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
|
# Contributing to sway
Contributing just involves sending a pull request. You will probably be more
successful with your contribution if you visit the [IRC
channel](http://webchat.freenode.net/?channels=sway&uio=d4) upfront and discuss
your plans.
## Coding Style
Sway is written in C. The style guidelines is [kernel
style](https://www.kernel.org/doc/Documentation/CodingStyle), but all braces go
on the same line (*"but K&R says so!" is a silly way of justifying something*).
Some points to note:
* Do not use typedefs unless you have a good reason
* Do not use macros unless you have a *really* good reason
* Align `case` with `switch`
* Tabs, not spaces
* `char *pointer` - note position of `*`
* Use logging with reckless abandon
* Always include braces for if/for/while/etc, even for one-liners
An example of well formatted code:
```C
#include <stdio.h>
#include <stdlib.h>
#include "log.h"
#include "example.h"
struct foobar {
char *foo;
int bar;
long baz;
}; // Do not typedef without a good reason
int main(int argc, const char **argv) {
if (argc != 4) {
sway_abort("Do not run this program manually. See man 5 sway and look for output options.");
}
if (!registry->desktop_shell) {
sway_abort("swaybg requires the compositor to support the desktop-shell extension.");
}
int desired_output = atoi(argv[1]);
sway_log(L_INFO, "Using output %d of %d", desired_output, registry->outputs->length);
int i;
struct output_state *output = registry->outputs->items[desired_output];
struct window *window = window_setup(registry, 100, 100, false);
if (!window) {
sway_abort("Failed to create surfaces.");
}
window->width = output->width;
window->height = output->height;
desktop_shell_set_background(registry->desktop_shell, output->output, window->surface);
list_add(surfaces, window);
cairo_surface_t *image = cairo_image_surface_create_from_png(argv[2]);
double width = cairo_image_surface_get_width(image);
double height = cairo_image_surface_get_height(image);
const char *scaling_mode_str = argv[3];
enum scaling_mode scaling_mode;
if (strcmp(scaling_mode_str, "stretch") == 0) {
scaling_mode = SCALING_MODE_STRETCH;
} else if (strcmp(scaling_mode_str, "fill") == 0) {
scaling_mode = SCALING_MODE_FILL;
} else if (strcmp(scaling_mode_str, "fit") == 0) {
scaling_mode = SCALING_MODE_FIT;
} else if (strcmp(scaling_mode_str, "center") == 0) {
scaling_mode = SCALING_MODE_CENTER;
} else if (strcmp(scaling_mode_str, "tile") == 0) {
scaling_mode = SCALING_MODE_TILE;
} else {
sway_abort("Unsupported scaling mode: %s", scaling_mode_str);
}
for (i = 0; i < surfaces->length; ++i) {
struct window *window = surfaces->items[i];
if (window_prerender(window) && window->cairo) {
switch (scaling_mode) {
case SCALING_MODE_STRETCH:
cairo_scale(window->cairo,
(double) window->width / width,
(double) window->height / height);
cairo_set_source_surface(window->cairo, image, 0, 0);
break;
case SCALING_MODE_FILL:
{
double window_ratio = (double) window->width / window->height;
double bg_ratio = width / height;
if (window_ratio > bg_ratio) {
double scale = (double) window->width / width;
cairo_scale(window->cairo, scale, scale);
cairo_set_source_surface(window->cairo, image,
0,
(double) window->height/2 / scale - height/2);
} else {
double scale = (double) window->height / height;
cairo_scale(window->cairo, scale, scale);
cairo_set_source_surface(window->cairo, image,
(double) window->width/2 / scale - width/2,
0);
}
}
break;
case SCALING_MODE_FIT:
{
double window_ratio = (double) window->width / window->height;
double bg_ratio = width / height;
if (window_ratio > bg_ratio) {
double scale = (double) window->height / height;
cairo_scale(window->cairo, scale, scale);
cairo_set_source_surface(window->cairo, image,
(double) window->width/2 / scale - width/2,
0);
} else {
double scale = (double) window->width / width;
cairo_scale(window->cairo, scale, scale);
cairo_set_source_surface(window->cairo, image,
0,
(double) window->height/2 / scale - height/2);
}
}
break;
case SCALING_MODE_CENTER:
cairo_set_source_surface(window->cairo, image,
(double) window->width/2 - width/2,
(double) window->height/2 - height/2);
break;
case SCALING_MODE_TILE:
{
cairo_pattern_t *pattern = cairo_pattern_create_for_surface(image);
cairo_pattern_set_extend(pattern, CAIRO_EXTEND_REPEAT);
cairo_set_source(window->cairo, pattern);
}
break;
default:
sway_abort("Scaling mode '%s' not implemented yet!", scaling_mode_str);
}
cairo_paint(window->cairo);
window_render(window);
}
}
while (wl_display_dispatch(registry->display) != -1);
for (i = 0; i < surfaces->length; ++i) {
struct window *window = surfaces->items[i];
window_teardown(window);
}
list_free(surfaces);
registry_teardown(registry);
return 0;
}
```
|
