w4d.layout.base source code

1 // Written in the D programming language.
2 /++
3  + Authors: KanzakiKino
4  + Copyright: KanzakiKino 2018
5  + License: LGPL-3.0
6 ++/
7 module w4d.layout.base;
8 import w4d.layout.exception,
9        w4d.style.widget;
10 import gl3n.linalg;
11 
12 /// A baseclass of Layout object.
13 /// Layout object decides children position to place
14 /// and calculates all styles.
15 abstract class Layout
16 {
17     protected Layoutable _owner;
18 
19     /// Owner of the layout.
20     inout @property owner () { return _owner; }
21 
22     protected @property style ()
23     {
24         return _owner.style;
25     }
26 
27     protected @property children ()
28     {
29         return _owner.childLayoutables;
30     }
31 
32     ///
33     this ( Layoutable owner )
34     {
35         enforce( owner, "Owner is null." );
36         _owner = owner;
37     }
38 
39     /// Calculates styles and decodes position of children.
40     void place ( vec2, vec2 );
41 }
42 
43 /// An interface of layoutable objects.
44 interface Layoutable
45 {
46     /// Style data.
47     @property WidgetStyle style ();
48 
49     /// Children.
50     @property Layoutable[] childLayoutables ();
51 
52     /// Wanted size.
53     @property vec2 wantedSize ();
54 
55     /// Places at the pos with the size.
56     vec2 layout ( vec2, vec2 );
57 
58     /// Shifts children.
59     void shiftChildren ( vec2 );
60 }