X-Git-Url: https://git.lyx.org/gitweb/?a=blobdiff_plain;f=development%2FPAINTING_ANALYSIS;h=a52a036aaa882ffa316da458fbd5ff44be8aa9a7;hb=cb3922093016875404aedc6d1fcf2e088944b5c9;hp=ec3566e06cd3d3982d857a4b364026f19c337d05;hpb=8d8988de475bf2055f253823e53fd5627be5de78;p=lyx.git

diff --git a/development/PAINTING_ANALYSIS b/development/PAINTING_ANALYSIS
index ec3566e06c..a52a036aaa 100644
--- a/development/PAINTING_ANALYSIS
+++ b/development/PAINTING_ANALYSIS
@@ -20,15 +20,9 @@ following section. Some actions are proposed.
 
 ** 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
 
@@ -40,6 +34,7 @@ a good value? NoScreenUpdate?
 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
@@ -60,6 +55,36 @@ cursor.
 
 * Clean-up of drawing code
 
+** Set Row::changed() in a finer way
+
+*** singleParUpdate
+
+When the height of the current paragraph changes, there is no need for
+a full screen update. Only the rows after the current one need to have
+their position recomputed.
+
+This is also true when scrolling (how to do that?)
+
+*** redoParagraph
+
+It should be possible to check whether the new row is the same as the
+old one and keep its changed() status in this case. This would reduce
+a lot the amount of stuff to redraw.
+
+** Put labels and friends in the Row as elements
+
+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.
+
 ** When a paragraph ends with a newline, compute correctly the height of the extra row.
 ** Merging bv::updateMetrics and tm::metrics
 
@@ -103,15 +128,14 @@ DecorationUpdate). It triggers a recomputation of the metrics when either:
  + 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.