Add unit tests for VLCj driver

webcam-capture-drivers/driver-vlcj/pom.xml

@@ -11,8 +11,8 @@
 	<artifactId>webcam-capture-driver-vlcj</artifactId>
 	<packaging>bundle</packaging>
 
-	<name>Webcam Capture - VLCj Driver</name>
-	<description>Webcam Capture driver using VLCj framework to grab frames from camera device</description>
+	<name>Webcam Capture - Vlcj Driver</name>
+	<description>Webcam Capture driver using vlcj library to grab frames from camera device</description>
 
 	<dependencies>
 		<dependency>
@@ -31,14 +31,30 @@
 			<artifactId>vlcj</artifactId>
 			<version>2.4.1</version>
 		</dependency>
+		<dependency>
+			<groupId>junit</groupId>
+			<artifactId>junit</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.easymock</groupId>
+			<artifactId>easymock</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.powermock</groupId>
+			<artifactId>powermock-module-junit4</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.powermock</groupId>
+			<artifactId>powermock-api-easymock</artifactId>
+			<scope>test</scope>
+		</dependency>
 	</dependencies>
 
 	<build>
 		<plugins>
-			<plugin>
-				<groupId>org.apache.maven.plugins</groupId>
-				<artifactId>maven-assembly-plugin</artifactId>
-			</plugin>
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-assembly-plugin</artifactId>

webcam-capture-drivers/driver-vlcj/src/main/java/com/github/sarxos/webcam/ds/vlcj/VlcjDevice.java

@@ -14,56 +14,9 @@
 import com.github.sarxos.webcam.WebcamDevice;
 import com.github.sarxos.webcam.WebcamException;
 import com.github.sarxos.webcam.WebcamResolution;
+import com.github.sarxos.webcam.ds.vlcj.impl.OS;
 
 
-/**
- * Just a simple enumeration with supported (not yet confirmed) operating
- * systems.
- * 
- * @author Bartosz Firyn (sarxos)
- */
-enum OS {
-
-	/**
-	 * Microsoft Windows
-	 */
-	WIN,
-
-	/**
-	 * Linux or UNIX.
-	 */
-	NIX,
-
-	/**
-	 * Mac OS X
-	 */
-	OSX;
-
-	private static OS os = null;
-
-	/**
-	 * Get operating system.
-	 * 
-	 * @return OS
-	 */
-	public static final OS getOS() {
-		if (os == null) {
-			String osp = System.getProperty("os.name").toLowerCase();
-			if (osp.indexOf("win") >= 0) {
-				os = WIN;
-			} else if (osp.indexOf("mac") >= 0) {
-				os = OSX;
-			} else if (osp.indexOf("nix") >= 0 || osp.indexOf("nux") >= 0) {
-				os = NIX;
-			} else {
-				throw new RuntimeException(osp + " is not supported");
-			}
-		}
-		return os;
-	}
-
-}
-
 /**
  * Capture driver which use vlcj project API to fetch images from camera. It
  * should not be used when you need performance since vlcj saves snapshot image
@@ -76,6 +29,9 @@ public static final OS getOS() {
  */
 public class VlcjDevice implements WebcamDevice {
 
+	/**
+	 * Logger.
+	 */
 	private static final Logger LOG = LoggerFactory.getLogger(VlcjDevice.class);
 
 	/**

webcam-capture-drivers/driver-vlcj/src/main/java/com/github/sarxos/webcam/ds/vlcj/VlcjDriver.java

@@ -2,6 +2,7 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 import uk.co.caprica.vlcj.binding.LibVlc;
 import uk.co.caprica.vlcj.medialist.MediaList;
@@ -13,6 +14,7 @@
 import com.github.sarxos.webcam.WebcamDevice;
 import com.github.sarxos.webcam.WebcamDiscoverySupport;
 import com.github.sarxos.webcam.WebcamDriver;
+import com.github.sarxos.webcam.ds.vlcj.impl.OS;
 import com.sun.jna.Native;
 
 
@@ -25,28 +27,59 @@
  */
 public class VlcjDriver implements WebcamDriver, WebcamDiscoverySupport {
 
-	static {
-		Native.loadLibrary(RuntimeUtil.getLibVlcLibraryName(), LibVlc.class);
-	}
+	/**
+	 * Default webcam discovery scan interval in milliseconds.
+	 */
+	public static final long DEFAULT_SCAN_INTERVAL = 3000;
+
+	/**
+	 * Are natives initialized.
+	 */
+	private static final AtomicBoolean initialized = new AtomicBoolean();
+
+	/**
+	 * The scan interval.
+	 */
+	private long scanInterval = -1;
 
 	public VlcjDriver() {
 		if (OS.getOS() == OS.WIN) {
 			System.err.println(String.format("WARNING: %s does not support Windows platform", getClass().getSimpleName()));
 		}
+		initialize();
+	}
+
+	/**
+	 * Initialize natives.
+	 */
+	protected static void initialize() {
+		initialize(true);
+	}
+
+	/**
+	 * Initialize natives. If argument is true the natives are being loaded. In
+	 * case of false this method do nothing. It's used mostly in unit tests.
+	 * 
+	 * @param load the control to decide whether to load natives or ignore them
+	 */
+	protected static void initialize(boolean load) {
+		if (load && initialized.compareAndSet(false, true)) {
+			Native.loadLibrary(RuntimeUtil.getLibVlcLibraryName(), LibVlc.class);
+		}
 	}
 
 	@Override
-	public List<WebcamDevice> getDevices() {
+	public final List<WebcamDevice> getDevices() {
 
-		MediaPlayerFactory mediaPlayerFactory = new MediaPlayerFactory();
+		MediaPlayerFactory mediaPlayerFactory = createMediaPlayerFactory();
 		MediaDiscoverer videoMediaDiscoverer = mediaPlayerFactory.newVideoMediaDiscoverer();
 		MediaList videoDeviceList = videoMediaDiscoverer.getMediaList();
 
 		List<WebcamDevice> devices = new ArrayList<WebcamDevice>();
-
 		List<MediaListItem> videoDevices = videoDeviceList.items();
+
 		for (MediaListItem item : videoDevices) {
-			devices.add(new VlcjDevice(item));
+			devices.add(mediaListItemToDevice(item));
 		}
 
 		videoDeviceList.release();
@@ -56,6 +89,25 @@ public List<WebcamDevice> getDevices() {
 		return devices;
 	}
 
+	/**
+	 * Converts media list itemn into webcam device.
+	 * 
+	 * @param item the item to be converted to webcam device instance
+	 * @return Webcam device created from media list item
+	 */
+	protected WebcamDevice mediaListItemToDevice(MediaListItem item) {
+		return new VlcjDevice(item);
+	}
+
+	/**
+	 * Creates media player factory.
+	 * 
+	 * @return New media player factory
+	 */
+	protected MediaPlayerFactory createMediaPlayerFactory() {
+		return new MediaPlayerFactory();
+	}
+
 	@Override
 	public boolean isThreadSafe() {
 		return false;
@@ -68,7 +120,22 @@ public String toString() {
 
 	@Override
 	public long getScanInterval() {
-		return 3000;
+		if (scanInterval <= 0) {
+			return DEFAULT_SCAN_INTERVAL;
+		}
+		return scanInterval;
+	}
+
+	/**
+	 * Set new scan interval. Value must be positive number. If negative or zero
+	 * is used, then the corresponding getter will return default scan interval
+	 * value.
+	 * 
+	 * @param scanInterval the new scan interval in milliseconds
+	 * @see VlcjDriver#DEFAULT_SCAN_INTERVAL
+	 */
+	public void setScanInterval(long scanInterval) {
+		this.scanInterval = scanInterval;
 	}
 
 	@Override

webcam-capture-drivers/driver-vlcj/src/main/java/com/github/sarxos/webcam/ds/vlcj/impl/OS.java

@@ -0,0 +1,48 @@
+package com.github.sarxos.webcam.ds.vlcj.impl;
+
+/**
+ * Just a simple enumeration with supported (not yet confirmed) operating
+ * systems.
+ * 
+ * @author Bartosz Firyn (sarxos)
+ */
+public enum OS {
+
+	/**
+	 * Microsoft Windows
+	 */
+	WIN,
+
+	/**
+	 * Linux or UNIX.
+	 */
+	NIX,
+
+	/**
+	 * Mac OS X
+	 */
+	OSX;
+
+	private static OS os = null;
+
+	/**
+	 * Get operating system.
+	 * 
+	 * @return OS
+	 */
+	public static final OS getOS() {
+		if (os == null) {
+			String osp = System.getProperty("os.name").toLowerCase();
+			if (osp.indexOf("win") >= 0) {
+				os = WIN;
+			} else if (osp.indexOf("mac") >= 0) {
+				os = OSX;
+			} else if (osp.indexOf("nix") >= 0 || osp.indexOf("nux") >= 0) {
+				os = NIX;
+			} else {
+				throw new RuntimeException(osp + " is not supported");
+			}
+		}
+		return os;
+	}
+}