Merge pull request android-async-http#530 from orientalsensation/AsyncHttpResponseHandler

Enable changing handler's operation mode in run-time.

Author: smarek

library/src/main/java/com/loopj/android/http/AsyncHttpResponseHandler.java

@@ -91,10 +91,10 @@ public abstract class AsyncHttpResponseHandler implements ResponseHandlerInterfa
 
     protected static final int BUFFER_SIZE = 4096;
 
-    private final Handler handler;
     public static final String DEFAULT_CHARSET = "UTF-8";
     private String responseCharset = DEFAULT_CHARSET;
-    private Boolean useSynchronousMode = false;
+    private Handler handler;
+    private boolean useSynchronousMode;
 
     private URI requestURI = null;
     private Header[] requestHeaders = null;
@@ -142,6 +142,21 @@ public boolean getUseSynchronousMode() {
 
     @Override
     public void setUseSynchronousMode(boolean value) {
+        // Test that a looper has been prepared prior to setting asynchronous mode.
+        if (value && null == Looper.myLooper()) {
+            value = false;
+            Log.i(LOG_TAG, "Current thread has not called Looper.prepare(). Forcing synchronous mode.");
+        }
+
+        // If using asynchronous mode.
+        if (value && handler == null) {
+            // Create a handler on current thread to submit tasks
+            handler = new ResponderHandler(this);
+        } else if (!value && handler != null) {
+            // TODO: Consider adding a flag to remove all queued messages.
+            handler = null;
+        }
+
         useSynchronousMode = value;
     }
 
@@ -163,19 +178,8 @@ public String getCharset() {
      * Creates a new AsyncHttpResponseHandler
      */
     public AsyncHttpResponseHandler() {
-	boolean missingLooper = null == Looper.myLooper();
-	// Try to create handler
-	if (!missingLooper)
-		handler = new ResponderHandler(this);
-	else {
-		// There is no Looper on this thread so synchronous mode should be used.
-		handler = null;
-		setUseSynchronousMode(true);
-		Log.i(LOG_TAG, "Current thread has not called Looper.prepare(). Forcing synchronous mode.");
-	}
-
-        // Init Looper by calling postRunnable without an argument.
-        postRunnable(null);
+        // Use asynchronous mode by default.
+        setUseSynchronousMode(false);
     }
 
     /**
@@ -314,7 +318,7 @@ protected void handleMessage(Message message) {
     }
 
     protected void sendMessage(Message msg) {
-        if (getUseSynchronousMode()) {
+        if (getUseSynchronousMode() || handler == null) {
             handleMessage(msg);
         } else if (!Thread.currentThread().isInterrupted()) { // do not send messages if request has been cancelled
             handler.sendMessage(msg);
@@ -328,9 +332,9 @@ protected void sendMessage(Message msg) {
      */
     protected void postRunnable(Runnable runnable) {
         if (runnable != null) {
-            if (getUseSynchronousMode()){
-		// This response handler is synchronous, run on current thread
-		runnable.run();
+            if (getUseSynchronousMode() || handler == null) {
+                // This response handler is synchronous, run on current thread
+                runnable.run();
             } else {
                 // Otherwise, run on provided handler
                 handler.post(runnable);
@@ -346,7 +350,15 @@ protected void postRunnable(Runnable runnable) {
      * @return Message instance, should not be null
      */
     protected Message obtainMessage(int responseMessageId, Object responseMessageData) {
-	return Message.obtain(handler, responseMessageId, responseMessageData);
+        Message msg;
+        if (handler == null) {
+            msg = Message.obtain();
+            msg.what = responseMessageId;
+            msg.obj = responseMessageData;
+        } else {
+            msg = Message.obtain(handler, responseMessageId, responseMessageData);
+        }
+        return msg;
     }
 
     @Override

library/src/main/java/com/loopj/android/http/ResponseHandlerInterface.java

@@ -104,7 +104,7 @@ public interface ResponseHandlerInterface {
     void setUseSynchronousMode(boolean useSynchronousMode);
 
     /**
-     * Can set, whether the handler should be asynchronous or synchronous
+     * Returns whether the handler is asynchronous or synchronous
      *
      * @return boolean if the ResponseHandler is running in synchronous mode
      */