Properly handle multibyte UTF-8 in Entry and Text

diff --git a/source/entry.cpp b/source/entry.cpp
index 8b638dea2206f07fd4fb6bace8353c336fcc67c5..6554f7cb1b5ada9e52cf6cad423baedc9f30337d 100644 (file)
--- a/source/entry.cpp
+++ b/source/entry.cpp
@@ -269,14 +269,20 @@ bool Entry::key_press(unsigned key, unsigned mod)
                if(selection_active)
                        erase_selection(true);
                else if(edit_pos>0)
-                       erase(edit_pos-1, 1);
+               {
+                       unsigned start_pos = text.move_offset(edit_pos, -1);
+                       erase(start_pos, edit_pos-start_pos);
+               }
        }
        else if(key==Input::KEY_DELETE)
        {
                if(selection_active)
                        erase_selection(true);
                else
-                       erase(edit_pos, 1);
+               {
+                       unsigned end_pos = text.move_offset(edit_pos, 1);
+                       erase(edit_pos, end_pos-edit_pos);
+               }
        }
        else if(key==Input::KEY_ENTER && multiline)
                insert(edit_pos, "\n");
@@ -378,15 +384,9 @@ void Entry::on_style_change()
 void Entry::move_edit_position(Navigation nav, bool select)
 {
        if(nav==NAV_LEFT)
-       {
-               if(edit_pos>0)
-                       set_edit_position(edit_pos-1, select);
-       }
+               set_edit_position(text.move_offset(edit_pos, -1), select);
        else if(nav==NAV_RIGHT)
-       {
-               if(edit_pos<text.size())
-                       set_edit_position(edit_pos+1, select);
-       }
+               set_edit_position(text.move_offset(edit_pos, 1), select);
        else if(nav==NAV_DOWN)
        {
                unsigned row, col;
@@ -399,6 +399,8 @@ void Entry::move_edit_position(Navigation nav, bool select)
                text.offset_to_coords(edit_pos, row, col);
                set_edit_position((row>0 ? text.coords_to_offset(row-1, col) : 0), select);
        }
+       else
+               throw invalid_argument("Entry::move_edit_position");
 }
 
 void Entry::set_edit_position(unsigned ep, bool select)

diff --git a/source/text.cpp b/source/text.cpp
index 45b6567db5c640bcec37e0dfccee877323fde230..a3ed762a2cd560754dcd973094e547d5977eae20 100644 (file)
--- a/source/text.cpp
+++ b/source/text.cpp
@@ -42,7 +42,7 @@ void Text::set_style(const Style *s)
                const GL::Font &font = style->get_font();
                float font_size = style->get_font_size();
                for(vector<Line>::iterator i=lines.begin(); i!=lines.end(); ++i)
-                       i->width = static_cast<unsigned>(font.get_string_width(text.substr(i->start, i->length))*font_size);
+                       i->width = static_cast<unsigned>(font.get_string_width(text.substr(i->start, i->bytes))*font_size);
        }
 }
 
@@ -81,16 +81,19 @@ void Text::set(const string &t)
 
 void Text::erase(unsigned pos, unsigned len)
 {
+       check_alignment(pos);
+       check_alignment(pos+len);
        text.erase(pos, len);
 
        vector<Line>::iterator i;
-       for(i=lines.begin(); (i!=lines.end() && i->start+i->length<pos); ++i) ;
+       for(i=lines.begin(); (i!=lines.end() && i->start+i->bytes<pos); ++i) ;
 
-       if(pos+len>i->start+i->length)
+       if(pos+len>i->start+i->bytes)
                find_lines();
        else
        {
-               i->length -= len;
+               i->bytes -= len;
+               i->length = count_characters(i->start, i->bytes);
 
                for(++i; i!=lines.end(); ++i)
                        i->start -= len;
@@ -99,6 +102,7 @@ void Text::erase(unsigned pos, unsigned len)
 
 void Text::insert(unsigned pos, const string &s)
 {
+       check_alignment(pos);
        text.insert(pos, s);
 
        if(s.find('\n')!=string::npos)
@@ -106,9 +110,10 @@ void Text::insert(unsigned pos, const string &s)
        else
        {
                vector<Line>::iterator i;
-               for(i=lines.begin(); (i!=lines.end() && i->start+i->length<pos); ++i) ;
+               for(i=lines.begin(); (i!=lines.end() && i->start+i->bytes<pos); ++i) ;
 
-               i->length += s.size();
+               i->bytes += s.size();
+               i->length = count_characters(i->start, i->bytes);
 
                for(++i; i!=lines.end(); ++i)
                        i->start += s.size();
@@ -139,6 +144,32 @@ unsigned Text::get_line_length(unsigned i) const
        return lines[i].length;
 }
 
+unsigned Text::move_offset(unsigned offs, int change) const
+{
+       check_alignment(offs);
+       if(!change)
+               return offs;
+
+       StringCodec::Utf8::Decoder dec(StringCodec::IGNORE_ERRORS);
+       string::const_iterator i = text.begin()+offs;
+       if(change>0)
+       {
+               for(; change>0; --change)
+                       dec.decode_char(text, i);
+       }
+       else
+       {
+               while(change<0 && i!=text.begin())
+               {
+                       --i;
+                       string::const_iterator j = i;
+                       if(dec.decode_char(text, j)!=-1)
+                               ++change;
+               }
+       }
+       return i-text.begin();
+}
+
 void Text::offset_to_coords(unsigned offs, unsigned &row, unsigned &col) const
 {
        if(lines.empty())
@@ -149,10 +180,13 @@ void Text::offset_to_coords(unsigned offs, unsigned &row, unsigned &col) const
        }
 
        for(unsigned i=0; i<lines.size(); ++i)
-               if(offs>=lines[i].start && offs<=lines[i].start+lines[i].length)
+               if(offs>=lines[i].start && offs<=lines[i].start+lines[i].bytes)
                {
                        row = i;
-                       col = offs-lines[i].start;
+                       if(lines[i].length==lines[i].bytes)
+                               col = offs-lines[i].start;
+                       else
+                               col = count_characters(lines[i].start, offs-lines[i].start);
                        return;
                }
 }
@@ -161,8 +195,20 @@ unsigned Text::coords_to_offset(unsigned row, unsigned col) const
 {
        if(row>=lines.size())
                return text.size();
+       const Line &line = lines[row];
+       if(col>line.length)
+               col = line.length;
 
-       return lines[row].start+min(col, lines[row].length);
+       if(line.length==line.bytes)
+               return line.start+col;
+       else
+       {
+               StringCodec::Utf8::Decoder dec;
+               string::const_iterator i = text.begin()+line.start;
+               for(col=min(col, line.length); col; --col)
+                       dec.decode_char(text, i);
+               return i-text.begin();
+       }
 }
 
 Geometry Text::coords_to_geometry(const Part &part, const Geometry &parent, unsigned first_row, unsigned row, unsigned col) const
@@ -219,11 +265,12 @@ void Text::find_lines()
 
                Line line;
                line.start = start;
-               line.length = (newline==string::npos ? text.size() : newline)-start;
+               line.bytes = (newline==string::npos ? text.size() : newline)-start;
+               line.length = count_characters(line.start, line.bytes);
                line.width = line.length;
                if(style)
                {
-                       string str = text.substr(line.start, line.length);
+                       string str = text.substr(line.start, line.bytes);
                        line.width = static_cast<unsigned>(style->get_font().get_string_width(str)*font_size);
                }
                lines.push_back(line);
@@ -234,6 +281,24 @@ void Text::find_lines()
        }
 }
 
+unsigned Text::count_characters(unsigned start, unsigned bytes) const
+{
+       StringCodec::Utf8::Decoder dec;
+       string::const_iterator i = text.begin()+start;
+       string::const_iterator end = i+bytes;
+       unsigned count = 0;
+       for(; i<end; dec.decode_char(text, i))
+               ++count;
+       return count;
+}
+
+void Text::check_alignment(unsigned offs) const
+{
+       StringCodec::Utf8::Decoder dec;
+       string::const_iterator i = text.begin()+offs;
+       dec.decode_char(text, i);
+}
+
 template<typename T>
 void Text::process_lines(const Part &part, const Geometry &parent, unsigned first_row, void (Text::*func)(unsigned, const Geometry &, T &) const, T &data) const
 {
@@ -271,14 +336,24 @@ void Text::build_line(unsigned i, const Geometry &rgeom, RenderData &data) const
        data.bld->matrix() *= GL::Matrix::translation(rgeom.x, rgeom.y, 0);
        data.bld->matrix() *= GL::Matrix::scaling(style->get_font_size());
 
-       style->get_font().build_string(text.substr(line.start, line.length), *data.bld);
+       style->get_font().build_string(text.substr(line.start, line.bytes), *data.bld);
 }
 
 void Text::coords_to_geom_line(unsigned i, const Geometry &rgeom, CoordsToGeomData &data) const
 {
        if(i==data.row)
        {
-               float w = style->get_font().get_string_width(text.substr(lines[i].start, data.col));
+               string::const_iterator begin = text.begin()+lines[i].start;
+               string::const_iterator j = begin;
+               if(lines[i].length==lines[i].bytes)
+                       j += data.col;
+               else
+               {
+                       StringCodec::Utf8::Decoder dec;
+                       for(unsigned c=data.col; c; --c)
+                               dec.decode_char(text, j);
+               }
+               float w = style->get_font().get_string_width(string(begin, j));
                data.result = rgeom;
                data.result.x += static_cast<unsigned>(w*style->get_font_size());
        }

diff --git a/source/text.h b/source/text.h
index 243c3a617f6cf2806a2272caf71cf4a44f45121e..6ddbb231b37871089f90e6cc90ecfa3ba1a735e9 100644 (file)
--- a/source/text.h
+++ b/source/text.h
@@ -22,6 +22,7 @@ private:
        struct Line
        {
                unsigned start;
+               unsigned bytes;
                unsigned length;
                unsigned width;
        };
@@ -51,6 +52,7 @@ public:
        unsigned get_n_lines() const { return lines.size(); }
        unsigned get_visible_lines(const Part &, const Geometry &, unsigned *) const;
        unsigned get_line_length(unsigned) const;
+       unsigned move_offset(unsigned, int) const;
        void offset_to_coords(unsigned, unsigned &, unsigned &) const;
        unsigned coords_to_offset(unsigned, unsigned) const;
        Geometry coords_to_geometry(const Part &, const Geometry &, unsigned, unsigned, unsigned) const;
@@ -61,6 +63,8 @@ public:
        Text &operator=(const std::string &);
 private:
        void find_lines();
+       unsigned count_characters(unsigned, unsigned) const;
+       void check_alignment(unsigned) const;
 
        template<typename T>
        void process_lines(const Part &, const Geometry &, unsigned, void (Text::*)(unsigned, const Geometry &, T &) const, T &) const;