src/BufferView.cpp

@@ -1053,7 +1053,6 @@ bool BufferView::scrollToCursor(DocIterator const & dit, ScrollType how)
 		bot_pit = max_pit;
 	}
 
-	// Add surrounding paragraph metrics to scroll properly with cursor up/down
 	if (bot_pit == tm.first().first - 1)
 		tm.newParMetricsUp();
 	else if (bot_pit == tm.last().first + 1)
@@ -1069,8 +1068,7 @@ bool BufferView::scrollToCursor(DocIterator const & dit, ScrollType how)
 			textMetrics(cs.text()).parMetrics(cs.pit());
 		Dimension const & row_dim =
 			inner_pm.getRow(cs.pos(), dit.boundary()).dim();
-		// Assume first that we do not have to scroll anything
-		int ynew = ypos;
+		int scrolled = 0;
 
 		// 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.
@@ -1078,55 +1076,51 @@ bool BufferView::scrollToCursor(DocIterator const & dit, ScrollType how)
 		// for a row in the inset that can be visualized completely.
 		if (row_dim.height() > height_) {
 			if (ypos < defaultRowHeight())
-				ynew = height_ / 4;
+				scrolled = scroll(ypos - height_ / 4);
 			else if (ypos > height_ - defaultRowHeight())
-				ynew = 3 * height_ / 4;
+				scrolled = scroll(ypos - 3 * height_ / 4);
 		}
+
 		// If the top part of the row falls of the screen, we scroll
 		// up to align the top of the row with the top of the screen.
-		else if (ypos - row_dim.ascent() < 0 && ypos < height_)
-			ynew = row_dim.ascent();
-		// If the bottom of the row falls of the screen, we scroll down.
-		else if (ypos + row_dim.descent() > height_ && ypos > 0)
-			ynew = height_ - row_dim.descent();
+		else if (ypos - row_dim.ascent() < 0 && ypos < height_) {
+			int const ynew = row_dim.ascent();
+			scrolled = scrollUp(ynew - ypos);
+		}
 
-		d->anchor_ypos_ += ynew - ypos;
-		return ynew != ypos;
+		// If the bottom of the row falls of the screen, we scroll down.
+		else if (ypos + row_dim.descent() > height_ && ypos > 0) {
+			int const ynew = height_ - row_dim.descent();
+			scrolled = scrollDown(ypos - ynew);
+		}
+
+		// else, nothing to do, the cursor is already visible so we just return.
+		return scrolled != 0;
 	}
 
 	// fix inline completion position
 	if (d->inlineCompletionPos_.fixIfBroken())
 		d->inlineCompletionPos_ = DocIterator();
 
-	pit_type const old_pit = d->anchor_pit_;
-	int const old_ypos = d->anchor_ypos_;
-
-	if (!tm.contains(bot_pit))
 	tm.redoParagraph(bot_pit);
 	int const offset = coordOffset(dit).y;
+	pit_type const old_pit = d->anchor_pit_;
+	d->anchor_pit_ = bot_pit;
 
 	CursorSlice const & cs = dit.innerTextSlice();
 	ParagraphMetrics const & inner_pm =
 		textMetrics(cs.text()).parMetrics(cs.pit());
-	// dimension of the contents of the text row that holds dit
-	Dimension const & row_dim = inner_pm.getRow(cs.pos(), dit.boundary()).contents_dim();
+	Dimension const & row_dim =
+		inner_pm.getRow(cs.pos(), dit.boundary()).dim();
 
-	// Compute typical ypos values.
-	int const ypos_center = height_/2 - row_dim.height() / 2 + row_dim.ascent() - offset;
-	int const ypos_top = (offset > height_) ? height_ - offset - defaultRowHeight()
-	                                        : defaultRowHeight() * 2;
-
-	// Select the right one.
-	d->anchor_pit_ = bot_pit;
-	switch(how) {
-	case SCROLL_CENTER:
-		d->anchor_ypos_ = ypos_center;
-		break;
-	case SCROLL_TOP:
-	case SCROLL_VISIBLE:
-		d->anchor_ypos_ = ypos_top;
-		// more to come: BOTTOM, TOGGLE
-	}
+	int const old_ypos = d->anchor_ypos_;
+	d->anchor_ypos_ = - offset + row_dim.ascent();
+	if (how == SCROLL_CENTER)
+		d->anchor_ypos_ += height_/2 - row_dim.height() / 2;
+	else if (offset > height_)
+		d->anchor_ypos_ = height_ - offset - defaultRowHeight();
+	else
+		d->anchor_ypos_ = defaultRowHeight() * 2;
 
 	return d->anchor_ypos_ != old_ypos || d->anchor_pit_ != old_pit;
 }
@@ -2854,13 +2848,34 @@ int BufferView::minVisiblePart()
 
 int BufferView::scroll(int pixels)
 {
-	d->anchor_ypos_ -= pixels;
-	return -pixels;
+	if (pixels > 0)
+		return scrollDown(pixels);
+	if (pixels < 0)
+		return scrollUp(-pixels);
+	return 0;
 }
 
 
 int BufferView::scrollDown(int pixels)
 {
+	Text * text = &buffer_.text();
+	TextMetrics & tm = d->text_metrics_[text];
+	int const ymax = height_ + pixels;
+	while (true) {
+		pair<pit_type, ParagraphMetrics const *> last = tm.last();
+		int bottom_pos = last.second->bottom();
+		if (lyxrc.scroll_below_document)
+			bottom_pos += height_ - minVisiblePart();
+		if (last.first + 1 == int(text->paragraphs().size())) {
+			if (bottom_pos <= height_)
+				return 0;
+			pixels = min(pixels, bottom_pos - height_);
+			break;
+		}
+		if (bottom_pos > ymax)
+			break;
+		tm.newParMetricsDown();
+	}
 	d->anchor_ypos_ -= pixels;
 	return -pixels;
 }
@@ -2868,6 +2883,22 @@ int BufferView::scrollDown(int pixels)
 
 int BufferView::scrollUp(int pixels)
 {
+	Text * text = &buffer_.text();
+	TextMetrics & tm = d->text_metrics_[text];
+	int ymin = - pixels;
+	while (true) {
+		pair<pit_type, ParagraphMetrics const *> first = tm.first();
+		int top_pos = first.second->top();
+		if (first.first == 0) {
+			if (top_pos >= 0)
+				return 0;
+			pixels = min(pixels, - top_pos);
+			break;
+		}
+		if (top_pos < ymin)
+			break;
+		tm.newParMetricsUp();
+	}
 	d->anchor_ypos_ += pixels;
 	return pixels;
 }