Improve device selection handling (fixes #7), update README, build.xml and version bump to 2.0.1

Author: kevinstadler

README.md

@@ -6,13 +6,15 @@ The new Sound library for Processing 3 provides a simple way to work with audio.
 
 The easiest way to install the Sound library is through Processing's Contribution Manager. The library comes with many example sketches, the full online reference can be found [here](https://www.processing.org/reference/libraries/sound/). Please report bugs [https://github.com/processing/processing-sound/issues](here).
 
+For detailed changelogs and to download older releases, have a look at the [Github releases page](https://github.com/processing/processing-sound/releases).
+
 ### How to build
 
 1. `git clone [email protected]:processing/processing-sound.git`
 2. into the `library/` folder copy (or soft-link) your Processsing's `core.jar` (and, optionally, also your Android SDK's `android.jar`, API level 26 or higher). Other dependencies (in particular Phil Burk's [JSyn](http://www.softsynth.com/jsyn/) engine on which this library is based) are downloaded automatically.
 3. `ant dist` (or, alternatively, run build.xml from within Eclipse)
 
-The resulting `processing-sound.zip` can be extracted into your Processing installation's `libraries/` folder.
+The resulting `sound.zip` can be extracted into your Processing installation's `libraries/` folder.
 
 ### License
 

build.xml

@@ -60,7 +60,7 @@
 	</target>
 
 	<target name="dist" depends="build,javadoc">
-		<zip destfile="../processing-sound.zip">
+		<zip destfile="../sound.zip">
 			<zipfileset dir="." prefix="sound">
 				<exclude name=".*" />
 				<exclude name="build.xml" />
@@ -72,7 +72,6 @@
 				<exclude name="src/**" />
 			</zipfileset>
 		</zip>
-		<!--copy file="library.properties"
-          toFile="../processing-sound.txt" /-->
+		<copy file="library.properties" toFile="../sound.txt" />
 	</target>
 </project>

library.properties

@@ -4,8 +4,8 @@ authors=The Processing Foundation
 url=https://processing.org/reference/libraries/sound/index.html
 sentence=Provides a simple way to work with audio.
 paragraph=
-version=9
-prettyVersion=2.0.0
+version=10
+prettyVersion=2.0.1
 lastUpdated=0
 minRevision=228
 maxRevision=0

src/processing/sound/Engine.java

@@ -48,8 +48,27 @@ private Engine(PApplet theParent) {
 
 		// create and start the synthesizer, and set this object as the singleton.
 		this.synth = JSyn.createSynthesizer(Engine.getAudioManager());
-		this.inputDevice = Engine.getAudioManager().getDefaultInputDeviceID();
-		this.outputDevice = Engine.getAudioManager().getDefaultOutputDeviceID();
+
+		// select default devices
+		for (int i = 0; i < Engine.getAudioManager().getDeviceCount(); i++) {
+			if (Engine.checkDeviceHasOutputs(i)) {
+				this.outputDevice = i;
+				break;
+			}
+			if (i == Engine.getAudioManager().getDeviceCount()) {
+				Engine.printError("library initalization failed: could not find any audio devices with a stereo output");
+				return;
+			}
+		}
+		for (int i = 0; i < Engine.getAudioManager().getDeviceCount(); i++) {
+			if (Engine.checkDeviceHasInputs(i)) {
+				this.inputDevice = i;
+				break;
+			}
+			if (i == Engine.getAudioManager().getDeviceCount()) {
+				Engine.printWarning("could not find any sound devices with input channels, you won't be able to use the AudioIn class");
+			}
+		}
 
 		this.lineOut = new LineOut(); // stereo lineout by default
 		this.synth.add(lineOut);
@@ -79,7 +98,6 @@ protected void startSynth() {
 			this.synth.stop();
 		}
 
-		// TODO do some more user-friendly checks based on getMaxInput/OutputChannels
 		this.synth.start(this.sampleRate,
 				this.inputDevice, Engine.getAudioManager().getMaxInputChannels(this.inputDevice),
 				// TODO limit number of output channels to 2?
@@ -103,14 +121,31 @@ protected void setSampleRate(int sampleRate) {
 		Engine.singleton.startSynth();
 	}
 
+	private static boolean checkDeviceHasInputs(int deviceId) {
+		return Engine.getAudioManager().getMaxInputChannels(deviceId) > 0;
+	}
+
+	private static boolean checkDeviceHasOutputs(int deviceId) {
+		// require stereo output
+		return Engine.getAudioManager().getMaxOutputChannels(deviceId) > 1;
+	}
+
 	protected void selectInputDevice(int deviceId) {
-		Engine.singleton.inputDevice = deviceId;
-		Engine.singleton.startSynth();
+		if (Engine.checkDeviceHasInputs(deviceId)) {
+			Engine.singleton.inputDevice = deviceId;
+			Engine.singleton.startSynth();
+		} else {
+			Engine.printError("audio device #" + deviceId + " has no input channels");
+		}
 	}
 
 	protected void selectOutputDevice(int deviceId) {
-		Engine.singleton.outputDevice = deviceId;
-		Engine.singleton.startSynth();
+		if (Engine.checkDeviceHasOutputs(deviceId)) {
+			Engine.singleton.outputDevice = deviceId;
+			Engine.singleton.startSynth();
+		} else {
+			Engine.printError("audio device #" + deviceId + " has no stereo output channel");
+		}
 	}
 
 	protected void setVolume(double volume) {

src/processing/sound/Sound.java

@@ -68,7 +68,7 @@ public static String[] list() {
 			int maxOutputs = audioManager.getMaxOutputChannels(i);
 			boolean isDefaultInput = (i == audioManager.getDefaultInputDeviceID());
 			boolean isDefaultOutput = (i == audioManager.getDefaultOutputDeviceID());
-			System.out.println("deviceId" + i + ": " + deviceName);
+			System.out.println("device id " + i + ": " + deviceName);
 			System.out.println("  max inputs : " + maxInputs + (isDefaultInput ? "   (default)" : ""));
 			System.out.println("  max outputs: " + maxOutputs + (isDefaultOutput ? "   (default)" : ""));
 		}