nsISelectionController::SELECTION_* are declared as bit-mask. However, no
methods of nsISelectionController treat them as bit-mask and these
values need a switch statement in nsFrameSelection to convert SelectionType to
array index of nsFrameSelection::mDOMSelections because it's too big to create
an array to do it. Additionally, this conversion appears profile of
attachment 8848015.
So, now, we should declare these values as sequential integer values.
However, only nsTextFrame uses these values as bit-mask. Therefore, this patch
adds new type, SelectionTypeMask and creates new inline method,
ToSelectionTypeMask(SelectionType), to retrieve mask value for a SelectionType.
MozReview-Commit-ID: 5Za8mA6iu4
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
