Store nativeDeviceZoom in widgets instead of zoom for win32

[amartya4256]

Addressed issues

• HiDPI improvements in SWT with single and multiple monitor setup. #62
• Dynamically adapt SWT on 'SWT.ZoomChanged' event on single monitor. #127

Unlocks

• Implementation of GC to enable multi zoom level support for win32 #1214

Description

This contribution is to provide the nativeDeviceZoom to all the widgets so that it can be used later on for e.g. font scaling and more. Currently, the nativeDeviceZoom is only available via the shell, which is not sufficient later when there is no shell available, e.g. GC.

In this following PR #1214 , we had discussed that instead of storing zoom for widgets, we should store nativeDeviceZoom, to make it more accessible where shell is not present. Because in some cases, there was no nativeDeviceZoom present because of the previous implementation and we discussed if a fallback might be necessary. This implementation makes sure that in those scenarios, nativeDeviceZoom would always be available for further usage.

The consumers can now have deviceZoom wherever necessary by using the utility method to translate nativeDeviceZoom to deviceZoom, which is available in DPIUtil.

[HeikoKlare]

In general, the changes look sound and storing the native zoom for which the actually used value can always be calculated on demand absolutely makes sense.

Currently, there are several naming and consistency issues, as identifiers have not been renamed, Javadoc has not been adapted etc.
Please have a look that all the identifiers (variable, field, method names) still properly capture their meaning.

[github-actions]

Test Results

   418 files  ±0     418 suites  ±0   7m 8s ⏱️ -19s
 4 121 tests ±0   4 113 ✅ ±0   8 💤 ±0  0 ❌ ±0 
16 313 runs  ±0  16 221 ✅ ±0  92 💤 ±0  0 ❌ ±0 

Results for commit 600418a. ± Comparison against base commit d3df796.

♻️ This comment has been updated with latest results.

[fedejeanne]

Changes look good, I only have one question and one minor remark for the method Image::setCurrentNativeZoom

Also, just for my understanding (recap of "the big picture"), this PR "merely":

• Replaces the previously cached device zoom in Image (currentDeviceZoom) by a calculated zoom (Image::getZoom() --> DPIUtil::getZoomForAutoscaleProperty(...))
• Propagates the native device zoom instead of the (current) device zoom in GC
• Adapts Image::handleDPIChange(int) to use the newly propagated native device zoom

Did I miss anything?

[HeikoKlare]

Thanks for updating the PR. I only have minor comments left.

Note that my review is currently based on GitHub UI, as I don't have a Windows laptop available. So I will not "formally" approve the PR as I would like to validate the changes in Eclipse for that.

[fedejeanne]

Thank you for addressing my previous comment @amartya4256 , I just have one final change request to improve readability. After that, this PR is good to go from my side.

[HeikoKlare]

In general, this PR looks good and sound to me. I only have some nitpicky comments regarding naming and one regarding visibilities.

Edit: and of course please address the remaining comments by @fedejeanne

[HeikoKlare]

@amartya4256 I don't see my previous comment (#1229 (comment)) addressed yet. Could you please check before I re-review the PR?

[HeikoKlare]

To me, this looks good now. Thank you!

[amartya4256]

Thank you for addressing my previous comment @amartya4256 , I just have one final change request to improve readability. After that, this PR is good to go from my side.

@fedejeanne can you approve the changes? :)