RFR: 8155030: The Menu Mnemonics are always displayed for GTK LAF

[Tejesh R]

On Mon, 29 Apr 2024 09:00:46 GMT, Abhishek Kumar <abhiscxk at openjdk.org> wrote:

> In GTK LAF, the menu mnemonics are always displayed which is different from the native behavior. In native application **(tested with gedit**), the menu mnemonics toggle on press of `ALT` key. Menu mnemonics are hidden initially and then toggles between show/hide on `ALT` press. 
> Proposed fix is to handle the `ALT` key press for GTK LAF and mimic the native behavior. Fix is similar to the `ALT` key processing in  Windows LAF. Automated test case is added to verify the fix and tested in Ubuntu and Oracle linux.
> 
> CI testing is green and link attached in JBS.

src/java.desktop/share/classes/javax/swing/plaf/synth/SynthLookAndFeel.java line 1066:

> 1064:      */
> 1065:     public static void setMnemonicHidden(boolean hide) {
> 1066:         if (UIManager.getBoolean("Button.showMnemonics") == true) {

Suggestion:

        if (UIManager.getBoolean("Button.showMnemonics")) {

src/java.desktop/share/classes/javax/swing/plaf/synth/SynthLookAndFeel.java line 1083:

> 1081:      */
> 1082:     public static boolean isMnemonicHidden() {
> 1083:         if (UIManager.getBoolean("Button.showMnemonics") == true) {

Suggestion:

        if (UIManager.getBoolean("Button.showMnemonics")) {

test/jdk/com/sun/java/swing/plaf/gtk/TestMenuMnemonicOnAltPress.java line 48:

> 46:     private static JFrame frame;
> 47:     private static JMenuBar menuBar;
> 48:     private static JMenu fileMenu;

`menuBar `and `fileMenu `can be converted to local variable.

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PR Review Comment: https://git.openjdk.org/jdk/pull/18992#discussion_r1593386113
PR Review Comment: https://git.openjdk.org/jdk/pull/18992#discussion_r1593386383
PR Review Comment: https://git.openjdk.org/jdk/pull/18992#discussion_r1593388831