# File : terminal_interface-curses-mouse.adb

    ------------------------------------------------------------------------------
    --                                                                          --
    --                           GNAT ncurses Binding                           --
    --                                                                          --
    --                     Terminal_Interface.Curses.Mouse                      --
    --                                                                          --
    --                                 B O D Y                                  --
    --                                                                          --
    ------------------------------------------------------------------------------
    -- Copyright 2018,2020 Thomas E. Dickey                                     --
    -- Copyright 1999-2009,2014 Free Software Foundation, Inc.                  --
    --                                                                          --
    -- Permission is hereby granted, free of charge, to any person obtaining a  --
    -- copy of this software and associated documentation files (the            --
    -- "Software"), to deal in the Software without restriction, including      --
    -- without limitation the rights to use, copy, modify, merge, publish,      --
    -- distribute, distribute with modifications, sublicense, and/or sell       --
    -- copies of the Software, and to permit persons to whom the Software is    --
    -- furnished to do so, subject to the following conditions:                 --
    --                                                                          --
    -- The above copyright notice and this permission notice shall be included  --
    -- in all copies or substantial portions of the Software.                   --
    --                                                                          --
    -- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  --
    -- OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               --
    -- MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   --
    -- IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   --
    -- DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    --
    -- OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    --
    -- THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               --
    --                                                                          --
    -- Except as contained in this notice, the name(s) of the above copyright   --
    -- holders shall not be used in advertising or otherwise to promote the     --
    -- sale, use or other dealings in this Software without prior written       --
    -- authorization.                                                           --
    ------------------------------------------------------------------------------
    --  Author:  Juergen Pfeifer, 1996
    --  Version Control:
    --  @Revision: 1.28 @
    --  @Date: 2020/06/27 18:50:44 @
    --  Binding Version 01.00
    ------------------------------------------------------------------------------
    with Terminal_Interface.Curses.Aux; use Terminal_Interface.Curses.Aux;
    with Interfaces.C; use Interfaces.C;
    use Interfaces;

    package body Terminal_Interface.Curses.Mouse is

       function Has_Mouse return Boolean
       is
          function Mouse_Avail return C_Int;
          pragma Import (C, Mouse_Avail, "has_mouse");
       begin
          if Has_Key (Key_Mouse) or else Mouse_Avail /= 0 then
             return True;
          else
             return False;
          end if;
       end Has_Mouse;

       function Get_Mouse return Mouse_Event
       is
          type Event_Access is access all Mouse_Event;

          function Getmouse (Ev : Event_Access) return C_Int;
          pragma Import (C, Getmouse, "getmouse");

          Event : aliased Mouse_Event;
       begin
          if Getmouse (Event'Access) = Curses_Err then
             raise Curses_Exception;
          end if;
          return Event;
       end Get_Mouse;

       procedure Register_Reportable_Event (Button : Mouse_Button;
                                            State  : Button_State;
                                            Mask   : in out Event_Mask)
       is
          Button_Nr : constant Natural := Mouse_Button'Pos (Button);
          State_Nr  : constant Natural := Button_State'Pos (State);
       begin
          if Button in Modifier_Keys and then State /= Pressed then
             raise Curses_Exception;
          else
             if Button in Real_Buttons then
                Mask := Mask or ((2 ** (6 * Button_Nr)) ** State_Nr);
             else
                Mask := Mask or (BUTTON_CTRL ** (Button_Nr - 4));
             end if;
          end if;
       end Register_Reportable_Event;

       procedure Register_Reportable_Events (Button : Mouse_Button;
                                             State  : Button_States;
                                             Mask   : in out Event_Mask)
       is
       begin
          for S in Button_States'Range loop
             if State (S) then
                Register_Reportable_Event (Button, S, Mask);
             end if;
          end loop;
       end Register_Reportable_Events;

       function Start_Mouse (Mask : Event_Mask := All_Events)
                             return Event_Mask
       is
          function MMask (M : Event_Mask;
                          O : access Event_Mask) return Event_Mask;
          pragma Import (C, MMask, "mousemask");
          R   : Event_Mask;
          Old : aliased Event_Mask;
       begin
          R := MMask (Mask, Old'Access);
          if R = No_Events then
             Beep;
          end if;
          return Old;
       end Start_Mouse;

       procedure End_Mouse (Mask : Event_Mask := No_Events)
       is
       begin
          if Mask /= No_Events then
             Beep;
          end if;
       end End_Mouse;

       procedure Dispatch_Event (Mask   : Event_Mask;
                                 Button : out Mouse_Button;
                                 State  : out Button_State);

       procedure Dispatch_Event (Mask   : Event_Mask;
                                 Button : out Mouse_Button;
                                 State  : out Button_State) is
          L : Event_Mask;
       begin
          Button := Alt;  --  preset to non real button;
          if (Mask and BUTTON1_EVENTS) /= 0 then
             Button := Left;
          elsif (Mask and BUTTON2_EVENTS) /= 0 then
             Button := Middle;
          elsif (Mask and BUTTON3_EVENTS) /= 0 then
             Button := Right;
          elsif (Mask and BUTTON4_EVENTS) /= 0 then
             Button := Button4;
          end if;
          if Button in Real_Buttons then
             State := Released;  --  preset to non real button;
             L := 2 ** (6 * Mouse_Button'Pos (Button));
             for I in Button_State'Range loop
                if (Mask and L) /= 0 then
                   State := I;
                   exit;
                end if;
                L := 2 * L;
             end loop;
          else
             State := Pressed;
             if (Mask and BUTTON_CTRL) /= 0 then
                Button := Control;
             elsif (Mask and BUTTON_SHIFT) /= 0 then
                Button := Shift;
             elsif (Mask and BUTTON_ALT) /= 0 then
                Button := Alt;
             end if;
          end if;
       end Dispatch_Event;

       procedure Get_Event (Event  : Mouse_Event;
                            Y      : out Line_Position;
                            X      : out Column_Position;
                            Button : out Mouse_Button;
                            State  : out Button_State)
       is
          Mask  : constant Event_Mask := Event.Bstate;
       begin
          X := Column_Position (Event.X);
          Y := Line_Position   (Event.Y);
          Dispatch_Event (Mask, Button, State);
       end Get_Event;

       procedure Unget_Mouse (Event : Mouse_Event)
       is
          function Ungetmouse (Ev : Mouse_Event) return C_Int;
          pragma Import (C, Ungetmouse, "ungetmouse");
       begin
          if Ungetmouse (Event) = Curses_Err then
             raise Curses_Exception;
          end if;
       end Unget_Mouse;

       function Enclosed_In_Window (Win    : Window := Standard_Window;
                                    Event  : Mouse_Event) return Boolean
       is
          function Wenclose (Win : Window; Y : C_Int; X : C_Int)
                             return Curses_Bool;
          pragma Import (C, Wenclose, "wenclose");
       begin
          if Wenclose (Win, C_Int (Event.Y), C_Int (Event.X))
            = Curses_Bool_False
          then
             return False;
          else
             return True;
          end if;
       end Enclosed_In_Window;

       function Mouse_Interval (Msec : Natural := 200) return Natural
       is
          function Mouseinterval (Msec : C_Int) return C_Int;
          pragma Import (C, Mouseinterval, "mouseinterval");
       begin
          return Natural (Mouseinterval (C_Int (Msec)));
       end Mouse_Interval;

    end Terminal_Interface.Curses.Mouse;