ShowcaseView.java 文件源码

@Override
protected void dispatchDraw(Canvas canvas) {
    if (showcaseX < 0 || showcaseY < 0 || isRedundant) {
        super.dispatchDraw(canvas);
        return;
    }

    boolean recalculatedCling = mShowcaseDrawer.calculateShowcaseRect(showcaseX, showcaseY);
    boolean recalculateText = recalculatedCling || mAlteredText;
    mAlteredText = false;

    if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.HONEYCOMB && !mHasNoTarget) {
        Path path = new Path();
        path.addCircle(showcaseX, showcaseY, showcaseRadius, Path.Direction.CW);
        canvas.clipPath(path, Op.DIFFERENCE);
    }

    //Draw background color
    canvas.drawColor(mBackgroundColor);

    // Draw the showcase drawable
    if (!mHasNoTarget) {
        mShowcaseDrawer
                .drawShowcase(canvas, showcaseX, showcaseY, scaleMultiplier, showcaseRadius);
    }

    // Draw the text on the screen, recalculating its position if necessary
    if (recalculateText) {
        mTextDrawer.calculateTextPosition(canvas.getWidth(), canvas.getHeight(), this);
    }
    mTextDrawer.draw(canvas, recalculateText);

    super.dispatchDraw(canvas);

}