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
ContentEventHandler will need to support query any types of selection. Therefore, it cannot use nsCopySupport::GetSelectionForCopy(). Instead, a part of it should be implemented by nsIPresShell::GetSelectionControllerForFocusedContent() and it should be shared by nsCopySupport::GetSelectionForCopy() and ContentEventHandler.
MozReview-Commit-ID: 1ItkkIUPFMG
This patch defines mozilla::SelectionType as an enum class. This is safer than nsISelectionController::SELECTION_* since setting illegal value to its variable is checked at build time. So, as far as possible, this should be used everywhere (but of course, this isn't available in scriptable interfaces).
And also this implements some useful methods for managing SelectionType and RawSelectionType which are implemented in layout/nsSelection.cpp because nsISelectionController is implemented by both PresShell and nsTextEditorState. Therefore, implementing one of them may make hard to find them. On the other hand, nsSelection.cpp is a better file name to look for them.
Note that this patch creates mozilla::Selection::RawType() for binding. Native code should keep using Selection::Type() but the binding code needs to use RawType() due to impossible to convert from SelectionType to RawSelectionType without explicit cast.
MozReview-Commit-ID: 81vX7A0hHQN
mozilla::SelectionType will be an enum class. Therefore, we need to rename SelectionType with a word "raw" since it's a type for raw nsISelectionController::SELECTION_*.
MozReview-Commit-ID: K8SO0bbpv0Y
The function doesn't need to be a non-static member of nsIPresShell: it only checks if the document of the passed in element matches the presshell's document, and then the remaining code could be static. It has only one user, nsDocumentViewer::FindContainerView, and it doesn't care about the specific presshell, it just wants the primary frame, so it doesn't need the document check.
This lets us simplify nsDocumentViewer::FindContainerView because it had to jump through hoops to get the presshell.
The function doesn't need to be a non-static member of nsIPresShell: it only checks if the document of the passed in element matches the presshell's document, and then the remaining code could be static. It has only one user, nsDocumentViewer::FindContainerView, and it doesn't care about the specific presshell, it just wants the primary frame, so it doesn't need the document check.
This lets us simplify nsDocumentViewer::FindContainerView because it had to jump through hoops to get the presshell.
