On Tue, 2 Aug 2022 10:22:48 GMT, Prasanta Sadhukhan <[email protected]> wrote:
> It is seen that using VK_F4 in JButton's setMnemonic(int i), causes the > letter 'S' in the JButton to be underlined if JButton's text has 'S' in its > string. > This is because > [**VK_F4**](https://github.com/openjdk/jdk/blob/master/src/java.desktop/share/classes/java/awt/event/KeyEvent.java#L506) > keycode is 0x73 (115 in decimal) which happens to be value of lowercase > [**'s'** ](https://www.cs.cmu.edu/~pattis/15-1XX/common/handouts/ascii.html) > so as per the logic implemented in > SwingUtilities.findDisplayedMnemonicIndex(), the first index of the character > (either lowecasr or uppercase) is returned as a mnemonic, which gets > underlined. > > Fix is made to ignore Action Keys from VK_F1->VK_F11 as displayed mnemonic > which corresponds to lowercase p->z src/java.desktop/share/classes/javax/swing/SwingUtilities.java line 2089: > 2087: return -1; > 2088: } > 2089: There are some issues with this implementation IMHO: - why invoke `KeyEvent.getKeyText(mnemonic)` eleven times? This creates eleven temporary strings. The result is always the same. - `KeyEvent.getKeyText()` may return localized strings, which would break the fix - why not simply compare `mnemonic` with ` KeyEvent.VK_F*`? Following should do the same: ~~~java if (mnemonic >= KeyEvent.VK_F1 && mnemonic <= KeyEvent.VK_F11) { return -1; } ~~~ But IMO **all lowercase ascii characters** should be excluded because there are more `VK_` keys in this range (e.g. `setMnemonic(VK_NUMPAD1)` would underline the 'a' character, but `Alt+A` does not click the button): ~~~java if (mnemonic >= 'a' && mnemonic <= 'z') { return -1; } ~~~ ------------- PR: https://git.openjdk.org/jdk/pull/9712
