The colony panel now has a non-rectangular shape when resizing. This avoids stealing mouse events that should be handled by the map instead (since a large part of the border is transparent).

src/net/sf/freecol/client/gui/panel/FreeColImageBorder.java

@@ -27,6 +27,7 @@ import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.Image;
 import java.awt.Insets;
+import java.awt.Rectangle;
 import java.awt.image.BufferedImage;
 import java.util.ArrayList;
 import java.util.List;
@@ -274,6 +275,39 @@ public class FreeColImageBorder extends AbstractBorder {
         ensureInitialized();
         return getBorderInsets(c, null);
     }
+    
+    /**
+     * Returns spaces that are open on this border.
+     * 
+     * @param c The component having the border.
+     * @return A list of areas that can be considered out-of-bounds for this border.
+     */
+    public List<Rectangle> getOpenSpace(Component c) {
+        ensureInitialized();
+        
+        final List<Rectangle> openSpace = new ArrayList<>();
+        
+        /*
+         * For now, only the top part of the border is handled. Feel free to extend this method.
+         */
+        
+        if (topStartImage != null && topStartImage.getHeight() < max(getHeight(topImage), getHeight(topEndImage))) {
+            final int openSpaceHeight = max(getHeight(topImage), getHeight(topEndImage)) - topStartImage.getHeight();
+            openSpace.add(new Rectangle(0, 0, topStartImage.getWidth(), openSpaceHeight));
+        }
+        if (topImage != null && topImage.getHeight() < max(getHeight(topStartImage), getHeight(topEndImage))) {
+            final int openSpaceHeight = max(getHeight(topStartImage), getHeight(topEndImage)) - topImage.getHeight();
+            final int x = getWidth(topStartImage);
+            final int width = c.getWidth() - getWidth(topStartImage) - getWidth(topEndImage);
+            openSpace.add(new Rectangle(x, 0, width, openSpaceHeight));
+        }
+        if (topEndImage != null && topEndImage.getHeight() < max(getHeight(topStartImage), getHeight(topImage))) {
+            final int openSpaceHeight = max(getHeight(topStartImage), getHeight(topImage)) - topEndImage.getHeight();
+            openSpace.add(new Rectangle(c.getWidth() - topEndImage.getWidth(), 0, topEndImage.getWidth(), openSpaceHeight));
+        }
+        
+        return openSpace;
+    }
 
     /**
      * Gets the insets of this border around the given component.

src/net/sf/freecol/client/gui/plaf/FreeColInternalFrameUI.java

@@ -0,0 +1,164 @@
+/**
+ *  Copyright (C) 2002-2024   The FreeCol Team
+ *
+ *  This file is part of FreeCol.
+ *
+ *  FreeCol 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 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  FreeCol 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 FreeCol.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.sf.freecol.client.gui.plaf;
+
+import java.awt.Component;
+import java.awt.Cursor;
+import java.awt.Rectangle;
+import java.awt.event.MouseEvent;
+import java.util.List;
+
+import javax.swing.JComponent;
+import javax.swing.JInternalFrame;
+import javax.swing.SwingUtilities;
+import javax.swing.border.Border;
+import javax.swing.event.MouseInputAdapter;
+import javax.swing.plaf.ComponentUI;
+import javax.swing.plaf.metal.MetalInternalFrameUI;
+
+import net.sf.freecol.client.gui.panel.FreeColImageBorder;
+
+public class FreeColInternalFrameUI extends MetalInternalFrameUI {
+
+    public FreeColInternalFrameUI(JInternalFrame b)   {
+        super(b);
+    }
+
+    public static ComponentUI createUI(JComponent b)    {
+        return new FreeColInternalFrameUI((JInternalFrame)b);
+    }
+    
+    @Override
+    protected MouseInputAdapter createBorderListener(JInternalFrame w) {
+        return new FreeColBorderListener();
+    }
+    
+    
+    /**
+     * Handles areas on the border that should be handled as out-of-bounds for
+     * the component. This allows a border to have a non-rectangular shape.
+     * 
+     * Events on areas that are considered out-of-bounds are delegated to the
+     * internal frame's parent.
+     */
+    private final class FreeColBorderListener extends BorderListener {
+        
+        private boolean resizing = false;
+        
+        @Override
+        public void mousePressed(MouseEvent e) {
+            if (isOutOfBounds(e)) {
+                handleOutOfBounds(e);
+            } else {
+                resizing = true;
+                super.mousePressed(e);
+            }
+        }
+        
+        @Override
+        public void mouseReleased(MouseEvent e) {
+            if (!resizing && isOutOfBounds(e)) {
+                handleOutOfBounds(e);
+            } else {
+                resizing = false;
+                super.mouseReleased(e);
+            }
+        }
+        
+        @Override
+        public void mouseDragged(MouseEvent e) {
+            if (!resizing && isOutOfBounds(e)) {
+                handleOutOfBounds(e);
+            } else {
+                super.mouseDragged(e);
+            }
+        }
+        
+        @Override
+        public void mouseMoved(MouseEvent e) {
+            if (!resizing && isOutOfBounds(e)) {
+                handleOutOfBounds(e);
+            } else {
+                super.mouseMoved(e);
+            }
+        }
+        
+        @Override
+        public void mouseClicked(MouseEvent e) {
+            if (!resizing && isOutOfBounds(e)) {
+                handleOutOfBounds(e);
+            } else {
+                super.mouseClicked(e);
+            }
+        }
+        
+        @Override
+        public void mouseEntered(MouseEvent e) {
+            if (!resizing && isOutOfBounds(e)) {
+                handleOutOfBounds(e);
+            } else {
+                super.mouseEntered(e);
+            }
+        }
+        
+        @Override
+        public void mouseExited(MouseEvent e) {
+            if (!resizing && isOutOfBounds(e)) {
+                handleOutOfBounds(e);
+            } else {
+                super.mouseExited(e);
+            }
+        }
+        
+        private void handleOutOfBounds(MouseEvent e) {
+            resetCursor();
+            
+            if (frame.getParent() == null) {
+                return;
+            }
+            
+            dispatchTo(e, frame.getParent());
+        }
+
+        private void resetCursor() {
+            Cursor lastCursor = frame.getLastCursor();
+            if (lastCursor == null) {
+                lastCursor = Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR);
+            }
+            frame.setCursor(lastCursor);
+        }
+        
+        private boolean isOutOfBounds(MouseEvent e) {
+            final Border border = frame.getBorder();
+            if (!(border instanceof FreeColImageBorder) ) {
+                return false;
+            }
+            
+            final List<Rectangle> bounds = ((FreeColImageBorder) border).getOpenSpace(frame);
+            return bounds.stream().anyMatch(b -> b.contains(e.getPoint()));
+        }
+        
+        private void dispatchTo(MouseEvent e, Component target) {
+            final Component source = (Component) e.getSource();
+            MouseEvent targetEvent = SwingUtilities.convertMouseEvent(source, e, target);
+            target.dispatchEvent(targetEvent);
+        }
+    }
+}

src/net/sf/freecol/client/gui/plaf/FreeColLookAndFeel.java

@@ -119,6 +119,7 @@ public class FreeColLookAndFeel extends MetalLookAndFeel {
         FreeColCheckBoxUI.class,
         FreeColComboBoxUI.class,
         FreeColFileChooserUI.class,
+        FreeColInternalFrameUI.class,
         FreeColLabelUI.class,
         FreeColListUI.class,
         FreeColMenuBarUI.class,