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104 | private with Ada.Containers.Indefinite_Doubly_Linked_Lists;
package Agpl.Drawing.Buffer is
-- This doesn't draw anything, but instead allows to keep a copy of what
-- a drawer is supposed to do.
pragma Preelaborate;
-- This type is the key abstraction to be used around...
-- It can be flushed into another drawer, or it can be passed as a drawable
-- to another drawer (useful when a drawable is expected)
type object is new Drawer and Drawable with private;
overriding
procedure Draw_Line (This : in out Object;
X1, Y1,
X2, Y2 : Float);
overriding
procedure Fill_Rectangle
(This : in out Object;
X1, Y1,
X2, Y2 : Float);
overriding
procedure Set_Color (This : in out Object;
Rgb : Types.Rgb_Triplet;
Alpha : Types.Unsigned_8);
overriding
procedure Write (This : in out Object;
X, Y : Float;
Utf8 : String);
not overriding
procedure Flush (This : Object;
Dest : in out Drawer'Class);
not overriding
procedure Clear (This : in out Object);
-- Start afresh
not overriding
procedure Flush_And_Clear (This : in out Object;
Dest : in out Drawer'Class);
-- Send to another drawer (@dest@) the buffered commands,
-- and optionally clear them to start afresh.
overriding
procedure Draw (This : Object;
Dest : in out Drawer'Class);
-- Flush to Dest
private
type Action is abstract tagged null record;
procedure Perform (This : Action;
Dest : in out Drawer'Class) is abstract;
-- Perform for real!
package Action_Lists is
new Ada.Containers.Indefinite_Doubly_Linked_Lists (Action'Class);
type Object is new Drawer and Drawable with record
Actions : Action_Lists.List;
end record;
type Action_Line is new Action with record
X1, Y1, X2, Y2 : Float;
end record;
overriding
procedure Perform (This : Action_Line;
Dest : in out Drawer'Class);
type Action_Fill is new Action with record
X1, Y1, X2, Y2 : Float;
end record;
overriding
procedure Perform (This : Action_Fill;
Dest : in out Drawer'Class);
type Action_Color is new Action with record
Rgb : Types.Rgb_triplet;
Alpha : Types.Unsigned_8;
end record;
overriding
procedure Perform (This : Action_Color;
Dest : in out Drawer'Class);
type Action_Write (Length : Natural) is new Action with record
X, Y : Float;
Utf8 : String (1 .. Length);
end record;
overriding
procedure Perform (This : Action_Write;
Dest : in out Drawer'Class);
end Agpl.Drawing.Buffer;
|