Merge pull request #972 from npwoods/fix_text_layout_actual_width

Fix text layout actual width

src/frontend/mame/ui/text.cpp

@@ -78,9 +78,10 @@ CORE IMPLEMENTATION
 //-------------------------------------------------
 
 text_layout::text_layout(render_font &font, float xscale, float yscale, float width, text_layout::text_justify justify, text_layout::word_wrapping wrap)
-	: m_font(font), m_xscale(xscale), m_yscale(yscale), m_width(width), m_maximum_line_width(0.0f), m_justify(justify), m_wrap(wrap), m_current_line(nullptr), m_last_break(0), m_text_position(0), m_truncating(false)
+	: m_font(font), m_xscale(xscale), m_yscale(yscale), m_width(width), m_justify(justify), m_wrap(wrap), m_current_line(nullptr), m_last_break(0), m_text_position(0), m_truncating(false)
 
 {
+	invalidate_calculated_actual_width();
 }
 
 
@@ -89,9 +90,10 @@ text_layout::text_layout(render_font &font, float xscale, float yscale, float wi
 //-------------------------------------------------
 
 text_layout::text_layout(text_layout &&that)
-	: m_font(that.m_font), m_xscale(that.m_xscale), m_yscale(that.m_yscale), m_width(that.m_width), m_maximum_line_width(that.m_maximum_line_width), m_justify(that.m_justify), m_wrap(that.m_wrap), m_lines(std::move(that.m_lines)),
+	: m_font(that.m_font), m_xscale(that.m_xscale), m_yscale(that.m_yscale), m_width(that.m_width), m_calculated_actual_width(that.m_calculated_actual_width), m_justify(that.m_justify), m_wrap(that.m_wrap), m_lines(std::move(that.m_lines)),
 	  m_current_line(that.m_current_line), m_last_break(that.m_last_break), m_text_position(that.m_text_position), m_truncating(false)
 {
+	that.invalidate_calculated_actual_width();
 }
 
 
@@ -115,6 +117,9 @@ void text_layout::add_text(const char *text, const char_style &style)
 
 	while(position < text_length)
 	{
+		// adding a character - we might change the width
+		invalidate_calculated_actual_width();
+
 		// do we need to create a new line?
 		if (m_current_line == nullptr)
 		{
@@ -159,7 +164,6 @@ void text_layout::add_text(const char *text, const char_style &style)
 				start_new_line(LEFT, style.size);
 
 			// and then close up the current line
-			update_maximum_line_width();
 			m_current_line = nullptr;
 		}
 		else if (!m_truncating)
@@ -202,12 +206,12 @@ void text_layout::add_text(const char *text, const char_style &style)
 
 
 //-------------------------------------------------
-//  update_maximum_line_width
+//  invalidate_calculated_actual_width
 //-------------------------------------------------
 
-void text_layout::update_maximum_line_width()
+void text_layout::invalidate_calculated_actual_width()
 {
-	m_maximum_line_width = actual_width();
+	m_calculated_actual_width = -1;
 }
 
 
@@ -245,8 +249,18 @@ float text_layout::actual_left() const
 
 float text_layout::actual_width() const
 {
-	float current_line_width = m_current_line ? m_current_line->width() : 0;
+	// do we need to calculate the width?
-	return std::max(m_maximum_line_width, current_line_width);
+	if (m_calculated_actual_width < 0)
+	{
+		// calculate the actual width
+		m_calculated_actual_width = 0;
+		for (const auto &line : m_lines)
+			m_calculated_actual_width = std::max(m_calculated_actual_width, line->width());
+
+	}
+
+	// return it
+	return m_calculated_actual_width;
 }
 
 
@@ -275,7 +289,6 @@ void text_layout::start_new_line(text_layout::text_justify justify, float height
 	std::unique_ptr<line> new_line(global_alloc_clear<line>(*this, justify, actual_height(), height * yscale()));
 
 	// update the current line
-	update_maximum_line_width();
 	m_current_line = new_line.get();
 	m_last_break = 0;
 	m_truncating = false;

src/frontend/mame/ui/text.h

@@ -66,7 +66,7 @@ public:
 	void restyle(size_t start, size_t span, rgb_t *fgcolor, rgb_t *bgcolor);
 	int get_wrap_info(std::vector<int> &xstart, std::vector<int> &xend) const;
 	void emit(render_container *container, float x, float y);
-	void add_text(const char *text, rgb_t fgcolor = rgb_t::white, rgb_t bgcolor = rgb_t(0,0,0,0), float size = 1.0)
+	void add_text(const char *text, rgb_t fgcolor = rgb_t::white, rgb_t bgcolor = rgb_t::transparent, float size = 1.0)
 	{
 		// create the style
 		char_style style = { 0, };
@@ -140,7 +140,7 @@ private:
 	float m_xscale;
 	float m_yscale;
 	float m_width;
-	float m_maximum_line_width;
+	mutable float m_calculated_actual_width;
 	text_justify m_justify;
 	word_wrapping m_wrap;
 	std::vector<std::unique_ptr<line>> m_lines;
@@ -155,7 +155,7 @@ private:
 	float get_char_width(unicode_char ch, float size);
 	void truncate_wrap();
 	void word_wrap();
-	void update_maximum_line_width();
+	void invalidate_calculated_actual_width();
 };
 
 } // namespace ui

src/frontend/mame/ui/ui.cpp

@@ -584,8 +584,11 @@ void mame_ui_manager::draw_text_full(render_container *container, const char *or
 
 void mame_ui_manager::draw_text_box(render_container *container, const char *text, ui::text_layout::text_justify justify, float xpos, float ypos, rgb_t backcolor)
 {
+	// cap the maximum width
+	float maximum_width = 1.0f - UI_BOX_LR_BORDER * 2;
+
 	// create a layout
-	ui::text_layout layout = create_layout(container, 1.0f, justify);
+	ui::text_layout layout = create_layout(container, maximum_width, justify);
 
 	// add text to it
 	layout.add_text(text);