try to implement partial transparency

As implemented in Notepad++, a partially transparent search/replace window could make it easier to interact with the editor (particularly in fullscreen contexts, when the "always on top" window could hide the search results).
Unfortunately, Java can only apply the transparency to undecorated window, so it's a no-go.
Java gurus, please come to the rescue :D

Author: facchinm

app/src/cc/arduino/view/findreplace/FindReplace.java

@@ -40,6 +40,7 @@
 import java.util.HashMap;
 import java.util.Map;
 
+import static java.awt.GraphicsDevice.WindowTranslucency.*;
 import static processing.app.I18n.tr;
 
 public class FindReplace extends javax.swing.JFrame {
@@ -55,6 +56,7 @@ public class FindReplace extends javax.swing.JFrame {
   public FindReplace(Editor editor, Map<String, Object> state) {
     this.editor = editor;
 
+    isTranslucencySupported();
     initComponents();
 
     if (OSUtils.isMacOS()) {
@@ -78,6 +80,10 @@ public void windowActivated(WindowEvent e) {
         findField.requestFocusInWindow();
         findField.selectAll();
         setAlwaysOnTop(true);
+        if (useTranslucency) {
+          // Window is decorated, so tranparency doesn't work :(
+          //setOpacity(0.7f);
+        }
       }
       public void windowDeactivated(WindowEvent e) {
         setAlwaysOnTop(false);
@@ -89,6 +95,10 @@ public void windowActivated(WindowEvent e) {
         findField.requestFocusInWindow();
         findField.selectAll();
         setAlwaysOnTop(true);
+        if (useTranslucency) {
+          // Window is decorated, so tranparency doesn't work :(
+          //setOpacity(1.0f);
+        }
       }
       public void windowDeactivated(WindowEvent e) {
       }
@@ -104,6 +114,15 @@ public void setVisible(boolean b) {
     super.setVisible(b);
   }
 
+  private boolean useTranslucency;
+
+  private void isTranslucencySupported() {
+    GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
+    GraphicsDevice gd = ge.getDefaultScreenDevice();
+    //If translucent windows aren't supported, exit.
+    useTranslucency = gd.isWindowTranslucencySupported(TRANSLUCENT);
+  }
+
   private Map<String, Object> findDialogState() {
     Map<String, Object> state = new HashMap<>();
     state.put(FIND_TEXT, findField.getText());