ethereal.src.rpm软件在linux（Red Hat/Fedora）下的安装和使用

日志表现出：startFling()方法先后在onFling()和onTouch()调用。按照逻辑来说，在onFling()中调用了，即使在onTouch()方法中调用也不会再执行。

11-01 16:09:55.147: D/WatchTvFragment(1026): ++programTouchListener.onTouch++
11-01 16:09:55.147: D/WatchTvFragment(1026): ++onFling++
11-01 16:09:55.147: D/WatchTvFragment(1026): velocityX:139.54526, velocityY:225.4602
11-01 16:09:55.147: D/WatchTvFragment(1026): onFling() set bFlinging to true
11-01 16:09:55.147: D/WatchTvFragment(1026): onFling() invode startFling()
11-01 16:09:55.147: D/WatchTvFragment(1026): ++startFling++
11-01 16:09:55.147: D/WatchTvFragment(1026): event.getAction():1
11-01 16:09:55.147: D/WatchTvFragment(1026): onTouch() set bFlinging to true
11-01 16:09:55.147: D/WatchTvFragment(1026): onTouch() invode startFling()
11-01 16:09:55.147: D/WatchTvFragment(1026): ++startFling++
11-01 16:09:55.197: D/WatchTvFragment(1026): run() set bFlinging to false
11-01 16:09:55.247: D/WatchTvFragment(1026): run() set bFlinging to false

经过处理，startFling()方法不会既执行onFling()方法的调用又去执行onTouch()方法的调用。
在onTouch()方法中的相关代码片段如下

case MotionEvent.ACTION_UP:
Logger.i(TAG, "event.getAction():" + MotionEvent.ACTION_UP);
programWidth = programListFragment.getView().getMeasuredWidth();
float velocityX = (programParams.leftMargin < programWidth / 2) ? -1000 : 1000;
Logger.i(TAG, "onTouch() invode startFling()");
startFling(velocityX);
break;

在onFling()方法中的相关代码片段如下

public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
Logger.i(TAG, "++onFling++");
Logger.i(TAG, "velocityX:" + velocityX + ", velocityY:" + velocityY);
Logger.i(TAG, "onFling() invode startFling()");
startFling(velocityX);
return true; // 需要返回true
}

方法startFling()的代码片段如下

boolean bFlinging = false;
void stopFling() {
bFlinging = false;
}
synchronized void startFling(final float velocityX) {
Logger.i(TAG, "++startFling++");
if (bFlinging) {
Logger.i(TAG, "invalid operation.");
return;
}
Logger.i(TAG, "flinging...");
bFlinging = true;
programWidth = programListFragment.getView().getMeasuredWidth();
new Thread() {
public void run() {
int interval = 50;
float xDistFling;
int newLeftMargin;
float decay = 0.98f;
float v;
// 速度从(+/-)1000px/s开始。
if (velocityX > 0 && velocityX < 1000)
v = 1000;
else if (velocityX < 0 && velocityX > -1000)
v = -1000;
else
v = velocityX;
// running表示while循环什么时候结束
boolean running = true;
while (running) {
v *= decay;
xDistFling = v / 1000 * interval;
newLeftMargin = programParams.leftMargin + (int) xDistFling;
if (newLeftMargin <= 0) {
newLeftMargin = 0;
running = false;
} else if (newLeftMargin >= channelWidth) {
newLeftMargin = channelWidth;
running = false;
}
programParams.leftMargin = newLeftMargin;
try {
Thread.sleep(interval);
} catch (InterruptedException e) {
e.printStackTrace();
}
handler.sendEmptyMessage(0);
}
Logger.i(TAG, "flinging finished.");
}
}.start();
}

打印出来的日志表现是符合逻辑的，日志如下。
（1）onFling()中执行startFling()方法，在onTouch()中再执行被视为无效操作。

11-01 16:30:29.427: D/WatchTvFragment(2654): ++programTouchListener.onTouch++
11-01 16:30:29.427: D/WatchTvFragment(2654): ++onFling++
11-01 16:30:29.427: D/WatchTvFragment(2654): velocityX:-348.25256, velocityY:215.86748
11-01 16:30:29.427: D/WatchTvFragment(2654): onFling() invode startFling()
11-01 16:30:29.427: D/WatchTvFragment(2654): ++startFling++
11-01 16:30:29.427: D/WatchTvFragment(2654): flinging...
11-01 16:30:29.427: D/WatchTvFragment(2654): event.getAction():1
11-01 16:30:29.427: D/WatchTvFragment(2654): onTouch() invode startFling()
11-01 16:30:29.427: D/WatchTvFragment(2654): ++startFling++
11-01 16:30:29.427: D/WatchTvFragment(2654): invalid operation.
11-01 16:30:29.987: D/WatchTvFragment(2654): flinging finished.

（2）onFling()中没有执行startFling()方法，在onTouch()中可以执行。

11-01 17:30:52.257: D/WatchTvFragment(8850): ++programTouchListener.onTouch++
11-01 17:30:52.257: D/WatchTvFragment(8850): event.getAction():1
11-01 17:30:52.257: D/WatchTvFragment(8850): onTouch() invode startFling()
11-01 17:30:52.257: D/WatchTvFragment(8850): ++startFling++
11-01 17:30:52.257: D/WatchTvFragment(8850): flinging...
11-01 17:30:52.307: D/WatchTvFragment(8850): flinging finished.