Handle \n chars.

include/mapnik/text/itemizer.hpp

@@ -29,6 +29,7 @@
 // stl
 #include <string>
 #include <list>
+#include <vector>
 
 // ICU
 #include <unicode/unistr.h>
@@ -63,7 +64,13 @@ public:
     void add_text(UnicodeString str, char_properties_ptr format);
     std::list<text_item> const& itemize(unsigned start=0, unsigned end=0);
     void clear();
-    UnicodeString const& get_text() { return text_; }
+    UnicodeString const& get_text() const { return text_; }
+    /** Returns the start and end position of a certain line.
+     *
+     * Only forced line breaks with \n characters are handled here.
+     */
+    std::pair<unsigned, unsigned> get_line(unsigned i) const;
+    unsigned num_lines() const;
 private:
     template<typename T> struct run
     {
@@ -91,6 +98,7 @@ private:
     void create_item_list();
     std::list<text_item> output_;
     template <typename T> typename T::const_iterator find_run(T const& list, unsigned position);
+    std::vector<unsigned> forced_line_breaks_; //Positions of \n characters
 };
 } //ns mapnik
 

include/mapnik/text/layout.hpp

@@ -65,6 +65,9 @@ public:
     double line_height() const { return line_height_; }
 
     void set_first_line(bool first_line);
+
+    unsigned get_first_char() const;
+    unsigned get_last_char() const;
 private:
     glyph_vector glyphs_;
     double line_height_; //Includes line spacing (returned by freetype)
@@ -97,7 +100,7 @@ public:
 
 private:
     void break_line(text_line_ptr line, double wrap_width, unsigned text_ratio);
-    void shape_text(text_line_ptr line, unsigned start, unsigned end);
+    void shape_text(text_line_ptr line);
     void add_line(text_line_ptr line);
 
     //input

src/text/itemizer.cpp

@@ -33,7 +33,7 @@ namespace mapnik
 
 text_itemizer::text_itemizer() : text_(), format_runs_(), direction_runs_(), script_runs_()
 {
-
+    forced_line_breaks_.push_back(0);
 }
 
 void text_itemizer::add_text(UnicodeString str, char_properties_ptr format)
@@ -41,6 +41,11 @@ void text_itemizer::add_text(UnicodeString str, char_properties_ptr format)
     unsigned start = text_.length();
     text_ += str;
     format_runs_.push_back(format_run_t(format, start, text_.length()));
+
+    while ((start = text_.indexOf('\n', start)+1) > 0)
+    {
+        forced_line_breaks_.push_back(start);
+    }
 }
 
 std::list<text_item> const& text_itemizer::itemize(unsigned start, unsigned end)
@@ -60,6 +65,26 @@ void text_itemizer::clear()
     output_.clear();
     text_.remove();
     format_runs_.clear();
+    forced_line_breaks_.clear();
+    forced_line_breaks_.push_back(0);
+}
+
+std::pair<unsigned, unsigned> text_itemizer::get_line(unsigned i) const
+{
+#ifdef MAPNIK_DEBUG
+    if (i >= forced_line_breaks_.size()) return std::make_pair(0, 0);
+#endif
+    if (i == forced_line_breaks_.size()-1)
+    {
+        return std::make_pair(forced_line_breaks_[i], text_.length());
+    }
+    //Note -1 offset to exclude the \n char
+    return std::make_pair(forced_line_breaks_[i], forced_line_breaks_[i+1]-1);
+}
+
+unsigned text_itemizer::num_lines() const
+{
+    return forced_line_breaks_.size();
 }
 
 void text_itemizer::itemize_direction(unsigned start, unsigned end)

src/text/layout.cpp

@@ -56,15 +56,19 @@ void text_layout::add_text(const UnicodeString &str, char_properties_ptr format)
 
 void text_layout::layout(double wrap_width, unsigned text_ratio)
 {
-    text_line_ptr line = boost::make_shared<text_line>(0, itemizer_.get_text().length());
-    shape_text(line, 0, itemizer_.get_text().length()); //Process full text
-    break_line(line, wrap_width, text_ratio); //Break line if neccessary
+    unsigned num_lines = itemizer_.num_lines();
+    for (unsigned i = 0; i < num_lines; i++)
+    {
+        std::pair<unsigned, unsigned> line_limits = itemizer_.get_line(i);
+        text_line_ptr line = boost::make_shared<text_line>(line_limits.first, line_limits.second);
+        shape_text(line);
+        break_line(line, wrap_width, text_ratio); //Break line if neccessary
+    }
 }
 
 
 void text_layout::break_line(text_line_ptr line, double wrap_width, unsigned text_ratio)
 {
-    //TODO: Handle \n chars.
     if (!wrap_width || line->width() < wrap_width)
     {
         add_line(line);
@@ -77,6 +81,7 @@ void text_layout::break_line(text_line_ptr line, double wrap_width, unsigned tex
         double string_width = line->width();
         double string_height = line->line_height();
         for (double i = 1.0; ((wrap_at = string_width/i)/(string_height*i)) > text_ratio && (string_width/i) > wrap_width; i += 1.0) ;
+        wrap_width = wrap_at;
     }
 
     UnicodeString const& text = itemizer_.get_text();
@@ -88,7 +93,7 @@ void text_layout::break_line(text_line_ptr line, double wrap_width, unsigned tex
     breakitr->setText(text);
     unsigned current_line_length = 0;
     unsigned last_break_position = 0;
-    for (unsigned i=0; i<text.length(); i++)
+    for (unsigned i=line->get_first_char(); i<line->get_last_char(); i++)
     {
         //TODO: Char spacing
         std::map<unsigned, double>::const_iterator width_itr = width_map_.find(i);
@@ -99,16 +104,21 @@ void text_layout::break_line(text_line_ptr line, double wrap_width, unsigned tex
         if (current_line_length > wrap_width)
         {
             unsigned break_position = breakitr->preceding(i);
-            if (break_position <= last_break_position)
+            if (break_position <= last_break_position || break_position == BreakIterator::DONE)
             {
                 //A single word is longer than the maximum line width.
                 //Violate line width requirement and choose next break position
                 break_position = breakitr->following(i);
-                std::cout << "Line overflow!\n";
+                if (break_position == BreakIterator::DONE)
+                {
+                    break_position = line->get_last_char();
+                    MAPNIK_LOG_WARN(text_layout) << "Unexpected result in break_line. Trying to recover...\n";
+                }
+//                std::cout << "Line overflow!\n";
             }
-            std::cout << "Line to long ("<< current_line_length << ") at "<< i <<  " going to " << break_position << ". Last break was at " << last_break_position << "\n";
+//            std::cout << "Line to long ("<< current_line_length << ") at "<< i <<  " going to " << break_position << ". Last break was at " << last_break_position << "\n";
             text_line_ptr new_line = boost::make_shared<text_line>(last_break_position, break_position);
-            shape_text(new_line, last_break_position, break_position);
+            shape_text(new_line);
             add_line(new_line);
             last_break_position = break_position;
             i = break_position - 1;
@@ -116,10 +126,18 @@ void text_layout::break_line(text_line_ptr line, double wrap_width, unsigned tex
             current_line_length = 0;
         }
     }
+    if (last_break_position != line->get_last_char())
+    {
+        text_line_ptr new_line = boost::make_shared<text_line>(last_break_position, line->get_last_char());
+        shape_text(new_line);
+        add_line(new_line);
+    }
 }
 
-void text_layout::shape_text(text_line_ptr line, unsigned start, unsigned end)
+void text_layout::shape_text(text_line_ptr line)
 {
+    unsigned start = line->get_first_char();
+    unsigned end = line->get_last_char();
     UnicodeString const& text = itemizer_.get_text();
 
     size_t length = end - start;
@@ -260,4 +278,14 @@ void text_line::set_first_line(bool first_line)
     first_line_ = first_line;
 }
 
+unsigned text_line::get_first_char() const
+{
+    return first_char_;
+}
+
+unsigned text_line::get_last_char() const
+{
+    return last_char_;
+}
+
 } //ns mapnik