Fixed issue with icon scaling in popup menu

src/dorkbox/systemTray/swing/SwingMenuEntry.java

@@ -20,16 +20,28 @@ import dorkbox.systemTray.ImageUtil;
 import dorkbox.systemTray.MenuEntry;
 import dorkbox.systemTray.SystemTray;
 import dorkbox.systemTray.SystemTrayMenuAction;
+import dorkbox.util.FileUtil;
 import dorkbox.util.SwingUtil;
 
+import javax.imageio.ImageIO;
+import javax.swing.Icon;
 import javax.swing.ImageIcon;
 import javax.swing.JMenuItem;
+import javax.swing.UIManager;
+import java.awt.Dimension;
+import java.awt.Graphics2D;
+import java.awt.Image;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
 
 class SwingMenuEntry implements MenuEntry {
+    private static final String tempDirPath = ImageUtil.TEMP_DIR.getAbsolutePath();
+
     private final SwingSystemTrayMenuPopup parent;
     private final SystemTray systemTray;
     private final JMenuItem menuItem;
@@ -38,6 +50,11 @@ class SwingMenuEntry implements MenuEntry {
     private volatile String text;
     private volatile SystemTrayMenuAction callback;
 
+    private int iconHeight = -1;
+
+
+
+
     SwingMenuEntry(final SwingSystemTrayMenuPopup parentMenu, final String label, final String imagePath, final SystemTrayMenuAction callback,
                    final SystemTray systemTray) {
         this.parent = parentMenu;
@@ -58,7 +75,7 @@ class SwingMenuEntry implements MenuEntry {
         menuItem.addActionListener(swingCallback);
 
         if (imagePath != null && !imagePath.isEmpty()) {
-            menuItem.setIcon(new ImageIcon(imagePath));
+            setImageIcon(imagePath);
         }
 
         parentMenu.add(menuItem);
@@ -98,16 +115,70 @@ class SwingMenuEntry implements MenuEntry {
             @Override
             public
             void run() {
-                if (imagePath != null && !imagePath.isEmpty()) {
-                    menuItem.setIcon(new ImageIcon(imagePath));
-                }
-                else {
-                    menuItem.setIcon(null);
-                }
+                setImageIcon(imagePath);
             }
         });
     }
 
+    private
+    void setImageIcon(final String imagePath) {
+        if (imagePath != null && !imagePath.isEmpty()) {
+
+            if (iconHeight != 0) {
+                // this will (and should) be the correct size for the system. On the systems tested, it was 16
+                // see: http://en-human-begin.blogspot.de/2007/11/javas-icons-by-default.html
+                Icon icon = UIManager.getIcon("FileView.fileIcon");
+                iconHeight = icon.getIconHeight();
+            }
+
+            ImageIcon origIcon = new ImageIcon(imagePath);
+            int origIconHeight = origIcon.getIconHeight();
+            int origIconWidth = origIcon.getIconWidth();
+
+            int savedIconHeight = this.iconHeight;
+
+            // it is necessary to resize this icon, so that it matches what our preferred size is for icons
+            if (origIconHeight != savedIconHeight && savedIconHeight != 0) {
+                //noinspection SuspiciousNameCombination
+                Dimension scaledDimension = getScaledDimension(origIconWidth, origIconHeight, savedIconHeight, savedIconHeight);
+
+                Image image = origIcon.getImage();
+
+                // scale it the smoothly
+                Image newImage = image.getScaledInstance(scaledDimension.width, scaledDimension.height, java.awt.Image.SCALE_SMOOTH);
+                origIcon = new ImageIcon(newImage);
+
+                // save it to temp spot on disk (so we don't have to KEEP on doing this). (but it MUST be the temp location, otherwise
+                // it's always 'on the fly')
+                if (imagePath.startsWith(tempDirPath)) {
+                    // have to delete the old one
+                    File file = new File(imagePath);
+                    boolean delete = file.delete();
+
+                    if (delete) {
+                        // now write out the new one
+                        String extension = FileUtil.getExtension(imagePath);
+                        if (extension == null) {
+                            extension = ".png"; // this is just made up
+                        }
+                        BufferedImage bufferedImage = getBufferedImage(image);
+                        try {
+                            ImageIO.write(bufferedImage, extension, file);
+                        } catch (IOException e) {
+                            // this shouldn't happen, but you never know...
+                            e.printStackTrace();
+                        }
+                    }
+                }
+            }
+
+            menuItem.setIcon(origIcon);
+        }
+        else {
+            menuItem.setIcon(null);
+        }
+    }
+
     @Override
     public
     void setImage(final String imagePath) {
@@ -171,4 +242,48 @@ class SwingMenuEntry implements MenuEntry {
             }
         });
     }
+
+    private static
+    Dimension getScaledDimension(int originalWidth, int originalHeight, int boundWidth, int boundHeight) {
+        //this function comes from http://stackoverflow.com/questions/10245220/java-image-resize-maintain-aspect-ratio
+
+        int newWidth = originalWidth;
+        int newHeight = originalHeight;
+
+        // first check if we need to scale width
+        if (originalWidth > boundWidth) {
+            //scale width to fit
+            newWidth = boundWidth;
+
+            //scale height to maintain aspect ratio
+            newHeight = (newWidth * originalHeight) / originalWidth;
+        }
+
+        // then check if we need to scale even with the new height
+        if (newHeight > boundHeight) {
+            //scale height to fit instead
+            newHeight = boundHeight;
+
+            //scale width to maintain aspect ratio
+            newWidth = (newHeight * originalWidth) / originalHeight;
+        }
+
+        return new Dimension(newWidth, newHeight);
+    }
+
+    private static
+    BufferedImage getBufferedImage(Image image) {
+        if (image instanceof BufferedImage) {
+            return (BufferedImage) image;
+        }
+
+        BufferedImage bimage = new BufferedImage(image.getWidth(null), image.getHeight(null), BufferedImage.TYPE_INT_ARGB);
+
+        Graphics2D bGr = bimage.createGraphics();
+        bGr.drawImage(image, 0, 0, null);
+        bGr.dispose();
+
+        // Return the buffered image
+        return bimage;
+    }
 }