This patch defines two constants kSelectionTypeCount and kPresentSelectionTypeCount. The former is same as nsISelectionController::NUM_SELECTIONTYPES. The latter is kSelectionTypeCount - 1 for excluding SELECTION_NONE. The latter is useful in some loops which handle all selection types except SELECTION_NONE.
Note that this patch fixes a bug of nsFrameSelection. That doesn't treat SELECTION_NONE as a selection (see the definition of index), however, it defines redundant item and doesn't use it actually. Additionally, it computes invalid selection type in each loop. Therefore, without this patch, debug build hits MOZ_ASSERT() in ToSelectionType(RawSelectionType).
Note that these constants are defined as anonymous enum because we cannot define as const (or static) even with extern. If we'd try to do it, it caused link error or not available in nsFrameSelection.cpp as constant value since they were not initialized if they were initialized in nsSelection.cpp. Therefore, these constants are defined as enum items but using "k" prefix.
MozReview-Commit-ID: H6sH7NBEXlE
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
Unlike when returning an nsCOMPtr in a ternary operator or passing to a
function, I used .get() here, since the operation is actually unsafe and
deserves to be marked explicitly.
Bug 655877 Part 20 made this deliberately to let nsTextFrame
QueryFrame-able. https://hg.mozilla.org/mozilla-central/rev/d8c6025c0881
But other types like nsPlaceholderFrame or nsBulletFrame are also
implemented QureyFrame, which do not have this inheritance indirection.
I guess it was for historical reason, and can be removed safely.
MozReview-Commit-ID: CPeQvpKzEKh
