Fix auto-complete popup on Windows

Focus behavior differences made the popup completely keyboard-inaccessible,
which is pretty terrible. Fix this by explicitly requesting focus after opening.
Also move all of the handlers to the popup, instead of just the JList, as it
seems simpler and some of the handlers affect the entire popup, anyway.

Author: garfieldnate

src/main/java/edu/umich/soar/visualsoar/components/AutocompletePopup.java

@@ -12,7 +12,6 @@
 import java.awt.event.MouseAdapter;
 import java.awt.event.MouseEvent;
 import java.awt.event.MouseMotionAdapter;
-import java.util.List;
 import java.util.Set;
 import java.util.Vector;
 import java.util.function.Consumer;
@@ -22,6 +21,9 @@
 import javax.swing.JPopupMenu;
 import javax.swing.JScrollPane;
 import javax.swing.ListSelectionModel;
+import javax.swing.SwingUtilities;
+import javax.swing.event.PopupMenuEvent;
+import javax.swing.event.PopupMenuListener;
 import javax.swing.text.BadLocationException;
 import javax.swing.text.JTextComponent;
 
@@ -42,7 +44,7 @@ public class AutocompletePopup extends JPopupMenu {
   /**
    * @param parent text component where completion will be performed
    * @param position position to perform completion at
-   * @param onCompletion
+   * @param onCompletion to pass the final selected completion string to
    */
   public AutocompletePopup(
       @NotNull JTextComponent parent,
@@ -58,7 +60,7 @@ public AutocompletePopup(
     suggestionList.setVisibleRowCount(maxVisibleRows);
 
     // single-click to accept selection
-    suggestionList.addMouseListener(
+    addMouseListener(
         new MouseAdapter() {
           @Override
           public void mouseClicked(MouseEvent e) {
@@ -67,7 +69,7 @@ public void mouseClicked(MouseEvent e) {
         });
 
     // highlight item hovered over with mouse
-    suggestionList.addMouseMotionListener(
+    addMouseMotionListener(
         new MouseMotionAdapter() {
           @Override
           public void mouseMoved(MouseEvent e) {
@@ -78,7 +80,7 @@ public void mouseMoved(MouseEvent e) {
           }
         });
 
-    suggestionList.addKeyListener(
+    addKeyListener(
         new KeyAdapter() {
           @Override
           public void keyPressed(KeyEvent e) {
@@ -92,6 +94,22 @@ public void keyTyped(KeyEvent e) {
           }
         });
 
+    // Ensure the suggestion list gains focus
+    // Without this, on Windows the popup shows but the keyboard becomes unresponsive
+    addPopupMenuListener(
+        new PopupMenuListener() {
+          @Override
+          public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
+            SwingUtilities.invokeLater(() -> requestFocusInWindow());
+          }
+
+          @Override
+          public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {}
+
+          @Override
+          public void popupMenuCanceled(PopupMenuEvent e) {}
+        });
+
     // Calculate the preferred height based on the number of items
     int rowHeight = suggestionList.getFixedCellHeight();
     if (rowHeight == 0) {
@@ -147,12 +165,14 @@ private void handleKeyPressed(
       return;
     }
     // Close the popup if a meta key (Ctrl, Alt, Cmd) is pressed with another key, as this is likely
-    // the invocation of some other shortcut such as undo/redo, and we would need more logic to handle
-    // that gracefully
-    if ((e.getModifiersEx() & (KeyEvent.CTRL_DOWN_MASK | KeyEvent.ALT_DOWN_MASK | KeyEvent.META_DOWN_MASK)) != 0
-      && e.getKeyCode() != KeyEvent.VK_CONTROL
-      && e.getKeyCode() != KeyEvent.VK_ALT
-      && e.getKeyCode() != KeyEvent.VK_META) {
+    // the invocation of some other shortcut such as undo/redo, and we would need more logic to
+    // handle that gracefully
+    if ((e.getModifiersEx()
+                & (KeyEvent.CTRL_DOWN_MASK | KeyEvent.ALT_DOWN_MASK | KeyEvent.META_DOWN_MASK))
+            != 0
+        && e.getKeyCode() != KeyEvent.VK_CONTROL
+        && e.getKeyCode() != KeyEvent.VK_ALT
+        && e.getKeyCode() != KeyEvent.VK_META) {
       setVisible(false);
       parent.dispatchEvent(e);
       return;