Fix various comments and issues

Author: JLLeitschuh

core/src/main/java/edu/wpi/grip/core/Source.java

@@ -5,6 +5,7 @@
 import java.io.IOException;
 import java.util.Optional;
 import java.util.Properties;
+import java.util.concurrent.TimeoutException;
 
 /**
  * Base class for an input into the pipeline.
@@ -55,7 +56,7 @@ public <T extends Source> T start(EventBus eventBus) throws IOException {
 
     /**
      * Starts this source.
-     * A source whose {@link #isRestartable()} returns true can also be stopped and started and stopped multiple times.
+     * A source whose {@link #canStopAndStart()} returns true can also be stopped and started and stopped multiple times.
      *
      * @return The source object that created the camera
      * @throws IOException If the source fails to be started
@@ -65,12 +66,12 @@ public <T extends Source> T start(EventBus eventBus) throws IOException {
     /**
      * Stops this source.
      * This will stop the source publishing new socket values after this method returns.
-     * A source whose {@link #isRestartable()} returns true can also be stopped and started and stopped multiple times.
+     * A source whose {@link #canStopAndStart()} returns true can also be stopped and started and stopped multiple times.
      *
      * @return The source that was stopped
-     * @throws Exception
+     * @throws TimeoutException if the thread running the source fails to stop
      */
-    public abstract Source stop() throws Exception;
+    public abstract Source stop() throws TimeoutException;
 
     /**
      * Used to indicate if the source is running or stopped
@@ -84,5 +85,5 @@ public <T extends Source> T start(EventBus eventBus) throws IOException {
      *
      * @return true if this source can be restarted once created
      */
-    public abstract boolean isRestartable();
+    public abstract boolean canStopAndStart();
 }

core/src/main/java/edu/wpi/grip/core/sources/CameraSource.java

@@ -230,7 +230,7 @@ public boolean isRunning() {
     }
 
     @Override
-    public boolean isRestartable() {
+    public boolean canStopAndStart() {
         return true;
     }
 

core/src/main/java/edu/wpi/grip/core/sources/ImageFileSource.java

@@ -50,10 +50,8 @@ public ImageFileSource() {
     }
 
     private void initialize(EventBus eventBus, String path) throws IOException {
-        checkNotNull(eventBus, "Event Bus was null.");
-        checkNotNull(path, "Path was null");
-
-        this.path = path;
+        this.eventBus = checkNotNull(eventBus, "Event Bus was null.");
+        this.path = checkNotNull(path, "Path was null");
         this.name = Files.getNameWithoutExtension(this.path);
         this.outputSocket = new OutputSocket<>(eventBus, imageOutputHint);
 
@@ -103,7 +101,7 @@ public boolean isRunning() {
     }
 
     @Override
-    public boolean isRestartable() {
+    public boolean canStopAndStart() {
         return false;
     }
 

ui/src/main/java/edu/wpi/grip/ui/pipeline/AddSourceView.java

@@ -22,26 +22,27 @@
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.util.List;
-import java.util.concurrent.Executor;
 import java.util.function.Consumer;
 import java.util.function.Predicate;
 
+import static com.google.common.base.Preconditions.checkNotNull;
+
 /**
  * A box of buttons that let the user add different kinds of {@link edu.wpi.grip.core.Source Source}s.  Depending on which button is pressed,
  * a different dialog is presented for the user to construct that source.  As an example, the image file source results
  * in a file picker that the user can use to browse for an image.
  */
 public class AddSourceView extends HBox {
 
+    private final EventBus eventBus;
+
     @FunctionalInterface
     private interface SupplierWithIO<T> {
         T getWithIO() throws IOException;
     }
 
-    private final EventBus eventBus;
-
     public AddSourceView(EventBus eventBus) {
-        this.eventBus = eventBus;
+        this.eventBus = checkNotNull(eventBus, "Event Bus can not be null");
 
         this.setFillHeight(true);
 
@@ -127,12 +128,11 @@ public AddSourceView(EventBus eventBus) {
     }
 
     /**
-     *
-     * @param dialog The dialog to load the camera with
+     * @param dialog               The dialog to load the camera with
      * @param cameraSourceSupplier The supplier that will create the camera
-     * @param failureCallback The handler for when the camera source supplier throws an IO Exception
+     * @param failureCallback      The handler for when the camera source supplier throws an IO Exception
      */
-    private void loadCamera(Dialog<ButtonType> dialog, SupplierWithIO<CameraSource> cameraSourceSupplier, Consumer<IOException> failureCallback){
+    private void loadCamera(Dialog<ButtonType> dialog, SupplierWithIO<CameraSource> cameraSourceSupplier, Consumer<IOException> failureCallback) {
         assert Platform.isFxApplicationThread() : "Should only run in FX thread";
         dialog.showAndWait().filter(Predicate.isEqual(ButtonType.OK)).ifPresent(result -> {
             try {

ui/src/main/java/edu/wpi/grip/ui/pipeline/SourceView.java

@@ -67,7 +67,7 @@ public SourceView(EventBus eventBus, Source source) {
 
         this.name.setText(source.getName());
 
-        if (!source.isRestartable()) startStopButton.setVisible(false);
+        if (!source.canStopAndStart()) startStopButton.setVisible(false);
         else {
             HBox.setHgrow(startStopButton, Priority.NEVER);
             startStopButton.setContentDisplay(ContentDisplay.RIGHT);