presenter: scroll slides with mouse wheel #916

lect-presenter-api/src/main/java/org/lecturestudio/presenter/api/input/MouseWheelHandler.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2020 TU Darmstadt, Department of Computer Science,
+ * Embedded Systems and Applications Group.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.lecturestudio.presenter.api.input;
+
+public interface MouseWheelHandler {
+
+	/**
+	 * An event dispatched when the mouse wheel was rotated in a component.
+	 *
+	 * @param x             The horizontal x coordinate for the mouse location.
+	 * @param y             The vertical y coordinate for the mouse location.
+	 * @param wheelRotation The integer number of "clicks" by which the mouse wheel was rotated.
+	 */
+	record MouseWheelEvent(int x, int y, int wheelRotation) {
+
+	}
+
+
+	/**
+	 * Invoked when the mouse wheel is rotated.
+	 *
+	 * @param e the event to be processed.
+	 *
+	 * @see MouseWheelEvent
+	 */
+	void mouseWheelMoved(MouseWheelEvent e);
+
+}

lect-presenter-api/src/main/java/org/lecturestudio/presenter/api/presenter/SlidesPresenter.java

@@ -111,6 +111,7 @@ import org.lecturestudio.presenter.api.event.ScreenShareEndEvent;
 import org.lecturestudio.presenter.api.event.ScreenShareStateEvent;
 import org.lecturestudio.presenter.api.event.StreamReconnectStateEvent;
 import org.lecturestudio.presenter.api.event.StreamingStateEvent;
+import org.lecturestudio.presenter.api.input.MouseWheelHandler;
 import org.lecturestudio.presenter.api.input.Shortcut;
 import org.lecturestudio.presenter.api.model.*;
 import org.lecturestudio.presenter.api.service.*;
@@ -1265,7 +1266,7 @@ public class SlidesPresenter extends Presenter<SlidesView> {
 	@Override
 	public void initialize() {
 		stylusHandler = new StylusHandler(toolController, () -> {
-			// Cancel page selection task.
+			// Cancel a page selection task.
 			if (nonNull(idleTimer)) {
 				idleTimer.stop();
 				idleTimer = null;
@@ -1349,6 +1350,8 @@ public class SlidesPresenter extends Presenter<SlidesView> {
 //			setUseMouse(newValue);
 //		});
 
+		view.setMouseWheelHandler(this::mouseWheelMoved);
+
 		setUseMouse(config.getUseMouseInput());
 
 		view.setOnExternalMessagesPositionChanged(this::externalMessagesPositionChanged);
@@ -1481,6 +1484,15 @@ public class SlidesPresenter extends Presenter<SlidesView> {
 		}
 	}
 
+	private void mouseWheelMoved(MouseWheelHandler.MouseWheelEvent e) {
+		if (e.wheelRotation() < 0) {
+			previousPage();
+		}
+		else {
+			nextPage();
+		}
+	}
+
 	private void initExternalScreenBehavior(ExternalWindowConfiguration config, BiConsumer<Boolean, Boolean> action) {
 		final ObservableList<Screen> screens = presentationController.getScreens();
 

lect-presenter-api/src/main/java/org/lecturestudio/presenter/api/view/SlidesView.java

@@ -34,6 +34,7 @@ import org.lecturestudio.core.model.DocumentOutline;
 import org.lecturestudio.core.model.DocumentOutlineItem;
 import org.lecturestudio.core.model.Page;
 import org.lecturestudio.core.view.*;
+import org.lecturestudio.presenter.api.input.MouseWheelHandler;
 import org.lecturestudio.presenter.api.model.*;
 import org.lecturestudio.presenter.api.config.SlideViewConfiguration;
 import org.lecturestudio.swing.model.ExternalWindowPosition;
@@ -82,6 +83,8 @@ public interface SlidesView extends View {
 
 	void setExtendedFullscreen(boolean extended);
 
+	void setMouseWheelHandler(MouseWheelHandler handler);
+
 	void createStylusInput(StylusHandler handler);
 
 	void createMouseInput(ToolController toolController);

lect-presenter-swing/src/main/java/org/lecturestudio/presenter/swing/view/SwingSlidesView.java

@@ -65,6 +65,7 @@ import org.lecturestudio.core.stylus.StylusHandler;
 import org.lecturestudio.core.view.*;
 import org.lecturestudio.core.view.Action;
 import org.lecturestudio.presenter.api.config.SlideViewConfiguration;
+import org.lecturestudio.presenter.api.input.MouseWheelHandler;
 import org.lecturestudio.presenter.api.model.*;
 import org.lecturestudio.presenter.api.service.UserPrivilegeService;
 import org.lecturestudio.presenter.api.view.SlidesView;
@@ -226,6 +227,8 @@ public class SwingSlidesView extends JPanel implements SlidesView {
 
 	private SlideView slideNotesView;
 
+	private MouseWheelListener mouseWheelListener;
+
 	private StylusListener stylusListener;
 
 	private BufferedImage peerViewImage;
@@ -610,6 +613,19 @@ public class SwingSlidesView extends JPanel implements SlidesView {
 		bottomTabPane.setVisible(show);
 	}
 
+	@Override
+	public void setMouseWheelHandler(MouseWheelHandler handler) {
+		if (nonNull(mouseWheelListener)) {
+			removeMouseWheelListener(mouseWheelListener);
+		}
+
+		mouseWheelListener = e -> {
+			handler.mouseWheelMoved(new MouseWheelHandler.MouseWheelEvent(e.getX(), e.getY(), e.getWheelRotation()));
+		};
+
+		addMouseWheelListener(mouseWheelListener);
+	}
+
 	@Override
 	public void createStylusInput(StylusHandler handler) {
 		if (nonNull(mouseListener)) {
@@ -2129,8 +2145,6 @@ public class SwingSlidesView extends JPanel implements SlidesView {
 			return false;
 		});
 
-		addMouseWheelListener(e -> scrollPreview(e.getWheelRotation()));
-
 		ToolTipManager.sharedInstance().registerComponent(outlineTree);
 
 		// Use one-way tree selection.