prolooks/StepEditor.vala

   1 using Gtk;
   2 using Gdk;
   3
   4 // template for new widgets
   5
   6 namespace Prolooks {
   7
   8 public class StepEditor : DrawingArea {
   9
  10     private float [] _step_values;
  11     private uint _steps;
  12     public uint steps {
  13         set {
  14             _steps = value;
  15             float[] oldsteps = _step_values;
  16             _step_values = new float[_steps];
  17             if (oldsteps != null) {
  18                 for (int i = 0; i < oldsteps.length && i < _step_values.length; i++)
  19                     _step_values[i] = oldsteps[i];
  20             }
  21             queue_draw();
  22         }
  23         get { return _steps; }
  24     }
  25
  26     private uint _spacing;
  27     public uint spacing {
  28         set { _spacing = value; queue_draw();}
  29         get { return _spacing; }
  30     }
  31
  32     protected int edited_step = -1;
  33
  34     private float first_step = 0.0f;
  35
  36     public StepEditor () {
  37
  38         _steps = 16;
  39         _spacing = 1;
  40
  41         // Enable the events you wish to get notified about.
  42         // The 'expose' event is already enabled by the DrawingArea.
  43         add_events (Gdk.EventMask.BUTTON_PRESS_MASK
  44                   | Gdk.EventMask.BUTTON_RELEASE_MASK
  45                   | Gdk.EventMask.POINTER_MOTION_MASK);
  46
  47         set_size_request(-1, 64);
  48     }
  49
  50     public override void size_request (out Gtk.Requisition requisition) {
  51         // width/height is hardwired at 40px now
  52         requisition.width = (int)(_steps * 12 - _spacing);
  53         requisition.height = this.requisition.height;
  54     }
  55
  56
  57
  58     /* Widget is asked to draw itself */
  59     public override bool expose_event (Gdk.EventExpose event) {
  60
  61         // Create a Cairo context
  62         var cr = Gdk.cairo_create (this.window);
  63
  64         // Set clipping area in order to avoid unnecessary drawing
  65         cr.rectangle (event.area.x, event.area.y,
  66                       event.area.width, event.area.height);
  67         cr.clip ();
  68
  69         int w = allocation.width;
  70         int h = allocation.height;
  71
  72         cr.set_source_rgba(0.0, 0.0, 0.0, 1);
  73         cr.rectangle(allocation.x, allocation.y, w, h);
  74         cr.fill();
  75
  76         for (int i = 0; i < steps; i++) {
  77             int pos = (int)(h * get_step(i));
  78             int p1 = (int)(allocation.x + i * (w + _spacing) / _steps);
  79             int p2 = (int)(allocation.x + (i + 1) * (w + _spacing) / _steps - _spacing);
  80             cr.set_source_rgba(0.1, 0.1, 0.1, 1);
  81             cr.rectangle(p1, allocation.y, p2 - p1, h - pos);
  82             cr.fill();
  83             cr.set_source_rgba(0.2, 0.5, 0.3, 1);
  84             cr.rectangle(p1, allocation.y + h - pos, p2 - p1, pos);
  85             cr.fill();
  86         }
  87
  88         // ...
  89
  90         return false;
  91     }
  92
  93     /* Mouse button got pressed over widget */
  94     public override bool button_press_event (Gdk.EventButton event) {
  95         edited_step = (int)(event.x * _steps / allocation.width);
  96         set_step(edited_step, (float)(1.0 - event.y / allocation.height));
  97         grab_focus ();
  98         grab_add (this);
  99         queue_draw();
 100         // ...
 101         return false;
 102     }
 103
 104     /* Mouse button got released */
 105     public override bool button_release_event (Gdk.EventButton event) {
 106         if (has_grab ())
 107             grab_remove (this);
 108         edited_step = -1;
 109         return false;
 110     }
 111
 112     /* Mouse pointer moved over widget */
 113     public override bool motion_notify_event (Gdk.EventMotion event) {
 114         if (edited_step != -1)
 115             set_step(edited_step, (float)(1.0 - event.y / allocation.height));
 116         // ...
 117         return false;
 118     }
 119
 120     public float get_step(uint step)
 121     {
 122         return _step_values[step];
 123     }
 124
 125     public void set_step(uint step, float value)
 126     {
 127         if (value < 0.0f)
 128             value = 0.0f;
 129         if (value > 1.0f)
 130             value = 1.0f;
 131         _step_values[step] = value;
 132         queue_draw();
 133     }
 134
 135         static int main (string[] args) {
 136             Gtk.init (ref args);
 137             var window = new Gtk.Window (Gtk.WindowType.TOPLEVEL);
 138             var widget = new StepEditor ();
 139             widget.steps = 16;
 140             for (int i = 0; i < 16; i++)
 141                 widget.set_step(i, (float)(i / 15.0));
 142
 143
 144             window.add (widget);
 145             window.destroy += Gtk.main_quit;
 146             window.show_all ();
 147             Gtk.main ();
 148             return 0;
 149         }
 150 }
 151
 152 } // namespace Prolooks