Simplify and hopely fix scrollToCursor

Remove some special cases that I do not really understand and
streamline the cases.

Also make sure that there is only one code path for centering.

Fixes bug #12491.

diff --git a/src/BufferView.cpp b/src/BufferView.cpp
index d3cf909ea351fd2c74547bd3f41adc9c85814725..8a8ec183b4b44b3ac7a7a7d899c20341c861e41b 100644 (file)
--- a/src/BufferView.cpp
+++ b/src/BufferView.cpp
@@ -995,9 +995,11 @@ bool BufferView::scrollToCursor(DocIterator const & dit, bool const recenter, bo
                return false;
 
        if (recenter)
-               LYXERR(Debug::SCROLLING, "recentering and scrolling to cursor");
+               LYXERR(Debug::SCROLLING, "Centering cursor in workarea");
+       else if (force)
+               LYXERR(Debug::SCROLLING, "Setting cursor to top of workarea");
        else
-               LYXERR(Debug::SCROLLING, "scrolling to cursor");
+               LYXERR(Debug::SCROLLING, "Making sure cursor is visible in workarea");
 
        CursorSlice const & bot = dit.bottom();
        TextMetrics & tm = textMetrics(bot.text());
@@ -1016,7 +1018,7 @@ bool BufferView::scrollToCursor(DocIterator const & dit, bool const recenter, bo
        else if (bot_pit == tm.last().first + 1)
                tm.newParMetricsDown();
 
-       if (tm.contains(bot_pit) && !force) {
+       if (tm.contains(bot_pit) && !force && !recenter) {
                ParagraphMetrics const & pm = tm.parMetrics(bot_pit);
                LBUFERR(!pm.rows().empty());
                // FIXME: smooth scrolling doesn't work in mathed.
@@ -1027,14 +1029,12 @@ bool BufferView::scrollToCursor(DocIterator const & dit, bool const recenter, bo
                Dimension const & row_dim =
                        inner_pm.getRow(cs.pos(), dit.boundary()).dim();
                int scrolled = 0;
-               if (recenter)
-                       scrolled = scroll(ypos - height_/2);
 
                // We try to visualize the whole row, if the row height is larger than
                // the screen height, we scroll to a heuristic value of height_ / 4.
                // FIXME: This heuristic value should be replaced by a recursive search
                // for a row in the inset that can be visualized completely.
-               else if (row_dim.height() > height_) {
+               if (row_dim.height() > height_) {
                        if (ypos < defaultRowHeight())
                                scrolled = scroll(ypos - height_ / 4);
                        else if (ypos > height_ - defaultRowHeight())
@@ -1063,28 +1063,20 @@ bool BufferView::scrollToCursor(DocIterator const & dit, bool const recenter, bo
                d->inlineCompletionPos_ = DocIterator();
 
        tm.redoParagraph(bot_pit);
-       ParagraphMetrics const & pm = tm.parMetrics(bot_pit);
        int const offset = coordOffset(dit).y_;
-
        d->anchor_pit_ = bot_pit;
+
        CursorSlice const & cs = dit.innerTextSlice();
        ParagraphMetrics const & inner_pm =
                textMetrics(cs.text()).parMetrics(cs.pit());
        Dimension const & row_dim =
                inner_pm.getRow(cs.pos(), dit.boundary()).dim();
 
+       int const old_ypos = d->anchor_ypos_;
+       d->anchor_ypos_ = - offset + row_dim.ascent();
        if (recenter)
-               d->anchor_ypos_ = height_/2;
-       else if (d->anchor_pit_ == 0)
-               d->anchor_ypos_ = offset + pm.ascent();
-       else if (d->anchor_pit_ == max_pit)
-               d->anchor_ypos_ = height_ - offset - row_dim.descent();
-       else if (offset > height_)
-               d->anchor_ypos_ = height_ - offset - row_dim.descent();
-       else
-               d->anchor_ypos_ = row_dim.ascent();
-
-       return true;
+               d->anchor_ypos_ += height_/2 - row_dim.height() / 2;
+       return d->anchor_ypos_ != old_ypos;
 }