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() { |
04 | boolean setInitialPosition; |
05 | public boolean onTouch(View v, MotionEvent event) { |
06 | if (mState == State.ANIMATING) { |
10 | // Log.d(TAG, "state: " + mState + " x: " + event.getX() + " y: " + event.getY()); |
11 | int action = event.getAction(); |
12 | if (action == MotionEvent.ACTION_DOWN) { |
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; |
23 | initX = mPosition == LEFT? -1 : 1; |
26 | setInitialPosition = true; |
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 |
39 | // offset every ACTION_MOVE & ACTION_UP event |
40 | event.offsetLocation(initX, initY); |
42 | if (!mGestureDetector.onTouchEvent(event)) { |
43 | if (action == MotionEvent.ACTION_UP) { |
44 | // tup up after scrolling |
替换为:
01 | OnTouchListener touchListener = new OnTouchListener() { |
04 | public boolean onTouch(View v, MotionEvent event) { |
05 | if (mState == State.ANIMATING) { |
10 | int action = event.getAction(); |
11 | if (action == MotionEvent.ACTION_DOWN) { |
15 | touchX = event.getX(); |
16 | touchY = event.getY(); |
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())); |
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)); |
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.youkuaiyun.com/hellogv/article/details/6264706