This adds helper functions to get specific types of content editors (if
possible) through the nsIEditor interface, as opposed to doing manual
casting and the ad hoc `GetHTMLEditor()` function.
Helper functions are spread out over multiple headers due to the
circular dependency issues that would be triggered otherwise.
This interface inly has a single implementation behind it, which is also
only used in 2 places after the previous commit. That's a lot of
additional complexity and compiler indirection for no good reason.
This change removes the interface and uses direct nsDocShell::Cast calls
instead of going through the interface in the few places left now that
we no longer build on a presentation context for links.
This removes the requirement for there to be a non-null PresShell to
dispatch `Click()` events on `<A>` elements (only), since the exception
to the rule has propagated to the spec.
With these changes it should now be possible do create an anchor and
`Click()` on it from JS without actually first attaching it to the DOM
of the presented document, as abused by scripted downloads in pages
(instead of using the A attribute to custom-name downloads).
This will prevent the keypress DOM event from firing on keypresses
that do not produce printable keys (e.g. editing nav keys) in content.
This should not affect any chrome events that are in use.
Event dispatch can be re-enabled if necessary with the added pref.
This is based on Bug 1395828
* Add nsHTMLElement::IsBlock()
* Rename nsHTMLTags methods
* Remove AssertParserServiceIsCorrect()
* Remove most uses of nsIParserService/nsParserService
IsSelectionEditable should check whether the focus node and anchor node
aren't null before trying to use them.
This also changes the initialization of selections' aOutIndex to the
last range in the selection as a fallback in case we don't add a range
later (in AddItem) which could also end up with a null selection
otherwise if the additional selection nodes are removed.