Merge "Make it easier to create asynchronous Handlers." into jb-mr1-dev

Author: Jeff Brown

core/java/android/os/Handler.java

@@ -101,37 +101,88 @@ public void dispatchMessage(Message msg) {
     }
 
     /**
-     * Default constructor associates this handler with the queue for the
+     * Default constructor associates this handler with the {@link Looper} for the
      * current thread.
      *
-     * If there isn't one, this handler won't be able to receive messages.
+     * If this thread does not have a looper, this handler won't be able to receive messages
+     * so an exception is thrown.
      */
     public Handler() {
-        if (FIND_POTENTIAL_LEAKS) {
-            final Class<? extends Handler> klass = getClass();
-            if ((klass.isAnonymousClass() || klass.isMemberClass() || klass.isLocalClass()) &&
-                    (klass.getModifiers() & Modifier.STATIC) == 0) {
-                Log.w(TAG, "The following Handler class should be static or leaks might occur: " +
-                    klass.getCanonicalName());
-            }
-        }
-
-        mLooper = Looper.myLooper();
-        if (mLooper == null) {
-            throw new RuntimeException(
-                "Can't create handler inside thread that has not called Looper.prepare()");
-        }
-        mQueue = mLooper.mQueue;
-        mCallback = null;
-        mAsynchronous = false;
+        this(null, false);
     }
 
     /**
-     * Constructor associates this handler with the queue for the
+     * Constructor associates this handler with the {@link Looper} for the
      * current thread and takes a callback interface in which you can handle
      * messages.
+     *
+     * If this thread does not have a looper, this handler won't be able to receive messages
+     * so an exception is thrown.
+     *
+     * @param callback The callback interface in which to handle messages, or null.
      */
     public Handler(Callback callback) {
+        this(callback, false);
+    }
+
+    /**
+     * Use the provided {@link Looper} instead of the default one.
+     *
+     * @param looper The looper, must not be null.
+     */
+    public Handler(Looper looper) {
+        this(looper, null, false);
+    }
+
+    /**
+     * Use the provided {@link Looper} instead of the default one and take a callback
+     * interface in which to handle messages.
+     *
+     * @param looper The looper, must not be null.
+     * @param callback The callback interface in which to handle messages, or null.
+     */
+    public Handler(Looper looper, Callback callback) {
+        this(looper, callback, false);
+    }
+
+    /**
+     * Use the {@link Looper} for the current thread
+     * and set whether the handler should be asynchronous.
+     *
+     * Handlers are synchronous by default unless this constructor is used to make
+     * one that is strictly asynchronous.
+     *
+     * Asynchronous messages represent interrupts or events that do not require global ordering
+     * with represent to synchronous messages.  Asynchronous messages are not subject to
+     * the synchronization barriers introduced by {@link MessageQueue#enqueueSyncBarrier(long)}.
+     *
+     * @param async If true, the handler calls {@link Message#setAsynchronous(boolean)} for
+     * each {@link Message} that is sent to it or {@link Runnable} that is posted to it.
+     *
+     * @hide
+     */
+    public Handler(boolean async) {
+        this(null, async);
+    }
+
+    /**
+     * Use the {@link Looper} for the current thread with the specified callback interface
+     * and set whether the handler should be asynchronous.
+     *
+     * Handlers are synchronous by default unless this constructor is used to make
+     * one that is strictly asynchronous.
+     *
+     * Asynchronous messages represent interrupts or events that do not require global ordering
+     * with represent to synchronous messages.  Asynchronous messages are not subject to
+     * the synchronization barriers introduced by {@link MessageQueue#enqueueSyncBarrier(long)}.
+     *
+     * @param callback The callback interface in which to handle messages, or null.
+     * @param async If true, the handler calls {@link Message#setAsynchronous(boolean)} for
+     * each {@link Message} that is sent to it or {@link Runnable} that is posted to it.
+     *
+     * @hide
+     */
+    public Handler(Callback callback, boolean async) {
         if (FIND_POTENTIAL_LEAKS) {
             final Class<? extends Handler> klass = getClass();
             if ((klass.isAnonymousClass() || klass.isMemberClass() || klass.isLocalClass()) &&
@@ -148,32 +199,11 @@ public Handler(Callback callback) {
         }
         mQueue = mLooper.mQueue;
         mCallback = callback;
-        mAsynchronous = false;
-    }
-
-    /**
-     * Use the provided queue instead of the default one.
-     */
-    public Handler(Looper looper) {
-        mLooper = looper;
-        mQueue = looper.mQueue;
-        mCallback = null;
-        mAsynchronous = false;
-    }
-
-    /**
-     * Use the provided queue instead of the default one and take a callback
-     * interface in which to handle messages.
-     */
-    public Handler(Looper looper, Callback callback) {
-        mLooper = looper;
-        mQueue = looper.mQueue;
-        mCallback = callback;
-        mAsynchronous = false;
+        mAsynchronous = async;
     }
 
     /**
-     * Use the provided queue instead of the default one and take a callback
+     * Use the provided {@link Looper} instead of the default one and take a callback
      * interface in which to handle messages.  Also set whether the handler
      * should be asynchronous.
      *
@@ -184,6 +214,8 @@ public Handler(Looper looper, Callback callback) {
      * with represent to synchronous messages.  Asynchronous messages are not subject to
      * the synchronization barriers introduced by {@link MessageQueue#enqueueSyncBarrier(long)}.
      *
+     * @param looper The looper, must not be null.
+     * @param callback The callback interface in which to handle messages, or null.
      * @param async If true, the handler calls {@link Message#setAsynchronous(boolean)} for
      * each {@link Message} that is sent to it or {@link Runnable} that is posted to it.
      *

policy/src/com/android/internal/policy/impl/KeyguardViewMediator.java

@@ -971,7 +971,7 @@ public void keyguardDoneDrawing() {
      * interacts with the keyguard ui should be posted to this handler, rather
      * than called directly.
      */
-    private Handler mHandler = new Handler(Looper.myLooper(), null, true /*async*/) {
+    private Handler mHandler = new Handler(true /*async*/) {
         @Override
         public void handleMessage(Message msg) {
             switch (msg.what) {

services/java/com/android/server/DockObserver.java

@@ -241,7 +241,7 @@ private static boolean isScreenSaverActivatedOnDock(Context context) {
                 SCREENSAVER_ACTIVATE_ON_DOCK, DEFAULT_SCREENSAVER_ACTIVATED_ON_DOCK) != 0;
     }
 
-    private final Handler mHandler = new Handler(Looper.myLooper(), null, true) {
+    private final Handler mHandler = new Handler(true /*async*/) {
         @Override
         public void handleMessage(Message msg) {
             switch (msg.what) {

services/java/com/android/server/input/InputManagerService.java

@@ -1438,6 +1438,10 @@ public KeyEvent dispatchUnhandledKey(InputWindowHandle focus,
      * Private handler for the input manager.
      */
     private final class InputManagerHandler extends Handler {
+        public InputManagerHandler() {
+            super(true /*async*/);
+        }
+
         @Override
         public void handleMessage(Message msg) {
             switch (msg.what) {

services/java/com/android/server/power/DisplayPowerController.java

@@ -1112,7 +1112,7 @@ public interface Callbacks {
 
     private final class DisplayControllerHandler extends Handler {
         public DisplayControllerHandler(Looper looper) {
-            super(looper);
+            super(looper, null, true /*async*/);
         }
 
         @Override

services/java/com/android/server/power/Notifier.java

@@ -422,7 +422,7 @@ public void onReceive(Context context, Intent intent) {
 
     private final class NotifierHandler extends Handler {
         public NotifierHandler(Looper looper) {
-            super(looper);
+            super(looper, null, true /*async*/);
         }
 
         @Override

services/java/com/android/server/power/PowerManagerService.java

@@ -1952,7 +1952,7 @@ public void onScreenOn() {
      */
     private final class PowerManagerHandler extends Handler {
         public PowerManagerHandler(Looper looper) {
-            super(looper);
+            super(looper, null, true /*async*/);
         }
 
         @Override