RFR: 8322135: javax/swing/JTable/JTableScrollPrintTest.java & javax/swing/JTable/PrintAllPagesTest.java throws java.lang.InternalError: HTHEME is null [v4]

[Alexey Ivanov]

On Tue, 23 Apr 2024 10:19:40 GMT, Tejesh R <tr at openjdk.org> wrote:

>> Getting a theme for particular dpi failed in windows L&F during print test. Before [JDK-8294427](https://bugs.openjdk.org/browse/JDK-8294427) fix, theme was independent of DPI. After the fix (https://github.com/openjdk/jdk/commit/a63afa4aa62863d1a199a0fb7d2f56ff8fcd04fd) getting a theme in Windows L&F became dependent on DPI. Now it works fine in paint to a frame or window but for printing the DPI is computed with scaling factor which might not be w.r.t set of connected monitors and hence error is returned according to [this from windows document](https://learn.microsoft.com/en-us/windows/win32/api/uxtheme/nf-uxtheme-openthemedatafordpi). 
>> The suggested fix is to handle printer cases with default dpi since in error condition 0 is returned with `openThemeImpl(widget, dpi)`. The fix seems to be working fine without causing any regression (Tested in CI systems and also the affected tests).
>
> Tejesh R has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Review updates

Looks good to me now.

You should add `8322135` to the list of bugs in the tests which failed because of this bug.

Update the copyright year in modified files.

src/java.desktop/windows/classes/sun/awt/windows/ThemeReader.java line 110:

> 108:            // See documentation for SetWindowTheme on MSDN.
> 109:            setWindowTheme(widget.substring(0, i));
> 110:            theme = getOpenThemeValue(widget.substring(i + 2), dpi);

I suggest changing the type of `theme` variable from `Long` to `long` as well as the return value of `openThemeImpl`.

src/java.desktop/windows/classes/sun/awt/windows/ThemeReader.java line 125:

> 123:         }
> 124:         return theme;
> 125:     }

Suggestion:

    private static long getOpenThemeValue(String widget, int dpi) {
        long theme = openTheme(widget, dpi);
        if (theme == 0) {
            theme = openTheme(widget, defaultDPI);
        }
        return theme;
    }

Yes, that's what I meant. Let's use the primitive `long`.

-------------

Changes requested by aivanov (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/18706#pullrequestreview-2016847876
PR Review Comment: https://git.openjdk.org/jdk/pull/18706#discussion_r1576019642
PR Review Comment: https://git.openjdk.org/jdk/pull/18706#discussion_r1576017834