自定义左右滑动布局

自定义布局左右滑动，内含GridView

    public class SlideLayout extends LinearLayout implements View.OnTouchListener {
    /**
     * 手指按下的横坐标
     */
    private float xDown;

    /**
     * 在被判定为滚动之前用户手指可以移动的最大值。
     */
    private int touchSlop;
    private boolean leftViewShow = true;
    private View lefter;

    private ViewGroup.MarginLayoutParams lefterLayoutParams;
    private int leftWidth;
    private GridView gridView;
    private boolean isSlided = false;

    public SlideLayout(Context context) {
        super(context);
        init(context);
    }

    public SlideLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context);
    }

    public SlideLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context);
    }

    private void init(Context context) {
        touchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
        lefter = LayoutInflater.from(context).inflate(R.layout.lefter_layout, null, true);
        addView(lefter, 0);
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        super.onLayout(changed, l, t, r, b);
        lefterLayoutParams = (MarginLayoutParams) lefter.getLayoutParams();
        leftWidth = lefter.getWidth();
        gridView = (GridView) getChildAt(1);
        gridView.setOnTouchListener(this);
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        int width = -leftWidth / 2;
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                xDown = event.getRawX();
                break;
            case MotionEvent.ACTION_MOVE:
                float xMove = event.getRawX();
                int distance = (int) (xMove - xDown);

                if (Math.abs(distance) < touchSlop) {
                    isSlided = false;
                } else
                    isSlided = true;
                // 要让gridView失去焦点，否则被点击的那一项会一直处于选中状态
                gridView.setPressed(false);
                gridView.setFocusable(false);
                gridView.setFocusableInTouchMode(false);

                if (distance < 0) {
                    if (leftViewShow) {
                        lefterLayoutParams.leftMargin = distance / 3;
                        lefter.setLayoutParams(lefterLayoutParams);
                    }
                }

                if (distance > 0) {
                    if (!leftViewShow) {
                        lefterLayoutParams.leftMargin = distance / 3 - leftWidth;
                        lefter.setLayoutParams(lefterLayoutParams);
                    }
                }

                break;
            case MotionEvent.ACTION_UP:
                // 判断leftView的坐标，如果隐藏的部分超过一半，就直接滑动过去全部隐藏
                // 如果显示的部分超过一半，也直接滑动过来直接显示
                if (lefterLayoutParams.leftMargin <= width) {
                    lefterLayoutParams.leftMargin = -leftWidth;
                    lefter.setLayoutParams(lefterLayoutParams);
                    leftViewShow = false;
                } else if (lefterLayoutParams.leftMargin >= width) {
                    lefterLayoutParams.leftMargin = 0;
                    lefter.setLayoutParams(lefterLayoutParams);
                    leftViewShow = true;
                }

                // 解决onTouch和onClick的冲突
                return isSlided;
        }
        return false;
    }

}