Bug 190570 – Changing view scale should zoom to initial scale if the page is already at initial scale

• Status: RESOLVED
• Resolution: FIXED
• Component: WebKit Misc.

[Wenson Hsieh]

Changing zoom levels should zoom to initial scale if the page is already at initial scale

[Radar WebKit Bug Importer]

<rdar://problem/45261877>

[Wenson Hsieh]

Created attachment 352320 [details]
Patch

[Wenson Hsieh]

Created attachment 352325 [details]
Add a layout test description

[Tim Horton]

Comment on attachment 352325 [details]
Add a layout test description

View in context: https://bugs.webkit.org/attachment.cgi?id=352325&action=review

> Source/WebKit/WebProcess/WebPage/ios/WebPageIOS.mm:2526
> +    if (m_viewportConfiguration.layoutSizeScaleFactor() != scaleFactor && std::abs(m_viewportConfiguration.initialScale() - pageScaleFactor()) <= 0.025)

I think you might want areEssentiallyEqual for float compare. At least, Ben used it in a few places because we do so much math with these scales that they’d end up “equal” but only in that sense, and things would break. Don’t know if it’s a concern in this path.

[Wenson Hsieh]

Comment on attachment 352325 [details]
Add a layout test description

View in context: https://bugs.webkit.org/attachment.cgi?id=352325&action=review

>> Source/WebKit/WebProcess/WebPage/ios/WebPageIOS.mm:2526
>> +    if (m_viewportConfiguration.layoutSizeScaleFactor() != scaleFactor && std::abs(m_viewportConfiguration.initialScale() - pageScaleFactor()) <= 0.025)
> 
> I think you might want areEssentiallyEqual for float compare. At least, Ben used it in a few places because we do so much math with these scales that they’d end up “equal” but only in that sense, and things would break. Don’t know if it’s a concern in this path.

I originally added this fudge factor so that if a user manually pinched to something close to initial scale, we'd still zoom to the new initial scale upon zoom level change.

On second thought, I don't think this behavior is all that valuable — I changed this to just use areEssentiallyEqualAsFloat(), like all of the other page scale checks in this file.

[Wenson Hsieh]

Created attachment 352335 [details]
Patch for landing

[WebKit Commit Bot]

Comment on attachment 352335 [details]
Patch for landing

Clearing flags on attachment: 352335

Committed r237127: <https://trac.webkit.org/changeset/237127>