source/slider.cpp

   1 #include "slider.h"
   2
   3 namespace Msp {
   4 namespace GLtk {
   5
   6 Slider::Slider():
   7         min(0),
   8         max(1),
   9         value(0),
  10         step(0.1),
  11         dragging(false),
  12         drag_area_size(0),
  13         drag_area_offset(0),
  14         slider_size(1)
  15 { }
  16
  17 void Slider::set_value(double v)
  18 {
  19         double old_value = value;
  20
  21         if(v<min)
  22                 value = min;
  23         else if(v>max)
  24                 value = max;
  25         else
  26         {
  27                 unsigned steps = static_cast<unsigned>((v-min)/step+0.5);
  28                 value = min+steps*step;
  29         }
  30
  31         if(value!=old_value)
  32         {
  33                 signal_value_changed.emit(value);
  34                 rebuild();
  35         }
  36 }
  37
  38 void Slider::set_range(double a, double b)
  39 {
  40         min = a;
  41         max = b;
  42         set_value(value);
  43 }
  44
  45 void Slider::set_step(double s)
  46 {
  47         step = s;
  48         set_value(value);
  49 }
  50
  51 void Slider::click(int p)
  52 {
  53         p -= drag_area_offset;
  54         if(p<0 || p>=static_cast<int>(drag_area_size))
  55                 return;
  56
  57         int sp = static_cast<int>((drag_area_size-slider_size)*(value-min)/(max-min));
  58         if(p<sp)
  59                 set_value(value-step*10);
  60         else if(p>=static_cast<int>(sp+slider_size))
  61                 set_value(value+step*10);
  62         else
  63                 start_drag(drag_area_offset+p);
  64 }
  65
  66 void Slider::start_drag(int p)
  67 {
  68         dragging = true;
  69         drag_start_pos = p;
  70         drag_start_value = value;
  71         set_state(ACTIVE);
  72 }
  73
  74 void Slider::drag(int p)
  75 {
  76         if(max>min)
  77                 set_value(drag_start_value+(p-drag_start_pos)*(max-min)/(drag_area_size-slider_size));
  78 }
  79
  80 void Slider::end_drag()
  81 {
  82         dragging = false;
  83         clear_state(ACTIVE);
  84 }
  85
  86
  87 Slider::Loader::Loader(Slider &s):
  88         DataFile::DerivedObjectLoader<Slider, Widget::Loader>(s)
  89 {
  90         add("range", &Slider::min, &Slider::max);
  91         add("step",  &Slider::step);
  92         add("value", &Slider::value);
  93 }
  94
  95 } // namespace GLtk
  96 } // namespace Msp