[Webkit-unassigned] [Bug 144934] New: View scale changes are temporarily lost after restoring a page from the page cache

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=144934

            Bug ID: 144934
           Summary: View scale changes are temporarily lost after
                    restoring a page from the page cache
    Classification: Unclassified
           Product: WebKit
           Version: 528+ (Nightly build)
          Hardware: Unspecified
                OS: Unspecified
            Status: NEW
          Severity: Normal
          Priority: P2
         Component: WebKit2
          Assignee: webkit-unassigned at lists.webkit.org
          Reporter: thorton at apple.com

Steps to Reproduce (through the code!):

1. Set a non-1 viewScale.
2. Navigate.
3. Set a different non-1 viewScale.
4. Go back.

Expected:

WebCore's pageScaleFactor should be equal to the viewScale set in #3.
The transform on the tiles should be a scale equal to the viewScale set in #3.

Actual:

WebCore's pageScaleFactor is equal to the viewScale set in #1.
The transform on the tiles is a scale equal to the viewScale set in #1.

Notes:

This is happening because the pageScaleFactor stored on HistoryItem is WebCore's pageScaleFactor, which has
the viewScale multiplied into it. When we come back from the PageCache, HistoryController does a setPageScaleFactor() with
the stored scale (with the old viewScale multiplied into it), disregarding any viewScale changes since that item went into the PageCache.

Since WebKit2 keeps pageScale and viewScale separately, doing a small pinch zoom will push the correct pageScaleFactor to WebCore and recover from this situation.

To fix this, I think we're going to have to inform WebCore of the viewScale, something I had previously been trying to avoid -- but only for the purposes of the PageCache, so hopefully it will be OK.

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.webkit.org/pipermail/webkit-unassigned/attachments/20150512/fb744844/attachment.html>