prolooks/Helpers.vala

   1 using Gtk;
   2 using Gdk;
   3
   4 namespace Prolooks {
   5     public enum ButtonState {
   6         NORMAL,
   7         PRESSED;
   8     }
   9
  10     public enum ButtonType {
  11         PRESS_BUTTON,
  12         TOGGLE_BUTTON;
  13     }
  14
  15     public static Gdk.Color color_from_string (string webcolor) {
  16         Gdk.Color color;
  17         Gdk.Color.parse(webcolor, out color);
  18         return color;
  19     }
  20
  21     public static void set_source_from_color (Cairo.Context cr, Gdk.Color color, double alpha = 1.0) {
  22         cr.set_source_rgba((double)color.red / (double)uint16.MAX, (double)color.green / (double)uint16.MAX, (double)color.blue / (double)uint16.MAX, alpha);
  23     }
  24
  25     public static void set_source_from_color_string (Cairo.Context cr, string color, double alpha = 1.0) {
  26         set_source_from_color (cr, color_from_string (color), alpha);
  27     }
  28
  29     public static void add_color_stop (Cairo.Pattern p, double offset, Gdk.Color color, double alpha = 1.0) {
  30         p.add_color_stop_rgba(offset, (double)color.red / (double)uint16.MAX, (double)color.green / (double)uint16.MAX, (double)color.blue / (double)uint16.MAX, alpha);
  31     }
  32
  33     public static Cairo.Pattern create_gradient (double x1, double y1, double x2, double y2, Gdk.Color start, Gdk.Color stop, double alpha_start = 1.0, double alpha_stop = 1.0) {
  34         Cairo.Pattern gradient = new Cairo.Pattern.linear(x1, y1, x2, y2);
  35         add_color_stop(gradient, 0, start, alpha_start);
  36         add_color_stop(gradient, 1, stop,  alpha_stop);
  37         return gradient;
  38     }
  39
  40     public static void rounded_rect (Cairo.Context cr, double x, double y, double w, double h, double radius_x=5, double radius_y=5) {
  41         // from mono moonlight aka mono silverlight
  42         // test limits (without using multiplications)
  43         // http://graphics.stanford.edu/courses/cs248-98-fall/Final/q1.html
  44         double ARC_TO_BEZIER = 0.55228475;
  45
  46         if (radius_x > w - radius_x)
  47             radius_x = w / 2;
  48         if (radius_y > h - radius_y)
  49             radius_y = h / 2;
  50
  51         // approximate (quite close) the arc using a bezier curve
  52         var c1 = ARC_TO_BEZIER * radius_x;
  53         var c2 = ARC_TO_BEZIER * radius_y;
  54
  55         cr.new_path();
  56         cr.move_to ( x + radius_x, y);
  57         cr.rel_line_to ( w - 2 * radius_x, 0.0);
  58         cr.rel_curve_to ( c1, 0.0, radius_x, c2, radius_x, radius_y);
  59         cr.rel_line_to ( 0, h - 2 * radius_y);
  60         cr.rel_curve_to ( 0.0, c2, c1 - radius_x, radius_y, -radius_x, radius_y);
  61         cr.rel_line_to ( -w + 2 * radius_x, 0);
  62         cr.rel_curve_to ( -c1, 0, -radius_x, -c2, -radius_x, -radius_y);
  63         cr.rel_line_to (0, -h + 2 * radius_y);
  64         cr.rel_curve_to (0.0, -c2, radius_x - c1, -radius_y, radius_x, -radius_y);
  65         cr.close_path ();
  66     }
  67
  68     public static void background_gradient(Cairo.Context cr, double w, double h) {
  69         // outside background
  70         Color background_gradient_start;
  71         Color background_gradient_stop;
  72         Color.parse("#bebdc2", out background_gradient_start);
  73         Color.parse("#b1b4b9", out background_gradient_stop);
  74
  75         cr.rectangle (0, 0, w, h);
  76         Cairo.Pattern background_gradient = new Cairo.Pattern.linear(0, 0, 0, h);
  77         add_color_stop(background_gradient, 0, background_gradient_start);
  78         add_color_stop(background_gradient, 1, background_gradient_stop);
  79         cr.set_source (background_gradient);
  80         cr.fill ();
  81     }
  82
  83     public static double modula(double number, double divisor) {
  84         return (((int)number % (int)divisor) + (number - (int)number));
  85     }
  86
  87     public class HSB {
  88         public double hue         {get; set;}
  89         public double saturation  {get; set;}
  90         public double brightness  {get; set;}
  91
  92         public string to_string() {
  93             return "HSB (%f, %f, %f)".printf (hue, saturation, brightness);
  94         }
  95
  96         public Gdk.Color to_gdk_color() {
  97             int i;
  98             var hue_shift = new double[3];
  99             var color_shift = new double[3];
 100             double m1;
 101             double m2;
 102             double m3;
 103
 104             Gdk.Color color = Gdk.Color();
 105
 106             if (brightness <= 0.5)
 107                 m2 = brightness * (1 + saturation);
 108             else
 109                 m2 = brightness + saturation - brightness * saturation;
 110
 111             m1 = 2 * brightness - m2;
 112
 113             hue_shift[0] = hue + 120;
 114             hue_shift[1] = hue;
 115             hue_shift[2] = hue - 120;
 116
 117             color_shift[0] = color_shift[1] = color_shift[2] = brightness;
 118
 119             i = (saturation == 0)?3:0;
 120
 121             for (; i < 3; i++)
 122             {
 123                 m3 = hue_shift[i];
 124
 125                 if (m3 > 360)
 126                     m3 = modula(m3, 360);
 127                 else if (m3 < 0)
 128                     m3 = 360 - modula(Math.fabs(m3), 360);
 129
 130                 if (m3 < 60)
 131                     color_shift[i] = m1 + (m2 - m1) * m3 / 60;
 132                 else if (m3 < 180)
 133                     color_shift[i] = m2;
 134                 else if (m3 < 240)
 135                     color_shift[i] = m1 + (m2 - m1) * (240 - m3) / 60;
 136                 else
 137                     color_shift[i] = m1;
 138             }
 139
 140             color.red   = (uint16) (color_shift[0] * (double)uint16.MAX);
 141             color.green = (uint16) (color_shift[1] * (double)uint16.MAX);
 142             color.blue  = (uint16) (color_shift[2] * (double)uint16.MAX);
 143
 144             return color;
 145         }
 146
 147     public void from_gdk_color(Gdk.Color color) {
 148         double min, max, delta;
 149         double red, green, blue;
 150
 151         red   = (double)color.red   / (double)uint16.MAX;
 152         green = (double)color.green / (double)uint16.MAX;
 153         blue  = (double)color.blue  / (double)uint16.MAX;
 154
 155         if (red > green) {
 156             if (red > blue)
 157               max = red;
 158             else
 159               max = blue;
 160
 161             if (green < blue)
 162               min = green;
 163             else
 164               min = blue;
 165         } else {
 166             if (green > blue)
 167               max = green;
 168             else
 169               max = blue;
 170
 171             if (red < blue)
 172               min = red;
 173             else
 174               min = blue;
 175         }
 176
 177         brightness = (max + min) / 2.0;
 178
 179         if (Math.fabs(max - min) < 0.0001)
 180         {
 181             hue = 0.0;
 182             saturation = 0.0;
 183         }
 184         else
 185         {
 186             if (brightness <= 0.5)
 187                 saturation = (max - min) / (max + min);
 188             else
 189                 saturation = (max - min) / (2.0 - max - min);
 190
 191             delta = max -min;
 192
 193             if (red == max)
 194                 hue = (green - blue) / delta;
 195             else if (green == max)
 196                 hue = 2.0 + (blue - red) / delta;
 197             else if (blue == max)
 198                 hue = 4.0 + (red - green) / delta;
 199
 200             hue *= 60.0;
 201             if (hue < 0.0)
 202                 hue += 360.0;
 203         }
 204     }
 205 }
 206
 207     public static Gdk.Color shade_color(Gdk.Color orig, double shade_ratio) {
 208         HSB hsb = new HSB ();
 209         hsb.from_gdk_color (orig);
 210
 211         hsb.brightness = Math.fmin (hsb.brightness * shade_ratio, 1.0);
 212         hsb.brightness = Math.fmax (hsb.brightness, 0.0);
 213
 214         hsb.saturation = Math.fmin (hsb.saturation * shade_ratio, 1.0);
 215         hsb.saturation = Math.fmax (hsb.saturation, 0.0);
 216
 217         Gdk.Color result = hsb.to_gdk_color ();
 218
 219         return result;
 220     }
 221 } // namespace Prolooks