CoverFlowLayoutManger.java 文件源码

/**
     * 变化Item的灰度值
     * @param child 需要设置灰度值的Item
     * @param frame 位置信息
     */
    private void greyItem(View child, Rect frame) {
        float value = computeGreyScale(frame.left - mOffsetAll);
        ColorMatrix cm = new ColorMatrix(new float[]{
                value, 0, 0, 0, 120*(1-value),
                0, value, 0, 0, 120*(1-value),
                0, 0, value, 0, 120*(1-value),
                0, 0, 0, 1, 250*(1-value),
        });
//            cm.setSaturation(0.9f);

        // Create a paint object with color matrix
        Paint greyPaint = new Paint();
        greyPaint.setColorFilter(new ColorMatrixColorFilter(cm));

        // Create a hardware layer with the grey paint
        child.setLayerType(View.LAYER_TYPE_HARDWARE, greyPaint);
        if (value >= 1) {
            // Remove the hardware layer
            child.setLayerType(View.LAYER_TYPE_NONE, null);
        }

    }