Refactor Image for Readability

[amartya4256]

This contribution refactors the Image class to improve readability. The following refactoring have been done:

1. Encapsulating Image metadata, i.e. Handle, width, height and zoom information per zoom level.
2. Abstracting ImageProviders, i.e. ImageDataProvider, ImageFileNameProvider.

contributes to #62 and #127

[github-actions]

Test Results

   382 files  ±0     382 suites  ±0   6m 44s ⏱️ - 1m 1s
 4 251 tests ±0   4 239 ✅  - 2   9 💤 ±0  1 ❌ ±0  2 🔥 +2 
12 305 runs  ±0  12 211 ✅  - 2  91 💤 ±0  1 ❌ ±0  2 🔥 +2 

For more details on these failures and errors, see this check.

Results for commit 231cd1e. ± Comparison against base commit 62ad8d9.

♻️ This comment has been updated with latest results.

[fedejeanne]

@amartya4256 I made some changes in 2 extra commits so you can review it better.

Here are my changes:

• Rename AbstractImageProvider to AbstractImageProviderWrapper

• Changed equals implemenation (made it shorter)

• Added Objects.requireNonNull to constructors in subclasses of AbstractImageProviderWrapper

• Changed return type of method createCopy(...) in subclasses

• Remove class StaticZoomUpdater (separate commit)

The part I would like you to check and validate/revert is the one about adding Objects.requireNonNull(...) to constructors since I can only assume that the providers that the subclasses hold are never null. My assumption is merely based on the fact that you didn't check for null in the equals(...) / hashCode() methods in those subclasses, but if you are not sure about this then please add null-checks to those methods and remove Objects.requireNonNull(...) from the constructors.

The ball is on your side again and therefore I marked this PR as "changes requested" ;-)

[amartya4256]

@amartya4256 I made some changes in 2 extra commits so you can review it better.

Here are my changes:

• Rename AbstractImageProvider to AbstractImageProviderWrapper
• Changed equals implemenation (made it shorter)
• Added Objects.requireNonNull to constructors in subclasses of AbstractImageProviderWrapper
• Changed return type of method createCopy(...) in subclasses
• Remove class StaticZoomUpdater (separate commit)

The part I would like you to check and validate/revert is the one about adding Objects.requireNonNull(...) to constructors since I can only assume that the providers that the subclasses hold are never null. My assumption is merely based on the fact that you didn't check for null in the equals(...) / hashCode() methods in those subclasses, but if you are not sure about this then please add null-checks to those methods and remove Objects.requireNonNull(...) from the constructors.

The ball is on your side again and therefore I marked this PR as "changes requested" ;-)

It looks good to go.

[fedejeanne]

Ignoring the usual suspects: #1676 and #1564

[fedejeanne]

These 2 tests in Test_org_eclipse_swt_graphics_Image failed with a NPE in yesterday's I-BUILD:

• test_ConstructorLorg_eclipse_swt_graphics_Device_ImageDataProvider
• test_ConstructorLorg_eclipse_swt_graphics_Device_ImageFileNameProvider

The exception is:

java.lang.NullPointerException
at java.base/java.util.Objects.requireNonNull(Objects.java:233)
at org.eclipse.swt.graphics.Image$ImageDataProviderWrapper.<init>(Image.java:2114)
at org.eclipse.swt.graphics.Image.<init>(Image.java:592)
...

I created a PR to fix them: #1688