The mobile session store saves the current document resolution in order to restore the previous zoom level when restoring a page. If the display width has changed since the session data was captured (e.g. because the device was rotated), the resolution might have to be scaled appropriately.
Currently, the session store does this scaling by itself by comparing the stored and current window widths, however this implementation is slightly simplified and doesn't cover all use cases, which means some pages can be restored at a wrong zoom level after rotation. To correctly cover all cases, the session store would have to compare viewport widths, too.
Because the MobileViewportManager doesn't wait for the session store to set the restore resolution, the latter has to call setRestoreResolution() as early as possible in order to guarantee that the restore resolution is set before the first paint of the document. Therefore the session store currently calls this after receiving a LocationChange notification. However at that time, the correct viewport for the current document is not yet available, which means the resolution cannot be recalculated by the session store at that point.
Therefore, this patch changes the approach taken and lets the MVM handle all resolution calculations instead. The session store now simply passes the stored previous display dimensions along with the previous document resolution to the MVM, which can then compare them to the current display and viewport widths and scale the resolution appropriately before using it during first paint.
MozReview-Commit-ID: IGxWw87yftK
The intention is for the session store to record the current window size and then pass it to the MobileViewportManager for restoring, so the latter can correctly scale the stored resolution if the display width has since changed. However currently all window dimensions available from the JS side are measured in CSS pixels rounded to integers. Transforming those values back into display pixels by multiplying them with "window.devicePixelRatio" (or accessing window.gScreenWidth/Height, which does the same thing internally) unfortunately introduces some rounding errors.
Therefore this patch introduces a new helper method in DOMWindowUtils which allows to access the content window width as measured in device pixels from the JS side, too.
MozReview-Commit-ID: FGNQlXhkgrU
The refresh driver may not be triggered regularly if the page is static.
In that case, we need to ensure a flush is scheduled for fullscreen
change, otherwise the page may get stuck.
MozReview-Commit-ID: c5FhqaIUQW
To test eQueryCharRectArray, I would like to add it to nsIDOMWindowUtils. Also this require unit test and will require external keyboard support on Android
Masayiki asks me more review to smaug this due IDL change.
MozReview-Commit-ID: 24lvQxXBnRX
Native IME handler may want to query content relative to start of selection (or composition if there is it). Additionally, in e10s mode, insertion point in actual content may be different from the cache in parent. Therefore, in some cases, it does make sense to query content with offset relative to start of selection or composition.
This patch implements it simply and only in non-e10s mode.
Additionally, this fixes a bug of nsQueryContentEventResult::GetOffset() which hasn't been accepted its calls even if the event message is valid (eQueryTextContent, eQueryTextRect and eQueryCaretRect).
MozReview-Commit-ID: 34I7vyTUAgO
This is useful for writing tests that test particular optimizations,
such as that a particular operation doesn't cause restyles. It sits
next to similar counters for frames constructed and frames reflowed.
I also snuck in a preference for the less-expensive mPresContext over
the more expensive mFrame->PresContext() (which dereferences multiple
pointers).
(Originally written for work I planned to be part of bug 1189598.)
MozReview-Commit-ID: 8PN7nwLJG9r
