keybindings for scrollbars

[Tim Janik <timj gtk org>]

hey all,

h/vscales currently support a good amount of keybinding, e.g
left/right/up/down/page-up/page-down together with modifiers,
to adjust their value.
the same keybindings are not supported for scrollbars though,
and i don't see a reason for that. note, that keybindings on
scales and scrollbars only take affect if they have focus,
and the developer needs to explicitely request focusability for
the widget (e.g. by setting "can_focus", TRUE on the widget),
in order for keybindings to take effect.

so i plan on comitting the following keybindings to GtkScrollbarClass
(these are simply the current scale bindings, copied 1:1) unless someone
feels there's further need to discuss this issue:


#define add_slider_binding(binding_set, keyval, mask, scroll)          \
  gtk_binding_entry_add_signal (binding_set, keyval, mask,             \
                                "move_slider", 1,                      \
                                GTK_TYPE_SCROLL_TYPE, scroll)

  /* All bindings (even arrow keys) are on both h/v scale, because
   * blind users etc. don't care about scale orientation.
   */
  
  add_slider_binding (binding_set, GDK_Left, 0,
                      GTK_SCROLL_STEP_LEFT);
  
  add_slider_binding (binding_set, GDK_Left, GDK_CONTROL_MASK,
                      GTK_SCROLL_PAGE_LEFT);
  
  add_slider_binding (binding_set, GDK_KP_Left, 0,
                      GTK_SCROLL_STEP_LEFT);
  
  add_slider_binding (binding_set, GDK_KP_Left, GDK_CONTROL_MASK,
                      GTK_SCROLL_PAGE_LEFT);
  
  add_slider_binding (binding_set, GDK_Right, 0,
                      GTK_SCROLL_STEP_RIGHT);
  
  add_slider_binding (binding_set, GDK_Right, GDK_CONTROL_MASK,
                      GTK_SCROLL_PAGE_RIGHT);
  
  add_slider_binding (binding_set, GDK_KP_Right, 0,
                      GTK_SCROLL_STEP_RIGHT);
  
  add_slider_binding (binding_set, GDK_KP_Right, GDK_CONTROL_MASK,
                      GTK_SCROLL_PAGE_RIGHT);
  
  add_slider_binding (binding_set, GDK_Up, 0,
                      GTK_SCROLL_STEP_UP);
  
  add_slider_binding (binding_set, GDK_Up, GDK_CONTROL_MASK,
                      GTK_SCROLL_PAGE_UP);
  
  add_slider_binding (binding_set, GDK_KP_Up, 0,
                      GTK_SCROLL_STEP_UP);
  
  add_slider_binding (binding_set, GDK_KP_Up, GDK_CONTROL_MASK,
                      GTK_SCROLL_PAGE_UP);
  
  add_slider_binding (binding_set, GDK_Down, 0,
                      GTK_SCROLL_STEP_DOWN);
  
  add_slider_binding (binding_set, GDK_Down, GDK_CONTROL_MASK,
                      GTK_SCROLL_PAGE_DOWN);
  
  add_slider_binding (binding_set, GDK_KP_Down, 0,
                      GTK_SCROLL_STEP_DOWN);
  
  add_slider_binding (binding_set, GDK_KP_Down, GDK_CONTROL_MASK,
                      GTK_SCROLL_PAGE_DOWN);
  
  add_slider_binding (binding_set, GDK_Page_Up, 0,
                      GTK_SCROLL_PAGE_LEFT);
  
  add_slider_binding (binding_set, GDK_KP_Page_Up, 0,
                      GTK_SCROLL_PAGE_LEFT);  
  
  add_slider_binding (binding_set, GDK_Page_Up, 0,
                      GTK_SCROLL_PAGE_UP);
  
  add_slider_binding (binding_set, GDK_KP_Page_Up, 0,
                      GTK_SCROLL_PAGE_UP);
  
  add_slider_binding (binding_set, GDK_Page_Down, 0,
                      GTK_SCROLL_PAGE_RIGHT);
  
  add_slider_binding (binding_set, GDK_KP_Page_Down, 0,
                      GTK_SCROLL_PAGE_RIGHT);
  
  add_slider_binding (binding_set, GDK_Page_Down, 0,
                      GTK_SCROLL_PAGE_DOWN);
  
  add_slider_binding (binding_set, GDK_KP_Page_Down, 0,
                      GTK_SCROLL_PAGE_DOWN);
  
  /* Logical bindings (vs. visual bindings above) */
  
  add_slider_binding (binding_set, GDK_plus, 0,
                      GTK_SCROLL_STEP_FORWARD);  
  
  add_slider_binding (binding_set, GDK_minus, 0,
                      GTK_SCROLL_STEP_BACKWARD);  
  
  add_slider_binding (binding_set, GDK_plus, GDK_CONTROL_MASK,
                      GTK_SCROLL_PAGE_FORWARD);  
  
  add_slider_binding (binding_set, GDK_minus, GDK_CONTROL_MASK,
                      GTK_SCROLL_PAGE_BACKWARD);
  
  
  add_slider_binding (binding_set, GDK_KP_Add, 0,
                      GTK_SCROLL_STEP_FORWARD);  
  
  add_slider_binding (binding_set, GDK_KP_Subtract, 0,
                      GTK_SCROLL_STEP_BACKWARD);  
  
  add_slider_binding (binding_set, GDK_KP_Add, GDK_CONTROL_MASK,
                      GTK_SCROLL_PAGE_FORWARD);  
  
  add_slider_binding (binding_set, GDK_KP_Subtract, GDK_CONTROL_MASK,
                      GTK_SCROLL_PAGE_BACKWARD);
  
  
  add_slider_binding (binding_set, GDK_Home, 0,
                      GTK_SCROLL_START);
  
  add_slider_binding (binding_set, GDK_KP_Home, 0,
                      GTK_SCROLL_START);
  
  add_slider_binding (binding_set, GDK_End, 0,
                      GTK_SCROLL_END);
  
  add_slider_binding (binding_set, GDK_KP_End, 0,
                      GTK_SCROLL_END);
  


---
ciaoTJ