WebView: mouse drag does not stop when within webview region

[kieferrm]

Issue Type: Bug

1. Open Release Notes in product
2. Try to increase sidebar size

-> Doesn't work, webview seems to eat up mousemove event, since it's still possible to decrease the sidebar size.

VS Code version: Code - Insiders 1.36.0-insider (c089daa, 2019-06-07T06:13:41.194Z)
OS version: Darwin x64 18.6.0
Remote OS version: Linux x64 4.18.0-1014-azure

[kieferrm]

This happens for all sashes. For example, also between two window groups.

[bpasero]

@kieferrm I cannot reproduce, what is special? Tried both with external mouse and touchpad.

[IllusionMH]

Looks like this problem is reproducible if I try to drag edge between editor/panel and webview.
I have no problem with resizing Explorer/SCM etc. if only editors are opened, however when I have Markdown preview, Response preview (REST Client extension), or PR Description (from GitHub Pull request extension).

TL;DR; looks like mouse events (mousemove, mouseup etc.) are lost when cursor is over webview that breaks resizing.

I can freely widen webview (mouse movement will be over editor/panel), but it is really hard to narrow webview (when during resize mouse will be over webview).
I've toggled Screencast mode and circle (that should be around mouse when I press button) stays on the same position on the edge when I move cursor over webview.
Moreover - circle stays visible even when I release mouse button, so when cursor is over editor/panel again (with released button) resizing continues and webview becomes wider.

---

VS Code version: Code - Insiders 1.36.0-insider (f291714, 2019-06-12T05:19:53.054Z)
OS version: Windows_NT x64 10.0.17763

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-8700 CPU @ 3.20GHz (12 x 3192)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on native_gpu_memory_buffers: disabled_software oop_rasterization: disabled_off protected_video_decode: enabled rasterization: enabled skia_deferred_display_list: disabled_off skia_renderer: disabled_off surface_synchronization: enabled_on video_decode: enabled viz_display_compositor: disabled_off webgl: enabled webgl2: enabled
Load (avg)	undefined
Memory (System)	31.72GB (15.43GB free)
Process Argv
Screen Reader	no
VM	0%

Extensions: none

[joaomoreno]

@bpasero: @IllusionMH is correct. I just came here to file this issue. Simply open the Release Notes in the product, and you won't be able to increase the sidebar size. It seems the webview is eating up the mouse events.

I'll update the original issue steps.

[clarkio]

This seems to happen for what I believe are web views. Open the release notes, Markdown Preview, Browser Preview, Github Pull Request description view, etc. in an editor and attempt to resize anything around it (side bar, Terminal, other editors in split view).

Here are some recordings for more context:

• https://clips.twitch.tv/PerfectTalentedMilkSwiftRage
• https://clips.twitch.tv/OriginalExuberantSaladTheTarFu

Version: 1.36.0-insider (user setup)
Electron: 4.2.4
Chrome: 69.0.3497.128
OS: Windows_NT x64 10.0.17763

[deepak1556]

https://gist.github.com/deepak1556/899491631e1c7e5e81c4252b6ff91163 is a simple repro without involving vscode. Dragging outside webview element shouldn't cause issues while dragging over it eats the events.

[zcbenz]

@deepak1556 I confirm this is a bug of Chrome, you can reproduce by loading this chrome app in Chrome browser:
https://gist.github.com/zcbenz/67f83babcdee37d7c3ee345bab775737

[deepak1556]

Thanks @zcbenz , I did a git bisect on chromium using https://www.chromium.org/developers/bisect-builds-py and found the commit that regressed this behavior https://chromium-review.googlesource.com/c/chromium/src/+/1099183/ . I am gonna report it upstream to get the right fix moving forward. But as temporary can we disable mouse capture on <webview> RenderWidgetHost to workaround this issue ?

[deepak1556]

Reported in https://bugs.chromium.org/p/chromium/issues/detail?id=978162