android最近的任务列表,对Android近期任务列表(Recent Applications)的简单分析

这里的近期任务列表就是长按Home键出来的那个Dialog，里面放着近期打开过的应用，当然3.0以上系统的多任务切换键也是。

这个Dialog的实现在Android源码的.

接下来就对这个源码分析一下。

先把整个源码贴出来：

1public class RecentApplicationsDialog extends Dialog implements OnClickListener { 2// Elements for debugging support

3// private static final String LOG_TAG = "RecentApplicationsDialog";

4private static final boolean DBG_FORCE_EMPTY_LIST = false;

5

6static private StatusBarManager sStatusBar;

7

8private static final int NUM_BUTTONS = 8;

9private static final int MAX_RECENT_TASKS = NUM_BUTTONS * 2; // allow for some discards

10

11final TextView[] mIcons = new TextView[NUM_BUTTONS];

12 View mNoAppsText;

13 IntentFilter mBroadcastIntentFilter = new

IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);

14

15class RecentTag {

16 ActivityManager.RecentTaskInfo info;

17 Intent intent;

18 }

19

20 Handler mHandler = new Handler();

21 Runnable mCleanup = new Runnable() {

22public void run() {

23// dump extra memory we're hanging on to

24for (TextView icon: mIcons) {

25 icon.setCompoundDrawables(null, null, null, null);

26 icon.setTag(null);

27 }

28 }

29 };

30

31public RecentApplicationsDialog(Context context) {

32super(context, com.android.internal.R.style.Theme_Dialog_RecentApplications);