X-Git-Url: https://git.lyx.org/gitweb/?a=blobdiff_plain;f=development%2FPAINTING_ANALYSIS;h=3ddfc7435227e26c4e16531cb455b5343507a68d;hb=c7c9744368cfabfaf29a6071954eb6c1500e6d55;hp=d1da54baa2c55baf0a91b96b708bf63e438c7457;hpb=26eb5092fb69464d181caaf212d6a4d9c9cff2f0;p=lyx.git

diff --git a/development/PAINTING_ANALYSIS b/development/PAINTING_ANALYSIS
index d1da54baa2..3ddfc74352 100644
--- a/development/PAINTING_ANALYSIS
+++ b/development/PAINTING_ANALYSIS
@@ -58,15 +58,58 @@ The global idea would be to extend FitCursor to cover also horizontal
 cursor.
 
 
-* Proposals
+* Clean-up of drawing code
 
-** set inset position during metrics phase
+The goal is to make painting with drawing disable fast enough that it
+can be used after every metrics computation. Then we can separate real
+drawing from metrics.
 
-This implies to set inset positions relative to outer inset during
-metrics phase and then in a second loop to descend into insets and
-update positions correctly.
+Other changes are only clean-ups.
 
-Effect: avoid going through the painter machinery when it is not necessary.
+** When a paragraph ends with a newline, compute correctly the height of the extra row.
+** Rewrite TextMetrics::editXY, checkInsetHit using row information (getPosNearX)?
+
+   The helper version should return a Row::Element instead of an InsetTable.
+
+** Remember rtl status in the row object
+
+This will avoid to pass a Paragraph object to methods that do not need it.
+
+** Rewrite RowPainter::paintSelection using row information
+
+Currently it uses some very complicated code. It should be possible to
+reuse the logic of paintStringAndSel.
+
+** Set inset position during metrics phase
+
+In order to do that, a no-paint drawing will be initiated after every
+redoParagraph. This code path will need to be made as fast as possible.
+
+Effect: avoid depending on actual drawing having taken place. In turn,
+it will allow to do drawing on paint events, like any reasonable
+application would do.
+
+** Cleanup after complete metrics
+   Then the following can be done:
+   + remove hack in InsetMathNest::drawSelection
+   + remove painting when not inside in drawParagraph
+   + remove Cursor::inCoordCache?
+
+** Use Row for MathData
+
+It may not be so difficult. Implement x2pos and pos2x from
+the TM:cursorX and TM::getPosNearX, and use them for both text and
+math.
+
+Will the strings display OK if drawing string-wise?
+
+Then it would be possible to streamline drawing with disabled painter.
+
+** Paint directly to screen
+
+Instead of using an intermediary pixmap. I have no idea of how
+difficult it will prove.
+One benefit will be that subpixel aliasing will work again (#9972)
 
 ** Merging bv::updateMetrics and tm::metrics
 
@@ -75,16 +118,10 @@ paragraphs that are rebroken, the version that is used for inner inset
 does not try any such optimization. This can be very bad for very tall
 insets. We should re-use the bv::updateMetrics logic:
  + transfer all the logic of bv::updateMetrics to tm.
- +  Main InsetText should not be special.
-
-** Metrics outside of visible area
+ + Main InsetText should not be special.
 
-Currently metrics are computed for current visible paet of text, the
-page above and the page below. It should be possible to compute hidden
-rows ony on demand, although it might be a bit slow.
-
-There was a proposal to always compute _all_ rows, but this may become
-expensive for large files. This would though help scrolling.
+The difficuly for a tall table cell for example, is that it may be
+necessary to break the whole contents to know the width of the cell.
 
 
 * Description of current drawing mechanism
@@ -127,12 +164,8 @@ update flag is Update::None.
 ** Metrics computation
 
 This is triggered by bv::updateMetrics, which calls tm::redoParagraph for
-  + all visible paragraphs
-  + paragraph above the screen (up to one page)
-  + paragraphs below the screen (up to one page again)
-
-The paragraphs outside of the screen are required to make PageUp/Down
-work.
+all visible paragraphs. Paragraphs above or below the screen (needed
+for page up/down) and computed as needed.
 
 tm::redoParagraph will call Inset::metrics for each inset. In the case
 of text insets, this will invoke recursively tm::metrics, which redoes