/* 
Copyright (c) 2011 by Simon Schneegans

This program is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the Free
Software Foundation, either version 3 of the License, or (at your option)
any later version.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
more details.

You should have received a copy of the GNU General Public License along with
this program.  If not, see <http://www.gnu.org/licenses/>. 
*/

namespace GnomePie {

/////////////////////////////////////////////////////////////////////////    
///  A class representing string, rendered on an Image.
/////////////////////////////////////////////////////////////////////////

public class RenderedText : Image {
    
    /////////////////////////////////////////////////////////////////////
    /// C'tor, creates a new image representation of a string.
    /////////////////////////////////////////////////////////////////////
    
    public RenderedText(string text, int width, int height, string font,
                        Color color, double scale) {
                        
        this.render_text(text, width, height, font, color, scale);
    }
    
    /////////////////////////////////////////////////////////////////////
    /// C'tor, creates a new image representation of a string. This
    /// string may contain markup information.
    /////////////////////////////////////////////////////////////////////
    
    public RenderedText.with_markup(string text, int width, int height, string font,
                        Color color, double scale) {

        this.render_markup(text, width, height, font, color, scale);
    }
    
    /////////////////////////////////////////////////////////////////////
    /// Creates a new transparent image, with text written onto.
    /////////////////////////////////////////////////////////////////////
    
    public void render_text(string text, int width, int height, string font, 
                            Color color, double scale) {
                  
        this.surface = new Cairo.ImageSurface(Cairo.Format.ARGB32, width, height);

        if (text != "") {

            var ctx = this.context();
            
            // set the color
            ctx.set_source_rgb(color.r, color.g, color.g);
            
            var layout = Pango.cairo_create_layout(ctx);        
            layout.set_width(Pango.units_from_double(width));
            
            var font_description = Pango.FontDescription.from_string(font);
            font_description.set_size((int)(font_description.get_size() * scale));
            
            layout.set_font_description(font_description);
            layout.set_text(text, -1);
            
            // add newlines at the end of each line, in order to allow ellipsizing
            string broken_string = "";
            
            for (int i=0; i<layout.get_line_count(); ++i) {
            
                string next_line = "";
                if (i == layout.get_line_count() -1) 
                    next_line = text.substring(layout.get_line(i).start_index, -1);
                else                                 
                    next_line = text.substring(layout.get_line(i).start_index, layout.get_line(i).length);
                
                if (broken_string == "") {
                    broken_string = next_line;
                } else if (next_line != "") {
                    // test whether the addition of a line would cause the height to become too large
                    string broken_string_tmp = broken_string + "\n" + next_line;
                    
                    var layout_tmp = Pango.cairo_create_layout(ctx);        
                    layout_tmp.set_width(Pango.units_from_double(width));
                    
                    layout_tmp.set_font_description(font_description);
            
                    layout_tmp.set_text(broken_string_tmp, -1);
                    Pango.Rectangle extents;
                    layout_tmp.get_pixel_extents(null, out extents);
                    
                    if (extents.height > height) broken_string = broken_string + next_line;
                    else                         broken_string = broken_string_tmp;
                }
            }
            
            layout.set_text(broken_string, -1);
            
            layout.set_ellipsize(Pango.EllipsizeMode.END);
            layout.set_alignment(Pango.Alignment.CENTER);
            
            Pango.Rectangle extents;
            layout.get_pixel_extents(null, out extents);
            ctx.move_to(0, (int)(0.5*(height - extents.height)));
            
            Pango.cairo_update_layout(ctx, layout);
            Pango.cairo_show_layout(ctx, layout);
        }
    }
    
    /////////////////////////////////////////////////////////////////////
    /// Creates a new transparent image, with text written onto.
    /////////////////////////////////////////////////////////////////////
    
    public void render_markup(string text, int width, int height, string font, 
                            Color color, double scale) {
                            
        this.surface = new Cairo.ImageSurface(Cairo.Format.ARGB32, width, height);

        var ctx = this.context();
        
        // set the color 
        ctx.set_source_rgb(color.r, color.g, color.g);
        
        var layout = Pango.cairo_create_layout(ctx);        
        layout.set_width(Pango.units_from_double(width));
        
        var font_description = Pango.FontDescription.from_string(font);
        font_description.set_size((int)(font_description.get_size() * scale));
        
        layout.set_font_description(font_description);
        layout.set_markup(text, -1);
        
        layout.set_ellipsize(Pango.EllipsizeMode.END);
        layout.set_alignment(Pango.Alignment.CENTER);
        
        Pango.Rectangle extents;
        layout.get_pixel_extents(null, out extents);
        ctx.move_to(0, (int)(0.5*(height - extents.height)));
        
        Pango.cairo_update_layout(ctx, layout);
        Pango.cairo_show_layout(ctx, layout);
    }
}

}