dlib C++ Library - style.cpp

    // Copyright (C) 2008  Davis E. King (davis@dlib.net), and Nils Labugt
    // License: Boost Software License   See LICENSE.txt for the full license.
    #ifndef DLIB_WIDGETs_STYLE_CPP_
    #define DLIB_WIDGETs_STYLE_CPP_

    #include "style.h"

    namespace dlib
    {

    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------
        // button style stuff
    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------

        void button_style_default::draw_button (
            const canvas& c,
            const rectangle& rect,
            const bool enabled,
            const font& mfont,
            const long ,
            const long ,
            const ustring& name,
            const bool is_depressed
        ) const
        {
            rectangle area = rect.intersect(c);
            if (area.is_empty())
                return;

            fill_rect(c,rect,rgb_pixel(212,208,200));

            unsigned char red, green, blue;
            if (enabled)
            {
                red = 0;
                green = 0;
                blue = 0;
            }
            else
            {
                red = 128;
                green = 128;
                blue = 128;
            }

            // compute the name length if it hasn't already been computed
            if (name_width == 0)
            {
                unsigned long height;
                mfont.compute_size(name,name_width,height);
            }

            // figure out where the name string should appear
            rectangle name_rect;
            const unsigned long width = name_width;
            const unsigned long height = mfont.height();
            name_rect.set_left((rect.right() + rect.left() - width)/2);
            name_rect.set_top((rect.bottom() + rect.top() - height)/2 + 1);
            name_rect.set_right(name_rect.left()+width-1);
            name_rect.set_bottom(name_rect.top()+height);

            if (is_depressed)
            {
                name_rect.set_left(name_rect.left()+1);
                name_rect.set_right(name_rect.right()+1);
                name_rect.set_top(name_rect.top()+1);
                name_rect.set_bottom(name_rect.bottom()+1);

                mfont.draw_string(c,name_rect,name,rgb_pixel(red,green,blue));

                draw_button_down(c,rect);
            }
            else
            {
                mfont.draw_string(c,name_rect,name,rgb_pixel(red,green,blue));

                // now draw the edge of the button
                draw_button_up(c,rect);
            }
        }

    // ----------------------------------------------------------------------------------------

        rectangle button_style_default::
        get_min_size (
            const ustring& name,
            const font& mfont
        ) const
        {

            unsigned long width;
            unsigned long height;
            mfont.compute_size(name,width,height);
            name_width = width;

            return rectangle(width+2*padding, height+2*padding);
        }

    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------

        void button_style_toolbar1::draw_button (
            const canvas& c,
            const rectangle& rect,
            const bool enabled,
            const font& mfont,
            const long lastx,
            const long lasty,
            const ustring& name,
            const bool is_depressed
        ) const
        {
            rectangle area = rect.intersect(c);
            if (area.is_empty())
                return;

            const long radius = 4;

            unsigned char red, green, blue;
            if (enabled)
            {
                red = 0;
                green = 0;
                blue = 0;

                long d = 0;
                if (rect.contains(lastx,lasty))
                    d = -70;

                if (is_depressed)
                    d = 20;

                if (d != 0)
                {
                    rectangle temp(rect);
                    temp.left()--; temp.top()--; temp.right()++; temp.bottom()++;
                    draw_rounded_rectangle(c, temp, radius, rgb_alpha_pixel(255,255,0,120));
                    temp.left()--; temp.top()--; temp.right()++; temp.bottom()++;
                    draw_rounded_rectangle(c, temp, radius, rgb_alpha_pixel(255,255,0,40));
                }

                fill_gradient_rounded(c,rect,radius,rgb_alpha_pixel(255, 255, 255,120-d),
                                      rgb_alpha_pixel(255, 255, 255,0));
                draw_rounded_rectangle(c,rect,radius, rgb_alpha_pixel(30,30,30,200));
            }
            else
            {
                red = 128;
                green = 128;
                blue = 128;
                draw_rounded_rectangle(c,rect,radius, rgb_alpha_pixel(red,green,blue,210));
            }

            // compute the name length if it hasn't already been computed
            if (name_width == 0)
            {
                unsigned long height;
                mfont.compute_size(name,name_width,height);
            }

            // figure out where the name string should appear
            rectangle name_rect;
            const unsigned long width = name_width;
            const unsigned long height = mfont.height();
            name_rect.set_left((rect.right() + rect.left() - width)/2);
            name_rect.set_top((rect.bottom() + rect.top() - height)/2 + 1);
            name_rect.set_right(name_rect.left()+width-1);
            name_rect.set_bottom(name_rect.top()+height);

            if (is_depressed)
            {
                name_rect.set_left(name_rect.left()+1);
                name_rect.set_right(name_rect.right()+1);
                name_rect.set_top(name_rect.top()+1);
                name_rect.set_bottom(name_rect.bottom()+1);

                mfont.draw_string(c,name_rect,name,rgb_pixel(red,green,blue));

            }
            else
            {
                mfont.draw_string(c,name_rect,name,rgb_pixel(red,green,blue));
            }
        }

    // ----------------------------------------------------------------------------------------

        rectangle button_style_toolbar1::
        get_min_size (
            const ustring& name,
            const font& mfont
        ) const
        {

            unsigned long width;
            unsigned long height;
            mfont.compute_size(name,width,height);
            name_width = width;

            return rectangle(width+2*padding, height+2*padding);
        }

    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------

        void button_style_toolbar_icon1::draw_button (
            const canvas& c,
            const rectangle& rect,
            const bool enabled,
            const font& ,
            const long lastx,
            const long lasty,
            const ustring& ,
            const bool is_depressed
        ) const
        {
            rectangle area = rect.intersect(c);
            if (area.is_empty())
                return;

            const long radius = padding;

            if (enabled)
            {
                if (rect.contains(lastx,lasty))
                {
                    if (is_depressed)
                    {
                        fill_gradient_rounded(c,rect,radius,rgb_alpha_pixel(100,100,200,150),
                                                            rgb_alpha_pixel(50,50,100,100));
                        draw_rounded_rectangle(c,rect,radius, rgb_alpha_pixel(150,150,30,200));
                    }
                    else
                    {
                        fill_gradient_rounded(c,rect,radius,rgb_alpha_pixel(150,150,250,130),
                                                            rgb_alpha_pixel(100,100,150,90));
                        draw_rounded_rectangle(c,rect,radius, rgb_alpha_pixel(150,150,30,200));
                    }
                }

                if (is_depressed)
                {
                    rectangle img_rect(translate_rect(centered_rect(rect,img_mouseover.nc(),img_mouseover.nr()),1,1));
                    point p(img_rect.left(),img_rect.top());
                    draw_image(c,p,img_mouseover);
                }
                else
                {
                    rectangle img_rect(centered_rect(rect,img_normal.nc(),img_normal.nr()));
                    point p(img_rect.left(),img_rect.top());
                    if (rect.contains(lastx,lasty))
                        draw_image(c,p,img_mouseover);
                    else
                        draw_image(c,p,img_normal);
                }

            }
            else
            {
                rectangle img_rect(centered_rect(rect,img_normal.nc(),img_normal.nr()));
                point p(img_rect.left(),img_rect.top());
                draw_image(c,p,img_disabled);
            }
        }

    // ----------------------------------------------------------------------------------------

        rectangle button_style_toolbar_icon1::
        get_min_size (
            const ustring& ,
            const font&
        ) const
        {
            return rectangle(img_normal.nc()+2*padding, img_normal.nr()+2*padding);
        }

    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------

        void button_style_arrow::
        draw_button (
            const canvas& c,
            const rectangle& rect,
            const bool enabled,
            const font& ,
            const long ,
            const long ,
            const ustring& ,
            const bool is_depressed
        ) const
        {
            rectangle area = rect.intersect(c);
            if (area.is_empty())
                return;

            fill_rect(c,rect,rgb_pixel(212,208,200));

            const long height = rect.height();
            const long width = rect.width();

            const long smallest = (width < height) ? width : height;

            const long rows = (smallest+3)/4;
            const long start = rows + rows/2-1;
            long dep;

            long tip_x = 0;
            long tip_y = 0;
            long wy = 0;
            long hy = 0;
            long wx = 0;
            long hx = 0;

            if (is_depressed)
            {
                dep = 0;

                // draw the button's border
                draw_button_down(c,rect);
            }
            else
            {
                dep = -1;

                // draw the button's border
                draw_button_up(c,rect);
            }

            switch (dir)
            {
                case UP:
                    tip_x = width/2 + rect.left() + dep;
                    tip_y = (height - start)/2 + rect.top() + dep + 1;
                    wy = 0;
                    hy = 1;
                    wx = 1;
                    hx = 0;
                    break;

                case DOWN:
                    tip_x = width/2 + rect.left() + dep;
                    tip_y = rect.bottom() - (height - start)/2 + dep;
                    wy = 0;
                    hy = -1;
                    wx = 1;
                    hx = 0;
                    break;

                case LEFT:
                    tip_x = rect.left() + (width - start)/2 + dep + 1;
                    tip_y = height/2 + rect.top() + dep;
                    wy = 1;
                    hy = 0;
                    wx = 0;
                    hx = 1;
                    break;

                case RIGHT:
                    tip_x = rect.right() - (width - start)/2 + dep;
                    tip_y = height/2 + rect.top() + dep;
                    wy = 1;
                    hy = 0;
                    wx = 0;
                    hx = -1;
                    break;
            }

            rgb_pixel color;
            if (enabled)
            {
                color.red = 0;
                color.green = 0;
                color.blue = 0;
            }
            else
            {
                color.red = 128;
                color.green = 128;
                color.blue = 128;
            }

            for (long i = 0; i < rows; ++i)
            {
                draw_line(c,point(tip_x + wx*i + hx*i, tip_y + wy*i + hy*i),
                          point(tip_x + wx*i*-1 + hx*i, tip_y + wy*i*-1 + hy*i),
                          color);
            }

        }

    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------
        // toggle button style stuff
    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------

        void toggle_button_style_default::draw_toggle_button (
            const canvas& c,
            const rectangle& rect,
            const bool enabled,
            const font& mfont,
            const long ,
            const long ,
            const ustring& name,
            const bool is_depressed,
            const bool is_checked
        ) const
        {
            rectangle area = rect.intersect(c);
            if (area.is_empty())
                return;

            fill_rect(c,rect,rgb_pixel(212,208,200));

            unsigned char red, green, blue;
            if (enabled)
            {
                red = 0;
                green = 0;
                blue = 0;
            }
            else
            {
                red = 128;
                green = 128;
                blue = 128;
            }

            // compute the name length if it hasn't already been computed
            if (name_width == 0)
            {
                unsigned long height;
                mfont.compute_size(name,name_width,height);
            }

            // figure out where the name string should appear
            rectangle name_rect;
            const unsigned long width = name_width;
            const unsigned long height = mfont.height();
            name_rect.set_left((rect.right() + rect.left() - width)/2);
            name_rect.set_top((rect.bottom() + rect.top() - height)/2 + 1);
            name_rect.set_right(name_rect.left()+width-1);
            name_rect.set_bottom(name_rect.top()+height);

            long d = 0;
            if (is_checked)
                d = 1;

            if (is_depressed)
                d = 2;

            name_rect.set_left(name_rect.left()+d);
            name_rect.set_right(name_rect.right()+d);
            name_rect.set_top(name_rect.top()+d);
            name_rect.set_bottom(name_rect.bottom()+d);

            mfont.draw_string(c,name_rect,name,rgb_pixel(red,green,blue));

            // now draw the edge of the button
            if (is_checked || is_depressed)
                draw_button_down(c,rect);
            else
                draw_button_up(c,rect);
        }

    // ----------------------------------------------------------------------------------------

        rectangle toggle_button_style_default::
        get_min_size (
            const ustring& name,
            const font& mfont
        ) const
        {

            unsigned long width;
            unsigned long height;
            mfont.compute_size(name,width,height);
            name_width = width;

            return rectangle(width+2*padding, height+2*padding);
        }

    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------

        void toggle_button_style_check_box::draw_toggle_button (
            const canvas& c,
            const rectangle& rect,
            const bool enabled,
            const font& mfont,
            const long ,
            const long ,
            const ustring& name,
            const bool is_depressed,
            const bool is_checked
        ) const
        {
            rectangle area = rect.intersect(c);
            if (area.is_empty())
                return;

            rgb_pixel color;
            if (enabled)
            {
                color.red = 0;
                color.green = 0;
                color.blue = 0;
            }
            else
            {
                color.red = 128;
                color.green = 128;
                color.blue = 128;
            }

            // figure out where the name string should appear
            rectangle name_rect, box_rect;
            unsigned long padding = 0;
            if (mfont.height() < 13)
                padding = (rect.height() - mfont.height())/2;

            name_rect = rect;
            name_rect.set_left(rect.left() + 17-1);
            name_rect.set_top(rect.top() + padding);
            name_rect.set_bottom(rect.bottom() - padding);

            box_rect = rect;
            box_rect.set_right(rect.left() + 12);
            box_rect.set_bottom(rect.top() + 12);

            mfont.draw_string(c,name_rect,name,color);

            if (enabled && is_depressed == false)
                fill_rect(c, box_rect,rgb_pixel(255,255,255));
            else
                fill_rect(c, box_rect,rgb_pixel(212,208,200));

            draw_sunken_rectangle(c, box_rect);

            if (is_checked)
            {
                const long x = box_rect.left();
                const long y = box_rect.top();
                draw_line(c,point(3+x,5+y),point(6+x,8+y),color);
                draw_line(c,point(3+x,6+y),point(5+x,8+y),color);
                draw_line(c,point(3+x,7+y),point(5+x,9+y),color);
                draw_line(c,point(6+x,6+y),point(9+x,3+y),color);
                draw_line(c,point(6+x,7+y),point(9+x,4+y),color);
                draw_line(c,point(6+x,8+y),point(9+x,5+y),color);
            }
        }

    // ----------------------------------------------------------------------------------------

        rectangle toggle_button_style_check_box::
        get_min_size (
            const ustring& name,
            const font& mfont
        ) const
        {
            unsigned long width;
            unsigned long height;
            mfont.compute_size(name,width,height);

            if (height < 13)
                height = 13;

            return rectangle(width + 17 -1, height -1);
        }

    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------

        void toggle_button_style_radio_button::draw_toggle_button (
            const canvas& c,
            const rectangle& rect,
            const bool enabled,
            const font& mfont,
            const long ,
            const long ,
            const ustring& name,
            const bool is_depressed,
            const bool is_checked
        ) const
        {
            rectangle area = rect.intersect(c);
            if (area.is_empty())
                return;

            rgb_pixel color;

            // figure out where the name string should appear
            rectangle name_rect, box_rect;
            unsigned long padding = 0;
            if (mfont.height() < 13)
                padding = (rect.height() - mfont.height())/2;

            name_rect = rect;
            name_rect.set_left(rect.left() + 17-1);
            name_rect.set_top(rect.top() + padding);
            name_rect.set_bottom(rect.bottom() - padding);

            box_rect = rect;
            box_rect.set_right(rect.left() + 12);
            box_rect.set_bottom(rect.top() + 12);

            const long x = box_rect.left();
            const long y = box_rect.top();

            if (enabled && is_depressed == false)
                draw_solid_circle(c,point(rect.left()+5,rect.top()+5),4.5,rgb_pixel(255,255,255));
            else
                draw_solid_circle(c,point(rect.left()+5,rect.top()+5),4.5,rgb_pixel(212,208,200));

            color = rgb_pixel(128,128,128);
            draw_line(c,point(0+x,4+y),point(0+x,7+y),color);
            draw_line(c,point(1+x,2+y),point(1+x,9+y),color);
            draw_line(c,point(2+x,1+y),point(9+x,1+y),color);
            draw_line(c,point(4+x,0+y),point(7+x,0+y),color);

            color = rgb_pixel(255,255,255);
            draw_line(c,point(4+x,11+y),point(7+x,11+y),color);
            draw_line(c,point(2+x,10+y),point(9+x,10+y),color);
            draw_line(c,point(10+x,2+y),point(10+x,9+y),color);
            draw_line(c,point(11+x,4+y),point(11+x,7+y),color);

            color = rgb_pixel(64,64,64);
            draw_line(c,point(1+x,4+y),point(1+x,7+y),color);
            draw_line(c,point(4+x,1+y),point(7+x,1+y),color);
            draw_pixel(c,point(2+x,3+y),color);
            draw_pixel(c,point(3+x,2+y),color);
            draw_pixel(c,point(2+x,2+y),color);
            draw_pixel(c,point(2+x,8+y),color);
            draw_pixel(c,point(8+x,2+y),color);
            draw_pixel(c,point(9+x,2+y),color);

            color = rgb_pixel(212,208,200);
            draw_line(c,point(4+x,10+y),point(7+x,10+y),color);
            draw_line(c,point(10+x,4+y),point(10+x,7+y),color);
            draw_pixel(c,point(3+x,9+y),color);
            draw_pixel(c,point(9+x,3+y),color);

            if (enabled)
            {
                color.red = 0;
                color.green = 0;
                color.blue = 0;
            }
            else
            {
                color.red = 128;
                color.green = 128;
                color.blue = 128;
            }

            mfont.draw_string(c,name_rect,name,color);

            if (is_checked)
            {
                draw_line(c,point(5+x,4+y),point(6+x,4+y),color);
                draw_line(c,point(4+x,5+y),point(7+x,5+y),color);
                draw_line(c,point(4+x,6+y),point(7+x,6+y),color);
                draw_line(c,point(5+x,7+y),point(6+x,7+y),color);
            }

        }

    // ----------------------------------------------------------------------------------------

        rectangle toggle_button_style_radio_button::
        get_min_size (
            const ustring& name,
            const font& mfont
        ) const
        {
            unsigned long width;
            unsigned long height;
            mfont.compute_size(name,width,height);

            if (height < 13)
                height = 13;

            return rectangle(width + 17 -1, height -1);
        }

    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------
        // scroll bar style stuff
    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------

        long scroll_bar_style_default::
        get_slider_length (
            long total_length,
            long max_pos
        ) const
        {
            // if the length is too small then we have to smash up the arrow buttons
            // and hide the slider.
            if (total_length <= get_width()*2)
            {
                return 0;
            }
            else
            {
                double range = total_length - get_button_length(total_length, max_pos)*2;

                double scale_factor = 30.0/(max_pos + 30.0);

                if (scale_factor < 0.1)
                    scale_factor = 0.1;

                double fraction = range/(max_pos + range)*scale_factor;
                double result = fraction * range;
                long res = static_cast<long>(result);
                if (res < 8)
                    res = 8;
                return res;
            }
        }

    // ----------------------------------------------------------------------------------------

        long scroll_bar_style_default::
        get_button_length (
            long total_length,
            long
        ) const
        {
            // if the length is too small then we have to smash up the arrow buttons
            // and hide the slider.
            if (total_length <= get_width()*2)
            {
                return total_length/2;
            }
            else
            {
                return get_width();
            }
        }

    // ----------------------------------------------------------------------------------------

        void scroll_bar_style_default::
        draw_scroll_bar_background (
            const canvas& c,
            const rectangle& rect,
            const bool ,
            const long ,
            const long ,
            const bool is_depressed
        ) const
        {
            if (is_depressed)
                draw_checkered(c, rect,rgb_pixel(0,0,0),rgb_pixel(43,47,55));
            else
                draw_checkered(c, rect,rgb_pixel(255,255,255),rgb_pixel(212,208,200));
        }

    // ----------------------------------------------------------------------------------------

        void scroll_bar_style_default::
        draw_scroll_bar_slider (
            const canvas& c,
            const rectangle& rect,
            const bool ,
            const long ,
            const long ,
            const bool
        ) const
        {
            fill_rect(c, rect, rgb_pixel(212,208,200));
            draw_button_up(c, rect);
        }

    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------
        // text_field styles
    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------

        unsigned long text_field_style_default::
        get_padding (
            const font& mfont
        ) const
        {
            return mfont.height()-mfont.ascender();
        }

    // ----------------------------------------------------------------------------------------

        void text_field_style_default::
        draw_text_field (
            const canvas& c,
            const rectangle& rect,
            const rectangle& text_rect,
            const bool enabled,
            const font& mfont,
            const ustring& text,
            const unsigned long cursor_x,
            const unsigned long text_pos,
            const rgb_pixel& text_color,
            const rgb_pixel& bg_color,
            const bool has_focus,
            const bool cursor_visible,
            const long highlight_start,
            const long highlight_end
        ) const
        {
            rectangle area = rect.intersect(c);

            if (enabled)
            {
                // first fill our area with the bg_color
                fill_rect(c, area,bg_color);
            }
            else
            {
                // first fill our area with gray
                fill_rect(c, area,rgb_pixel(212,208,200));
            }

            if (enabled)
                mfont.draw_string(c,text_rect,text,text_color,text_pos);
            else
                mfont.draw_string(c,text_rect,text,rgb_pixel(128,128,128),text_pos);

            // now draw the edge of the text_field
            draw_sunken_rectangle(c, rect);

            if (highlight_start <= highlight_end && enabled)
            {
                rectangle highlight_rect = text_rect;
                unsigned long left_pad = 0, right_pad = mfont.left_overflow();

                long i;
                for (i = text_pos; i <= highlight_end; ++i)
                {
                    if (i == highlight_start)
                        left_pad = right_pad;

                    right_pad += mfont[text[i]].width();
                }

                highlight_rect.set_left(text_rect.left()+left_pad);
                highlight_rect.set_right(text_rect.left()+right_pad);

                // highlight the highlight_rect area
                highlight_rect = highlight_rect.intersect(c);
                for (long row = highlight_rect.top(); row <= highlight_rect.bottom(); ++row)
                {
                    for (long col = highlight_rect.left(); col <= highlight_rect.right(); ++col)
                    {
                        canvas::pixel& pixel = c[row-c.top()][col-c.left()];
                        if (pixel.red == 255 && pixel.green == 255 && pixel.blue == 255)
                        {
                            // this is a background (and white) pixel so set it to a dark
                            // blueish color.
                            pixel.red = 10;
                            pixel.green = 36;
                            pixel.blue = 106;
                        }
                        else
                        {
                            // this should be a pixel that is part of a letter so set it to white
                            pixel.red = 255;
                            pixel.green = 255;
                            pixel.blue = 255;
                        }
                    }
                }
            }

            // now draw the cursor if we need to
            if (cursor_visible && has_focus && enabled)
            {
                const unsigned long top = rect.top()+3;
                const unsigned long bottom = rect.bottom()-3;
                draw_line(c, point(rect.left()+cursor_x,top),point(rect.left()+cursor_x,bottom));
            }

        }

    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------
        // text_box styles
    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------

        void text_box_style_default::
        draw_text_box (
            const canvas& c,
            const rectangle& display_rect,
            const rectangle& text_rect,
            const bool enabled,
            const font& mfont,
            const ustring& text,
            const rectangle& cursor_rect,
            const rgb_pixel& text_color,
            const rgb_pixel& bg_color,
            const bool has_focus,
            const bool cursor_visible,
            const long highlight_start,
            const long highlight_end
        ) const
        {
            rectangle area = display_rect.intersect(c);

            if (enabled)
            {
                // first fill our area with the bg_color
                fill_rect(c, area,bg_color);
            }
            else
            {
                // first fill our area with gray
                fill_rect(c, area,rgb_pixel(212,208,200));
            }

            if (enabled)
                mfont.draw_string(c,text_rect,text,text_color, 0, ustring::npos, area);
            else
                mfont.draw_string(c,text_rect,text,rgb_pixel(128,128,128), 0, ustring::npos, area);

            // now draw the highlight if there is any
            if (highlight_start <= highlight_end && enabled)
            {
                const rectangle first_pos = mfont.compute_cursor_rect(text_rect, text, highlight_start);
                const rectangle last_pos = mfont.compute_cursor_rect(text_rect, text, highlight_end+1);

                const rgb_alpha_pixel color(10, 30, 106, 90);

                // if the highlighted text is all on one line
                if (first_pos.top() == last_pos.top())
                {
                    fill_rect(c, (first_pos + last_pos).intersect(display_rect), color);
                }
                else
                {
                    const rectangle min_boundary(display_rect.left()+4, display_rect.top()+4,
                                                 display_rect.right()-4, display_rect.bottom()-4);
                    const rectangle boundary( display_rect.intersect(text_rect) + min_boundary);

                    rectangle first_row, last_row, middle_rows;
                    first_row += first_pos;
                    first_row += point(boundary.right(), first_pos.top());
                    last_row += last_pos;
                    last_row += point(boundary.left(), last_pos.bottom());

                    middle_rows.left() = boundary.left();
                    middle_rows.right() = boundary.right();
                    middle_rows.top() = first_row.bottom()+1;
                    middle_rows.bottom() = last_row.top()-1;

                    fill_rect(c, first_row.intersect(display_rect), color);
                    fill_rect(c, middle_rows, color);
                    fill_rect(c, last_row.intersect(display_rect), color);
                }
            }

            // now draw the cursor if we need to
            if (cursor_visible && has_focus && enabled)
            {
                draw_line(c, point(cursor_rect.left(), cursor_rect.top()),point(cursor_rect.left(), cursor_rect.bottom()), 0, area);
            }

        }

    // ----------------------------------------------------------------------------------------

    }

    #endif // DLIB_WIDGETs_STYLE_CPP_