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();
125 Container *container;
126 std::list<Slot *> slots;
128 unsigned row_spacing;
129 unsigned col_spacing;
130 Geometry autosize_geom;
132 static Pointers pointers[2];
138 void set_container(Container &);
139 void set_margin(const Sides &);
140 void set_spacing(unsigned);
141 void set_row_spacing(unsigned);
142 void set_column_spacing(unsigned);
144 void add_widget(Widget &);
145 void remove_widget(Widget &);
147 virtual Slot *create_slot(Widget &);
148 Slot &get_slot_for_widget(Widget &);
149 static ConstraintType complement(ConstraintType);
151 void add_constraint(Widget &, ConstraintType, Widget &);
152 void set_gravity(Widget &, int, int);
153 void set_expand(Widget &, bool, bool);
159 void solve_constraints(int, SolveMode);