1 #ifndef MSP_GLTK_LAYOUT_H_
2 #define MSP_GLTK_LAYOUT_H_
6 #include <sigc++/trackable.h>
16 Positions Widgets inside a Container.
18 A layout operates on constraints, which are used to form a linear program that
19 is then solved to obtain positions and dimensions that fulfill the constraints.
20 There are three kinds of constraints available: ordering, alignment and
23 Ordering constraints specify that the widgets should be placed next to each
24 other along X or Y axis. These operate on one axis at a time, so a widget
25 could be "right of" another even if they are separated by hundreds of pixels
26 vertically. The widgets will be separated by a spacing value, which is
27 settable on a per-layout basis.
29 Alignment constraints make the corresponding edges of two widgets be on the
30 same line. These are incompatible with ordering constraints, so only one or
31 the other should be used between any pair of widgets for the same axis.
33 Dimension matching constraints force the two widgets to have the same dimension
34 along the relevant axis.
36 In addition to constraints, there are some other properties that can be set on
37 widgets to determine how they are laid out. Gravity affects which edge of the
38 container the widget should be placed at. This is a relatively weak hint and
39 will be overridden by many other things. Margins can also be specified to
40 prevent widgets from getting too close to the container's edges.
42 Usually widgets are made as small as their content allows. Setting the expand
43 flag for a widget causes it to use as much space as possible. If multiple co-
44 dependent widgets have the expand flag set, the results are currently
47 Since specifiyng constraints manually can be quite tedious, there are some
48 derived Layout classes that implement common positioning patterns. See Row,
49 Column, MixedRows and Grid.
68 ABOVE = VERTICAL|SELF_POS|TARGET_POS|TARGET_DIM|SPACING,
69 BELOW = VERTICAL|SELF_POS|SELF_DIM|TARGET_POS|SPACING,
70 RIGHT_OF = HORIZONTAL|SELF_POS|TARGET_POS|TARGET_DIM|SPACING,
71 LEFT_OF = HORIZONTAL|SELF_POS|SELF_DIM|TARGET_POS|SPACING,
72 ALIGN_TOP = VERTICAL|SELF_POS|SELF_DIM|TARGET_POS|TARGET_DIM,
73 ALIGN_BOTTOM = VERTICAL|SELF_POS|TARGET_POS,
74 ALIGN_RIGHT = HORIZONTAL|SELF_POS|SELF_DIM|TARGET_POS|TARGET_DIM,
75 ALIGN_LEFT = HORIZONTAL|SELF_POS|TARGET_POS,
76 COPY_WIDTH = HORIZONTAL|SELF_DIM|TARGET_DIM,
77 COPY_HEIGHT = VERTICAL|SELF_DIM|TARGET_DIM
88 Constraint(ConstraintType, Slot &);
99 struct Slot: public sigc::trackable
104 Geometry autosize_geom;
106 std::list<Constraint> constraints;
110 Slot(Layout &, Widget &);
113 void autosize_changed();
119 Container *container;
120 std::list<Slot *> slots;
122 unsigned row_spacing;
123 unsigned col_spacing;
125 static Pointers pointers[2];
131 void set_container(Container &);
132 void set_margin(const Sides &);
133 void set_spacing(unsigned);
134 void set_row_spacing(unsigned);
135 void set_column_spacing(unsigned);
137 void add_widget(Widget &);
138 void remove_widget(Widget &);
140 virtual Slot *create_slot(Widget &);
141 Slot &get_slot_for_widget(Widget &);
142 static ConstraintType complement(ConstraintType);
144 void add_constraint(Widget &, ConstraintType, Widget &);
145 void set_gravity(Widget &, int, int);
146 void set_expand(Widget &, bool, bool);
151 void solve_constraints(int);