* Make the selection drawing algorithm in Text aware of RTL and LTR mixed in a paragraph

  (fixes bug 3550: Selection in mixed RTL-LTR paragraphs is broken)

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@18668 a592a061-630c-0410-9148-cb99ea01b6c8

diff --git a/src/Text.cpp b/src/Text.cpp
index b2c20bf073953c766172dc4287dc0517e75ee7d8..3bac412353826f1b26552e080d48b462dc18a047 100644 (file)
--- a/src/Text.cpp
+++ b/src/Text.cpp
@@ -8,6 +8,7 @@
  * \author Jean-Marc Lasgouttes
  * \author John Levon
  * \author André Pönitz
+ * \author Stefan Schimanski
  * \author Dekel Tsur
  * \author Jürgen Vigna
  *
@@ -1412,91 +1413,151 @@ void Text::drawSelection(PainterInfo & pi, int x, int) const
        DocIterator end = cur.selectionEnd();
 
        BufferView & bv = *pi.base.bv;
-       Buffer const & buffer = *bv.buffer();
 
-       // the selection doesn't touch the visible screen
+       // the selection doesn't touch the visible screen?
        if (bv_funcs::status(&bv, beg) == bv_funcs::CUR_BELOW
            || bv_funcs::status(&bv, end) == bv_funcs::CUR_ABOVE)
                return;
 
-       Paragraph const & par1 = pars_[beg.pit()];
-       Paragraph const & par2 = pars_[end.pit()];
        TextMetrics const & tm = bv.textMetrics(this);
        ParagraphMetrics const & pm1 = tm.parMetrics(beg.pit());
        ParagraphMetrics const & pm2 = tm.parMetrics(end.pit());
+       Row const & row1 = pm1.getRow(beg.pos(), beg.boundary());
+       Row const & row2 = pm2.getRow(end.pos(), end.boundary());
+
+       // clip above
+       int middleTop;
+       bool const clipAbove = 
+               (bv_funcs::status(&bv, beg) == bv_funcs::CUR_ABOVE);
+       if (clipAbove)
+               middleTop = 0;
+       else
+               middleTop = bv_funcs::getPos(bv, beg, beg.boundary()).y_ + row1.descent();
+       
+       // clip below
+       int middleBottom;
+       bool const clipBelow = 
+               (bv_funcs::status(&bv, end)     == bv_funcs::CUR_BELOW);
+       if (clipBelow)
+               middleBottom = bv.workHeight();
+       else
+               middleBottom = bv_funcs::getPos(bv, end, end.boundary()).y_ - row2.ascent();
 
-       bool const above = (bv_funcs::status(&bv, beg)
-                           == bv_funcs::CUR_ABOVE);
-       bool const below = (bv_funcs::status(&bv, end)
-                           == bv_funcs::CUR_BELOW);
-       int y1,y2,x1,x2;
-       if (above) {
-               y1 = 0;
-               y2 = 0;
-               x1 = 0;
-               x2 = tm.width();
-       } else {
-               Row const & row1 = pm1.getRow(beg.pos(), beg.boundary());
-               y1 = bv_funcs::getPos(bv, beg, beg.boundary()).y_ - row1.ascent();
-               y2 = y1 + row1.height();
-               int const startx = cursorX(bv, beg.top(), beg.boundary());
-               if (!isRTL(buffer, par1)) {
-                       x1 = startx;
-                       x2 = 0 + tm.width();
+       // start and end in the same line?
+       if (!(clipAbove || clipBelow) && &row1 == &row2)
+               // then only draw this row's selection
+               drawRowSelection(pi, x, row1, beg, end, false, false);
+       else {
+               if (!clipAbove) {
+                       // get row end
+                       DocIterator begRowEnd = beg;
+                       begRowEnd.pos() = row1.endpos();
+                       begRowEnd.boundary(true);
+                       
+                       // draw upper rectangle
+                       drawRowSelection(pi, x, row1, beg, begRowEnd, false, true);
                }
-               else {
-                       x1 = 0;
-                       x2 = startx;
+                       
+               if (middleTop < middleBottom) {
+                       // draw middle rectangle
+                       pi.pain.fillRectangle(x, middleTop, 
+                                                                                                               tm.width(), middleBottom - middleTop, 
+                                                                                                               Color::selection);
                }
-       }
 
-       int Y1,Y2,X1,X2;
-       if (below) {
-               Y1 = bv.workHeight();
-               Y2 = bv.workHeight();
-               X1 = 0;
-               X2 = tm.width();
-       } else {
-               Row const & row2 = pm2.getRow(end.pos(), end.boundary());
-               Y1 = bv_funcs::getPos(bv, end, end.boundary()).y_ - row2.ascent();
-               Y2 = Y1 + row2.height();
-               int const endx = cursorX(bv, end.top(), end.boundary());
-               if (!isRTL(buffer, par2)) {
-                       X1 = 0;
-                       X2 = endx;
-               }
-               else {
-                       X1 = endx;
-                       X2 = 0 + tm.width();
+               if (!clipBelow) {
+                       // get row begin
+                       DocIterator endRowBeg = end;
+                       endRowBeg.pos() = row2.pos();
+                       endRowBeg.boundary(false);
+                       
+                       // draw low rectangle
+                       drawRowSelection(pi, x, row2, endRowBeg, end, true, false);
                }
        }
+}
 
-       if (!above && !below && &pm1.getRow(beg.pos(), beg.boundary())
-           == &pm2.getRow(end.pos(), end.boundary()))
-       {
-               // paint only one rectangle
-               int const b( !isRTL(*bv.buffer(), par1) ? x + x1 : x + X1 );
-               int const w( !isRTL(*bv.buffer(), par1) ? X2 - x1 : x2 - X1 );
-               pi.pain.fillRectangle(b, y1, w, y2 - y1, Color::selection);
-               return;
-       }
 
-       LYXERR(Debug::DEBUG) << " y1: " << y1 << " y2: " << y2
-               << "X1:" << X1 << " x2: " << X2 << " wid: " << tm.width()
-               << endl;
-
-       // paint upper rectangle
-       pi.pain.fillRectangle(x + x1, y1, x2 - x1, y2 - y1,
-                                     Color::selection);
-       // paint bottom rectangle
-       pi.pain.fillRectangle(x + X1, Y1, X2 - X1, Y2 - Y1,
-                                     Color::selection);
-       // paint center rectangle
-       pi.pain.fillRectangle(x, y2, tm.width(),
-                             Y1 - y2, Color::selection);
+void Text::drawRowSelection(PainterInfo & pi, int x, Row const & row,
+                                                                                                               DocIterator const & beg, DocIterator const & end, 
+                                                                                                               bool drawOnBegMargin, bool drawOnEndMargin) const
+{
+       BufferView & bv = *pi.base.bv;
+       Buffer & buffer = *bv.buffer();
+       TextMetrics const & tm = bv.textMetrics(this);
+       DocIterator cur = beg;
+       int x1 = cursorX(bv, beg.top(), beg.boundary());
+       int x2 = cursorX(bv, end.top(), end.boundary());
+       int y1 = bv_funcs::getPos(bv, cur, cur.boundary()).y_ - row.ascent();
+       int y2 = y1 + row.height();
+       
+       // draw the margins
+       if (drawOnBegMargin) {
+               if (isRTL(buffer, beg.paragraph()))
+                       pi.pain.fillRectangle(x + x1, y1, tm.width() - x1, y2 - y1, Color::selection);
+               else
+                       pi.pain.fillRectangle(x, y1, x1, y2 - y1, Color::selection);
+       }
+       
+       if (drawOnEndMargin) {
+               if (isRTL(buffer, beg.paragraph()))
+                       pi.pain.fillRectangle(x, y1, x2, y2 - y1, Color::selection);
+               else
+                       pi.pain.fillRectangle(x + x2, y1, tm.width() - x2, y2 - y1, Color::selection);
+       }
+       
+       // if we are on a boundary from the beginning, it's probably
+       // a RTL boundary and we jump to the other side directly as this
+       // segement is 0-size and confuses the logic below
+       if (cur.boundary())
+               cur.boundary(false);
+       
+       // go through row and draw from RTL boundary to RTL boundary
+       while (cur < end) {
+               bool drawNow = false;
+               
+               // simplified cursorRight code below which does not
+               // descend into insets and which does not go into the
+               // next line. Compare the logic with the original cursorRight
+               
+               // if left of boundary -> just jump to right side
+               // but for RTL boundaries don't, because: abc|DDEEFFghi -> abcDDEEF|Fghi
+               if (cur.boundary()) {
+                       cur.boundary(false);
+               }       else if (bidi.isBoundary(buffer, cur.paragraph(), cur.pos() + 1)) {
+                       // in front of RTL boundary -> Stay on this side of the boundary because:
+                       //   ab|cDDEEFFghi -> abc|DDEEFFghi
+                       ++cur.pos();
+                       cur.boundary(true);
+                       drawNow = true;
+               } else {
+                       // move right
+                       ++cur.pos();
+                       
+                       // line end?
+                       if (cur.pos() == row.endpos())
+                               cur.boundary(true);
+               }
+                       
+               if (x1 == -1) {
+                       // the previous segment was just drawn, now the next starts
+                       x1 = cursorX(bv, cur.top(), cur.boundary());
+               }
+               
+               if (!(cur < end) || drawNow) {
+                       x2 = cursorX(bv, cur.top(), cur.boundary());
+                       pi.pain.fillRectangle(x + min(x1,x2), y1, abs(x2 - x1), y2 - y1,
+                                                                                                               Color::selection);
+                       
+                       // reset x1, so it is set again next round (which will be on the 
+                       // right side of a boundary or at the selection end)
+                       x1 = -1;
+               }
+       }
 }
 
 
+
 bool Text::isLastRow(pit_type pit, Row const & row) const
 {
        return row.endpos() >= pars_[pit].size()

diff --git a/src/Text.h b/src/Text.h
index f7c9d9d24fe34a89bd339f698eb6036b5fff3ff8..ca136207f13a289e9bbe631814cc94df462a51fb 100644 (file)
--- a/src/Text.h
+++ b/src/Text.h
@@ -407,6 +407,11 @@ private:
        void charInserted();
        /// set 'number' font property
        void number(Cursor & cur);
+       /// draw selection for a single row
+       void drawRowSelection(PainterInfo & pi, int x, Row const & row,
+                                                                                               DocIterator const & beg, DocIterator const & end, 
+                                                                                               bool drawOnBegMargin, bool drawOnEndMargin) const;
+
 
        /// paste plain text at current cursor.
        /// \param str string to paste