summaryrefslogtreecommitdiff
path: root/gui-over.c
blob: 3a0d295f3d9dfa7f73ab02bb88d37faeda1998d7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/*
 * gui-over.c - GUI: overlays
 *
 * Written 2016 by Werner Almesberger
 * Copyright 2016 by Werner Almesberger
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

/*
 * Resources:
 *
 * http://zetcode.com/gfx/cairo/cairobackends/
 * https://developer.gnome.org/gtk3/stable/gtk-migrating-2-to-3.html
 * https://www.cairographics.org/samples/rounded_rectangle/
 */

#include <stddef.h>
#include <stdlib.h>
#include <math.h>

#include <cairo/cairo.h>

#include "util.h"
#include "gui-aoi.h"
#include "gui-over.h"


#define	OVER_FONT_SIZE	16
#define	OVER_BORDER	8
#define	OVER_RADIUS	6
#define	OVER_SEP	8
#define	OVER_X0		10
#define	OVER_Y0		10


struct overlay {
	const char *s;

	struct aoi **aois;
	bool (*hover)(void *user, bool on);
	void (*click)(void *user);
	void *user;

	const struct aoi *aoi;

	struct overlay *next;
};


static void rrect(cairo_t *cr, int x, int y, int w, int h, int r)
{
	const double deg = M_PI / 180.0;

	cairo_new_path(cr);
	cairo_arc(cr, x + w - r, y + r, r, -90 * deg, 0);
	cairo_arc(cr, x + w - r, y + h - r, r, 0, 90 * deg);
	cairo_arc(cr, x + r, y + h - r, r, 90 * deg, 180 * deg);
	cairo_arc(cr, x + r, y + r, r, 180 * deg, 270 * deg);
	cairo_close_path(cr);
}


static void overlay_draw(struct overlay *over, cairo_t *cr, int *x, int *y)
{
	cairo_text_extents_t ext;
	int w, h;

	cairo_set_font_size(cr, OVER_FONT_SIZE);
	cairo_text_extents(cr, over->s, &ext);

	w = ext.width + 2 * OVER_BORDER;
	h = ext.height + 2 * OVER_BORDER;

	rrect(cr, *x, *y, w, h, OVER_RADIUS);

	cairo_set_source_rgba(cr, 0.8, 0.9, 1, 0.8);
	cairo_fill_preserve(cr);
	cairo_set_source_rgba(cr, 0.5, 0.5, 1, 0.7);
	cairo_set_line_width(cr, 2);
	cairo_stroke(cr);

	cairo_set_source_rgb(cr, 0, 0, 0);
	cairo_move_to(cr, *x + OVER_BORDER, *y + OVER_BORDER + ext.height);
	cairo_show_text(cr, over->s);

	if (over->hover || over->click) {
		struct aoi aoi = {
			.x	= *x,
			.y	= *y,
			.w	= w,
			.h	= h,
			.hover	= over->hover,
			.click	= over->click,
			.user	= over->user,
		};

		if (over->aoi)
			aoi_remove(over->aois, over->aoi);
		over->aoi = aoi_add(over->aois, &aoi);
	}

	*y += ext.height + OVER_SEP;
}


void overlay_draw_all(struct overlay *overlays, cairo_t *cr)
{
	struct overlay *over;
	int x = OVER_X0;
	int y = OVER_Y0;

	for (over = overlays; over; over = over->next)
		overlay_draw(over, cr, &x, &y);
}


struct overlay *overlay_add(struct overlay **overlays, const char *s,
    struct aoi **aois,
    bool (*hover)(void *user, bool on), void (*click)(void *user), void *user)
{
	struct overlay *over;
	struct overlay **anchor;
	
	over = alloc_type(struct overlay);
	over->s = stralloc(s);

	over->aois = aois;
	over->hover = hover;
	over->click = click;
	over->user = user;
	over->aoi = NULL;

	for (anchor = overlays; *anchor; anchor = &(*anchor)->next);
	over->next = NULL;
	*anchor = over;

	return over;
}


static void overlay_free(struct overlay *over)
{
	if (over->aoi)
		aoi_remove(over->aois, over->aoi);
	free((void *) over->s);
	free(over);
}


void overlay_remove(struct overlay **overlays, struct overlay *over)
{
	struct overlay **anchor;

	for (anchor = overlays; *anchor; anchor = &(*anchor)->next)
		if (*anchor == over) {
			*anchor = over->next;
			overlay_free(over);
			return;
		}
	abort();
}


void overlay_remove_all(struct overlay **overlays)
{
	struct overlay *next;

	while (*overlays) {
		next = (*overlays)->next;
		overlay_free(*overlays);
		*overlays = next;
	}
}