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

[Alexander Zuev]

On Tue, 11 May 2021 10:53:06 GMT, Alexey Ivanov <aivanov at openjdk.org> wrote:

>> Alexander Zuev has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains five additional commits since the last revision:
>> 
>>  - Small fixes
>>    Added testing for MultiResolutionImage
>>  - Merge remote-tracking branch 'origin/master' into JDK-8182043
>>  - Update src/java.desktop/windows/native/libawt/windows/ShellFolder2.cpp
>>    
>>    Select one icon at a time.
>>    
>>    Co-authored-by: Alexey Ivanov <70774172+aivanov-jdk at users.noreply.github.com>
>>  - Small fixes
>>    Remived size parameter from makeIcon
>>    Removed useVGAColors usage as irrelevant since it is ignored on all
>>    supported platforms now
>>  - 8182043: Access to Windows Large Icons
>>    Fix updated based on the previous review.
>
> src/java.desktop/windows/classes/sun/awt/shell/Win32ShellFolder2.java line 1192:
> 
>> 1190:      */
>> 1191:     static Image getShell32Icon(int iconID, int size) {
>> 1192:         long hIcon = getIconResource("shell32.dll", iconID, size, size);
> 
> It's outside the scope for this code review but still, should `getIconResource` free the loaded library? With each call, the library gets loaded but it's never freed and thus it's never unloaded even if it's not needed any more.

I will create a separate bug to track this - i do not know if library loading gets cached on some level and what impact on performance will we have if we release it every call. But i will check it out separately.

> 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.

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