gtk2_ardour/cairo_widget.cc

   1 #include "cairo_widget.h"
   2 #include "gui_thread.h"
   3
   4 CairoWidget::CairoWidget ()
   5         : _width (1),
   6           _height (1),
   7           _dirty (true),
   8           _pixmap (0)
   9 {
  10
  11 }
  12
  13 CairoWidget::~CairoWidget ()
  14 {
  15         if (_pixmap) {
  16                 gdk_pixmap_unref (_pixmap);
  17         }
  18 }
  19
  20 bool
  21 CairoWidget::on_expose_event (GdkEventExpose *event)
  22 {
  23         Gdk::Rectangle const exposure (
  24                 event->area.x, event->area.y, event->area.width, event->area.height
  25                 );
  26
  27         Gdk::Rectangle r = exposure;
  28         Gdk::Rectangle content (0, 0, _width, _height);
  29         bool intersects;
  30         r.intersect (content, intersects);
  31
  32         if (intersects) {
  33
  34                 GdkDrawable* drawable = get_window()->gobj ();
  35
  36                 if (_dirty) {
  37
  38                         if (_pixmap) {
  39                                 gdk_pixmap_unref (_pixmap);
  40                         }
  41
  42                         _pixmap = gdk_pixmap_new (drawable, _width, _height, -1);
  43
  44                         cairo_t* cr = gdk_cairo_create (_pixmap);
  45                         render (cr);
  46                         cairo_destroy (cr);
  47
  48                         _dirty = false;
  49                 }
  50
  51                 gdk_draw_drawable (
  52                         drawable,
  53                         get_style()->get_fg_gc (Gtk::STATE_NORMAL)->gobj(),
  54                         _pixmap,
  55                         r.get_x(),
  56                         r.get_y(),
  57                         r.get_x(),
  58                         r.get_y(),
  59                         r.get_width(),
  60                         r.get_height()
  61                         );
  62         }
  63
  64         return true;
  65 }
  66
  67 void
  68 CairoWidget::set_dirty ()
  69 {
  70         ENSURE_GUI_THREAD (mem_fun (*this, &CairoWidget::set_dirty));
  71
  72         _dirty = true;
  73         queue_draw ();
  74 }
  75
  76 /** Handle a size allocation.
  77  *  @param alloc GTK allocation.
  78  */
  79 void
  80 CairoWidget::on_size_allocate (Gtk::Allocation& alloc)
  81 {
  82         Gtk::EventBox::on_size_allocate (alloc);
  83
  84         _width = alloc.get_width ();
  85         _height = alloc.get_height ();
  86
  87         set_dirty ();
  88 }