Added zooming and scrolling shortcuts to "DefaultModeAdapter" for topography creator

VadereGui/src/org/vadere/gui/onlinevisualization/view/OnlineVisualisationWindow.java:
- Fixed bug: The scroll pane was not added to the underlying model.
  Therefore, it was not possible to capture mouse wheel events.

CHANGELOG.md

@@ -14,6 +14,11 @@
 
 - `FootStepProcessor` interpolates the pedestrian's foot step to obtain a more precise position.  
 Was previously known as `PedestrianFootStepProcessor`
+- Use following shortcuts for zooming and scrolling in the topography creator:
+  * Ctrl + Mouse Wheel Scroll: Zoom in/out.
+  * Mouse Wheel Scroll: Scroll vertically.
+  * Shift + Mouse Wheel Scroll: Scroll horizontally.
+  * Use Alt key to decrease the step size while scrolling.
 
 # v1.4 (2019-09-05)
 

VadereGui/src/org/vadere/gui/components/control/DefaultModeAdapter.java

@@ -68,23 +68,70 @@ public class DefaultModeAdapter implements IMode {
 		panelModel.notifyObservers();
 	}
 
+	/**
+	 * Use following shortcuts for zooming and scrolling:
+	 * <ul>
+	 *     <li>Ctrl + Mouse Wheel Scroll: Zoom in/out.</li>
+	 *     <li>Mouse Wheel Scroll: Scroll vertically.</li>
+	 *     <li>Shift + Mouse Wheel Scroll: Scroll horizontally.</li>
+	 *     <li>Use Alt key to decrease the step size while scrolling.</li>
+	 * </ul>
+	 * @param e
+	 */
 	@Override
 	public void mouseWheelMoved(MouseWheelEvent e) {
-		if (e.getWheelRotation() > 0) {
-			if (panelModel.zoomOut()) {
-				panelModel.notifyScaleListeners();
-				panelModel.notifyObservers();
+		if (e.isControlDown()) {
+			if (e.getWheelRotation() > 0) {
+				if (panelModel.zoomOut()) {
+					panelModel.notifyScaleListeners();
+					panelModel.notifyObservers();
+				}
+				delay();
+			} else if (e.getWheelRotation() < 0) {
+				if (panelModel.zoomIn()) {
+					panelModel.notifyScaleListeners();
+					panelModel.notifyObservers();
+				}
+				delay();
 			}
-			delay();
-		} else if (e.getWheelRotation() < 0) {
-			if (panelModel.zoomIn()) {
-				panelModel.notifyScaleListeners();
-				panelModel.notifyObservers();
-			}
-			delay();
+		} else {
+			MouseWheelEvent scrollEvent = (e.isAltDown()) ? getSmallStepScrollEvent(e) : getBigStepScrollEvent(e);
+			panelModel.getScrollPane().dispatchEvent(scrollEvent);
 		}
 	}
 
+	private MouseWheelEvent getSmallStepScrollEvent(MouseWheelEvent baseEvent) {
+		MouseWheelEvent smallScrollEvent = new MouseWheelEvent(
+				(Component) baseEvent.getSource(),
+				baseEvent.getID(),
+				baseEvent.getWhen(),
+				baseEvent.getModifiersEx(),
+				baseEvent.getX(),
+				baseEvent.getY(),
+				baseEvent.getClickCount(),
+				baseEvent.isPopupTrigger(),
+				MouseWheelEvent.WHEEL_UNIT_SCROLL,
+				baseEvent.getScrollAmount(),
+				baseEvent.getWheelRotation());
+		return smallScrollEvent;
+	}
+
+	private MouseWheelEvent getBigStepScrollEvent(MouseWheelEvent baseEvent) {
+		MouseWheelEvent smallScrollEvent = new MouseWheelEvent(
+				(Component) baseEvent.getSource(),
+				baseEvent.getID(),
+				baseEvent.getWhen(),
+				baseEvent.getModifiersEx(),
+				baseEvent.getX(),
+				baseEvent.getY(),
+				baseEvent.getClickCount(),
+				baseEvent.isPopupTrigger(),
+				MouseWheelEvent.WHEEL_BLOCK_SCROLL,
+				baseEvent.getScrollAmount(),
+				baseEvent.getWheelRotation());
+		return smallScrollEvent;
+	}
+
 	private void delay() {
 		try {
 			Thread.sleep(10);

VadereGui/src/org/vadere/gui/onlinevisualization/view/OnlineVisualisationWindow.java

@@ -48,6 +48,7 @@ public class OnlineVisualisationWindow extends JPanel implements Observer {
 		mainPanel.setScrollPane(scrollPane);
 		scrollPane.getViewport()
 				.addChangeListener(new JViewportChangeListener(model, scrollPane.getVerticalScrollBar()));
+		model.addScrollPane(scrollPane);
 
 		IViewportChangeListener viewportChangeListener = new ViewportChangeListener(model, scrollPane);
 		model.addViewportChangeListener(viewportChangeListener);