Change tracking cue: InsetText and InsetCollapsible

* Underline or strike through the label as if it was text (it is).

* Strike through deleted InsetText, but let RowPainter handle the case of
  non-MultiPar text insets.

* Change the colour of the frame as a cue, unless its colour is customised (not
  Color_foreground). (Essentially do the border of CharStyles like Tabular does
  it already.)

* The change info needs to be reset when entering InsetText. Otherwise labels
  are painted with the change of their n+1-th parent.

src/insets/InsetCollapsable.cpp

@@ -33,6 +33,7 @@
 #include "support/gettext.h"
 #include "support/lassert.h"
 #include "support/lstrings.h"
+#include "support/RefChanger.h"
 
 using namespace std;
 
@@ -228,9 +229,7 @@ void InsetCollapsable::draw(PainterInfo & pi, int x, int y) const
 
 	view_[&bv].auto_open_ = bv.cursor().isInside(this);
 
-	FontInfo tmpfont = pi.base.font;
-	pi.base.font = getFont();
-	pi.base.font.realize(tmpfont);
+	Changer dummy = pi.base.font.change(getFont(), true);
 
 	// Draw button first -- top, left or only
 	Dimension dimc = dimensionCollapsed(bv);
@@ -247,6 +246,10 @@ void InsetCollapsable::draw(PainterInfo & pi, int x, int y) const
 		labelfont.setColor(labelColor());
 		pi.pain.buttonText(x, y, buttonLabel(bv), labelfont,
 		                   view_[&bv].mouse_hover_);
+		// Draw the change tracking cue on the label, unless RowPainter already
+		// takes care of it.
+		if (canPaintChange(bv))
+			pi.change_.paintCue(pi, x, y, x + dimc.width(), labelfont);
 	} else {
 		view_[&bv].button_dim_.x1 = 0;
 		view_[&bv].button_dim_.y1 = 0;
@@ -257,17 +260,24 @@ void InsetCollapsable::draw(PainterInfo & pi, int x, int y) const
 	Dimension const textdim = InsetText::dimension(bv);
 	int const baseline = y;
 	int textx, texty;
-	switch (geometry(bv)) {
+	Geometry g = geometry(bv);
+	switch (g) {
 	case LeftButton:
+	case TopButton: {
+		if (g == LeftButton) {
 			textx = x + dimc.width();
 			texty = baseline;
-		InsetText::draw(pi, textx, texty);
-		break;
-	case TopButton:
+		} else {
 			textx = x;
 			texty = baseline + dimc.des + textdim.asc;
+		}
+		// Do not draw the cue for INSERTED -- it is already in the button and
+		// that's enough.
+		Changer dummy = make_change(pi.change_, Change(),
+		                            pi.change_.type == Change::INSERTED);
 		InsetText::draw(pi, textx, texty);
 		break;
+	}
 	case ButtonOnly:
 		break;
 	case NoButton:
@@ -279,38 +289,43 @@ void InsetCollapsable::draw(PainterInfo & pi, int x, int y) const
 	case Corners:
 		textx = x;
 		texty = baseline;
+		{	// We will take care of the frame and the change tracking cue
+			// ourselves, below.
+			Changer dummy = make_change(pi.change_, Change());
 			const_cast<InsetCollapsable *>(this)->setDrawFrame(false);
 			InsetText::draw(pi, textx, texty);
 			const_cast<InsetCollapsable *>(this)->setDrawFrame(true);
+		}
 
 		int desc = textdim.descent();
-		if (geometry(bv) == Corners)
+		if (g == Corners)
 			desc -= 3;
 
+		// Colour the frame according to the change type. (Like for tables.)
+		Color colour = pi.change_.changed() ? pi.change_.color()
+		                                    : Color_foreground;
 		const int xx1 = x + TEXT_TO_INSET_OFFSET - 1;
 		const int xx2 = x + textdim.wid - TEXT_TO_INSET_OFFSET + 1;
 		pi.pain.line(xx1, y + desc - 4,
-			     xx1, y + desc,
-			Color_foreground);
+		             xx1, y + desc, colour);
 		if (status_ == Open)
 			pi.pain.line(xx1, y + desc,
-				xx2, y + desc,
-				Color_foreground);
+			             xx2, y + desc, colour);
 		else {
 			// Make status_ value visible:
 			pi.pain.line(xx1, y + desc,
-				xx1 + 4, y + desc,
-				Color_foreground);
+			             xx1 + 4, y + desc, colour);
 			pi.pain.line(xx2 - 4, y + desc,
-				xx2, y + desc,
-				Color_foreground);
+			             xx2, y + desc, colour);
 		}
 		pi.pain.line(x + textdim.wid - 3, y + desc, x + textdim.wid - 3,
-			y + desc - 4, Color_foreground);
+		             y + desc - 4, colour);
 
 		// the label below the text. Can be toggled.
-		if (geometry(bv) == SubLabel) {
+		if (g == SubLabel) {
 			FontInfo font(getLabelfont());
+			if (pi.change_.changed())
+				font.setPaintColor(colour);
 			font.realize(sane_font);
 			font.decSize();
 			font.decSize();
@@ -323,20 +338,21 @@ void InsetCollapsable::draw(PainterInfo & pi, int x, int y) const
 				buttonLabel(bv), font, Color_none, Color_none);
 		}
 
+		int const y1 = y - textdim.asc + 3;
 		// a visual cue when the cursor is inside the inset
 		Cursor const & cur = bv.cursor();
 		if (cur.isInside(this)) {
-			y -= textdim.asc;
-			y += 3;
-			pi.pain.line(xx1, y + 4, xx1, y, Color_foreground);
-			pi.pain.line(xx1 + 4, y, xx1, y, Color_foreground);
-			pi.pain.line(xx2, y + 4, xx2, y, Color_foreground);
-			pi.pain.line(xx2 - 4, y, xx2, y, Color_foreground);
+			pi.pain.line(xx1, y1 + 4, xx1, y1, colour);
+			pi.pain.line(xx1 + 4, y1, xx1, y1, colour);
+			pi.pain.line(xx2, y1 + 4, xx2, y1, colour);
+			pi.pain.line(xx2 - 4, y1, xx2, y1, colour);
 		}
+		// Strike through the inset if deleted and not already handled by
+		// RowPainter.
+		if (pi.change_.deleted() && canPaintChange(bv))
+			pi.change_.paintCue(pi, xx1, y1, xx2, y + desc);
 		break;
 	}
-
-	pi.base.font = tmpfont;
 }
 
 
@@ -618,16 +634,18 @@ string InsetCollapsable::contextMenuName() const
 
 bool InsetCollapsable::canPaintChange(BufferView const & bv) const
 {
+	// return false to let RowPainter draw the change tracking cue consistently
+	// with the surrounding text, when the inset is inline: for buttons, for
+	// non-allowMultiPar insets.
 	switch (geometry(bv)) {
 	case Corners:
 	case SubLabel:
+		return allowMultiPar();
 	case ButtonOnly:
-		// these cases are handled by RowPainter since the inset is inline.
 		return false;
 	default:
 		break;
 	}
-	// TODO: implement the drawing in the remaining cases
 	return true;
 }
 

src/insets/InsetText.cpp

@@ -56,13 +56,13 @@
 #include "frontends/alert.h"
 #include "frontends/Painter.h"
 
+#include "support/bind.h"
 #include "support/convert.h"
 #include "support/debug.h"
 #include "support/gettext.h"
-#include "support/lstrings.h"
-
-#include "support/bind.h"
 #include "support/lassert.h"
+#include "support/lstrings.h"
+#include "support/RefChanger.h"
 
 #include <algorithm>
 
@@ -215,24 +215,48 @@ void InsetText::draw(PainterInfo & pi, int x, int y) const
 {
 	TextMetrics & tm = pi.base.bv->textMetrics(&text_);
 
-	if (drawFrame_ || pi.full_repaint) {
 	int const w = tm.width() + TEXT_TO_INSET_OFFSET;
 	int const yframe = y - TEXT_TO_INSET_OFFSET - tm.ascent();
 	int const h = tm.height() + 2 * TEXT_TO_INSET_OFFSET;
 	int const xframe = x + TEXT_TO_INSET_OFFSET / 2;
+	bool change_drawn = false;
+	if (drawFrame_ || pi.full_repaint) {
 		if (pi.full_repaint)
 			pi.pain.fillRectangle(xframe, yframe, w, h,
 				pi.backgroundColor(this));
 
+		// Change color of the frame in tracked changes, like for tabulars.
+        // Only do so if the color is not custom. But do so even if RowPainter
+        // handles the strike-through already.
+		Color c;
+		if (pi.change_.changed()
+		    // Originally, these are the colors with role Text, from role() in
+		    // ColorCache.cpp.  The code is duplicated to avoid depending on Qt
+		    // types, and also maybe it need not match in the future.
+		    && (frameColor() == Color_foreground
+		        || frameColor() == Color_cursor
+		        || frameColor() == Color_preview
+		        || frameColor() == Color_tabularline
+		        || frameColor() == Color_previewframe)) {
+			c = pi.change_.color();
+			change_drawn = true;
+		} else
+			c = frameColor();
 		if (drawFrame_)
-			pi.pain.rectangle(xframe, yframe, w, h, frameColor());
+			pi.pain.rectangle(xframe, yframe, w, h, c);
 	}
-	ColorCode const old_color = pi.background_color;
-	pi.background_color = pi.backgroundColor(this, false);
-
+	{
+		Changer dummy = make_change(pi.background_color,
+		                            pi.backgroundColor(this, false));
+		// The change tracking cue must not be inherited
+		Changer dummy2 = make_change(pi.change_, Change());
 		tm.draw(pi, x + TEXT_TO_INSET_OFFSET, y);
-
-	pi.background_color = old_color;
+	}
+	if (canPaintChange(*pi.base.bv) && (!change_drawn || pi.change_.deleted()))
+		// Do not draw the change tracking cue if already done by RowPainter and
+		// do not draw the cue for INSERTED if the information is already in the
+		// color of the frame
+		pi.change_.paintCue(pi, xframe, yframe, xframe + w, yframe + h);
 }
 
 

src/insets/InsetText.h

@@ -63,8 +63,8 @@ public:
 	bool editable() const { return true; }
 	///
 	bool canTrackChanges() const { return true; }
-	///
-	bool canPaintChange(BufferView const &) const { return false; }
+	/// Rely on RowPainter to draw the cue of inline insets.
+	bool canPaintChange(BufferView const &) const { return allowMultiPar(); }
 	///
 	InsetText * asInsetText() { return this; }
 	///