Better error messaging when input can't be used

src/com/limelight/Limelight.java

@@ -45,18 +45,24 @@ public class Limelight implements NvConnectionListener {
 	 */
 	private void startUp(StreamConfiguration streamConfig, List<String> inputs) {
 		conn = new NvConnection(host, this, streamConfig);
-		conn.start(PlatformBinding.getDeviceName(), null,
-				VideoDecoderRenderer.FLAG_PREFER_QUALITY,
-				PlatformBinding.getAudioRenderer(),
-				PlatformBinding.getVideoDecoderRenderer());
-		
+
 		for (String input:inputs) {
 			try {
 				new EvdevHandler(conn, input).start();
 			} catch (FileNotFoundException ex) {
 				displayError("Input", "Input (" + input + ") could not be found");
+				return;
+			} catch (IOException ex) {
+				displayError("Input", "Input (" + input + ") could not be read");
+				displayError("Input", "Are you running as root?");
+				return;
 			}
-		}
+		}		
+		
+		conn.start(PlatformBinding.getDeviceName(), null,
+				VideoDecoderRenderer.FLAG_PREFER_QUALITY,
+				PlatformBinding.getAudioRenderer(),
+				PlatformBinding.getVideoDecoderRenderer());
 	}
 	
 	private void pair() {

src/com/limelight/input/EvdevHandler.java

@@ -4,6 +4,7 @@ import com.limelight.nvstream.NvConnection;
 import com.limelight.nvstream.input.KeyboardPacket;
 import com.limelight.nvstream.input.MouseButtonPacket;
 import java.awt.event.KeyEvent;
+import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
@@ -167,9 +168,15 @@ public class EvdevHandler implements Runnable {
 	private FileChannel deviceInput;
 	private ByteBuffer inputBuffer;
 	
-	public EvdevHandler(NvConnection conn, String device) throws FileNotFoundException {
+	public EvdevHandler(NvConnection conn, String device) throws FileNotFoundException, IOException {
 		this.conn = conn;
-		FileInputStream in = new FileInputStream(device);
+		File file = new File(device);
+		if (!file.exists())
+			throw new FileNotFoundException("File " + device + " not found");
+		if (!file.canRead())
+			throw new IOException("Can't read from " + device);
+			
+		FileInputStream in = new FileInputStream(file);
         deviceInput = in.getChannel();
 		inputBuffer = ByteBuffer.allocate(MAX_STRUCT_SIZE_BYTES);
 		inputBuffer.order(ByteOrder.nativeOrder());