Enable Update::SinglePar in nested insets too

The idea of single par update is to try to re-break only the paragraph
containing the cursor (if this paragraph contains insets etc.,
re-breaking will recursively descend).

The existing single paragraph update mechanism was tailored to work
only at top level. Indeed changing a paragraph nested into an inset may
lead to larger changes.

This commit tries a rather naive approach that seems to work well: we
need a full redraw if either

1/ the height has changed
or
2/ the width has changed and it was equal to the text metrics width;
   the goal is to catch the case of a one-row inset that grows with
   its contents, but optimize the case of typing in a short paragraph
   part of a larger inset.

NOTE: if only the height has changed, then it should be
  possible to update all metrics at minimal cost. However,
  since this is risky, we do not try that right now.

Part of bug #12297.
This commit is contained in:
Jean-Marc Lasgouttes 2023-07-17 14:43:29 +02:00
parent f5bbadbad9
commit 9a96726bcd

View File

@ -3063,24 +3063,36 @@ Cursor const & BufferView::cursor() const
bool BufferView::singleParUpdate()
{
Text & buftext = buffer_.text();
pit_type const bottom_pit = d->cursor_.bottom().pit();
TextMetrics & tm = textMetrics(&buftext);
Dimension const old_dim = tm.parMetrics(bottom_pit).dim();
CursorSlice const & its = d->cursor_.innerTextSlice();
pit_type const pit = its.pit();
TextMetrics & tm = textMetrics(its.text());
Dimension const old_dim = tm.parMetrics(pit).dim();
// make sure inline completion pointer is ok
if (d->inlineCompletionPos_.fixIfBroken())
d->inlineCompletionPos_ = DocIterator();
// In Single Paragraph mode, rebreak only
// the (main text, not inset!) paragraph containing the cursor.
// (if this paragraph contains insets etc., rebreaking will
// recursively descend)
tm.redoParagraph(bottom_pit);
ParagraphMetrics & pm = tm.parMetrics(bottom_pit);
if (pm.height() != old_dim.height()) {
// Paragraph height has changed so we cannot proceed to
// the singlePar optimisation.
/* Try to rebreak only the paragraph containing the cursor (if
* this paragraph contains insets etc., rebreaking will
* recursively descend). We need a full redraw if either
* 1/ the height has changed
* or
* 2/ the width has changed and it was equal to the textmetrics
* width; the goal is to catch the case of a one-row inset that
* grows with its contents, but optimize the case of typing at
* the end of a mmultiple-row paragraph.
*
* NOTE: if only the height has changed, then it should be
* possible to update all metrics at minimal cost. However,
* since this is risky, we do not try that right now.
*/
tm.redoParagraph(pit);
ParagraphMetrics & pm = tm.parMetrics(pit);
if (pm.height() != old_dim.height()
|| (pm.width() != old_dim.width() && old_dim.width() == tm.width())) {
// Paragraph height or width has changed so we cannot proceed
// to the singlePar optimisation.
LYXERR(Debug::PAINTING, "SinglePar optimization failed.");
return false;
}
// Since position() points to the baseline of the first row, we
@ -3088,11 +3100,11 @@ bool BufferView::singleParUpdate()
// the height does not change but the ascent does.
pm.setPosition(pm.position() - old_dim.ascent() + pm.ascent());
tm.updatePosCache(bottom_pit);
tm.updatePosCache(pit);
LYXERR(Debug::PAINTING, "\ny1: " << pm.position() - pm.ascent()
<< " y2: " << pm.position() + pm.descent()
<< " pit: " << bottom_pit
<< " pit: " << pit
<< " singlepar: 1");
return true;
}