Abbreviations:
bv: BufferView
pm: ParagraphMetrics
-tm::TextMetrics
+tm: TextMetrics
* Questions / Ideas
** SinglePar update
-The flag Update::SinglePar is set in many places but never acted on.
-Instead, metrics update is skipped whenever the recorded height of
-current paragraph did not change and Update::Force was not specified.
-Is it better to keep that (which incurs extra work) or to condition it
-on Update::SinglePar? If the first solution is kept, the flag
-SingleParUpdate shall be removed.
-
-Moreover, I fail to see (yet) where the 'single' part of the program
-is acted on.
+This flag only has an effect in the current BufferView, but I think it
+is useful in other views too. Doing this will require some work on the
+update pipeline, though.
** Buffer::change issues
On a related note, what is the semantics of a call to
Buffer::changed(false)? What does the caller mean?
+
** How to avoid redraw with FitCursor when the cursor is already OK?
In this case, we invoke Buffer::change(false) with drawing disabled
* Clean-up of drawing code
-** Make SinglePar update flag useful again.
-
-The current code can be very expensive when moving cursor inside a
-huge table, for example. We should test the flag again, although this
-will probably lead to some glitches here and there.
-
** Set Row::changed() in a finer way
*** singleParUpdate
It should not be necessary to access the Paragraph object to draw.
Adding the static elements to Row is a lot of work, but worth it IMO.
-** Create a unique row by paragraph and break it afterwards
-
-This should be a performance gain (only if paragraph breaking still
-shows as expensive after the rest is done)
-
** do not add the vertical margin of main text to first/last row
Would make code cleaner. Probably no so difficult.
+ Update::Force has been specified
+ Update::FitCursor has been specified and there is a need to scroll
the display.
- + the current paragraph, after rebreak, does not have the same height as in
- existing metrics. Note that the Update::SinglePar flag is *never*
- taken into account.
+ + Update::SinglePar has been specified and the current paragraph has
+ not changed height.
If a computation of metrics has taken place, Force is removed from the
flags and ForceDraw is added instead.
-It is OK to call processUptateFlags several times before an update. In
-this case, the effects are cumulative.processUpdateFlags execute the
+It is OK to call processUpateFlags several times before an update. In
+this case, the effects are cumulative. processUpdateFlags executes the
metrics-related actions, but defers the actual drawing to the next
paint event.