<Swing Dev> RFR: 8182043: Access to Windows Large Icons [v4]

[Alexey Ivanov]

On Tue, 11 May 2021 18:48:31 GMT, Alexander Zuev <kizune at openjdk.org> wrote:

>> src/java.desktop/windows/classes/sun/awt/shell/Win32ShellFolder2.java line 1196:
>> 
>>> 1194:             Image icon = makeIcon(hIcon);
>>> 1195:             disposeIcon(hIcon);
>>> 1196:             return icon;
>> 
>> Shall it not be wrapped into multi-resolution image if the `size` is different from the actual size of the icon?
>> Previously, it was inside `makeIcon`.
>
> Wherever it is necessary down the line we are wrapping the result in multi-resolution and if we wrap it here too we will have multi-resolution icon that contains multi-resolution images as a resolution variant. Unfortunately AWT can't handle painting of such abomination.

No, it isn't wrapped: if `getShell32Icon` is called in `getIcon(final boolean getLargeIcon)`, the returned value is immediately returned to the caller, see lines 1157–1163 in the updated code:

                        if (hIcon <= 0) {
                            if (isDirectory()) {
                                return getShell32Icon(FOLDER_ICON_ID, size);
                            } else {
                                return getShell32Icon(FILE_ICON_ID, size);
                            }
                        }

It's not wrapped into multi-resolution icon when called from `Win32ShellFolder2.get()` for keys `shell32Icon *` and `shell32LargeIcon *` (lines 411/413–414).

Neither is the returned value of `Win32ShellFolder2.getSystemIcon` wrapped; it's also called from `Win32ShellFolder2.get()` when getting icons for `optionPaneIcon *` (lines 405/407). These icons are supposed to be large 32×32 icons, thus if the size of the icon in `getSystemIcon(SystemIcon iconType)` differs from 32, it should be wrapped. Otherwise, it could cause regression for [JDK-8151385](https://bugs.openjdk.java.net/browse/JDK-8151385): _[hidpi] JOptionPane-Icons only partially visible when using Windows 10 L&F_.

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PR: https://git.openjdk.java.net/jdk/pull/2875