]> git.lyx.org Git - lyx.git/blobdiff - src/BufferView.cpp
Merge branch 'master' of git.lyx.org:lyx
[lyx.git] / src / BufferView.cpp
index 7cb99cdf4d9cb298a2d34370e71057e14c5320ab..6922770f2966c558fe8d28f867c094f43eeeed0d 100644 (file)
@@ -227,14 +227,17 @@ enum ScreenUpdateStrategy {
 
 struct BufferView::Private
 {
-       Private(BufferView & bv): wh_(0), cursor_(bv),
+       Private(BufferView & bv) : update_strategy_(NoScreenUpdate),
+               wh_(0), cursor_(bv),
                anchor_pit_(0), anchor_ypos_(0),
                inlineCompletionUniqueChars_(0),
                last_inset_(0), clickable_inset_(false),
                mouse_position_cache_(),
                bookmark_edit_position_(-1), gui_(0),
                horiz_scroll_offset_(0)
-       {}
+       {
+               xsel_cache_.set = false;
+       }
 
        ///
        ScrollbarParameters scrollbarParameters_;
@@ -348,11 +351,12 @@ BufferView::~BufferView()
 
 int BufferView::rightMargin() const
 {
+       // The value used to be hardcoded to 10, which is 2.5mm at 100dpi
+       int const default_margin = Length(2.5, Length::MM).inPixels(0);
        // The additional test for the case the outliner is opened.
-       if (!full_screen_ ||
-               !lyxrc.full_screen_limit ||
-               width_ < lyxrc.full_screen_width + 20)
-                       return 10;
+       if (!full_screen_ || !lyxrc.full_screen_limit
+           || width_ < lyxrc.full_screen_width + 2 * default_margin)
+               return default_margin;
 
        return (width_ - lyxrc.full_screen_width) / 2;
 }
@@ -366,13 +370,13 @@ int BufferView::leftMargin() const
 
 bool BufferView::isTopScreen() const
 {
-       return d->scrollbarParameters_.position == d->scrollbarParameters_.min;
+       return 0 == d->scrollbarParameters_.min;
 }
 
 
 bool BufferView::isBottomScreen() const
 {
-       return d->scrollbarParameters_.position == d->scrollbarParameters_.max;
+       return 0 == d->scrollbarParameters_.max;
 }
 
 
@@ -412,7 +416,7 @@ Buffer const & BufferView::buffer() const
 }
 
 
-bool BufferView::fitCursor()
+bool BufferView::needsFitCursor() const
 {
        if (cursorStatus(d->cursor_) == CUR_INSIDE) {
                frontend::FontMetrics const & fm =
@@ -430,7 +434,7 @@ bool BufferView::fitCursor()
 void BufferView::processUpdateFlags(Update::flags flags)
 {
        // This is close to a hot-path.
-       LYXERR(Debug::DEBUG, "BufferView::processUpdateFlags()"
+       LYXERR(Debug::PAINTING, "BufferView::processUpdateFlags()"
                << "[fitcursor = " << (flags & Update::FitCursor)
                << ", forceupdate = " << (flags & Update::Force)
                << ", singlepar = " << (flags & Update::SinglePar)
@@ -443,6 +447,7 @@ void BufferView::processUpdateFlags(Update::flags flags)
        // Now do the first drawing step if needed. This consists on updating
        // the CoordCache in updateMetrics().
        // The second drawing step is done in WorkArea::redraw() if needed.
+       // FIXME: is this still true now that Buffer::changed() is used all over?
 
        // Case when no explicit update is requested.
        if (!flags) {
@@ -460,7 +465,7 @@ void BufferView::processUpdateFlags(Update::flags flags)
        if (flags == Update::FitCursor
                || flags == (Update::Decoration | Update::FitCursor)) {
                // tell the frontend to update the screen if needed.
-               if (fitCursor()) {
+               if (needsFitCursor()) {
                        showCursor();
                        return;
                }
@@ -470,7 +475,7 @@ void BufferView::processUpdateFlags(Update::flags flags)
                        return;
                }
                // no screen update is needed in principle, but this
-               // could change if cursor row needs scrolling.
+               // could change if cursor row needs horizontal scrolling.
                d->update_strategy_ = NoScreenUpdate;
                buffer_.changed(false);
                return;
@@ -492,7 +497,7 @@ void BufferView::processUpdateFlags(Update::flags flags)
        // This is done at draw() time. So we need a redraw!
        buffer_.changed(false);
 
-       if (fitCursor()) {
+       if (needsFitCursor()) {
                // The cursor is off screen so ensure it is visible.
                // refresh it:
                showCursor();
@@ -554,7 +559,6 @@ void BufferView::updateScrollbar()
        for (size_t i = last.first + 1; i != parsize; ++i)
                d->scrollbarParameters_.max += d->par_height_[i];
 
-       d->scrollbarParameters_.position = 0;
        // The reference is the top position so we remove one page.
        if (lyxrc.scroll_below_document)
                d->scrollbarParameters_.max -= minVisiblePart();
@@ -595,17 +599,19 @@ string BufferView::contextMenu(int x, int y) const
 }
 
 
-void BufferView::scrollDocView(int value, bool update)
+
+void BufferView::scrollDocView(int const value, bool update)
 {
-       int const offset = value - d->scrollbarParameters_.position;
+       // The scrollbar values are relative to the top of the screen, therefore the
+       // offset is equal to the target value.
 
        // No scrolling at all? No need to redraw anything
-       if (offset == 0)
+       if (value == 0)
                return;
 
        // If the offset is less than 2 screen height, prefer to scroll instead.
-       if (abs(offset) <= 2 * height_) {
-               d->anchor_ypos_ -= offset;
+       if (abs(value) <= 2 * height_) {
+               d->anchor_ypos_ -= value;
                buffer_.changed(true);
                updateHoveredInset();
                return;
@@ -702,9 +708,7 @@ Change const BufferView::getCurrentChange() const
 
        DocIterator dit = d->cursor_.selectionBegin();
        // The selected content might have been changed (see #7685)
-       while (dit.inMathed())
-               // Find enclosing text cursor
-               dit.pop_back();
+       dit = dit.getInnerText();
        return dit.paragraph().lookupChange(dit.pos());
 }
 
@@ -804,11 +808,13 @@ bool BufferView::moveToPosition(pit_type bottom_pit, pos_type bottom_pos,
                setCursor(dit);
                // set the current font.
                d->cursor_.setCurrentFont();
+               // Do not forget to reset the anchor (see #9912)
+               d->cursor_.resetAnchor();
                // To center the screen on this new position we need the
                // paragraph position which is computed at draw() time.
                // So we need a redraw!
                buffer_.changed(false);
-               if (fitCursor())
+               if (needsFitCursor())
                        showCursor();
        }
 
@@ -986,7 +992,7 @@ void BufferView::updateDocumentClass(DocumentClassConstPtr olddc)
 }
 
 
-/** Return the change status at cursor position, taking in account the
+/** Return the change status at cursor position, taking into account the
  * status at each level of the document iterator (a table in a deleted
  * footnote is deleted).
  * When \param outer is true, the top slice is not looked at.
@@ -1112,46 +1118,22 @@ bool BufferView::getStatus(FuncRequest const & cmd, FuncStatus & flag)
                iss >> opt;
                flag.setEnabled(opt.repl_buf_name.empty()
                                || !buffer_.isReadonly());
+               break;
        }
 
-       case LFUN_LABEL_GOTO: {
+       case LFUN_LABEL_GOTO:
                flag.setEnabled(!cmd.argument().empty()
                    || getInsetByCode<InsetRef>(cur, REF_CODE));
                break;
-       }
-
-       case LFUN_CHANGES_TRACK:
-               flag.setEnabled(true);
-               flag.setOnOff(buffer_.params().track_changes);
-               break;
-
-       case LFUN_CHANGES_OUTPUT:
-               flag.setEnabled(true);
-               flag.setOnOff(buffer_.params().output_changes);
-               break;
 
        case LFUN_CHANGES_MERGE:
        case LFUN_CHANGE_NEXT:
        case LFUN_CHANGE_PREVIOUS:
        case LFUN_ALL_CHANGES_ACCEPT:
        case LFUN_ALL_CHANGES_REJECT:
-               // TODO: context-sensitive enabling of LFUNs
-               // In principle, these command should only be enabled if there
-               // is a change in the document. However, without proper
-               // optimizations, this will inevitably result in poor performance.
-               flag.setEnabled(true);
+               flag.setEnabled(buffer_.areChangesPresent());
                break;
 
-       case LFUN_BUFFER_TOGGLE_COMPRESSION: {
-               flag.setOnOff(buffer_.params().compressed);
-               break;
-       }
-
-       case LFUN_BUFFER_TOGGLE_OUTPUT_SYNC: {
-               flag.setOnOff(buffer_.params().output_sync);
-               break;
-       }
-
        case LFUN_SCREEN_UP:
        case LFUN_SCREEN_DOWN:
        case LFUN_SCROLL:
@@ -1236,6 +1218,7 @@ void BufferView::dispatch(FuncRequest const & cmd, DispatchResult & dr)
 
        string const argument = to_utf8(cmd.argument());
        Cursor & cur = d->cursor_;
+       Cursor old = cur;
 
        // Don't dispatch function that does not apply to internal buffers.
        if (buffer_.isInternal()
@@ -1414,20 +1397,21 @@ void BufferView::dispatch(FuncRequest const & cmd, DispatchResult & dr)
                for (Buffer * b = &buffer_; i == 0 || b != &buffer_;
                        b = theBufferList().next(b)) {
 
-                       DocIterator dit = b->getParFromID(id);
-                       if (dit.atEnd()) {
+                       Cursor cur(*this);
+                       cur.setCursor(b->getParFromID(id));
+                       if (cur.atEnd()) {
                                LYXERR(Debug::INFO, "No matching paragraph found! [" << id << "].");
                                ++i;
                                continue;
                        }
-                       LYXERR(Debug::INFO, "Paragraph " << dit.paragraph().id()
+                       LYXERR(Debug::INFO, "Paragraph " << cur.paragraph().id()
                                << " found in buffer `"
                                << b->absFileName() << "'.");
 
                        if (b == &buffer_) {
                                // Set the cursor
-                               dit.pos() = pos;
-                               setCursor(dit);
+                               cur.pos() = pos;
+                               mouseSetCursor(cur);
                                dr.screenUpdate(Update::Force | Update::FitCursor);
                        } else {
                                // Switch to other buffer view and resend cmd
@@ -1452,33 +1436,6 @@ void BufferView::dispatch(FuncRequest const & cmd, DispatchResult & dr)
                break;
        }
 
-       case LFUN_CHANGES_TRACK:
-               buffer_.params().track_changes = !buffer_.params().track_changes;
-               break;
-
-       case LFUN_CHANGES_OUTPUT:
-               buffer_.params().output_changes = !buffer_.params().output_changes;
-               if (buffer_.params().output_changes) {
-                       bool dvipost    = LaTeXFeatures::isAvailable("dvipost");
-                       bool xcolorulem = LaTeXFeatures::isAvailable("ulem") &&
-                                         LaTeXFeatures::isAvailable("xcolor");
-
-                       if (!dvipost && !xcolorulem) {
-                               Alert::warning(_("Changes not shown in LaTeX output"),
-                                              _("Changes will not be highlighted in LaTeX output, "
-                                                "because neither dvipost nor xcolor/ulem are installed.\n"
-                                                "Please install these packages or redefine "
-                                                "\\lyxadded and \\lyxdeleted in the LaTeX preamble."));
-                       } else if (!xcolorulem) {
-                               Alert::warning(_("Changes not shown in LaTeX output"),
-                                              _("Changes will not be highlighted in LaTeX output "
-                                                "when using pdflatex, because xcolor and ulem are not installed.\n"
-                                                "Please install both packages or redefine "
-                                                "\\lyxadded and \\lyxdeleted in the LaTeX preamble."));
-                       }
-               }
-               break;
-
        case LFUN_CHANGE_NEXT:
                findNextChange(this);
                // FIXME: Move this LFUN to Buffer so that we don't have to do this:
@@ -1631,7 +1588,7 @@ void BufferView::dispatch(FuncRequest const & cmd, DispatchResult & dr)
                break;
 
        case LFUN_MARK_TOGGLE:
-               cur.setSelection(false);
+               cur.selection(false);
                if (cur.mark()) {
                        cur.setMark(false);
                        dr.setMessage(from_utf8(N_("Mark removed")));
@@ -1718,15 +1675,6 @@ void BufferView::dispatch(FuncRequest const & cmd, DispatchResult & dr)
        }
                break;
 
-       case LFUN_BUFFER_TOGGLE_COMPRESSION:
-               // turn compression on/off
-               buffer_.params().compressed = !buffer_.params().compressed;
-               break;
-
-       case LFUN_BUFFER_TOGGLE_OUTPUT_SYNC:
-               buffer_.params().output_sync = !buffer_.params().output_sync;
-               break;
-
        case LFUN_SCREEN_UP:
        case LFUN_SCREEN_DOWN: {
                Point p = getPos(cur);
@@ -1743,7 +1691,6 @@ void BufferView::dispatch(FuncRequest const & cmd, DispatchResult & dr)
                        p = Point(0, 0);
                if (act == LFUN_SCREEN_DOWN && scrolled < height_)
                        p = Point(width_, height_);
-               Cursor old = cur;
                bool const in_texted = cur.inTexted();
                cur.setCursor(doc_iterator_begin(cur.buffer()));
                cur.selHandle(false);
@@ -1825,26 +1772,30 @@ void BufferView::dispatch(FuncRequest const & cmd, DispatchResult & dr)
        }
 
 
-       case LFUN_INSET_SELECT_ALL:
-               if (cur.depth() > 1
+       case LFUN_INSET_SELECT_ALL: {
+               // true if all cells are selected
+               bool const all_selected = cur.depth() > 1
                    && cur.selBegin().at_begin()
-                   && cur.selEnd().at_end()) {
-                       // All the contents of the inset if selected.
+                   && cur.selEnd().at_end();
+               // true if some cells are selected
+               bool const cells_selected = cur.depth() > 1
+                   && cur.selBegin().at_cell_begin()
+                       && cur.selEnd().at_cell_end();
+               if (all_selected || (cells_selected && !cur.inset().isTable())) {
+                       // All the contents of the inset if selected, or only at
+                       // least one cell but inset is not a table.
                        // Select the inset from outside.
                        cur.pop();
                        cur.resetAnchor();
-                       cur.setSelection(true);
+                       cur.selection(true);
                        cur.posForward();
-               } else if (cur.selBegin().idx() != cur.selEnd().idx()
-                          || (cur.depth() > 1
-                                  && cur.selBegin().at_cell_begin()
-                              && cur.selEnd().at_cell_end())) {
-                       // At least one complete cell is selected.
+               } else if (cells_selected) {
+                       // At least one complete cell is selected and inset is a table.
                        // Select all cells
                        cur.idx() = 0;
                        cur.pos() = 0;
                        cur.resetAnchor();
-                       cur.setSelection(true);
+                       cur.selection(true);
                        cur.idx() = cur.lastidx();
                        cur.pos() = cur.lastpos();
                } else {
@@ -1852,12 +1803,14 @@ void BufferView::dispatch(FuncRequest const & cmd, DispatchResult & dr)
                        cur.pit() = 0;
                        cur.pos() = 0;
                        cur.resetAnchor();
-                       cur.setSelection(true);
+                       cur.selection(true);
                        cur.pit() = cur.lastpit();
                        cur.pos() = cur.lastpos();
                }
+               cur.setCurrentFont();
                dr.screenUpdate(Update::Force);
                break;
+       }
 
 
        // This would be in Buffer class if only Cursor did not
@@ -1897,9 +1850,17 @@ void BufferView::dispatch(FuncRequest const & cmd, DispatchResult & dr)
                        if (!cur.nextInset() || cur.nextInset() == ins)
                                cur.forwardInset();
                }
-               cur.endUndoGroup();
                cur = savecur;
                cur.fixIfBroken();
+               /** This is a dummy undo record only to remember the cursor
+                * that has just been set; this will be used on a redo action
+                * (see ticket #10097)
+
+                * FIXME: a better fix would be to have a way to set the
+                * cursor value directly, but I am not sure it is worth it.
+                */
+               cur.recordUndo();
+               cur.endUndoGroup();
                dr.screenUpdate(Update::Force);
                dr.forceBufferUpdate();
 
@@ -2065,6 +2026,21 @@ void BufferView::dispatch(FuncRequest const & cmd, DispatchResult & dr)
 
        buffer_.undo().endUndoGroup();
        dr.dispatched(dispatched);
+
+       // NOTE: The code below is copied from Cursor::dispatch. If you
+       // need to modify this, please update the other one too.
+
+       // notify insets we just entered/left
+       if (cursor() != old) {
+               old.beginUndoGroup();
+               old.fixIfBroken();
+               bool badcursor = notifyCursorLeavesOrEnters(old, cursor());
+               if (badcursor) {
+                       cursor().fixIfBroken();
+                       resetInlineCompletionPos();
+               }
+               old.endUndoGroup();
+       }
 }
 
 
@@ -2156,7 +2132,7 @@ void BufferView::updateHoveredInset() const
        int const y = d->mouse_position_cache_.y_;
        Inset const * covering_inset = getCoveringInset(buffer_.text(), x, y);
 
-       d->clickable_inset_ = covering_inset && covering_inset->clickable(x, y);
+       d->clickable_inset_ = covering_inset && covering_inset->clickable(*this, x, y);
 
        if (covering_inset == d->last_inset_)
                // Same inset, no need to do anything...
@@ -2212,7 +2188,7 @@ void BufferView::mouseEventDispatch(FuncRequest const & cmd0)
        Cursor old = cursor();
        Cursor cur(*this);
        cur.push(buffer_.inset());
-       cur.setSelection(d->cursor_.selection());
+       cur.selection(d->cursor_.selection());
 
        // Either the inset under the cursor or the
        // surrounding Text will handle this event.
@@ -2230,6 +2206,20 @@ void BufferView::mouseEventDispatch(FuncRequest const & cmd0)
 
        // Build temporary cursor.
        Inset * inset = d->text_metrics_[&buffer_.text()].editXY(cur, cmd.x(), cmd.y());
+       if (inset) {
+               // If inset is not editable, cur.pos() might point behind the
+               // inset (depending on cmd.x(), cmd.y()). This is needed for
+               // editing to fix bug 9628, but e.g. the context menu needs a
+               // cursor in front of the inset.
+               if ((inset->hasSettings() || !inset->contextMenuName().empty()
+                    || inset->lyxCode() == SEPARATOR_CODE) &&
+                   cur.nextInset() != inset && cur.prevInset() == inset)
+                       cur.posBackward();
+       } else if (cur.inTexted() && cur.pos()
+                       && cur.paragraph().isEnvSeparator(cur.pos() - 1)) {
+               // Always place cursor in front of a separator inset.
+               cur.posBackward();
+       }
 
        // Put anchor at the same position.
        cur.resetAnchor();
@@ -2248,8 +2238,6 @@ void BufferView::mouseEventDispatch(FuncRequest const & cmd0)
        if (!inset || !cur.result().dispatched())
                cur.dispatch(cmd);
 
-       cur.endUndoGroup();
-
        // Notify left insets
        if (cur != old) {
                bool badcursor = old.fixIfBroken() | cur.fixIfBroken();
@@ -2258,6 +2246,8 @@ void BufferView::mouseEventDispatch(FuncRequest const & cmd0)
                        cursor().fixIfBroken();
        }
 
+       cur.endUndoGroup();
+
        // Do we have a selection?
        theSelection().haveSelection(cursor().selection());
 
@@ -2337,13 +2327,19 @@ int BufferView::scrollUp(int offset)
 
 
 void BufferView::setCursorFromRow(int row)
+{
+       setCursorFromRow(row, buffer_.texrow());
+}
+
+
+void BufferView::setCursorFromRow(int row, TexRow const & texrow)
 {
        int tmpid;
        int tmppos;
        pit_type newpit = 0;
        pos_type newpos = 0;
 
-       buffer_.texrow().getIdFromRow(row, tmpid, tmppos);
+       texrow.getIdFromRow(row, tmpid, tmppos);
 
        bool posvalid = (tmpid != -1);
        if (posvalid) {
@@ -2379,7 +2375,7 @@ void BufferView::setCursorFromRow(int row)
        }
        d->cursor_.reset();
        buffer_.text().setCursor(d->cursor_, newpit, newpos);
-       d->cursor_.setSelection(false);
+       d->cursor_.selection(false);
        d->cursor_.resetAnchor();
        recenter();
 }
@@ -2413,9 +2409,9 @@ void BufferView::gotoLabel(docstring const & label)
                Buffer const * buf = *it;
 
                // find label
-               Toc & toc = buf->tocBackend().toc("label");
-               TocIterator toc_it = toc.begin();
-               TocIterator end = toc.end();
+               shared_ptr<Toc> toc = buf->tocBackend().toc("label");
+               Toc::const_iterator toc_it = toc->begin();
+               Toc::const_iterator end = toc->end();
                for (; toc_it != end; ++toc_it) {
                        if (label == toc_it->str()) {
                                lyx::dispatch(toc_it->action());
@@ -2465,7 +2461,8 @@ void BufferView::setCursor(DocIterator const & dit)
                dit[i].inset().edit(d->cursor_, true);
 
        d->cursor_.setCursor(dit);
-       d->cursor_.setSelection(false);
+       d->cursor_.selection(false);
+       d->cursor_.setCurrentFont();
        // FIXME
        // It seems on general grounds as if this is probably needed, but
        // it is not yet clear.
@@ -2493,7 +2490,7 @@ bool BufferView::checkDepm(Cursor & cur, Cursor & old)
        d->cursor_ = cur;
 
        // we would rather not do this here, but it needs to be done before
-       // the changed() signal is sent.
+       // the changed() signal is sent.
        buffer_.updateBuffer();
 
        buffer_.changed(true);
@@ -2593,7 +2590,7 @@ bool BufferView::selectIfEmpty(DocIterator & cur)
        d->cursor_.setCursor(cur);
        d->cursor_.pit() = beg_pit;
        d->cursor_.pos() = 0;
-       d->cursor_.setSelection(false);
+       d->cursor_.selection(false);
        d->cursor_.resetAnchor();
        d->cursor_.pit() = end_pit;
        d->cursor_.pos() = end_pos;
@@ -2782,7 +2779,7 @@ Point BufferView::coordOffset(DocIterator const & dit) const
        int lastw = 0;
 
        // Addup contribution of nested insets, from inside to outside,
-       // keeping the outer paragraph for a special handling below
+       // keeping the outer paragraph for a special handling below
        for (size_t i = dit.depth() - 1; i >= 1; --i) {
                CursorSlice const & sl = dit[i];
                int xx = 0;
@@ -2812,8 +2809,7 @@ Point BufferView::coordOffset(DocIterator const & dit) const
                        // FIXME (Abdel 23/09/2007): this is a bit messy because of the
                        // elimination of Inset::dim_ cache. This coordOffset() method needs
                        // to be rewritten in light of the new design.
-                       Dimension const & dim = parMetrics(dit[i - 1].text(),
-                               dit[i - 1].pit()).insetDimension(&sl.inset());
+                       Dimension const & dim = coordCache().getInsets().dim(&sl.inset());
                        lastw = dim.wid;
                } else {
                        Dimension const dim = sl.inset().dimension(*this);
@@ -2919,15 +2915,26 @@ int BufferView::horizScrollOffset() const
 }
 
 
-CursorSlice const & BufferView::currentRowSlice() const
+int BufferView::horizScrollOffset(Text const * text,
+                                  pit_type pit, pos_type pos) const
 {
-       return d->current_row_slice_;
+       // Is this a row that is currently scrolled?
+       if (!d->current_row_slice_.empty()
+           && &text->inset() == d->current_row_slice_.inset().asInsetText()
+           && pit ==  d->current_row_slice_.pit()
+           && pos ==  d->current_row_slice_.pos())
+               return d->horiz_scroll_offset_;
+       return 0;
 }
 
 
-CursorSlice const & BufferView::lastRowSlice() const
+bool BufferView::hadHorizScrollOffset(Text const * text,
+                                      pit_type pit, pos_type pos) const
 {
-       return d->last_row_slice_;
+       return !d->last_row_slice_.empty()
+              && &text->inset() == d->last_row_slice_.inset().asInsetText()
+              && pit ==  d->last_row_slice_.pit()
+              && pos ==  d->last_row_slice_.pos();
 }
 
 
@@ -2963,52 +2970,67 @@ void BufferView::checkCursorScrollOffset(PainterInfo & pi)
                return;
        ParagraphMetrics const & pm = tm.parMetrics(rowSlice.pit());
        Row const & row = pm.getRow(rowSlice.pos(),
-                                   d->cursor_.boundary()
-                                   && rowSlice == d->cursor_.top());
+                                   d->cursor_.boundary() && rowSlice == d->cursor_.top());
        rowSlice.pos() = row.pos();
 
        // Set the row on which the cursor lives.
        setCurrentRowSlice(rowSlice);
 
-       /** FIXME: the code below adds an extraneous computation of inset
-        * positions, and can therefore be bad for performance (think for
-        * example about a very large tabular inset. Redawing the row
-        * where it is means redrawing the whole screen).
-        *
-        * The bug that this fixes is the following: assume that there is
-        * a very large math inset. Upon entering the inset, when pressing
-        * `End', the row is not scrolled and the cursor is not visible. I
-        * am not sure why the extra row computation fixes the problem,
-        * actually.
-        *
-        * A proper fix should be found and this code should be removed.
-        */
-       // Force the recomputation of inset positions
-       bool const drawing = pi.pain.isDrawingEnabled();
-       pi.pain.setDrawingEnabled(false);
-       // No need to care about vertical position.
-       RowPainter rp(pi, buffer().text(), d->cursor_.bottom().pit(), row,
-                     -d->horiz_scroll_offset_, 0);
-       rp.paintText();
-       pi.pain.setDrawingEnabled(drawing);
-       /** END of bad code */
+       // If insets referred to by cursor are not all in the cache, the positions
+       // need to be recomputed.
+       if (!d->cursor_.inCoordCache()) {
+               /** FIXME: the code below adds an extraneous computation of
+                * inset positions, and can therefore be bad for performance
+                * (think for example about a very large tabular inset.
+                * Redawing the row where it is means redrawing the whole
+                * screen).
+                *
+                * The bug that this fixes is the following: assume that there
+                * is a very large math inset. Upon entering the inset, when
+                * pressing `End', the row is not scrolled and the cursor is
+                * not visible. The extra row computation makes sure that the
+                * inset positions are correctly computed and set in the
+                * cache. This would not happen if we did not have two-stage
+                * drawing.
+                *
+                * A proper fix would be to always have proper inset positions
+                * at this point.
+                */
+               // Force the recomputation of inset positions
+               bool const drawing = pi.pain.isDrawingEnabled();
+               pi.pain.setDrawingEnabled(false);
+               // No need to care about vertical position.
+               RowPainter rp(pi, buffer().text(), row, -d->horiz_scroll_offset_, 0);
+               rp.paintText();
+               pi.pain.setDrawingEnabled(drawing);
+       }
 
        // Current x position of the cursor in pixels
-       int const cur_x = getPos(d->cursor_).x_;
+       int cur_x = getPos(d->cursor_).x_;
 
        // Horizontal scroll offset of the cursor row in pixels
        int offset = d->horiz_scroll_offset_;
-       int const MARGIN = Length(2, Length::EM).inPixels(workWidth());
-       if (cur_x < offset + MARGIN) {
-               // scroll right
-               offset = cur_x - MARGIN;
-       } else if (cur_x > offset + workWidth() - MARGIN) {
-               // scroll left
-               offset = cur_x - workWidth() + MARGIN;
+       int const MARGIN = 2 * theFontMetrics(d->cursor_.real_current_font).em()
+                          + row.right_margin;
+       if (row.right_x() <= workWidth() - row.right_margin) {
+               // Row is narrower than the work area, no offset needed.
+               offset = 0;
+       } else {
+               if (cur_x - offset < MARGIN) {
+                       // cursor would be too far right
+                       offset = cur_x - MARGIN;
+               } else if (cur_x - offset > workWidth() - MARGIN) {
+                       // cursor would be too far left
+                       offset = cur_x - workWidth() + MARGIN;
+               }
+               // Correct the offset to make sure that we do not scroll too much
+               if (offset < 0)
+                       offset = 0;
+               if (row.right_x() - offset < workWidth() - row.right_margin)
+                       offset = row.right_x() - workWidth() + row.right_margin;
        }
 
-       if (offset < row.left_margin || row.width() <= workWidth())
-               offset = 0;
+       //lyxerr << "cur_x=" << cur_x << ", offset=" << offset << ", row.wid=" << row.width() << ", margin=" << MARGIN << endl;
 
        if (offset != d->horiz_scroll_offset_)
                LYXERR(Debug::PAINTING, "Horiz. scroll offset changed from "
@@ -3049,7 +3071,7 @@ void BufferView::draw(frontend::Painter & pain)
                LYXERR(Debug::PAINTING, "Strategy: NoScreenUpdate");
                pi.full_repaint = true;
                pi.pain.setDrawingEnabled(false);
-               tm.draw(pi, 0, y);
+               tm.draw(pi, 0, y);
                break;
 
        case SingleParUpdate:
@@ -3058,7 +3080,7 @@ void BufferView::draw(frontend::Painter & pain)
                // In general, only the current row of the outermost paragraph
                // will be redrawn. Particular cases where selection spans
                // multiple paragraph are correctly detected in TextMetrics.
-               tm.draw(pi, 0, y);
+               tm.draw(pi, 0, y);
                break;
 
        case DecorationUpdate: