Use OfFloat Point values to create precise highlight brackets

[ShahzaibIbrahim]

Because of rounding errors the bracket selection highlight is often inconsistent. Making use of residual values provides precise rectangle values and highlight is consistent across all zooms

Problem: At 250% (the problem is also there for all zooms, at 250 its just better visible), After every three line the fourth line x axis is bit too much on the left. (rounding error)

line 29: the width of highlight is 17px

line 30: the width of highlight is 16px

How to test

• Run the runtime workspace with monitor-specific scaling turned on
• Add some brackets in Java file { }
• Select the opening bracket, the closing bracket will be highlighted.
• See if the rectangle around highlighted bracket is surrounded the bracket correctly (no-cutoffs)

Result

Before Fix:

After Fix:

Requires:

• Add Rectangle.of(Point,Point) supporting OfFloat eclipse.platform.swt#2907

[github-actions]

Test Results

 3 015 files  ±0   3 015 suites  ±0   2h 12m 1s ⏱️ - 3m 56s
 8 258 tests ±0   8 010 ✅ ±0  248 💤 ±0  0 ❌ ±0 
23 598 runs  ±0  22 807 ✅ ±0  791 💤 ±0  0 ❌ ±0 

Results for commit d0b4a1c. ± Comparison against base commit 93acda3.

♻️ This comment has been updated with latest results.

[HeikoKlare]

Is it intended that with removing the -1 from the height calculation, the highlight is now too high and exceeds the line?

Before:

[ShahzaibIbrahim]

Is it intended that with removing the -1 from the height calculation, the highlight is now too high and exceeds the line?

Before:

Yes, it is intended. We either cutoff the highlighted bracket or we go over the line.

[HeikoKlare]

So if I understand correctly, we have two issues with two solutions here:

1. The highlight is drawn over the bracket, which is solved by removing the -1.
2. The highlight is too small on higher zooms because of bad rounding, which is solved by using Rectangle.of().

If propose to make two separate PRs, one for each of the issues, out of this. While the usage of Rectangle.of() to solve the scaling issue should be without any discusionss, the -1 has been added intentionally to make the highlight fit to the line, so changing that behavior might be more of a discussion.

[ShahzaibIbrahim]

So if I understand correctly, we have two issues with two solutions here:

1. The highlight is drawn over the bracket, which is solved by removing the -1.
2. The highlight is too small on higher zooms because of bad rounding, which is solved by using Rectangle.of().

If propose to make two separate PRs, one for each of the issues, out of this. While the usage of Rectangle.of() to solve the scaling issue should be without any discusionss, the -1 has been added intentionally to make the highlight fit to the line, so changing that behavior might be more of a discussion.

This PR now keep the height as it was before. The other PR that increases the height is here: #3653