Android "多方向"抽屉

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：

01	OnTouchListener touchListener = new OnTouchListener() {

02	int initX;

03	int initY;

04	boolean setInitialPosition;

05	public boolean onTouch(View v, MotionEvent event) {

06	if (mState == State.ANIMATING) {

07	// we are animating

08	return false;

09

}

10	//          Log.d(TAG, "state: " + mState + " x: " + event.getX() + " y: " + event.getY());

11	int action = event.getAction();

12	if (action == MotionEvent.ACTION_DOWN) {

13	if (mBringToFront) {

14	bringToFront();

15

}

16	initX = 0;

17	initY = 0;

18	if (mContent.getVisibility() == GONE) {

19	// since we may not know content dimensions we use factors here

20	if (mOrientation == VERTICAL) {

21	initY = mPosition == TOP? -1 : 1;

22

} else {

23	initX = mPosition == LEFT? -1 : 1;

24

}

25

}

26	setInitialPosition = true;

27

} else {

28	if (setInitialPosition) {

29	// now we know content dimensions, so we multiply factors...

30	initX *= mContentWidth;

31	initY *= mContentHeight;

32	// ... and set initial panel's position

33	mGestureListener.setScroll(initX, initY);

34	setInitialPosition = false;

35	// for offsetLocation we have to invert values

36	initX = -initX;

37	initY = -initY;

38

}

39	// offset every ACTION_MOVE & ACTION_UP event

40	event.offsetLocation(initX, initY);

41

}

42	if (!mGestureDetector.onTouchEvent(event)) {

43	if (action == MotionEvent.ACTION_UP) {

44	// tup up after scrolling

45	post(startAnimation);

46

}

47

}

48	return false;

49

}

50

};

替换为：

01	OnTouchListener touchListener = new OnTouchListener() {

02	float touchX, touchY;

03

04	public boolean onTouch(View v, MotionEvent event) {

05	if (mState == State.ANIMATING) {

06	// we are animating

07	return false;

08

}

09

10	int action = event.getAction();

11	if (action == MotionEvent.ACTION_DOWN) {

12	if (mBringToFront) {

13	bringToFront();

14

}

15	touchX = event.getX();

16	touchY = event.getY();

17

}

18

19	if (!mGestureDetector.onTouchEvent(event)) {

20	if (action == MotionEvent.ACTION_UP) {

21	// tup up after scrolling

22	int size = (int) (Math.abs(touchX - event.getX()) + Math

23	.abs(touchY - event.getY()));

24

25	if (size == mContentWidth || size == mContentHeight) {

26	mState = State.ABOUT_TO_ANIMATE;

27	//Log.e("size", String.valueOf(size));

28	//Log.e(String.valueOf(mContentWidth),String.valueOf(mContentHeight));

29

}

30

31	post(startAnimation);

32

}

33

}

34	return false;

35

}

36

};

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！

原文出处：http://blog.csdn.net/hellogv/article/details/6264706