show mnemonics always when a menu bar is active or a popup menu is visible

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/BasicComponentsPanel.java

@@ -602,14 +602,17 @@ class BasicComponentsPanel
 
 			//---- cutMenuItem ----
 			cutMenuItem.setText("Cut");
+			cutMenuItem.setMnemonic('C');
 			popupMenu1.add(cutMenuItem);
 
 			//---- copyMenuItem ----
 			copyMenuItem.setText("Copy");
+			copyMenuItem.setMnemonic('O');
 			popupMenu1.add(copyMenuItem);
 
 			//---- pasteMenuItem ----
 			pasteMenuItem.setText("Paste");
+			pasteMenuItem.setMnemonic('P');
 			popupMenu1.add(pasteMenuItem);
 		}
 		// JFormDesigner - End of component initialization  //GEN-END:initComponents

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/BasicComponentsPanel.jfd

@@ -601,14 +601,17 @@ new FormModel {
 			add( new FormComponent( "javax.swing.JMenuItem" ) {
 				name: "cutMenuItem"
 				"text": "Cut"
+				"mnemonic": 67
 			} )
 			add( new FormComponent( "javax.swing.JMenuItem" ) {
 				name: "copyMenuItem"
 				"text": "Copy"
+				"mnemonic": 79
 			} )
 			add( new FormComponent( "javax.swing.JMenuItem" ) {
 				name: "pasteMenuItem"
 				"text": "Paste"
+				"mnemonic": 80
 			} )
 		}, new FormLayoutConstraints( null ) {
 			"location": new java.awt.Point( 0, 500 )