TouchImageView.java 文件源码

/**
 * This function will transform the coordinates in the touch event to the coordinate
 * system of the drawable that the imageview contain
 *
 * @param x            x-coordinate of touch event
 * @param y            y-coordinate of touch event
 * @param clipToBitmap Touch event may occur within view, but outside image content. True, to clip return value
 *                     to the bounds of the bitmap size.
 * @return Coordinates of the point touched, in the coordinate system of the original drawable.
 */
private PointF transformCoordTouchToBitmap(float x, float y, boolean clipToBitmap) {
    matrix.getValues(m);
    float origW = getDrawable().getIntrinsicWidth();
    float origH = getDrawable().getIntrinsicHeight();
    float transX = m[Matrix.MTRANS_X];
    float transY = m[Matrix.MTRANS_Y];
    float finalX = ((x - transX) * origW) / getImageWidth();
    float finalY = ((y - transY) * origH) / getImageHeight();

    if (clipToBitmap) {
        finalX = Math.min(Math.max(finalX, 0), origW);
        finalY = Math.min(Math.max(finalY, 0), origH);
    }

    return new PointF(finalX, finalY);
}