Use "\uFEFF" instead of "." in WebInspector.ViewportControl's gap elements.

Use "\uFEFF" instead of "." in WebInspector.ViewportControl's gap elements.

When the gap elements have height:0px, the "." text contributes to the
container's height, which produces strange effects during scrolling.

BUG=579444
Committed: https://crrev.com/2708759cc0028611c97f12a2adeb424c0747f6c4
Cr-Commit-Position: refs/heads/master@{#370878}

[skobes, 2016-01-21 23:52:35]

Patchset #1 (id:1) has been deleted

[skobes, 2016-01-21 23:54:12]

Description was changed from

==========
Don't set text content of gap elements in WebInspector.ViewportControl.

When the gap elements have height:0px, the text contributes to the
container's height, which is not intended and produces strange effects during
scrolling.  It's also unclear why these elements need text in the first place.

BUG=579444
==========

to

==========
Use "\uFEFF" instead of "." in WebInspector.ViewportControl's gap elements.

When the gap elements have height:0px, the "." text contributes to the
container's height, which produces strange effects during scrolling.

BUG=579444
==========

[skobes, 2016-01-22 00:56:31]

skobes@chromium.org changed reviewers:
+ lushnikov@chromium.org

[pfeldman, 2016-01-22 01:37:33]

pfeldman@chromium.org changed reviewers:
+ pfeldman@chromium.org

[pfeldman, 2016-01-22 01:37:34]

https://codereview.chromium.org/1613703004/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/devtools/front_end/ui/ViewportControl.js (left):

https://codereview.chromium.org/1613703004/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/ui/ViewportControl.js:40:
this._topGapElement.textContent = ".";
lushnikov@ says that "." was here to render selection that spans beyond the
viewport prettier. and it seems it is no longer needed - either new selection
rendering helped or other things changed over time.

https://codereview.chromium.org/1613703004/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/ui/ViewportControl.js:41:
this._topGapElement.style.height = "0px";
how come it contributes to the height? - it has zero height.

[skobes, 2016-01-22 01:51:53]

https://codereview.chromium.org/1613703004/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/devtools/front_end/ui/ViewportControl.js (left):

https://codereview.chromium.org/1613703004/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/ui/ViewportControl.js:40:
this._topGapElement.textContent = ".";
On 2016/01/22 01:37:34, pfeldman wrote:
> lushnikov@ says that "." was here to render selection that spans beyond the
> viewport prettier. and it seems it is no longer needed - either new selection
> rendering helped or other things changed over time.

I first tried eliminating the text content but
inspector/console/console-viewport-selection.html failed.  I think the
range.intersectsNode calls in _updateSelectionModel depend on having non-empty
text content.

https://codereview.chromium.org/1613703004/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/ui/ViewportControl.js:41:
this._topGapElement.style.height = "0px";
On 2016/01/22 01:37:34, pfeldman wrote:
> how come it contributes to the height? - it has zero height.

The text content produces overflow which contributes to the container's height. 
Example: https://jsbin.com/zisowo/edit?html,output

[pfeldman, 2016-01-22 01:59:14]

> The text content produces overflow which contributes to the container's
height. 
> Example: https://jsbin.com/zisowo/edit?html,output

Is this scroll-specific behavior? Because it does not contribute to the
container's height in this simple case:

<div>
  <div style="height: 0;">A</div>
  <div style="height: 0;">B</div>
</div>

[skobes, 2016-01-22 02:06:33]

On 2016/01/22 01:59:14, pfeldman wrote:
> > The text content produces overflow which contributes to the container's
> height. 
> > Example: https://jsbin.com/zisowo/edit?html,output
> 
> Is this scroll-specific behavior? Because it does not contribute to the
> container's height in this simple case:
> 
> <div>
>   <div style="height: 0;">A</div>
>   <div style="height: 0;">B</div>
> </div>

There are multiple notions of height in layout.  It won't contribute to
element.offsetHeight, but it contributes to the height of the "layout overflow"
returned by LayoutBox::layoutOverflowRect().

[pfeldman, 2016-01-22 02:08:07]

lgtm

Thanks for following up and explanations.

[skobes, 2016-01-22 02:10:02]

The CQ bit was checked by skobes@chromium.org

[commit-bot: I haz the power, 2016-01-22 02:11:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1613703004/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1613703004/20001

[commit-bot: I haz the power, 2016-01-22 02:17:01]

Description was changed from

==========
Use "\uFEFF" instead of "." in WebInspector.ViewportControl's gap elements.

When the gap elements have height:0px, the "." text contributes to the
container's height, which produces strange effects during scrolling.

BUG=579444
==========

to

==========
Use "\uFEFF" instead of "." in WebInspector.ViewportControl's gap elements.

When the gap elements have height:0px, the "." text contributes to the
container's height, which produces strange effects during scrolling.

BUG=579444
==========

[commit-bot: I haz the power, 2016-01-22 02:17:02]

Committed patchset #1 (id:20001)

[commit-bot: I haz the power, 2016-01-22 02:19:10]

Description was changed from

==========
Use "\uFEFF" instead of "." in WebInspector.ViewportControl's gap elements.

When the gap elements have height:0px, the "." text contributes to the
container's height, which produces strange effects during scrolling.

BUG=579444
==========

to

==========
Use "\uFEFF" instead of "." in WebInspector.ViewportControl's gap elements.

When the gap elements have height:0px, the "." text contributes to the
container's height, which produces strange effects during scrolling.

BUG=579444

Committed: https://crrev.com/2708759cc0028611c97f12a2adeb424c0747f6c4
Cr-Commit-Position: refs/heads/master@{#370878}
==========

[commit-bot: I haz the power, 2016-01-22 02:19:11]

Patchset 1 (id:??) landed as
https://crrev.com/2708759cc0028611c97f12a2adeb424c0747f6c4
Cr-Commit-Position: refs/heads/master@{#370878}