Cleanup Painter text() API

* remove optional arguments to the helpers that use a FontInfo
* add a textwidth argument to the text() methods that are used by rowpainter.

Now textwidth is only computed if a null value was passed to the
text() method. This means that in the use case of rowpainter, no
textwidth needs to be computed.

development/PAINTING_ANALYSIS

@@ -60,6 +60,7 @@ cursor.
 
 * Proposals
 
+
 * Clean-up of drawing code
 
 The goal is to make painting with drawing disable fast enough that it
@@ -81,7 +82,7 @@ paintInset needs to be called.
 The only thing we want to do here is to set inset positions (for
 text). The other insets still use the painter with drawing disabled.
 
-** Painter::text
+** DONE Painter::text
 
 We cannot remove (or make private) the version that uses a
 FontInfo because it is used by PainterInfo::draw. Document this and
@@ -99,6 +100,26 @@ version.
 
 ==> more versions, no optional parameters.
 
+** make Inset::display() more useful
+
+Extending the DisplayType enum would allow to remove special cases
+from the code.
+
+The enumeration could be like
+: Inline = 0
+: BreakBefore = 1 // break row before this inset
+: BreakAfter = 2 // break row after this inset
+: CanBreakAfter = 4 // optionally break row after this inset
+: AlignLeft = 8
+: AlignRight = 16
+: NoBoundary = 32 // do not allow cursor to go at the end of the row
+:                 //before display inset
+: Display = BreakBefore|BreakAfter
+
+A display equation would be Display, other could be Display|AlignLeft
+BreakAfter can be used by Newline or separator insets
+CanBreakAfter can be used by the optional hyphen InsetSpecialChar.
+
 ** Set inset position during metrics phase
 
 In order to do that, a no-paint drawing will be initiated after every

src/RowPainter.cpp

@@ -246,13 +246,14 @@ void RowPainter::paintStringAndSel(Row::Element const & e)
 		Color const col = e.change.changed() ? e.change.color()
 		                                     : Color_selectiontext;
 		copy.fontInfo().setPaintColor(col);
-		pi_.pain.text(int(x_), yo_, e.str, copy, e.extra);
+		pi_.pain.text(int(x_), yo_, e.str, copy, e.extra, e.full_width());
 	} else if (!some_sel) {
-		pi_.pain.text(int(x_), yo_, e.str, e.font, e.extra);
+		pi_.pain.text(int(x_), yo_, e.str, e.font, e.extra, e.full_width());
 	} else {
 		pi_.pain.text(int(x_), yo_, e.str, e.font, Color_selectiontext,
 		              max(row_.sel_beg, e.pos) - e.pos,
-                        min(row_.sel_end, e.endpos) - e.pos, e.extra);
+		              min(row_.sel_end, e.endpos) - e.pos,
+		              e.extra, e.full_width());
 	}
 	x_ += e.full_width();
 }

src/frontends/Painter.h

@@ -133,21 +133,17 @@ public:
 	virtual void image(int x, int y, int w, int h,
 		graphics::Image const & image) = 0;
 
-	/** draw a character at position x, y (y is the baseline)
+	/// draw a string at position x, y (y is the baseline).
-	 */
+	virtual void text(int x, int y, docstring const & str, FontInfo const & f) = 0;
-	virtual void text(int x, int y, char_type c, FontInfo const & f) = 0;
 
-	/** draw a string at position x, y (y is the baseline). The
+	/// draw a char at position x, y (y is the baseline)
-	 * text direction is given by \c rtl.
+	virtual void text(int x, int y, char_type c, FontInfo const & f) = 0;
-	 */
-	virtual void text(int x, int y, docstring const & str, FontInfo const & f,
-                      bool rtl = false, double wordspacing = 0.0) = 0;
 
 	/** draw a string at position x, y (y is the baseline). The
 	 * text direction is enforced by the \c Font.
 	 */
 	virtual void text(int x, int y, docstring const & str, Font const & f,
-                      double wordspacing = 0.0) = 0;
+                      double wordspacing, double textwidth) = 0;
 
 	/** draw a string at position x, y (y is the baseline), but
 	 * make sure that the part between \c from and \c to is in
@@ -155,7 +151,7 @@ public:
 	 */
 	virtual void text(int x, int y, docstring const & str, Font const & f,
 	                  Color other, size_type from, size_type to,
-	                  double const wordspacing) = 0;
+                      double wordspacing, double textwidth) = 0;
 
 	void setDrawingEnabled(bool drawing_enabled)
 	{ drawing_enabled_ = drawing_enabled; }

src/frontends/qt4/GuiPainter.cpp

@@ -333,6 +333,12 @@ void GuiPainter::text(int x, int y, char_type c, FontInfo const & f)
 }
 
 
+void GuiPainter::text(int x, int y, docstring const & s, FontInfo const & f)
+{
+	text(x, y, s, f, false, 0.0, 0.0);
+}
+
+
 void GuiPainter::do_drawText(int x, int y, QString str, bool rtl, FontInfo const & f, QFont ff)
 {
 	setQPainterPen(computeColor(f.realColor()));
@@ -370,7 +376,7 @@ void GuiPainter::do_drawText(int x, int y, QString str, bool rtl, FontInfo const
 
 void GuiPainter::text(int x, int y, docstring const & s,
                       FontInfo const & f, bool const rtl,
-                      double const wordspacing)
+                      double const wordspacing, double const tw)
 {
 	//LYXERR0("text: x=" << x << ", s=" << s);
 	if (s.empty() || !isDrawingEnabled())
@@ -383,7 +389,7 @@ void GuiPainter::text(int x, int y, docstring const & s,
 	frontend. This is just wrong, because the symbol is no UCS4 character at
 	all. You can think of this number as the code point of the symbol in a
 	custom symbol encoding. It works because this char_type is later on again
-	interpreted as a position in the font again.
+	interpreted as a position in the font.
 	The correct solution would be to have extra functions for symbols, but that
 	would require to duplicate a lot of frontend and mathed support code.
 	*/
@@ -400,11 +406,12 @@ void GuiPainter::text(int x, int y, docstring const & s,
 	ff.setWordSpacing(wordspacing);
 	GuiFontMetrics const & fm = getFontMetrics(f);
 
-	// Here we use the font width cache instead of
+	int textwidth = 0;
-	//   textwidth = fontMetrics().width(str);
+	if (tw == 0.0)
-	// because the above is awfully expensive on MacOSX
 		// Note that we have to take in account space stretching (word spacing)
-	int const textwidth = fm.width(s) + count(s.begin(), s.end(), ' ') * wordspacing;
+		textwidth = fm.width(s) + count(s.begin(), s.end(), ' ') * wordspacing;
+	else
+		textwidth = static_cast<int>(tw);
 
 	textDecoration(f, x, y, textwidth);
 
@@ -464,15 +471,15 @@ void GuiPainter::text(int x, int y, docstring const & s,
 
 
 void GuiPainter::text(int x, int y, docstring const & str, Font const & f,
-                      double const wordspacing)
+                      double const wordspacing, double const tw)
 {
-	text(x, y, str, f.fontInfo(), f.isVisibleRightToLeft(), wordspacing);
+	text(x, y, str, f.fontInfo(), f.isVisibleRightToLeft(), wordspacing, tw);
 }
 
 
 void GuiPainter::text(int x, int y, docstring const & str, Font const & f,
                       Color other, size_type const from, size_type const to,
-                      double const wordspacing)
+                      double const wordspacing, double const tw)
 {
 	GuiFontMetrics const & fm = getFontMetrics(f.fontInfo());
 	FontInfo fi = f.fontInfo();
@@ -491,7 +498,7 @@ void GuiPainter::text(int x, int y, docstring const & str, Font const & f,
 	fi.setPaintColor(other);
 	QRegion const clip(x + xmin, y - ascent, xmax - xmin, height);
 	setClipRegion(clip);
-	text(x, y, str, fi, rtl, wordspacing);
+	text(x, y, str, fi, rtl, wordspacing, tw);
 
 	// Then the part in normal color
 	// Note that in Qt5, it is not possible to use Qt::UniteClip,
@@ -499,7 +506,7 @@ void GuiPainter::text(int x, int y, docstring const & str, Font const & f,
 	fi.setPaintColor(orig);
 	QRegion region(viewport());
 	setClipRegion(region - clip);
-	text(x, y, str, fi, rtl, wordspacing);
+	text(x, y, str, fi, rtl, wordspacing, tw);
 	setClipping(false);
 }
 

src/frontends/qt4/GuiPainter.h

@@ -105,17 +105,17 @@ public:
 	virtual void image(int x, int y, int w, int h,
 		lyx::graphics::Image const & image);
 
-	/** draw a string at position x, y (y is the baseline). The
+	/// draw a string at position x, y (y is the baseline).
-	 * text direction is given by \c rtl.
+	virtual void text(int x, int y, docstring const & str, FontInfo const & f);
-	 */
+
-	virtual void text(int x, int y, docstring const & str, FontInfo const & f,
+	/// draw a char at position x, y (y is the baseline)
-                      bool rtl = false, double wordspacing = 0.0);
+	virtual void text(int x, int y, char_type c, FontInfo const & f);
 
 	/** draw a string at position x, y (y is the baseline). The
 	 * text direction is enforced by the \c Font.
 	 */
 	virtual void text(int x, int y, docstring const & str, Font const & f,
-                      double wordspacing = 0.0);
+                      double wordspacing, double textwidth);
 
 	/** draw a string at position x, y (y is the baseline), but
 	 * make sure that the part between \c from and \c to is in
@@ -123,10 +123,7 @@ public:
 	 */
 	virtual void text(int x, int y, docstring const & str, Font const & f,
 	                  Color other, size_type from, size_type to,
-                      double const wordspacing);
+                      double wordspacing, double textwidth);
-
-	/// draw a char at position x, y (y is the baseline)
-	virtual void text(int x, int y, char_type c, FontInfo const & f);
 
 	///
 	virtual void textDecoration(FontInfo const & f, int x, int y, int width);
@@ -186,6 +183,11 @@ private:
 	// Helper for text() method
 	void do_drawText(int x, int y, QString str, bool rtl, FontInfo const & f, QFont ff);
 
+	// Real text() method
+	void text(int x, int y, docstring const & s,
+              FontInfo const & f, bool const rtl,
+              double const wordspacing, double tw);
+
 	QColor current_color_;
 	Painter::line_style current_ls_;
 	int current_lw_;