Expose more information about text layout.

doc/type/style.txt

@@ -110,9 +110,10 @@ The rest of the properties depend on the type of [[type:field]] this style is fo
 		 			 			 		<img src="style-text-mask.png" alt=""/><br/>
 		 			 			 		The same mask image is also used to determine the size and shape of the box.
 		 			 			 		To include a certain pixel in the size/shape but not allow text to be placed there, it can be made dark gray (a value less than 128).
-| ^^^		@content width@		[[type:double]]		''automatic''	When read from a script, gives the width of the current content in this box.
+| ^^^		@layout@		[[type:text layout]]		''automatic''	When read from a script, gives information on the layout of text in this box.
-| ^^^		@content height@	[[type:double]]		''automatic''	When read from a script, gives the height of the current content in this box.
+| ^^^		@content width@		[[type:double]]		''automatic''	When read from a script, gives the width of the current content in this box. Equivalent to @layout.width@
-| ^^^		@content lines@		[[type:int]]		''automatic''	When read from a script, gives the number of lines of the current content in this box.
+| ^^^		@content height@	[[type:double]]		''automatic''	When read from a script, gives the height of the current content in this box. Equivalent to @layout.height@
+| ^^^		@content lines@		[[type:int]]		''automatic''	When read from a script, gives the number of lines of the current content in this box. Equivalent to @length(layout.lines)@
 	
 !	<<<	<<<	<<<	<<<
 | @"choice"@,<br/>@"multiple choice"@,<br/>@"boolean"@

doc/type/text_layout.txt

@@ -0,0 +1,28 @@
+Data type: text layout info
+
+DOC_MSE_VERSION: since 2.0.2
+
+This type contains information on rendered text.
+
+The text is devided into 'lines', 'paragraphs' and 'blocks.
+A line is a line on the screen.
+A paragraph is one or more lines, ending in an explicit line break, a "\n" in the text.
+A block is one or more paragraphs, ending in a line, "<line>\n</line>".
+
+It is possible to dig deeper into blocks, for example
+
+> card_style.text.layout.blocks[1].lines[0].middle
+
+Is the middle of the first line of the second block.
+
+--Properties--
+! Property	Type					Description
+| @width@		[[type:double]]		Width of this line or group of lines in pixels.
+| @height@	[[type:double]]		Height of this line or group of lines in pixels.
+| @top@			[[type:double]]		Top y coordinate
+| @middle@	[[type:double]]		Middle y coordinate
+| @bottom@	[[type:double]]		Bottom y coordinate
+| @lines@				[[type:list]] of [[type:text layout]]s	The lines in this part of the text.
+| @paragraphs@	[[type:list]] of [[type:text layout]]s	The paragraphs in this part of the text.
+| @blocks@			[[type:list]] of [[type:text layout]]s	The blocks in this part of the text.
+| @separators@	[[type:list]] of [[type:double]]s	The y coordinates of separators between blocks.

src/data/field/text.cpp

@@ -97,11 +97,38 @@ void TextStyle::checkContentDependencies(Context& ctx, const Dependency& dep) co
   alignment.initDependencies(ctx, dep);
 }
 
-template <typename T> void reflect_content(T& handler,         const TextStyle& ts) {}
+template <typename T> void reflect_layout(T& handler,         const TextStyle& ts) {}
-template <>           void reflect_content(GetMember& handler, const TextStyle& ts) {
+template <>           void reflect_layout(GetMember& handler, const TextStyle& ts) {
-  REFLECT_N("content_width",  ts.content_width);
+  REFLECT(ts.layout);
-  REFLECT_N("content_height", ts.content_height);
+  if (ts.layout) {
-  REFLECT_N("content_lines",  ts.content_lines);
+    REFLECT_N("content_width",  ts.layout->width);
+    REFLECT_N("content_height", ts.layout->height);
+    REFLECT_N("content_lines",  ts.layout->lines.size());
+  } else {
+    REFLECT_N("content_width", 0.);
+    REFLECT_N("content_height", 0.);
+    REFLECT_N("content_lines", 0);
+  }
+}
+
+template <> void GetMember::handle(LineLayout const& obj) { obj.reflect(*this); }
+template <> void GetDefaultMember::handle(LineLayout const& obj) {}
+void LineLayout::reflect(GetMember& handler) const {
+  REFLECT(width);
+  REFLECT(top);
+  REFLECT(height);
+  REFLECT_N("bottom", bottom());
+  REFLECT_N("middle", top + height/2);
+  if (type > Type::LINE) REFLECT(lines);
+  if (type > Type::PARAGRAPH) REFLECT(paragraphs);
+  if (type > Type::BLOCK) REFLECT(blocks);
+}
+
+template <> void GetMember::handle(TextLayout const& obj) { obj.reflect(*this); }
+template <> void GetDefaultMember::handle(TextLayout const& obj) {}
+void TextLayout::reflect(GetMember& handler) const {
+  REFLECT_BASE(LineLayout);
+  REFLECT(separators);
 }
 
 IMPLEMENT_REFLECTION(TextStyle) {
@@ -127,7 +154,7 @@ IMPLEMENT_REFLECTION(TextStyle) {
   REFLECT(line_height_line_max);
   REFLECT(paragraph_height);
   REFLECT(direction);
-  reflect_content(handler, *this);
+  reflect_layout(handler, *this);
 }
 
 // ----------------------------------------------------------------------------- : TextValue

src/data/field/text.hpp

@@ -25,6 +25,8 @@ DECLARE_POINTER_TYPE(TextField);
 DECLARE_POINTER_TYPE(TextStyle);
 DECLARE_POINTER_TYPE(TextValue);
 DECLARE_POINTER_TYPE(TextBackground);
+DECLARE_POINTER_TYPE(TextLayout);
+DECLARE_POINTER_TYPE(LineLayout);
 
 /// A field for values containing tagged text
 class TextField : public Field {
@@ -44,6 +46,26 @@ class TextField : public Field {
 
 // ----------------------------------------------------------------------------- : TextStyle
 
+// information coming from text rendering
+class LineLayout : public IntrusivePtrVirtualBase {
+public:
+  double width, top, height;
+  enum class Type { LINE, PARAGRAPH, BLOCK, ALL } type;
+  vector<LineLayoutP> lines, paragraphs, blocks;
+
+  LineLayout() {}
+  LineLayout(double width, double top, double height, Type type) : width(width), top(top), height(height), type(type) {}
+  inline double bottom() const { return top+height; }
+  void reflect(GetMember& gm) const;
+};
+
+class TextLayout : public LineLayout {
+public:
+  vector<double> separators;
+  TextLayout() : LineLayout(0,0,0,Type::ALL) {}
+  void reflect(GetMember& gm) const;
+};
+
 /// The Style for a TextField
 class TextStyle : public Style {
   public:
@@ -69,6 +91,7 @@ class TextStyle : public Style {
       paragraph_height;                       ///< Fixed height of paragraphs
   Direction direction;                        ///< In what direction is text layed out?
   // information from text rendering
+  TextLayoutP layout;
   double content_width, content_height;       ///< Size of the rendered text
   int    content_lines;                       ///< Number of rendered lines
   

src/render/text/viewer.cpp

@@ -344,24 +344,55 @@ void TextViewer::prepareElements(const String& text, const TextStyle& style, Con
 
 // ----------------------------------------------------------------------------- : Layout
 
+
+void update_size(LineLayout& layout, TextViewer::Line const& l) {
+  layout.width = max(layout.width, l.width());
+  layout.height = max(layout.height, l.bottom() - layout.top);
+}
+
+TextLayoutP TextViewer::extractLayoutInfo() const {
+  // store information about the content/layout
+  TextLayoutP layout = make_intrusive<TextLayout>();
+  LineBreak last_break = BREAK_LINE;
+  LineLayoutP paragraph, block;
+  for (auto const& l : lines) {
+    LineLayoutP line = make_intrusive<LineLayout>(l.width(), l.top, l.line_height, LineLayout::Type::LINE);
+    if (!block) {
+      block = make_intrusive<LineLayout>(*line);
+      block->type = LineLayout::Type::BLOCK;
+      layout->blocks.push_back(block);
+    }
+    if (!paragraph) {
+      paragraph = make_intrusive<LineLayout>(*line);
+      paragraph->type = LineLayout::Type::PARAGRAPH;
+      block->paragraphs.push_back(paragraph);
+      layout->paragraphs.push_back(paragraph);
+    }
+    paragraph->lines.push_back(line);
+    block->lines.push_back(line);
+    layout->lines.push_back(line);
+    if (l.line_height > 0) {
+      update_size(*paragraph, l);
+      update_size(*block, l);
+      update_size(*layout, l);
+    }
+    if (l.break_after == BREAK_LINE) {
+      paragraph = block = nullptr;
+    } else if (l.break_after == BREAK_HARD) {
+      paragraph = nullptr;
+    }
+  }
+  for (size_t i=0; i+1 < layout->blocks.size() ; ++i) {
+    layout->separators.push_back((layout->blocks[i]->bottom() + layout->blocks[i]->top)/2);
+  }
+  return layout;
+}
+
 void TextViewer::prepareLines(RotatedDC& dc, const String& text, TextStyle& style, Context& ctx) {
   vector<CharInfo> chars;
   prepareLinesTryScales(dc, text, style, chars);
   assert(!lines.empty());
   
-  // store information about the content/layout, allow this to change alignment
-  style.content_width  = 0;
-  FOR_EACH(l, lines) {
-    style.content_width = max(style.content_width, l.width());
-  }
-  style.content_height = 0;
-  FOR_EACH_REVERSE(l, lines) {
-    style.content_height = l.top + l.line_height;
-    if (l.line_height) break; // not an empty line
-  }
-  style.content_lines = (int)lines.size();
-  style.alignment.update(ctx); // allow this to affect the alignment
-  
   // no text, find a dummy height for the single line we have
   if (lines.size() == 1 && lines[0].width() < 0.0001) {
     if (style.always_symbol && style.symbol_font.valid()) {
@@ -372,6 +403,12 @@ void TextViewer::prepareLines(RotatedDC& dc, const String& text, TextStyle& styl
     }
   }
   
+  // store information about the content/layout, allow this to change alignment
+  if (style.alignment.isScripted()) {
+    style.layout = extractLayoutInfo();
+    style.alignment.update(ctx); // allow this to affect the alignment
+  }
+  
   // align
   alignLines(dc, chars, style);
   
@@ -382,6 +419,9 @@ void TextViewer::prepareLines(RotatedDC& dc, const String& text, TextStyle& styl
     lines[0].line_height =  h;
     lines[0].top         -= h;
   }
+
+  // make layout available to scripts
+  style.layout = extractLayoutInfo();
 }
 
 // bound on max_scale, given that scale fits and produces the given lines
@@ -465,7 +505,7 @@ void TextViewer::prepareLinesTryScales(RotatedDC& dc, const String& text, const
     max_scale = min(max_scale, bound_on_max_scale(dc,style,lines,scale));
   }
   
-  // The common case optimization fialed, try a binary search
+  // The common case optimization failed, try a binary search
   // Invariant:
   //    a. The text fits at min_scale (or we force it anyway)
   //    b. but not at max_scale

src/render/text/viewer.hpp

@@ -145,6 +145,9 @@ class TextViewer {
   /// Align the lines of a single paragraph (a set of lines)
   void alignParagraph(size_t start_line, size_t end_line, const vector<CharInfo>& chars, const TextStyle& style, const RealRect& box);
   
+  /// Make layout info available to scripts
+  TextLayoutP extractLayoutInfo() const;
+
   /// Find the line the given index is on, returns the first line if the index is not found
   const Line& findLine(size_t index) const;