Need to coordinate scroll and font size preferences

[redmunds]

My new lenovo laptop is high DPI, so I have Brackets editor font-size zoomed at +2 notches larger than default, and Word Wrap is off.

Recipe:

1. Open Brackets
2. View > Increase Font Size (2 times)
3. View > Word Wrap (click to turn off)
4. Open a file with 500 lines or so and put selection at end of file
5. Shutdown and restart Brackets

Results:
Same file is re-opened, cursor position is restored, zoom setting is restored to +2, and page is scrolled down, but it's not scrolled all the way to where cursor is. Seems that the combination of zoom + font-size needs to be coordinated better.

Expected:
Cursor is scrolled into view

This was split off of #7054

[peterflynn]

@redmunds @dangoor Should this be required for Sprint 37 since it's a newly-injected regression?

[redmunds]

It does not repro in Sprint 33.

Interesting that I can see this slightly happens in Sprint 35/36 (scrolling is only off by 12 lines in a 1378 line file). I don't have Sprint 34 installed because new installer makes it more difficult :)

It's much worse in Sprint 37 (scrolling is off by 213 lines in 1344 line file).

I think it's worth a look for Sprint 37, but not critical.

[peterflynn]

Makes sense, I'm assuming it's due to the view-state prefs migration

[dangoor]

Medium priority to @RaymondLim as he likely would be quickest to spot the issue given his work on the view state migration.

@RaymondLim this is a recent regression, so if you can check this out soon that would be helpful. If you don't think you can get to it soon, I can try taking a look.

[RaymondLim]

@redmunds How do you change your Lenovo Win 7 laptop to zoom +2. I think I have the same laptop as you, but don't know what zoom level it is using.

Are you using Control panel Display setting to "Larger - 150%" or "Medium - 125%"? Mine is "Smaller - 100%".

[redmunds]

@RaymondLim This is not OS Zoom, this is Brackets font-size zoom: Ctrl-+ (2 times)

[RaymondLim]

This issue has to do with the scroll positions we saved for each document in the working set. I tried with two different files in the working set by setting cursor on the same line. Once I set cursor on the same line in the second file, then I increase font two times and then reload Brackets. Then I see the issue of incorrect scroll position in the current file. If I switch to the other file in the working set, the scroll position is off by more than the one we had increased font size in the previous session. So I see two issues with my testing. First, the scroll position that we calculate and store for each document is not quite precise (regardless of font size). Second, all inactive files in the working set do not have the correct scroll position remembered (or recalculated in the current session) if we have changed the font size in previous session.

[TomMalbran]

The first issue might be because of #3115 which is still happening.

[redmunds]

@TomMalbran Thanks for adding that link -- I wasn't aware of that issue. As I stated above, part of the problem was introduced in Sprint 34 or 35, and then got much worse since Sprint 36 was released.

[TomMalbran]

@redmunds peter just made me realize that #3115 has been fixed in CM, and the fix was merged to Brackets after sprint 36. This made the hack that I used to calculate how to adjust the scroll after a font resize work really bad.

There is also another issue with not recalculating the saved scroll positions after a font-size change, but I don't think we ever did that before. Maybe a combination of both things makes this seem to be a lot worst in master?

@RaymondLim Maybe instead of recalculating the scroll positions when changing the font size, we should save the font size with the scroll position and adjust the scroll when switching documents and or opening them.

I submitted PR #7118 to fix the scroll adjustment issue when increasing the font size.