ComboBox on macOS: fixed keyboard navigation and show/hide popup

CHANGELOG.md

@@ -10,6 +10,7 @@ FlatLaf Change Log
   longer `null`.
 - Tree on macOS: Fixed <kbd>Left</kbd> and <kbd>Right</kbd> keys to collapse or
   expand nodes.
+- ComboBox on macOS: Fixed keyboard navigation and show/hide popup.
 - Button and ToggleButton: Support per component minimum height (set client
   property `JComponent.minimumHeight` to an integer). (issue #44)
 - Button and ToggleButton: Do not apply minimum width if button border was

flatlaf-core/src/main/java/com/formdev/flatlaf/FlatLaf.java

@@ -344,9 +344,26 @@ public abstract class FlatLaf
 	private void initInputMaps( UIDefaults defaults ) {
 		if( SystemInfo.IS_MAC ) {
 			// AquaLookAndFeel (the base for UI defaults on macOS) uses special
-			// action keys (e.g. "aquaExpandNode") for its macOS typical tree node
-			// expanding/collapsing, which are not available in FlatLaf.
-			// --> map the keys back to default Java actions
+			// action keys (e.g. "aquaExpandNode") for some macOS specific behaviour.
+			// Those action keys are not available in FlatLaf, which makes it
+			// necessary to make some modifications.
+
+			// combobox
+			defaults.put( "ComboBox.ancestorInputMap", new UIDefaults.LazyInputMap( new Object[] {
+				     "ESCAPE", "hidePopup",
+				    "PAGE_UP", "pageUpPassThrough",
+				  "PAGE_DOWN", "pageDownPassThrough",
+				       "HOME", "homePassThrough",
+				        "END", "endPassThrough",
+				       "DOWN", "selectNext",
+				    "KP_DOWN", "selectNext",
+				      "SPACE", "spacePopup",
+				      "ENTER", "enterPressed",
+				         "UP", "selectPrevious",
+				      "KP_UP", "selectPrevious"
+			} ) );
+
+			// tree node expanding/collapsing
 			modifyInputMap( defaults, "Tree.focusInputMap",
 				         "RIGHT", "selectChild",
 				      "KP_RIGHT", "selectChild",
@@ -486,6 +503,9 @@ public abstract class FlatLaf
 
 	//---- class LazyModifyInputMap -------------------------------------------
 
+	/**
+	 * Takes a (lazy) base input map and lazily applies modifications to it specified in bindings.
+	 */
 	private static class LazyModifyInputMap
 		implements LazyValue
 	{
@@ -515,6 +535,5 @@ public abstract class FlatLaf
 
 			return inputMap;
 		}
-
 	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatComboBoxUI.java

@@ -28,6 +28,8 @@ import java.awt.Insets;
 import java.awt.LayoutManager;
 import java.awt.Rectangle;
 import java.awt.Shape;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
 import java.awt.event.FocusEvent;
 import java.awt.event.FocusListener;
 import java.awt.event.MouseListener;
@@ -35,13 +37,16 @@ import java.awt.geom.Rectangle2D;
 import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
 import java.lang.ref.WeakReference;
+import javax.swing.AbstractAction;
 import javax.swing.BorderFactory;
 import javax.swing.DefaultListCellRenderer;
+import javax.swing.InputMap;
 import javax.swing.JButton;
 import javax.swing.JComboBox;
 import javax.swing.JComponent;
 import javax.swing.JList;
 import javax.swing.JPanel;
+import javax.swing.KeyStroke;
 import javax.swing.ListCellRenderer;
 import javax.swing.LookAndFeel;
 import javax.swing.SwingConstants;
@@ -54,6 +59,7 @@ import javax.swing.plaf.basic.BasicComboPopup;
 import javax.swing.plaf.basic.ComboPopup;
 import javax.swing.text.JTextComponent;
 import com.formdev.flatlaf.FlatClientProperties;
+import com.formdev.flatlaf.util.SystemInfo;
 import com.formdev.flatlaf.util.UIScale;
 
 /**
@@ -271,6 +277,18 @@ public class FlatComboBoxUI
 		editor.applyComponentOrientation( comboBox.getComponentOrientation() );
 
 		updateEditorColors();
+
+		// macOS
+		if( SystemInfo.IS_MAC && editor instanceof JTextComponent ) {
+			// delegate actions from editor text field to combobox, which is necessary
+			// because text field on macOS (based on Aqua LaF UI defaults)
+			// already handle those keys
+			InputMap inputMap = ((JTextComponent)editor).getInputMap();
+			new EditorDelegateAction( inputMap, KeyStroke.getKeyStroke( "UP" ) );
+			new EditorDelegateAction( inputMap, KeyStroke.getKeyStroke( "KP_UP" ) );
+			new EditorDelegateAction( inputMap, KeyStroke.getKeyStroke( "DOWN" ) );
+			new EditorDelegateAction( inputMap, KeyStroke.getKeyStroke( "KP_DOWN" ) );
+		}
 	}
 
 	private void updateEditorColors() {
@@ -608,4 +626,31 @@ public class FlatComboBoxUI
 				rendererBorder.paintBorder( c, g, x, y, width, height );
 		}
 	}
+
+	//---- class EditorDelegateAction -----------------------------------------
+
+	/**
+	 * Delegates actions from editor text field to combobox.
+	 */
+	private class EditorDelegateAction
+		extends AbstractAction
+	{
+		private final KeyStroke keyStroke;
+
+		EditorDelegateAction( InputMap inputMap, KeyStroke keyStroke ) {
+			this.keyStroke = keyStroke;
+
+			// add to input map
+			inputMap.put( keyStroke, this );
+		}
+
+		@Override
+		public void actionPerformed( ActionEvent e ) {
+			ActionListener action = comboBox.getActionForKeyStroke( keyStroke );
+			if( action != null ) {
+				action.actionPerformed( new ActionEvent( comboBox, e.getID(),
+					e.getActionCommand(), e.getWhen(), e.getModifiers() ) );
+			}
+		}
+	}
 }