On Apr 5, 2010, at 10:30 PM, Roland Steiner wrote:
One additional question on position classes:
The current implementation allows for (and operates on) positions
such as [img, 0] - [img, 1] or [br,0] - [br, 1]. Is there a
fundamental reason to keep such positions within the internal
representation rather than normalize them to [parent-of-img, index-
of-img(+1)] - round-tripping perhaps?
Having fake positions like that is not good. I don't think there is a
good reason for it. But the assumption got deeply embedded into the
code, and it will take some doing to remove. One step in that
direction would be to phase out all use of
Position.deprecatedEditingOffset() and Position.node().
Another possible step in the right direction: make
rangeCompliantEquivalent a direct method on VisiblePosition instead of
a free function, and start phasing out use of
VisiblePositon.deepEquivalent() in favor of
VisiblePosition.rangeCompliantEquivalent(). Eventually the internal
representation can be changed.
I am not sure offhand what other code uses the "deep" form of
positions that may give positions at offset 0 or 1 from a void element.
Regards,
Maciej
Cheers,
- Roland
On Fri, Apr 2, 2010 at 2:43 PM, Roland Steiner <rolandstei...@google.com
> wrote:
Hi all,
As I am working on WebKit rich text editing these days, there are 2
issues that I would like to address. From a brief internal
discussion both seem feasible and worthwhile, but since they involve
changes to current code and behavior I wanted to ask the WebKit
community in general, and the original authors of WebKit editing in
particular, about your opinion:
.) When a selection that starts in a table and ends outside it is
deleted, the current code drags the adjacent outside content into
the table. To me this is counter-intuitive (text can be "dragged"
in, but not between cells, and not back outside), and it's also
contrary to the behavior of other editors (FireFox, TextEdit, Word,
etc.). The behavior is, however, enshrined in various layout tests,
so I wonder if there was/is a reason to implement it this way. As
this behavior also complicates fixing other bugs I wanted to see
whether there would be much opposition to changing it (i.e., to
content outside of a table staying outside on a delete operation).
.) The current Position classes are IMHO rather unfocused in their
implementation, with lots of special cases and "magical" behavior,
that still is often incorrect (e.g., with text that has padding,
margins, or :before/:after content). For ease of further development
they would therefore benefit from refactoring. The idea would be to
change the classes into something along the lines of:
DOMPosition: based on the current RangeBoundaryPoint, working on
node + offset, interfacing with JavaScript
EditingPosition (or TypeablePosition): based on the current
PositionIterator for fast iteration, with most of the code of
Position except for code that queries renderers
VisiblePosition: change to work on renderers rather than nodes
(moving such code from the current Position into this class).
with explicit, but not implicit, conversion between them. Similarly
for Ranges.
In addition, a refactoring could add (or at least allow for) non-
contiguous ranges and allow editing operations to work on arbitrary
ranges/positions rather than just the (single) selection, which
again currently is a pain point. In the long run I would envision to
extend the code to allow multiple selections (such as for concurrent
editing, or highlighting of find results, etc.), but that probably
needs to be discussed separately.
It would be great if you could share your thoughts,
Cheers,
- Roland
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