getLocationInWindow源码

/**
     * <p>Computes the coordinates of this view in its window. The argument
     * must be an array of two integers. After the method returns, the array
     * contains the x and y location in that order.</p>
     *
     * @param outLocation an array of two integers in which to hold the coordinates
     */
    public void getLocationInWindow(@Size(2) int[] outLocation) {
        if (outLocation == null || outLocation.length < 2) {
            throw new IllegalArgumentException("outLocation must be an array of two integers");
        }

        outLocation[0] = 0;
        outLocation[1] = 0;

        transformFromViewToWindowSpace(outLocation);
    }


    public void transformFromViewToWindowSpace(@Size(2) int[] inOutLocation) {
        if (inOutLocation == null || inOutLocation.length < 2) {
            throw new IllegalArgumentException("inOutLocation must be an array of two integers");
        }

        if (mAttachInfo == null) {
            // When the view is not attached to a window, this method does not make sense
            inOutLocation[0] = inOutLocation[1] = 0;
            return;
        }

        float position[] = mAttachInfo.mTmpTransformLocation;
        position[0] = inOutLocation[0];
        position[1] = inOutLocation[1];

        if (!hasIdentityMatrix()) {
            getMatrix().mapPoints(position);
        }

        position[0] += mLeft;
        position[1] += mTop;

        ViewParent viewParent = mParent;
        while (viewParent instanceof View) {
            final View view = (View) viewParent;

            position[0] -= view.mScrollX;
            position[1] -= view.mScrollY;

            if (!view.hasIdentityMatrix()) {
                view.getMatrix().mapPoints(position);
            }

            position[0] += view.mLeft;
            position[1] += view.mTop;

            viewParent = view.mParent;
         }

        if (viewParent instanceof ViewRootImpl) {
            // *cough*
            final ViewRootImpl vr = (ViewRootImpl) viewParent;
            position[1] -= vr.mCurScrollY;
        }

        inOutLocation[0] = Math.round(position[0]);
        inOutLocation[1] = Math.round(position[1]);
    }