pango.c.gravity source code

1 /*
2  * Distributed under the Boost Software License, Version 1.0.
3  *    (See accompanying file LICENSE_1_0.txt or copy at
4  *          http://www.boost.org/LICENSE_1_0.txt)
5  */
6 module pango.c.gravity;
7 
8 import pango.c.script;
9 import pango.c.matrix;
10 
11 import glib;
12 
13 
14 /**
15  * PangoGravity:
16  * @PANGO_GRAVITY_SOUTH: Glyphs stand upright (default)
17  * @PANGO_GRAVITY_EAST: Glyphs are rotated 90 degrees clockwise
18  * @PANGO_GRAVITY_NORTH: Glyphs are upside-down
19  * @PANGO_GRAVITY_WEST: Glyphs are rotated 90 degrees counter-clockwise
20  * @PANGO_GRAVITY_AUTO: Gravity is resolved from the context matrix
21  *
22  * The #PangoGravity type represents the orientation of glyphs in a segment
23  * of text.  This is useful when rendering vertical text layouts.  In
24  * those situations, the layout is rotated using a non-identity PangoMatrix,
25  * and then glyph orientation is controlled using #PangoGravity.
26  * Not every value in this enumeration makes sense for every usage of
27  * #PangoGravity; for example, %PANGO_GRAVITY_AUTO only can be passed to
28  * pango_context_set_base_gravity() and can only be returned by
29  * pango_context_get_base_gravity().
30  *
31  * See also: #PangoGravityHint
32  *
33  * Since: 1.16
34  **/
35 enum PangoGravity {
36   PANGO_GRAVITY_SOUTH,
37   PANGO_GRAVITY_EAST,
38   PANGO_GRAVITY_NORTH,
39   PANGO_GRAVITY_WEST,
40   PANGO_GRAVITY_AUTO
41 }
42 
43 /**
44  * PangoGravityHint:
45  * @PANGO_GRAVITY_HINT_NATURAL: scripts will take their natural gravity based
46  * on the base gravity and the script.  This is the default.
47  * @PANGO_GRAVITY_HINT_STRONG: always use the base gravity set, regardless of
48  * the script.
49  * @PANGO_GRAVITY_HINT_LINE: for scripts not in their natural direction (eg.
50  * Latin in East gravity), choose per-script gravity such that every script
51  * respects the line progression.  This means, Latin and Arabic will take
52  * opposite gravities and both flow top-to-bottom for example.
53  *
54  * The #PangoGravityHint defines how horizontal scripts should behave in a
55  * vertical context.  That is, English excerpt in a vertical paragraph for
56  * example.
57  *
58  * See #PangoGravity.
59  *
60  * Since: 1.16
61  **/
62 enum PangoGravityHint {
63   PANGO_GRAVITY_HINT_NATURAL,
64   PANGO_GRAVITY_HINT_STRONG,
65   PANGO_GRAVITY_HINT_LINE
66 }
67 
68 /**
69  * PANGO_GRAVITY_IS_VERTICAL:
70  * @gravity: the #PangoGravity to check
71  *
72  * Whether a #PangoGravity represents vertical writing directions.
73  *
74  * Returns: %TRUE if @gravity is %PANGO_GRAVITY_EAST or %PANGO_GRAVITY_WEST,
75  *          %FALSE otherwise.
76  *
77  * Since: 1.16
78  **/
79 auto PANGO_GRAVITY_IS_VERTICAL(G)(G gravity) {
80     return gravity == PANGO_GRAVITY_EAST || gravity == PANGO_GRAVITY_WEST;
81 }
82 
83 /**
84  * PANGO_GRAVITY_IS_IMPROPER:
85  * @gravity: the #PangoGravity to check
86  *
87  * Whether a #PangoGravity represents a gravity that results in reversal of text direction.
88  *
89  * Returns: %TRUE if @gravity is %PANGO_GRAVITY_WEST or %PANGO_GRAVITY_NORTH,
90  *          %FALSE otherwise.
91  *
92  * Since: 1.32
93  **/
94 auto PANGO_GRAVITY_IS_IMPROPER(G)(G gravity) {
95 	return (gravity) == PANGO_GRAVITY_WEST || (gravity) == PANGO_GRAVITY_NORTH;
96 }
97 
98 
99 pure double       pango_gravity_to_rotation    (PangoGravity       gravity);
100 
101 pure PangoGravity pango_gravity_get_for_matrix (const(PangoMatrix) *matrix);
102 
103 pure PangoGravity pango_gravity_get_for_script (PangoScript        script,
104 					   PangoGravity       base_gravity,
105 					   PangoGravityHint   hint);
106 
107 pure PangoGravity pango_gravity_get_for_script_and_width
108 					  (PangoScript        script,
109 					   gboolean           wide,
110 					   PangoGravity       base_gravity,
111 					   PangoGravityHint   hint);
112