Cursor not behaving correctly in memory view editor while chaging variable value on Hi-DPI

[mshahzadiftikhar]

Description
Changing value of a hex digit in a cell in Memory View is not working correctly on higher resolution displays.

Problem
GC.getAdvanceWidth(...) method is being used to calculate character width which doesn't take zooming in consideration as it gets width using native OS method

public int getAdvanceWidth(char ch) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	checkGC(FONT);
	int[] width = new int[1];
	OS.GetCharWidth(handle, ch, ch, width);
	return width[0];
}

Resolution
Used GC.textExtent() method which automatically handles zooming using DPIUtil.autoScaleDown(..) API

public Point textExtent (String string) {
	return DPIUtil.autoScaleDown(drawable, textExtentInPixels(string, SWT.DRAW_DELIMITER | SWT.DRAW_TAB));
}

Fixes #641

[mshahzadiftikhar]

@jonahgraham kindly review this PR once you get some time. Thanks.

[jonahgraham]

Thanks @mshahzadiftikhar this change looks good. It was really helpful that you included screen recordings to make it very easy to understand the problem and resolution.

Waiting for the CI to complete to make sure no version bumps or similar are needed and then we can proceed with the merge.

[jonahgraham]

The build failed because it needs bumps on the modified bundles:

The following bundles are missing a service segment version bump:
  - org.eclipse.cdt.debug.ui.memory.floatingpoint
  - org.eclipse.cdt.debug.ui.memory.traditional
Please bump service segment by [10](https://github.com/eclipse-cdt/cdt/actions/runs/7286790709/job/19991019490?pr=645#step:9:11)0 if on main branch
The log of this build is above
See: https://wiki.eclipse.org/Version_Numbering#When_to_change_the_service_segment

I'll submit that change this time in a moment.

[jonahgraham]

The other thing I did was reformat the commit message to meet standard git commit messaging formatting (short summary on line 1, blank line 2)

[mshahzadiftikhar]

Thanks @jonahgraham for reviewing this PR. CI is now failing for code cleanliness related checks: https://github.com/eclipse-cdt/cdt/pull/645/checks?check_run_id=19991696258

[jonahgraham]

Test testSetInvalidCreatingDescription (org.eclipse.cdt.core.settings.model.CProjectDescriptionBasicTests) failed, but it is unrelated and a somewhat flaky test.

[jonahgraham]

Thanks @mshahzadiftikhar for the fix. I really appreciate the detailed description and resolution.