xptracker: Add drag and drop reordering for tracker panel bars (#4118)

This commit implements a custom component which extends JLayeredPane,
allowing reordering child components via drag and drop. This requires
its children components to forward the necessary MouseEvents.

runelite-client/src/main/java/net/runelite/client/plugins/xptracker/XpInfoBox.java

@@ -35,6 +35,7 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import javax.swing.ImageIcon;
+import javax.swing.JComponent;
 import javax.swing.JLabel;
 import javax.swing.JMenuItem;
 import javax.swing.JPanel;
@@ -54,6 +55,7 @@ import net.runelite.client.ui.ColorScheme;
 import net.runelite.client.ui.DynamicGridLayout;
 import net.runelite.client.ui.FontManager;
 import net.runelite.client.ui.SkillColor;
+import net.runelite.client.ui.components.MouseDragEventForwarder;
 import net.runelite.client.ui.components.ProgressBar;
 import net.runelite.client.util.ColorUtil;
 import net.runelite.client.util.LinkBrowser;
@@ -80,7 +82,7 @@ class XpInfoBox extends JPanel
 	private static final String ADD_STATE = "Add to canvas";
 
 	// Instance members
-	private final JPanel panel;
+	private final JComponent panel;
 
 	@Getter(AccessLevel.PACKAGE)
 	private final Skill skill;
@@ -107,7 +109,7 @@ class XpInfoBox extends JPanel
 
 	private boolean paused = false;
 
-	XpInfoBox(XpTrackerPlugin xpTrackerPlugin, XpTrackerConfig xpTrackerConfig, Client client, JPanel panel, Skill skill, SkillIconManager iconManager)
+	XpInfoBox(XpTrackerPlugin xpTrackerPlugin, XpTrackerConfig xpTrackerConfig, Client client, JComponent panel, Skill skill, SkillIconManager iconManager)
 	{
 		this.xpTrackerConfig = xpTrackerConfig;
 		this.panel = panel;
@@ -217,13 +219,19 @@ class XpInfoBox extends JPanel
 		container.setComponentPopupMenu(popupMenu);
 		progressBar.setComponentPopupMenu(popupMenu);
 
+		// forward mouse drag events to parent panel for drag and drop reordering
+		MouseDragEventForwarder mouseDragEventForwarder = new MouseDragEventForwarder(panel);
+		container.addMouseListener(mouseDragEventForwarder);
+		container.addMouseMotionListener(mouseDragEventForwarder);
+		progressBar.addMouseListener(mouseDragEventForwarder);
+		progressBar.addMouseMotionListener(mouseDragEventForwarder);
+
 		add(container, BorderLayout.NORTH);
 	}
 
 	void reset()
 	{
 		canvasItem.setText(ADD_STATE);
-		container.remove(statsPanel);
 		panel.remove(this);
 		panel.revalidate();
 	}

runelite-client/src/main/java/net/runelite/client/plugins/xptracker/XpPanel.java

@@ -31,6 +31,7 @@ import java.util.HashMap;
 import java.util.Map;
 import javax.swing.BoxLayout;
 import javax.swing.ImageIcon;
+import javax.swing.JComponent;
 import javax.swing.JLabel;
 import javax.swing.JMenuItem;
 import javax.swing.JPanel;
@@ -44,6 +45,7 @@ import net.runelite.client.game.SkillIconManager;
 import net.runelite.client.ui.ColorScheme;
 import net.runelite.client.ui.FontManager;
 import net.runelite.client.ui.PluginPanel;
+import net.runelite.client.ui.components.DragAndDropReorderPane;
 import net.runelite.client.ui.components.PluginErrorPanel;
 import net.runelite.client.util.LinkBrowser;
 import okhttp3.HttpUrl;
@@ -120,9 +122,8 @@ class XpPanel extends PluginPanel
 		overallPanel.add(overallIcon, BorderLayout.WEST);
 		overallPanel.add(overallInfo, BorderLayout.CENTER);
 
+		final JComponent infoBoxPanel = new DragAndDropReorderPane();
 
-		final JPanel infoBoxPanel = new JPanel();
-		infoBoxPanel.setLayout(new BoxLayout(infoBoxPanel, BoxLayout.Y_AXIS));
 		layoutPanel.add(overallPanel);
 		layoutPanel.add(infoBoxPanel);
 

runelite-client/src/main/java/net/runelite/client/ui/components/DragAndDropReorderPane.java

@@ -0,0 +1,199 @@
+/*
+ * Copyright (c) 2020, Shingyx <https://github.com/Shingyx>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package net.runelite.client.ui.components;
+
+import java.awt.Component;
+import java.awt.Container;
+import java.awt.LayoutManager;
+import java.awt.Point;
+import java.awt.dnd.DragSource;
+import java.awt.event.MouseAdapter;
+import java.awt.event.MouseEvent;
+import javax.swing.BoxLayout;
+import javax.swing.JLayeredPane;
+import javax.swing.SwingUtilities;
+
+/**
+ * Pane which allows reordering its components via drag and drop.
+ */
+public class DragAndDropReorderPane extends JLayeredPane
+{
+	private Point dragStartPoint;
+	private Component draggingComponent;
+	private int dragYOffset = 0;
+	private int dragIndex = -1;
+
+	public DragAndDropReorderPane()
+	{
+		super();
+		setLayout(new DragAndDropReorderLayoutManager());
+		MouseAdapter mouseAdapter = new DragAndDropReorderMouseAdapter();
+		addMouseListener(mouseAdapter);
+		addMouseMotionListener(mouseAdapter);
+	}
+
+	@Override
+	public void setLayout(LayoutManager layoutManager)
+	{
+		if (layoutManager != null && !(layoutManager instanceof DragAndDropReorderLayoutManager))
+		{
+			throw new IllegalArgumentException("DragAndDropReorderPane only supports DragAndDropReorderLayoutManager");
+		}
+		super.setLayout(layoutManager);
+	}
+
+	private void startDragging(Point point)
+	{
+		draggingComponent = getDefaultLayerComponentAt(dragStartPoint);
+		if (draggingComponent == null)
+		{
+			dragStartPoint = null;
+			return;
+		}
+		dragYOffset = SwingUtilities.convertPoint(this, dragStartPoint, draggingComponent).y;
+		dragIndex = getPosition(draggingComponent);
+		setLayer(draggingComponent, DRAG_LAYER);
+		moveDraggingComponent(point);
+	}
+
+	private void drag(Point point)
+	{
+		moveDraggingComponent(point);
+
+		// reorder components overlapping with the dragging components mid-point
+		Point draggingComponentMidPoint = SwingUtilities.convertPoint(
+			draggingComponent,
+			new Point(draggingComponent.getWidth() / 2, draggingComponent.getHeight() / 2),
+			this
+		);
+		Component component = getDefaultLayerComponentAt(draggingComponentMidPoint);
+		if (component != null)
+		{
+			int index = getPosition(component);
+			dragIndex = index < dragIndex ? index : index + 1;
+			revalidate();
+		}
+	}
+
+	private void finishDragging()
+	{
+		if (draggingComponent != null)
+		{
+			setLayer(draggingComponent, DEFAULT_LAYER, dragIndex);
+			draggingComponent = null;
+			dragYOffset = 0;
+			dragIndex = -1;
+			revalidate();
+		}
+		dragStartPoint = null;
+	}
+
+	private void moveDraggingComponent(Point point)
+	{
+		// shift the dragging component to match it's earlier y offset with the mouse
+		int y = point.y - dragYOffset;
+		// clamp the height to stay within the pane
+		y = Math.max(y, 0);
+		y = Math.min(y, getHeight() - draggingComponent.getHeight());
+
+		draggingComponent.setLocation(new Point(0, y));
+	}
+
+	private Component getDefaultLayerComponentAt(Point point)
+	{
+		for (Component component : getComponentsInLayer(DEFAULT_LAYER))
+		{
+			if (component.contains(point.x - component.getX(), point.y - component.getY()))
+			{
+				return component;
+			}
+		}
+		return null;
+	}
+
+	private class DragAndDropReorderLayoutManager extends BoxLayout
+	{
+		private DragAndDropReorderLayoutManager()
+		{
+			super(DragAndDropReorderPane.this, BoxLayout.Y_AXIS);
+		}
+
+		@Override
+		public void layoutContainer(Container target)
+		{
+			if (draggingComponent != null)
+			{
+				// temporarily move the dragging component to the default layer for correct layout calculation
+				Point location = draggingComponent.getLocation();
+				setLayer(draggingComponent, DEFAULT_LAYER, dragIndex);
+				super.layoutContainer(target);
+				setLayer(draggingComponent, DRAG_LAYER);
+				draggingComponent.setLocation(location);
+			}
+			else
+			{
+				super.layoutContainer(target);
+			}
+		}
+	}
+
+	private class DragAndDropReorderMouseAdapter extends MouseAdapter
+	{
+		@Override
+		public void mousePressed(MouseEvent e)
+		{
+			if (SwingUtilities.isLeftMouseButton(e) && getComponentCount() > 1)
+			{
+				dragStartPoint = e.getPoint();
+			}
+		}
+
+		@Override
+		public void mouseDragged(MouseEvent e)
+		{
+			if (SwingUtilities.isLeftMouseButton(e) && dragStartPoint != null)
+			{
+				Point point = e.getPoint();
+				if (draggingComponent != null)
+				{
+					drag(point);
+				}
+				else if (point.distance(dragStartPoint) > DragSource.getDragThreshold())
+				{
+					startDragging(point);
+				}
+			}
+		}
+
+		@Override
+		public void mouseReleased(MouseEvent e)
+		{
+			if (SwingUtilities.isLeftMouseButton(e))
+			{
+				finishDragging();
+			}
+		}
+	}
+}

runelite-client/src/main/java/net/runelite/client/ui/components/MouseDragEventForwarder.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2020, Shingyx <https://github.com/Shingyx>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package net.runelite.client.ui.components;
+
+import java.awt.Component;
+import java.awt.event.MouseAdapter;
+import java.awt.event.MouseEvent;
+import javax.swing.SwingUtilities;
+
+/**
+ * Forwards left mouse button drag events to the target Component.
+ */
+public class MouseDragEventForwarder extends MouseAdapter
+{
+	private final Component target;
+
+	public MouseDragEventForwarder(Component target)
+	{
+		this.target = target;
+	}
+
+	@Override
+	public void mousePressed(MouseEvent e)
+	{
+		processEvent(e);
+	}
+
+	@Override
+	public void mouseDragged(MouseEvent e)
+	{
+		processEvent(e);
+	}
+
+	@Override
+	public void mouseReleased(MouseEvent e)
+	{
+		processEvent(e);
+	}
+
+	private void processEvent(MouseEvent e)
+	{
+		if (SwingUtilities.isLeftMouseButton(e))
+		{
+			MouseEvent eventForTarget = SwingUtilities.convertMouseEvent((Component) e.getSource(), e, target);
+			target.dispatchEvent(eventForTarget);
+		}
+	}
+}