Commit e49aed80 authored by Scott Anderson's avatar Scott Anderson
Browse files

Updated CONTRIBUTING.md

Changed the contribution guidelines to be more consistent with the style
that wlroots has evolved into, and removed some duplicate information
that already exists in the kernel style.
parent a48dedba
......@@ -2,8 +2,7 @@
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-devel&uio=d4) upfront and discuss
your plans.
channel](irc://chat.freenode.net/sway-devel) upfront and discuss your plans.
## Pull Requests
......@@ -11,35 +10,36 @@ If you already have your own pull request habits, feel free to use them. If you
don't, however, allow me to make a suggestion: feature branches pulled from
upstream. Try this:
1. Fork sway
2. Clone your fork
3. git remote add upstream https://github.com/SirCmpwn/wlroots
1. Fork wlroots
2. `git clone https://github.com/username/wlroots && cd wlroots`
3. `git remote add upstream https://github.com/SirCmpwn/wlroots`
You only need to do this once. You're never going to use your fork's master
branch. Instead, when you start working on a feature, do this:
1. git fetch upstream
2. git checkout -b add-so-and-so-feature upstream/master
3. work
4. git push -u origin add-so-and-so-feature
5. Make pull request from your feature branch
1. `git fetch upstream`
2. `git checkout -b add-so-and-so-feature upstream/master`
3. Add and commit your changes
4. `git push -u origin add-so-and-so-feature`
5. Make a pull request from your feature branch
## Commit Messages
Please strive to write good commit messages. Here's some guidelines to follow:
The first line should be limited to 50 characters and should be a sentence that
completes the thought [When applied, this commit will...] "Implement cmd_move"
or "Fix #742" or "Improve performance of arrange_windows on ARM" or similar.
completes the thought [When applied, this commit will...] *"Implement
cmd_move"* or *"Fix #742"* or *"Improve performance of arrange_windows on ARM"*
or similar.
The subsequent lines should be seperated from the subject line by a single
The subsequent lines should be separated from the subject line by a single
blank line, and include optional details. In this you can give justification
for the change, [reference Github
issues](https://help.github.com/articles/closing-issues-via-commit-messages/),
or explain some of the subtler details of your patch. This is important because
when someone finds a line of code they don't understand later, they can use the
`git blame` command to find out what the author was thinking when they wrote
it. It's also easier to review your pull requests if they're seperated into
it. It's also easier to review your pull requests if they're separated into
logical commits that have good commit messages and justify themselves in the
extended commit description.
......@@ -47,158 +47,93 @@ As a good rule of thumb, anything you might put into the pull request
description on Github is probably fair game for going into the extended commit
message as well.
See [here](https://chris.beams.io/posts/git-commit/) for more details.
## Coding Style
wlroots is written in C with the same style as Sway. The style guidelines is
[kernel
wlroots is written in C with a style similar to the [kernel
style](https://www.kernel.org/doc/Documentation/process/coding-style.rst), 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.");
}
with a few notable differences.
if (!registry->desktop_shell) {
sway_abort("swaybg requires the compositor to support the desktop-shell extension.");
}
Try to keep your code conforming to C11 and POSIX as much as possible, and do
not use GNU extensions.
### Brackets
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.");
Brackets always go on the same line, including in functions.
Always include brackets for if/while/for, even if it's a single statement.
```c
void function() {
if (condition1) {
do_thing1();
}
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;
if (condition2) {
do_thing2();
} else {
sway_abort("Unsupported scaling mode: %s", scaling_mode_str);
do_thing3();
}
}
```
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);
}
}
### Indentation
while (wl_display_dispatch(registry->display) != -1);
Indentations are a single tab.
for (i = 0; i < surfaces->length; ++i) {
struct window *window = surfaces->items[i];
window_teardown(window);
}
list_free(surfaces);
registry_teardown(registry);
return 0;
For long lines that need to be broken, the continuation line should be indented
with an additional tab.
If the line being broken is opening a new block (functions, if, while, etc.),
the continuation line should be indented with two tabs, so they can't be
misread as being part of the block.
```c
really_long_function(argument1, argument2, ...,
argument3, argument4);
if (condition1 && condition2 && ...
condition3 && condition4) {
do_thing();
}
```
Try to break the line in the place which you think is the most appropriate.
### Line Length
Try to keep your lines under 80 columns, but you can go up to 100 if it
improves readability.
### Names
Function and type names should be prefixed with `wlr_submodule_` (e.g. `struct
wlr_drm_plane`, `wlr_output_set_cursor`). For static functions and types local
to a file, the names chosen aren't as important.
### Construction/Destruction Functions
For functions that are responsible for constructing and destructing an object,
they should be written as a pair of one of two forms:
* `init`/`finish`: These initialize/deinitialize a type, but are **NOT**
responsible for allocating it. They should accept a pointer to some
pre-allocated memory (e.g. a member of a struct).
* `create`/`destroy`: These also initialize/deinitialize, but will return a
pointer to a `malloc`ed chunk of memory, and will `free` it in `destroy`.
A destruction function should always be able to accept a NULL pointer or an
otherwise uninitialised value and exit cleanly; this simplifies error handling
a lot.
### Error Codes
For functions not returning a value, they should return a (stdbool.h) bool to
indicated if they succeeded or not.
### Macros
Try to keep the use of macros to a minimum, especially if a function can do the
job. If you do need to use them, try to keep them close to where they're being
used and `#undef` them after.
## Meson Coding Style
The Meson style is similar to the C style, but indentations are 2 spaces.
......@@ -7,9 +7,7 @@ This is a WIP: [status](https://github.com/SirCmpwn/wlroots/issues/9)
## Contributing
Development is organized in our [IRC
channel](http://webchat.freenode.net/?channels=sway-devel&uio=d4), #sway-devel on
irc.freenode.net. Join us and ask how you can help!
See [CONTRIBUTING.md](https://github.com/SirCmpwn/wlroots/blob/master/CONTRIBUTING.md)
## Building
......
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment