[PATCH weston 3/4] compositor: Add internal output object used for layout configuration

[Armin Krezović]

This adds weston specific output object, which contains information
about output's position, relative to other outputs. DRM and Windowed
backends code has been updated to make use of the new code and
parse new configuration options for a given output, if it was
specified.

New configuration file options for [output] section have been added:

left-of: Specifies which output should be on the right side of the
current output.

right-of: Specifies which output should be on the left side of the
current output.

Signed-off-by: Armin Krezović <krezovic.armin at gmail.com>
---
 compositor/main.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)

diff --git a/compositor/main.c b/compositor/main.c
index 503016e..e379d8d 100644
--- a/compositor/main.c
+++ b/compositor/main.c
@@ -78,6 +78,18 @@ struct wet_compositor {
 	struct weston_config *config;
 	struct wet_output_config *parsed_options;
 	struct wl_listener pending_output_listener;
+	struct wl_list output_layout_list;
+};
+
+struct wet_output {
+	struct weston_output *output;
+	struct wl_listener output_destroy_listener;
+	struct wl_list link;
+
+	char *left_output_name;
+	char *right_output_name;
+
+	bool position_set;
 };
 
 static FILE *weston_logfile = NULL;
@@ -492,6 +504,51 @@ wet_get_config(struct weston_compositor *ec)
 	return compositor->config;
 }
 
+static void
+wet_output_destroy(struct wet_output *output)
+{
+	wl_list_remove(&output->output_destroy_listener.link);
+	wl_list_remove(&output->link);
+
+	free(output->left_output_name);
+	free(output->right_output_name);
+
+	free(output);
+}
+
+static void
+handle_output_destroy(struct wl_listener *listener, void *data)
+{
+	struct wet_output *output = container_of(listener,
+		struct wet_output, output_destroy_listener);
+
+	wet_output_destroy(output);
+}
+
+static struct wet_output *
+wet_output_create(struct weston_output *output)
+{
+	struct wet_compositor *compositor = to_wet_compositor(output->compositor);
+	struct wet_output *out;
+
+	out = zalloc(sizeof *out);
+	if (!out)
+		return NULL;
+
+	out->output = output;
+	out->position_set = false;
+
+	out->left_output_name = NULL;
+	out->right_output_name = NULL;
+
+	out->output_destroy_listener.notify = handle_output_destroy;
+	wl_signal_add(&output->destroy_signal, &out->output_destroy_listener);
+
+	wl_list_insert(compositor->output_layout_list.prev, &out->link);
+
+	return out;
+}
+
 static const char xdg_error_message[] =
 	"fatal: environment variable XDG_RUNTIME_DIR is not set.\n";
 
@@ -1057,10 +1114,12 @@ wet_configure_windowed_output_from_config(struct weston_output *output,
 	struct weston_config_section *section = NULL;
 	struct wet_compositor *compositor = to_wet_compositor(output->compositor);
 	struct wet_output_config *parsed_options = compositor->parsed_options;
+	struct wet_output *wet_output = wet_output_create(output);
 	int width = defaults->width;
 	int height = defaults->height;
 
 	assert(parsed_options);
+	assert(wet_output);
 
 	if (!api) {
 		weston_log("Cannot use weston_windowed_output_api.\n");
@@ -1071,6 +1130,7 @@ wet_configure_windowed_output_from_config(struct weston_output *output,
 
 	if (section) {
 		char *mode;
+		char *out;
 
 		weston_config_section_get_string(section, "mode", &mode, NULL);
 		if (!mode || sscanf(mode, "%dx%d", &width,
@@ -1081,6 +1141,14 @@ wet_configure_windowed_output_from_config(struct weston_output *output,
 			height = defaults->height;
 		}
 		free(mode);
+
+		weston_config_section_get_string(section, "left-of", &out, NULL);
+		wet_output->right_output_name = out ? strdup(out) : NULL;
+		free(out);
+
+		weston_config_section_get_string(section, "right-of", &out, NULL);
+		wet_output->left_output_name = out ? strdup(out) : NULL;
+		free(out);
 	}
 
 	if (parsed_options->width)
@@ -1134,16 +1202,20 @@ drm_backend_output_configure(struct wl_listener *listener, void *data)
 {
 	struct weston_output *output = data;
 	struct weston_config *wc = wet_get_config(output->compositor);
+	struct wet_output *wet_output = wet_output_create(output);
 	struct weston_config_section *section;
 	const struct weston_drm_output_api *api = weston_drm_output_get_api(output->compositor);
 	enum weston_drm_backend_output_mode mode =
 		WESTON_DRM_BACKEND_OUTPUT_PREFERRED;
 
 	char *s;
+	char *out;
 	char *modeline = NULL;
 	char *gbm_format = NULL;
 	char *seat = NULL;
 
+	assert(wet_output);
+
 	if (!api) {
 		weston_log("Cannot use weston_drm_output_api.\n");
 		return;
@@ -1164,6 +1236,14 @@ drm_backend_output_configure(struct wl_listener *listener, void *data)
 	}
 	free(s);
 
+	weston_config_section_get_string(section, "left-of", &out, NULL);
+	wet_output->right_output_name = out ? strdup(out) : NULL;
+	free(out);
+
+	weston_config_section_get_string(section, "right-of", &out, NULL);
+	wet_output->left_output_name = out ? strdup(out) : NULL;
+	free(out);
+
 	if (api->set_mode(output, mode, modeline) < 0) {
 		weston_log("Cannot configure an output using weston_drm_output_api.\n");
 		free(modeline);
@@ -1829,6 +1909,7 @@ int main(int argc, char *argv[])
 		goto out_signals;
 	user_data.config = config;
 	user_data.parsed_options = NULL;
+	wl_list_init(&user_data.output_layout_list);
 
 	section = weston_config_get_section(config, "core", NULL, NULL);
 
-- 
2.10.0