Android提高第十九篇之"多方向"抽屉

本文来自http://blog.csdn.net/hellogv/ ，引用必须注明出处！

       在android上要实现类似Launch的抽屉效果，大家一定首先会想起SlidingDrawer。SlidingDrawer是android官方控件之一，本文的主角不是它，而是民间的控件工具集合~~~android-misc-widgets。android-misc-widgets里面包含几个widget：Panel、SmoothButton、Switcher、VirtualKeyboard,还有一些动画特效，本文主要介绍抽屉容器Panel的用法。android-misc-widgets的google工程地址：-widgets/http://code.google.com/p/android-misc，工程代码中Panel的演示效果如下：

       这个Panel控件可以轻易实现不同方向的抽屉效果，比SlidingDrawer有更强的扩展性！

       在多次使用Panel的过程中，发现Panel有个bug，会间断性出现“闪烁”，也就是在onTouchListener里面的触发ACTION_DOWN后，抽屉瞬间弹出然后瞬间回收(版本日期为Feb 3, 2009)。把原Panel的OnTouchListener，即以下代码：

OnTouchListener touchListener = new OnTouchListener() {int initX;int initY;boolean setInitialPosition;public boolean onTouch(View v, MotionEvent event) {if (mState == State.ANIMATING) {// we are animatingreturn false;}//Log.d(TAG, "state: " + mState + " x: " + event.getX() + " y: " + event.getY());int action = event.getAction();if (action == MotionEvent.ACTION_DOWN) {if (mBringToFront) {bringToFront();}initX = 0;initY = 0;if (mContent.getVisibility() == GONE) {// since we may not know content dimensions we use factors hereif (mOrientation == VERTICAL) {initY = mPosition == TOP? -1 : 1;} else {initX = mPosition == LEFT? -1 : 1;}}setInitialPosition = true;} else {if (setInitialPosition) {// now we know content dimensions, so we multiply factors...initX *= mContentWidth;initY *= mContentHeight;// ... and set initial panel's positionmGestureListener.setScroll(initX, initY);setInitialPosition = false;// for offsetLocation we have to invert valuesinitX = -initX;initY = -initY;}// offset every ACTION_MOVE & ACTION_UP event event.offsetLocation(initX, initY);}if (!mGestureDetector.onTouchEvent(event)) {if (action == MotionEvent.ACTION_UP) {// tup up after scrollingpost(startAnimation);}}return false;}};

替换为：

OnTouchListener touchListener = new OnTouchListener() {float touchX, touchY;public boolean onTouch(View v, MotionEvent event) {if (mState == State.ANIMATING) {// we are animatingreturn false;}int action = event.getAction();if (action == MotionEvent.ACTION_DOWN) {if (mBringToFront) {bringToFront();}touchX = event.getX();touchY = event.getY();}if (!mGestureDetector.onTouchEvent(event)) {if (action == MotionEvent.ACTION_UP) {// tup up after scrollingint size = (int) (Math.abs(touchX - event.getX()) + Math.abs(touchY - event.getY()));if (size == mContentWidth || size == mContentHeight) {mState = State.ABOUT_TO_ANIMATE;//Log.e("size", String.valueOf(size));//Log.e(String.valueOf(mContentWidth),String.valueOf(mContentHeight));}post(startAnimation);}}return false;}};

即可修复这个bug，并且也同样实现了OnClickListener的功能，可以把原Panel的OnClickListener给删掉了！