Two methods from CircleImageView.java, which aims to display a circular image, with a white border and some shadow. Calling Canvas.saveLayer() on line 56 makes the CircleImageView display properly, but causes lots of UI lag (such as scrolling when the CircleImageView is in a ListView, or when a DrawerLayout is opened/closed on top of a View cont…

gistfile1.java

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);

        if (mRectFRound == null) {
            return;
        }

        mRectFRound.set(0, 0, w, h);
        mRectFRound.set(0, 0, w, h);
    }

    @Override
    public void onDraw(Canvas canvas) {
        Drawable drawable = getDrawable();
        if (drawable == null) {
            return;
        }

        if (!(drawable instanceof BitmapDrawable)) {
            super.onDraw(canvas);
            return;
        }

        if (getWidth() == 0 || getHeight() == 0) {
            return;
        }

        if (mRectF == null) {
            mRectF = new RectF(0, 0, getWidth(), getHeight());
        }
        if (mRectFRound == null) {
            mRectFRound = new RectF(0, 0, getWidth(), getHeight());
        }
        
        // Find dimensions
        float scaledWidth = getWidth();
        float scaledHeight = getHeight();
        float length = Math.min(scaledHeight, scaledWidth);
        float centerX = (scaledWidth / 2) + (scaledWidth * .03f);
        float centerY = (scaledHeight / 2) + (scaledHeight * .03f);
        float radius = (length / 2) - (length * .04f);
        canvas.drawCircle(centerX, centerY, radius, mShadowPaint);

        centerX = (scaledWidth / 2);
        centerY = (scaledHeight / 2);
        radius = (length / 2) - (length * .04f);
        canvas.drawCircle(centerX, centerY, radius, mWhitePaint);

        final int xfer = 0xFF99CC00;
        final Paint xferPaint = ((BitmapDrawable) drawable).getPaint();
        xferPaint.setAntiAlias(true);
        xferPaint.setColor(xfer);
        xferPaint.setAlpha(255);

        mRectF.set(drawable.getBounds());
        int saveCount = canvas.saveLayer(mRectFRound, null,
            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);
        getImageMatrix().mapRect(mRectF);

        centerX = (scaledWidth / 2);
        centerY = (scaledHeight / 2);
        radius = (length / 2) - (length * .075f);
        canvas.drawARGB(0, 0, 0, 0);
        canvas.drawCircle(centerX, centerY, radius, xferPaint);

        Xfermode oldMode = xferPaint.getXfermode();
        xferPaint.setXfermode(XferMode);

        super.onDraw(canvas);

        xferPaint.setXfermode(oldMode);
        canvas.restoreToCount(saveCount);
    }