Hook up the Volume control

Show how to use the Pause() function from the UI
Show how to use the AudioSession to prevent the iPhone from suspending us

StreamingAudio/Main.cs

@@ -30,22 +30,58 @@ namespace StreamingAudio
 		{
 		}
 		
+		StreamingPlayback player = null;
+		bool paused;
+		
 		public override bool FinishedLaunching (UIApplication app, NSDictionary options)
 		{
 			window.AddSubview (viewController.View);
+			AudioSession.Initialize ();
 			
 			// Nice creative commons source.
 			entry.Text = "http://ccmixter.org/content/bradstanfield/bradstanfield_-_People_Let_s_Stop_The_War.mp3";
 			entry.EditingDidEnd += delegate {
 				entry.ResignFirstResponder ();
 			};
+			
 			window.MakeKeyAndVisible ();
 			
 			return true;
 		}
 
+		partial void playControlClicked (UIButton sender)
+		{
+			paused = !paused;
+					
+			if (player == null)
+				return;
+			
+			if (paused)
+				player.Pause ();
+			else
+				player.Play ();
+			
+			string title = paused ? "Play" : "Pause";
+			button.SetTitle (title, UIControlState.Normal);
+			button.SetTitle (title, UIControlState.Selected);
+		}
+
+		partial void volumeSet (UISlider sender)
+		{
+			if (player == null)
+				return;
+			
+			player.OutputQueue.Volume = sender.Value;
+		}
+
 		partial void startPlayback (UIButton sender)
 		{
+			status.Text = "Starting HTTP request";
+			AudioSession.Category = AudioSessionCategory.MediaPlayback;
+			AudioSession.RoutingOverride = AudioSessionRoutingOverride.Speaker;
+			
+			button.TitleLabel.Text = "Pause";
+			
 			try {
 				var request = (HttpWebRequest) WebRequest.Create (entry.Text);
 				request.BeginGetResponse (StreamDownloaded, request);
@@ -69,21 +105,21 @@ namespace StreamingAudio
 				});
 				
 				pushed = true;
-				StreamingPlayback player = null;
 				
-				try {
-					player = new StreamingPlayback ();
-				} catch (Exception e){
-					Console.WriteLine (e);
-				}
-				
-				while ((n = stream.Read (buffer, 0, buffer.Length)) != 0){
-					l += n;
-					player.ParseBytes (buffer, n, false);
-					
-					InvokeOnMainThread (delegate {
-						progress.Progress = l / (float) response.ContentLength;
-					});
+				// 
+				// Create StreamingPlayer, the using statement will automatically
+				// force the resources to be disposed and the AudioSession to be
+				// reset when the playback is over
+				//
+				using (player = new StreamingPlayback ()){
+					while ((n = stream.Read (buffer, 0, buffer.Length)) != 0){
+						l += n;
+						player.ParseBytes (buffer, n, false);
+						
+						InvokeOnMainThread (delegate {
+							progress.Progress = l / (float) response.ContentLength;
+						});
+					}
 				}
 			} catch (Exception e){
 				InvokeOnMainThread (delegate {

StreamingAudio/MainWindow.xib

@@ -2,10 +2,10 @@
 <archive type="com.apple.InterfaceBuilder3.CocoaTouch.XIB" version="7.10">
 	<data>
 		<int key="IBDocument.SystemTarget">768</int>
-		<string key="IBDocument.SystemVersion">10B504</string>
+		<string key="IBDocument.SystemVersion">10C540</string>
 		<string key="IBDocument.InterfaceBuilderVersion">740</string>
-		<string key="IBDocument.AppKitVersion">1038.22</string>
-		<string key="IBDocument.HIToolboxVersion">457.00</string>
+		<string key="IBDocument.AppKitVersion">1038.25</string>
+		<string key="IBDocument.HIToolboxVersion">458.00</string>
 		<object class="NSMutableDictionary" key="IBDocument.PluginVersions">
 			<string key="NS.key.0">com.apple.InterfaceBuilder.IBCocoaTouchPlugin</string>
 			<string key="NS.object.0">62</string>
@@ -13,8 +13,8 @@
 		<object class="NSMutableArray" key="IBDocument.EditedObjectIDs">
 			<bool key="EncodedWithXMLCoder">YES</bool>
 			<integer value="2"/>
-			<integer value="21"/>
 			<integer value="39"/>
+			<integer value="21"/>
 		</object>
 		<object class="NSArray" key="IBDocument.PluginDependencies">
 			<bool key="EncodedWithXMLCoder">YES</bool>
@@ -62,7 +62,7 @@
 					<bool key="IBUIClipsSubviews">YES</bool>
 					<bool key="IBUIMultipleTouchEnabled">YES</bool>
 				</object>
-				<object class="NSArray" key="IBUIViewControllers">
+				<object class="NSMutableArray" key="IBUIViewControllers">
 					<bool key="EncodedWithXMLCoder">YES</bool>
 					<object class="IBUIViewController" id="138859781">
 						<object class="IBUIView" key="IBUIView" id="812770021">
@@ -96,14 +96,14 @@
 									<bool key="IBUIClearsContextBeforeDrawing">NO</bool>
 									<int key="IBUIContentHorizontalAlignment">0</int>
 									<int key="IBUIContentVerticalAlignment">0</int>
-									<object class="NSFont" key="IBUIFont">
+									<object class="NSFont" key="IBUIFont" id="120824268">
 										<string key="NSName">Helvetica-Bold</string>
 										<double key="NSSize">15</double>
 										<int key="NSfFlags">16</int>
 									</object>
 									<int key="IBUIButtonType">1</int>
 									<string key="IBUINormalTitle">Start Playback</string>
-									<object class="NSColor" key="IBUIHighlightedTitleColor">
+									<object class="NSColor" key="IBUIHighlightedTitleColor" id="592136135">
 										<int key="NSColorSpace">3</int>
 										<bytes key="NSWhite">MQA</bytes>
 									</object>
@@ -111,7 +111,7 @@
 										<int key="NSColorSpace">1</int>
 										<bytes key="NSRGB">MC4xOTYwNzg0MyAwLjMwOTgwMzkzIDAuNTIxNTY4NjYAA</bytes>
 									</object>
-									<object class="NSColor" key="IBUINormalTitleShadowColor">
+									<object class="NSColor" key="IBUINormalTitleShadowColor" id="780032884">
 										<int key="NSColorSpace">3</int>
 										<bytes key="NSWhite">MC41AA</bytes>
 									</object>
@@ -218,7 +218,7 @@
 							<bool key="IBUIOpaque">NO</bool>
 							<bool key="IBUIClipsSubviews">YES</bool>
 							<bool key="IBUIUserInteractionEnabled">NO</bool>
-							<string key="IBUIText">Volume: (Not hooked up yet)</string>
+							<string key="IBUIText">Volume:</string>
 							<reference key="IBUITextColor" ref="79086812"/>
 							<nil key="IBUIHighlightedColor"/>
 							<int key="IBUIBaselineAdjustment">1</int>
@@ -270,6 +270,25 @@
 							<bool key="IBUIClipsSubviews">YES</bool>
 							<bool key="IBUIMultipleTouchEnabled">YES</bool>
 						</object>
+						<object class="IBUIButton" id="412927193">
+							<reference key="NSNextResponder" ref="983264090"/>
+							<int key="NSvFlags">292</int>
+							<string key="NSFrame">{{124, 372}, {72, 37}}</string>
+							<reference key="NSSuperview" ref="983264090"/>
+							<bool key="IBUIOpaque">NO</bool>
+							<bool key="IBUIClearsContextBeforeDrawing">NO</bool>
+							<int key="IBUIContentHorizontalAlignment">0</int>
+							<int key="IBUIContentVerticalAlignment">0</int>
+							<reference key="IBUIFont" ref="120824268"/>
+							<int key="IBUIButtonType">1</int>
+							<string key="IBUINormalTitle">Pause</string>
+							<reference key="IBUIHighlightedTitleColor" ref="592136135"/>
+							<object class="NSColor" key="IBUINormalTitleColor">
+								<int key="NSColorSpace">1</int>
+								<bytes key="NSRGB">MC4xOTYwNzg0MyAwLjMwOTgwMzkzIDAuNTIxNTY4NjYAA</bytes>
+							</object>
+							<reference key="IBUINormalTitleShadowColor" ref="780032884"/>
+						</object>
 					</object>
 					<string key="NSFrameSize">{320, 460}</string>
 					<reference key="NSSuperview"/>
@@ -359,6 +378,32 @@
 					</object>
 					<int key="connectionID">47</int>
 				</object>
+				<object class="IBConnectionRecord">
+					<object class="IBCocoaTouchOutletConnection" key="connection">
+						<string key="label">button</string>
+						<reference key="source" ref="987256611"/>
+						<reference key="destination" ref="412927193"/>
+					</object>
+					<int key="connectionID">52</int>
+				</object>
+				<object class="IBConnectionRecord">
+					<object class="IBCocoaTouchEventConnection" key="connection">
+						<string key="label">playControlClicked:</string>
+						<reference key="source" ref="412927193"/>
+						<reference key="destination" ref="987256611"/>
+						<int key="IBEventType">1</int>
+					</object>
+					<int key="connectionID">53</int>
+				</object>
+				<object class="IBConnectionRecord">
+					<object class="IBCocoaTouchEventConnection" key="connection">
+						<string key="label">volumeSet:</string>
+						<reference key="source" ref="230519471"/>
+						<reference key="destination" ref="987256611"/>
+						<int key="IBEventType">13</int>
+					</object>
+					<int key="connectionID">54</int>
+				</object>
 			</object>
 			<object class="IBMutableOrderedSet" key="objectRecords">
 				<object class="NSArray" key="orderedObjects">
@@ -477,6 +522,7 @@
 							<reference ref="343504676"/>
 							<reference ref="85541954"/>
 							<reference ref="1021442588"/>
+							<reference ref="412927193"/>
 						</object>
 						<reference key="parent" ref="75935306"/>
 					</object>
@@ -515,6 +561,11 @@
 						<reference key="object" ref="1021442588"/>
 						<reference key="parent" ref="983264090"/>
 					</object>
+					<object class="IBObjectRecord">
+						<int key="objectID">51</int>
+						<reference key="object" ref="412927193"/>
+						<reference key="parent" ref="983264090"/>
+					</object>
 				</object>
 			</object>
 			<object class="NSMutableDictionary" key="flattenedProperties">
@@ -549,6 +600,7 @@
 					<string>48.IBPluginDependency</string>
 					<string>49.IBPluginDependency</string>
 					<string>50.IBPluginDependency</string>
+					<string>51.IBPluginDependency</string>
 				</object>
 				<object class="NSMutableArray" key="dict.values">
 					<bool key="EncodedWithXMLCoder">YES</bool>
@@ -574,7 +626,7 @@
 					<string>com.apple.InterfaceBuilder.IBCocoaTouchPlugin</string>
 					<string>com.apple.InterfaceBuilder.IBCocoaTouchPlugin</string>
 					<string>com.apple.InterfaceBuilder.IBCocoaTouchPlugin</string>
-					<string>{{306, 185}, {320, 480}}</string>
+					<string>{{355, 258}, {320, 480}}</string>
 					<string>com.apple.InterfaceBuilder.IBCocoaTouchPlugin</string>
 					<string>com.apple.InterfaceBuilder.IBCocoaTouchPlugin</string>
 					<string>AppDelegate</string>
@@ -586,6 +638,7 @@
 					<string>com.apple.InterfaceBuilder.IBCocoaTouchPlugin</string>
 					<string>com.apple.InterfaceBuilder.IBCocoaTouchPlugin</string>
 					<string>com.apple.InterfaceBuilder.IBCocoaTouchPlugin</string>
+					<string>com.apple.InterfaceBuilder.IBCocoaTouchPlugin</string>
 				</object>
 			</object>
 			<object class="NSMutableDictionary" key="unlocalizedProperties">
@@ -604,7 +657,7 @@
 				</object>
 			</object>
 			<nil key="sourceID"/>
-			<int key="maxID">50</int>
+			<int key="maxID">54</int>
 		</object>
 		<object class="IBClassDescriber" key="IBDocument.Classes">
 			<object class="NSMutableArray" key="referencedPartialClassDescriptions">
@@ -612,13 +665,25 @@
 				<object class="IBPartialClassDescription">
 					<string key="className">AppDelegate</string>
 					<object class="NSMutableDictionary" key="actions">
-						<string key="NS.key.0">startPlayback:</string>
-						<string key="NS.object.0">id</string>
+						<bool key="EncodedWithXMLCoder">YES</bool>
+						<object class="NSArray" key="dict.sortedKeys">
+							<bool key="EncodedWithXMLCoder">YES</bool>
+							<string>playControlClicked:</string>
+							<string>startPlayback:</string>
+							<string>volumeSet:</string>
+						</object>
+						<object class="NSMutableArray" key="dict.values">
+							<bool key="EncodedWithXMLCoder">YES</bool>
+							<string>id</string>
+							<string>id</string>
+							<string>id</string>
+						</object>
 					</object>
 					<object class="NSMutableDictionary" key="outlets">
 						<bool key="EncodedWithXMLCoder">YES</bool>
 						<object class="NSArray" key="dict.sortedKeys">
 							<bool key="EncodedWithXMLCoder">YES</bool>
+							<string>button</string>
 							<string>entry</string>
 							<string>playController</string>
 							<string>progress</string>
@@ -636,6 +701,7 @@
 							<string>id</string>
 							<string>id</string>
 							<string>id</string>
+							<string>id</string>
 						</object>
 					</object>
 					<object class="IBClassDescriptionSource" key="sourceIdentifier">

StreamingAudio/MainWindow.xib.designer.cs

@@ -19,6 +19,12 @@ namespace StreamingAudio {
 		[MonoTouch.Foundation.Export("startPlayback:")]
 		partial void startPlayback (MonoTouch.UIKit.UIButton sender);
 
+		[MonoTouch.Foundation.Export("playControlClicked:")]
+		partial void playControlClicked (MonoTouch.UIKit.UIButton sender);
+
+		[MonoTouch.Foundation.Export("volumeSet:")]
+		partial void volumeSet (MonoTouch.UIKit.UISlider sender);
+
 		[MonoTouch.Foundation.Connect("window")]
 		private MonoTouch.UIKit.UIWindow window {
 			get {
@@ -88,5 +94,15 @@ namespace StreamingAudio {
 				this.SetNativeField("status", value);
 			}
 		}
+		
+		[MonoTouch.Foundation.Connect("button")]
+		private MonoTouch.UIKit.UIButton button {
+			get {
+				return ((MonoTouch.UIKit.UIButton)(this.GetNativeField("button")));
+			}
+			set {
+				this.SetNativeField("button", value);
+			}
+		}
 	}
 }

StreamingAudio/StreamingPlayback.cs

@@ -40,11 +40,25 @@ namespace StreamingAudio
 		int packetsFilled;
 		AudioStreamPacketDescription [] pdesc = new AudioStreamPacketDescription [512];
 		
+		public void Pause ()
+		{
+			OutputQueue.Pause ();
+		}
+		
+		public void Play ()
+		{
+			OutputQueue.Start ();
+		}
+		
 		public StreamingPlayback ()
 		{
 			fileStream = new AudioFileStream (AudioFileType.MP3);
 			fileStream.PacketDecoded += AudioPacketDecoded;
 			fileStream.PropertyFound += AudioPropertyFound;
+			
+			// The following line prevents the audio from stopping 
+			// when the device autolocks.
+			AudioSession.Category = AudioSessionCategory.MediaPlayback;
 		}
 		
 		public void ParseBytes (byte [] buffer, int count, bool discontinuity)
@@ -62,6 +76,11 @@ namespace StreamingAudio
 		{
 			// Release unmanaged buffers, flush output, close files.
 			if (disposing){
+				AudioSession.Category = AudioSessionCategory.SoloAmbientSound;
+				
+				if (OutputQueue != null)
+					OutputQueue.Stop (false);
+				
 				if (outputBuffers != null)
 					foreach (var b in outputBuffers)
 						OutputQueue.FreeBuffer (b);
@@ -70,7 +89,7 @@ namespace StreamingAudio
 					fileStream.Close ();
 					fileStream = null;
 				}
-				if (OutputQueue != null){
+				if (OutputQueue != null){	
 					OutputQueue.Dispose ();
 					OutputQueue = null;
 				}
@@ -111,7 +130,6 @@ namespace StreamingAudio
 		{
 			EnqueueBuffer ();
 			OutputQueue.Flush ();
-			OutputQueue.Stop (false);
 			
 			// Release resources
 			Dispose ();