {
    Paint paint = new Paint();
    paint.setColor(0xffffffff);
    paint.setAntiAlias(true); //smooths out the edges of what is being drawn
    PorterDuffXfermode xfermode = new PorterDuffXfermode(PorterDuff.Mode.SRC_IN);
    // set flags
    int saveFlags = Canvas.MATRIX_SAVE_FLAG
            | Canvas.CLIP_SAVE_FLAG
            | Canvas.HAS_ALPHA_LAYER_SAVE_FLAG
            | Canvas.FULL_COLOR_LAYER_SAVE_FLAG
            | Canvas.CLIP_TO_LAYER_SAVE_FLAG;
    canvas.saveLayer(0, 0, width, height, null, saveFlags);

    if (shapeType == 1) {
        canvas.drawCircle(width / 2, height / 2, width / 2 - 1, paint);
    } else if (shapeType == 2) {
        RectF rectf = new RectF(1, 1, getWidth() - 1, getHeight() - 1);
        canvas.drawRoundRect(rectf, radius + 1, radius + 1, paint);
    }

    paint.setXfermode(xfermode);

    float scaleWidth = ((float) getWidth()) / bitmap.getWidth();
    float scaleHeight = ((float) getHeight()) / bitmap.getHeight();

    Matrix matrix = new Matrix();
    matrix.postScale(scaleWidth, scaleHeight);

    //bitmap scale
    bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);

    canvas.drawBitmap(bitmap, 0, 0, paint);
    canvas.restore();
}
 

private void drawDrawable(Canvas canvas, Bitmap bitmap) {
    Paint paint = new Paint();
    paint.setColor(0xffffffff);
    paint.setAntiAlias(true);

    int saveFlags = Canvas.MATRIX_SAVE_FLAG
            | Canvas.CLIP_SAVE_FLAG
            | Canvas.HAS_ALPHA_LAYER_SAVE_FLAG
            | Canvas.FULL_COLOR_LAYER_SAVE_FLAG
            | Canvas.CLIP_TO_LAYER_SAVE_FLAG;

    canvas.saveLayer(0, 0, width, height, null, saveFlags);

    if (shapeType == ShapeType.RECTANGLE) {
        RectF rectf = new RectF(borderWidth / 2, borderWidth / 2, getWidth() - borderWidth / 2, getHeight() - borderWidth / 2);
        canvas.drawRoundRect(rectf, radius, radius, paint);
    } else {
        canvas.drawCircle(width / 2, height / 2, width / 2 - borderWidth, paint);
    }

    paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN)); // SRC_IN 只显示两层图像交集部分的上层图像

    //Bitmap缩放
    float scaleWidth = ((float) getWidth()) / bitmap.getWidth();
    float scaleHeight = ((float) getHeight()) / bitmap.getHeight();
    Matrix matrix = new Matrix();
    matrix.postScale(scaleWidth, scaleHeight);
    bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
    canvas.drawBitmap(bitmap, 0, 0, paint);
    canvas.restore();
}
 

/**
 * 实现圆角的绘制
 *
 * @param canvas
 * @param bitmap
 */
@SuppressLint("WrongConstant")
private void drawDrawable(Canvas canvas, Bitmap bitmap) {
    // 画笔
    Paint paint = new Paint();
    // 颜色设置
    paint.setColor(0xffffffff);
    // 抗锯齿
    paint.setAntiAlias(true);
    //Paint 的 Xfermode，PorterDuff.Mode.SRC_IN 取两层图像的交集部门, 只显示上层图像。
    PorterDuffXfermode xfermode = new PorterDuffXfermode(PorterDuff.Mode.SRC_IN);
    // 标志
    int saveFlags = Canvas.MATRIX_SAVE_FLAG
            | Canvas.CLIP_SAVE_FLAG
            | Canvas.HAS_ALPHA_LAYER_SAVE_FLAG
            | Canvas.FULL_COLOR_LAYER_SAVE_FLAG
            | Canvas.CLIP_TO_LAYER_SAVE_FLAG;
    canvas.saveLayer(0, 0, width, height, null, saveFlags);

    if (shapeType == 1) {
        // 画遮罩，画出来就是一个和空间大小相匹配的圆（这里在半径上 -1 是为了不让图片超出边框）
        canvas.drawCircle(width / 2, height / 2, width / 2 - 1, paint);
    } else if (shapeType == 2) {
        // 当ShapeType == 2 时 图片为圆角矩形 （这里在宽高上 -1 是为了不让图片超出边框）
        RectF rectf = new RectF(1, 1, getWidth() - 1, getHeight() - 1);
        canvas.drawRoundRect(rectf, radius + 1, radius + 1, paint);
    }

    paint.setXfermode(xfermode);

    // 空间的大小 / bitmap 的大小 = bitmap 缩放的倍数
    float scaleWidth = ((float) getWidth()) / bitmap.getWidth();
    float scaleHeight = ((float) getHeight()) / bitmap.getHeight();

    Matrix matrix = new Matrix();
    matrix.postScale(scaleWidth, scaleHeight);

    //bitmap 缩放
    bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);

    //draw 上去
    canvas.drawBitmap(bitmap, 0, 0, paint);
    canvas.restore();
}