1. package Widgets.Scrollbars is 
  2.  
  3.     type Scrollbar is abstract new Widget with private; 
  4.  
  5.     procedure Calculate_Button( this : access Scrollbar; min, max : out Integer ) is abstract; 
  6.  
  7.     procedure Set_Client( this : not null access Scrollbar'Class; client : A_Widget ); 
  8.  
  9.     ---------------------------------------------------------------------------- 
  10.  
  11.     type H_Scrollbar is new Scrollbar with private; 
  12.     type A_H_Scrollbar is access all H_Scrollbar'Class; 
  13.  
  14.     function Create_H_Scrollbar( view : not null access Game_Views.Game_View'Class; 
  15.                                  id   : String ) return A_H_Scrollbar; 
  16.     pragma Precondition( id'Length > 0 ); 
  17.     pragma Postcondition( Create_H_Scrollbar'Result /= null ); 
  18.  
  19.     ---------------------------------------------------------------------------- 
  20.  
  21.     type V_Scrollbar is new Scrollbar with private; 
  22.     type A_V_Scrollbar is access all V_Scrollbar'Class; 
  23.  
  24.     function Create_V_Scrollbar( view : not null access Game_Views.Game_View'Class; 
  25.                                  id   : String ) return A_V_Scrollbar; 
  26.     pragma Precondition( id'Length > 0 ); 
  27.     pragma Postcondition( Create_V_Scrollbar'Result /= null ); 
  28.  
  29. private 
  30.  
  31.     type Scrollbar is abstract new Widget with 
  32.         record 
  33.             client : A_Widget := null;      -- widget to scroll 
  34.             pageUp,                         -- true when paging up 
  35.             pageDown,                       -- true when paging down 
  36.             dragging : Boolean := False;    -- true when button is dragged 
  37.             dragPos  : Integer := 0; 
  38.         end record; 
  39.  
  40.     procedure Construct( this : access Scrollbar; 
  41.                          view : not null access Game_Views.Game_View'Class; 
  42.                          id   : String ); 
  43.     pragma Precondition( id'Length > 0 ); 
  44.  
  45.     procedure Handle_Mouse_Release( this : access Scrollbar; 
  46.                                     evt  : not null A_Mouse_Button_Event ); 
  47.  
  48.     ---------------------------------------------------------------------------- 
  49.  
  50.     type H_Scrollbar is new Scrollbar with null record; 
  51.  
  52.     procedure Calculate_Button( this : access H_Scrollbar; min, max : out Integer ); 
  53.  
  54.     procedure Draw_Content( this : access H_Scrollbar; dc : Drawing_Context ); 
  55.  
  56.     procedure Handle_Mouse_Held( this : access H_Scrollbar; 
  57.                                  evt  : not null A_Mouse_Button_Event ); 
  58.  
  59.     procedure Handle_Mouse_Move( this : access H_Scrollbar; 
  60.                                  evt  : not null A_Mouse_Event ); 
  61.  
  62.     procedure Handle_Mouse_Press( this : access H_Scrollbar; 
  63.                                   evt  : not null A_Mouse_Button_Event ); 
  64.  
  65.     ---------------------------------------------------------------------------- 
  66.  
  67.     type V_Scrollbar is new Scrollbar with null record; 
  68.  
  69.     procedure Calculate_Button( this : access V_Scrollbar; min, max : out Integer ); 
  70.  
  71.     procedure Draw_Content( this : access V_Scrollbar; dc : Drawing_Context ); 
  72.  
  73.     procedure Handle_Mouse_Held( this : access V_Scrollbar; 
  74.                                  evt  : not null A_Mouse_Button_Event ); 
  75.  
  76.     procedure Handle_Mouse_Move( this : access V_Scrollbar; 
  77.                                  evt  : not null A_Mouse_Event ); 
  78.  
  79.     procedure Handle_Mouse_Press( this : access V_Scrollbar; 
  80.                                   evt  : not null A_Mouse_Button_Event ); 
  81.  
  82. end Widgets.Scrollbars;