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with FLTK.Text_Buffers;
with Ada.Strings.Unbounded; use Ada.Strings.Unbounded;
use type FLTK.Text_Buffers.Modification;
use type FLTK.Text_Buffers.Position;
with Ada.Text_IO;
package body Change_Vectors is
function Continues_Insert
(Orig, Cont : in Change)
return Boolean is
begin
return
Orig.Action = FLTK.Text_Buffers.Insert and then
Integer (Orig.Place) + Orig.Length = Integer (Cont.Place) and then
Cont.Length = 1 and then
(Element (Orig.Text, Orig.Length) /= ' ' or else Element (Cont.Text, 1) = ' ');
end Continues_Insert;
function Continues_Delete
(Orig, Cont : in Change)
return Boolean is
begin
return
Orig.Action = FLTK.Text_Buffers.Delete and then
Orig.Place = Cont.Place and then
Cont.Length = 1;
end Continues_Delete;
function Continues_Backspace
(Orig, Cont : in Change)
return Boolean is
begin
return
Orig.Action = FLTK.Text_Buffers.Delete and then
Orig.Place = Cont.Place + 1 and then
Cont.Length = 1;
end Continues_Backspace;
procedure Push
(This : in out Change_Vector;
Item : in Change)
is
procedure App (Ch : in out Change) is
begin
Ch.Length := Ch.Length + 1;
Append (Ch.Text, Item.Text);
end App;
procedure Pre (Ch : in out Change) is
begin
Ch.Length := Ch.Length + 1;
Ch.Text := Item.Text & Ch.Text;
Ch.Place := Ch.Place - 1;
end Pre;
begin
if Item.Action = FLTK.Text_Buffers.Insert then
if This.Near > 0 and then
Continues_Insert (This.List.Element (This.Near), Item)
then
This.List.Update_Element (This.Near, App'Access);
else
This.Near := This.Near + 1;
This.List.Insert (This.Near, Item);
end if;
elsif Item.Action = FLTK.Text_Buffers.Delete then
if This.Near > 0 then
if Continues_Delete (This.List.Element (This.Near), Item)
then
This.List.Update_Element (This.Near, App'Access);
elsif
Continues_Backspace (This.List.Element (This.Near), Item)
then
This.List.Update_Element (This.Near, Pre'Access);
else
This.Near := This.Near + 1;
This.List.Insert (This.Near, Item);
end if;
end if;
end if;
This.Far := This.Near;
while Integer (This.List.Length) > This.Far loop
This.List.Delete_Last;
end loop;
end Push;
function Pop
(This : in out Change_Vector)
return Boolean is
begin
if This.Near > 0 then
This.Near := This.Near - 1;
return True;
else
return False;
end if;
end Pop;
procedure Pop
(This : in out Change_Vector) is
begin
if This.Near > 0 then
This.Near := This.Near - 1;
end if;
end Pop;
function Peek
(This : in Change_Vector;
Item : out Change)
return Boolean is
begin
if This.Near > 0 then
Item := This.List.Element (This.Near);
return True;
else
return False;
end if;
end Peek;
procedure Peek
(This : in Change_Vector;
Item : out Change) is
begin
if This.Near > 0 then
Item := This.List.Element (This.Near);
end if;
end Peek;
function Re_Push
(This : in out Change_Vector)
return Boolean is
begin
if This.Near < This.Far then
This.Near := This.Near + 1;
return True;
else
return False;
end if;
end Re_Push;
procedure Re_Push
(This : in out Change_Vector) is
begin
if This.Near < This.Far then
This.Near := This.Near + 1;
end if;
end Re_Push;
function At_Start
(This : in Change_Vector)
return Boolean is
begin
return This.Near = 0;
end At_Start;
function At_End
(This : in Change_Vector)
return Boolean is
begin
return This.Near >= This.Far;
end At_End;
end Change_Vectors;
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