Android 更好的Activity生命周期回调

/**
* This class allows you to listen to when the user is entering the background (i.e. after a home button press,
* or opening recent apps etc) and when the user resumes the application from the background.
*
* @author John McDonnell
*/
public class BetterActivityLifecycleCallbacks implements Application.ActivityLifecycleCallbacks {

private int mForegroundActivities;
private boolean mHasSeenFirstActivity;
private boolean mChangingConfiguration;

@Override public void onActivityCreated(Activity activity, Bundle savedInstanceState) {

}

@Override public void onActivityStarted(Activity activity) {
mForegroundActivities++;

if (mHasSeenFirstActivity && mForegroundActivities == 1 && !mChangingConfiguration) {
applicationDidEnterForeground(activity);
}

mHasSeenFirstActivity = true;
mChangingConfiguration = false;
}

@Override public void onActivityResumed(Activity activity) {

}

@Override public void onActivityPaused(Activity activity) {

}

@Override public void onActivityStopped(Activity activity) {
mForegroundActivities--;

if (mForegroundActivities == 0) {
applicationDidEnterBackground(activity);
}

mChangingConfiguration = activity.isChangingConfigurations();
}

@Override public void onActivitySaveInstanceState(Activity activity, Bundle outState) {

}

@Override public void onActivityDestroyed(Activity activity) {

}

/**
* One day we'll be as cool as iOS
*/
protected void applicationDidEnterForeground(Activity topActivity) {

}

protected void applicationDidEnterBackground(Activity lastActivity) {

}

}