Add integration with kanshi daemon

meson_options.txt

@@ -0,0 +1,2 @@
+option('kanshi', type: 'feature', value: 'auto', description: 'Enable integration with the kanshi daemon')
+

src/kanshi.h

@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2017-2019 emersion
+ * Copyright (C) 2019 cyclopsian
+
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/*
+ * Parts of this file are taken from emersion/kanshi:
+ * https://github.com/emersion/kanshi/blob/38d27474b686fcc8324cc5e454741a49577c0988/include/config.h
+ * https://github.com/emersion/kanshi/blob/38d27474b686fcc8324cc5e454741a49577c0988/include/parser.h
+ */
+
+#ifndef WDISPLAYS_KANSHI_H
+#define WDISPLAYS_KANSHI_H
+
+#include <stdbool.h>
+#include <wayland-client.h>
+
+enum kanshi_output_field {
+  KANSHI_OUTPUT_ENABLED = 1 << 0,
+  KANSHI_OUTPUT_MODE = 1 << 1,
+  KANSHI_OUTPUT_POSITION = 1 << 2,
+  KANSHI_OUTPUT_SCALE = 1 << 3,
+  KANSHI_OUTPUT_TRANSFORM = 1 << 4,
+};
+
+struct kanshi_profile_output {
+  char *name;
+  unsigned int fields; // enum kanshi_output_field
+  struct wl_list link;
+
+  bool enabled;
+  struct {
+    int width, height;
+    int refresh; // mHz
+  } mode;
+  struct {
+    int x, y;
+  } position;
+  float scale;
+  enum wl_output_transform transform;
+};
+
+
+struct kanshi_profile_command {
+  struct wl_list link;
+  char *command;
+};
+
+struct kanshi_profile {
+  struct wl_list link;
+  char *name;
+  // Wildcard outputs are stored at the end of the list
+  struct wl_list commands;
+  struct wl_list outputs;
+};
+
+struct kanshi_config {
+  struct wl_list profiles;
+};
+
+/*
+ * Loads the kanshi config from the given file.
+ */
+struct kanshi_config *kanshi_parse_config(const char *path);
+
+/*
+ * Saves the kanshi config to the given file.
+ */
+void kanshi_save_config(const char *path, struct kanshi_config *config);
+
+/*
+ * Destroys the config structure.
+ */
+void kanshi_destroy_config(struct kanshi_config *config);
+
+#endif

src/meson.build

@@ -7,15 +7,31 @@ gtk = dependency('gtk+-3.0')
 assert(gdk.get_pkgconfig_variable('targets').split().contains('wayland'), 'Wayland GDK backend not present')
 epoxy = dependency('epoxy')
 
-executable(
+wdisplays_src = files(
-  'wdisplays',
-  [
   'main.c',
   'outputs.c',
   'render.c',
   'glviewport.c',
-    'overlay.c',
+  'overlay.c'
-    resources,
+)
+wdisplays_args = []
+
+kanshictl = find_program('kanshictl', required:  get_option('kanshi'))
+if kanshictl.found()
+  wdisplays_src += files(
+    'parser.c'
+  )
+  wdisplays_args += [
+    '-DHAVE_KANSHI',
+    '-DKANSHICTL_PATH="@0@"'.format(kanshictl.path())
+  ]
+endif
+
+executable(
+  'wdisplays',
+  [
+    wdisplays_src,
+    resources
   ],
   dependencies : [
     m_dep,
@@ -25,5 +41,6 @@ executable(
     epoxy,
     gtk
   ],
+  c_args: wdisplays_args,
   install: true
 )

src/outputs.c

@@ -27,7 +27,6 @@
  * https://github.com/emersion/kanshi/blob/38d27474b686fcc8324cc5e454741a49577c0988/main.c
  */
 
-#define _GNU_SOURCE
 #include <assert.h>
 #include <stdlib.h>
 #include <string.h>
@@ -40,7 +39,12 @@
 #include <fcntl.h>
 #include <unistd.h>
 
+#include <glib.h>
+
 #include "wdisplays.h"
+#ifdef HAVE_KANSHI
+#include "kanshi.h"
+#endif
 
 #include "wlr-output-management-unstable-v1-client-protocol.h"
 #include "xdg-output-unstable-v1-client-protocol.h"
@@ -66,6 +70,109 @@ static void destroy_pending(struct wd_pending_config *pending) {
   free(pending);
 }
 
+#ifdef HAVE_KANSHI
+static struct kanshi_profile *find_active_profile(
+    const struct kanshi_config *config, const struct wl_list *outputs) {
+  struct kanshi_profile *profile;
+  int head_count = wl_list_length(outputs);
+  wl_list_for_each(profile, &config->profiles, link) {
+    unsigned found_count = 0;
+    struct kanshi_profile_output *output;
+    wl_list_for_each(output, &profile->outputs, link) {
+      struct wd_head_config *head;
+      wl_list_for_each(head, outputs, link) {
+        if (strcmp(output->name, head->head->name) == 0) {
+          found_count++;
+          break;
+        }
+      }
+    }
+    if (found_count == head_count) {
+      return profile;
+    }
+  }
+  return NULL;
+}
+
+static void update_profile_output(struct kanshi_profile_output *output,
+    const struct wd_head_config *head) {
+  output->enabled = head->enabled;
+  output->fields |= KANSHI_OUTPUT_ENABLED;
+  if (head->enabled) {
+    output->fields |= KANSHI_OUTPUT_MODE | KANSHI_OUTPUT_POSITION
+      | KANSHI_OUTPUT_SCALE | KANSHI_OUTPUT_TRANSFORM;
+    output->mode.width = head->width;
+    output->mode.height = head->height;
+    output->mode.refresh = head->refresh;
+    output->position.x = head->x;
+    output->position.y = head->y;
+    output->scale = head->scale;
+    output->transform = head->transform;
+  }
+}
+
+static bool save_config(const struct wl_list *outputs) {
+  g_autofree const char *config_dir = g_strjoin("/",
+      g_get_user_config_dir(), "kanshi/config.d", NULL);
+  if (g_mkdir_with_parents(config_dir, 0700) == -1) {
+    fprintf(stderr, "g_mkdir_with_parents failed: %s: %s\n",
+        config_dir, strerror(errno));
+    return false;
+  }
+  g_autofree const char *config_path = g_strjoin("/",
+      config_dir, "50-wdisplays", NULL);
+  struct kanshi_config *config = kanshi_parse_config(config_path);
+  if (config == NULL) {
+    config = calloc(1, sizeof(*config));
+    wl_list_init(&config->profiles);
+  }
+  struct kanshi_profile *profile = find_active_profile(config, outputs);
+  if (profile == NULL) {
+    profile = calloc(1, sizeof(*profile));
+    wl_list_init(&profile->outputs);
+    struct wd_head_config *head;
+    wl_list_for_each(head, outputs, link) {
+      struct kanshi_profile_output *output = calloc(1, sizeof(*output));
+      output->name = strdup(head->head->name);
+      update_profile_output(output, head);
+      wl_list_insert(profile->outputs.prev, &output->link);
+    }
+    wl_list_insert(&config->profiles, &profile->link);
+  } else {
+    struct kanshi_profile_output *output;
+    wl_list_for_each(output, &profile->outputs, link) {
+      struct wd_head_config *head;
+      wl_list_for_each(head, outputs, link) {
+        if (strcmp(output->name, head->head->name) == 0) {
+          update_profile_output(output, head);
+          break;
+        }
+      }
+    }
+  }
+
+  kanshi_save_config(config_path, config);
+  kanshi_destroy_config(config);
+
+  GError *error = NULL;
+  gchar *argv[] = { KANSHICTL_PATH, "reload", NULL };
+  gint status;
+  g_spawn_sync(NULL, argv, NULL, G_SPAWN_DEFAULT, NULL, NULL,
+      NULL, NULL, &status, &error);
+  if (error != NULL) {
+    fprintf(stderr, "Could not execute " KANSHICTL_PATH ": %s\n",
+        error->message);
+    g_error_free(error);
+    return false;
+  }
+  if (status != EXIT_SUCCESS) {
+    fprintf(stderr, "Could not execute " KANSHICTL_PATH "\n");
+    return false;
+  }
+  return true;
+}
+#endif
+
 static void config_handle_succeeded(void *data,
     struct zwlr_output_configuration_v1 *config) {
   struct wd_pending_config *pending = data;
@@ -103,13 +210,21 @@ static const struct zwlr_output_configuration_v1_listener config_listener = {
 
 void wd_apply_state(struct wd_state *state, struct wl_list *new_outputs,
     struct wl_display *display) {
-  struct zwlr_output_configuration_v1 *config =
-    zwlr_output_manager_v1_create_configuration(state->output_manager, state->serial);
-
   struct wd_pending_config *pending = calloc(1, sizeof(*pending));
   pending->state = state;
   pending->outputs = new_outputs;
 
+#ifdef HAVE_KANSHI
+  if (save_config(new_outputs)) {
+    wd_ui_apply_done(pending->state, pending->outputs);
+    destroy_pending(pending);
+    return;
+  }
+#endif
+
+  struct zwlr_output_configuration_v1 *config =
+    zwlr_output_manager_v1_create_configuration(state->output_manager, state->serial);
+
   zwlr_output_configuration_v1_add_listener(config, &config_listener, pending);
 
   ssize_t i = -1;
@@ -177,20 +292,13 @@ static void wd_frame_destroy(struct wd_frame *frame) {
 }
 
 static int create_shm_file(size_t size, const char *fmt, ...) {
-  char *shm_name = NULL;
   int fd = -1;
 
   va_list vl;
   va_start(vl, fmt);
-  int result = vasprintf(&shm_name, fmt, vl);
+  char *shm_name = g_strdup_vprintf(fmt, vl);
   va_end(vl);
 
-  if (result == -1) {
-    fprintf(stderr, "asprintf: %s\n", strerror(errno));
-    shm_name = NULL;
-    return -1;
-  }
-
   fd = shm_open(shm_name, O_CREAT | O_RDWR, S_IRUSR | S_IWUSR);
   if (fd == -1) {
     fprintf(stderr, "shm_open: %s\n", strerror(errno));

src/parser.c

@@ -0,0 +1,668 @@
+/*
+ * Copyright (C) 2017-2019 emersion
+ * Copyright (C) 2019 cyclopsian
+
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/*
+ * Parts of this file are taken from emersion/kanshi:
+ * https://github.com/emersion/kanshi/blob/38d27474b686fcc8324cc5e454741a49577c0988/parser.c
+ * https://github.com/emersion/kanshi/blob/38d27474b686fcc8324cc5e454741a49577c0988/include/config.h
+ */
+
+#define _POSIX_C_SOURCE 200809L
+#include <assert.h>
+#include <ctype.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "kanshi.h"
+
+enum kanshi_token_type {
+  KANSHI_TOKEN_LBRACKET,
+  KANSHI_TOKEN_RBRACKET,
+  KANSHI_TOKEN_STR,
+  KANSHI_TOKEN_NEWLINE,
+  KANSHI_TOKEN_COMMENT,
+};
+
+struct kanshi_parser {
+  FILE *f;
+  int next;
+  int line, col;
+
+  enum kanshi_token_type tok_type;
+  char tok_str[1024];
+  size_t tok_str_len;
+};
+static char commentSign = '#';
+
+static const char *token_type_str(enum kanshi_token_type t) {
+  switch (t) {
+  case KANSHI_TOKEN_LBRACKET:
+    return "'{'";
+  case KANSHI_TOKEN_RBRACKET:
+    return "'}'";
+  case KANSHI_TOKEN_STR:
+    return "string";
+  case KANSHI_TOKEN_NEWLINE:
+    return "newline";
+  case KANSHI_TOKEN_COMMENT:
+    return "comment";
+  }
+  assert(0);
+}
+
+static int parser_read_char(struct kanshi_parser *parser) {
+  if (parser->next >= 0) {
+    int ch = parser->next;
+    parser->next = -1;
+    return ch;
+  }
+
+  errno = 0;
+  int ch = fgetc(parser->f);
+  if (ch == EOF) {
+    if (errno != 0) {
+      fprintf(stderr, "fgetc failed: %s\n", strerror(errno));
+    } else {
+      return '\0';
+    }
+    return -1;
+  }
+
+  if (ch == '\n') {
+    parser->line++;
+    parser->col = 0;
+  } else {
+    parser->col++;
+  }
+
+  return ch;
+}
+
+static int parser_peek_char(struct kanshi_parser *parser) {
+  int ch = parser_read_char(parser);
+  parser->next = ch;
+  return ch;
+}
+
+static bool parser_append_tok_ch(struct kanshi_parser *parser, char ch) {
+  // Always keep enough room for a terminating NULL char
+  if (parser->tok_str_len + 1 >= sizeof(parser->tok_str)) {
+    fprintf(stderr, "string too long\n");
+    return false;
+  }
+  parser->tok_str[parser->tok_str_len] = ch;
+  parser->tok_str_len++;
+  return true;
+}
+
+static bool parser_read_quoted(struct kanshi_parser *parser) {
+  while (1) {
+    int ch = parser_read_char(parser);
+    if (ch < 0) {
+      return false;
+    } else if (ch == '\0') {
+      fprintf(stderr, "unterminated quoted string\n");
+      return false;
+    }
+
+    if (ch == '"') {
+      parser->tok_str[parser->tok_str_len] = '\0';
+      return true;
+    }
+
+    if (!parser_append_tok_ch(parser, ch)) {
+      return false;
+    }
+  }
+}
+
+static void parser_ignore_line(struct kanshi_parser *parser) {
+  while (1) {
+    int ch = parser_read_char(parser);
+    if (ch < 0) {
+      return;
+    }
+
+    if (ch == '\n' || ch == '\0') {
+      return;
+    }
+  }
+}
+
+static bool parser_read_line(struct kanshi_parser *parser) {
+  while (1) {
+    int ch = parser_peek_char(parser);
+    if (ch < 0) {
+      return false;
+    }
+
+    if (ch == '\n' || ch == '\0') {
+      parser->tok_str[parser->tok_str_len] = '\0';
+      return true;
+    }
+
+    if (!parser_append_tok_ch(parser, parser_read_char(parser))) {
+      return false;
+    }
+  }
+}
+
+static bool parser_read_str(struct kanshi_parser *parser) {
+  while (1) {
+    int ch = parser_peek_char(parser);
+    if (ch < 0) {
+      return false;
+    }
+
+    if (isspace(ch) || ch == '{' || ch == '}' || ch == '\0') {
+      parser->tok_str[parser->tok_str_len] = '\0';
+      return true;
+    }
+
+    if (!parser_append_tok_ch(parser, parser_read_char(parser))) {
+      return false;
+    }
+  }
+}
+
+static bool parser_next_token(struct kanshi_parser *parser) {
+  while (1) {
+    int ch = parser_read_char(parser);
+    if (ch < 0) {
+      return ch;
+    }
+
+    if (ch == '{') {
+      parser->tok_type = KANSHI_TOKEN_LBRACKET;
+      return true;
+    } else if (ch == '}') {
+      parser->tok_type = KANSHI_TOKEN_RBRACKET;
+      return true;
+    } else if (ch == '\n') {
+      parser->tok_type = KANSHI_TOKEN_NEWLINE;
+      return true;
+    } else if (isspace(ch)) {
+      continue;
+    } else if (ch == '"') {
+      parser->tok_type = KANSHI_TOKEN_STR;
+      parser->tok_str_len = 0;
+      return parser_read_quoted(parser);
+    } else if (ch == commentSign) {
+      parser->tok_type = KANSHI_TOKEN_COMMENT;
+      parser->tok_str_len = 0;
+      return true;
+    } else {
+      parser->tok_type = KANSHI_TOKEN_STR;
+      parser->tok_str[0] = ch;
+      parser->tok_str_len = 1;
+      return parser_read_str(parser);
+    }
+  }
+}
+
+static bool parser_expect_token(struct kanshi_parser *parser,
+    enum kanshi_token_type want) {
+  if (!parser_next_token(parser)) {
+    return false;
+  }
+  if (parser->tok_type != want) {
+    fprintf(stderr, "expected %s, got %s\n",
+      token_type_str(want), token_type_str(parser->tok_type));
+    return false;
+  }
+  return true;
+}
+
+static bool parse_int(int *dst, const char *str) {
+  char *end;
+  errno = 0;
+  int v = strtol(str, &end, 10);
+  if (errno != 0 || end[0] != '\0' || str[0] == '\0') {
+    return false;
+  }
+  *dst = v;
+  return true;
+}
+
+static bool parse_mode(struct kanshi_profile_output *output, char *str) {
+  const char *width = strtok(str, "x");
+  const char *height = strtok(NULL, "@");
+  const char *refresh = strtok(NULL, "");
+
+  if (width == NULL || height == NULL) {
+    fprintf(stderr, "invalid output mode: missing width/height\n");
+    return false;
+  }
+
+  if (!parse_int(&output->mode.width, width)) {
+    fprintf(stderr, "invalid output mode: invalid width\n");
+    return false;
+  }
+  if (!parse_int(&output->mode.height, height)) {
+    fprintf(stderr, "invalid output mode: invalid height\n");
+    return false;
+  }
+
+  if (refresh != NULL) {
+    char *end;
+    errno = 0;
+    float v = strtof(refresh, &end);
+    if (errno != 0 || (end[0] != '\0' && strcmp(end, "Hz") != 0) ||
+        str[0] == '\0') {
+      fprintf(stderr, "invalid output mode: invalid refresh rate\n");
+      return false;
+    }
+    output->mode.refresh = v * 1000;
+  }
+
+  return true;
+}
+
+static bool parse_position(struct kanshi_profile_output *output, char *str) {
+  const char *x = strtok(str, ",");
+  const char *y = strtok(NULL, "");
+
+  if (x == NULL || y == NULL) {
+    fprintf(stderr, "invalid output position: missing x/y\n");
+    return false;
+  }
+
+  if (!parse_int(&output->position.x, x)) {
+    fprintf(stderr, "invalid output position: invalid x\n");
+    return false;
+  }
+  if (!parse_int(&output->position.y, y)) {
+    fprintf(stderr, "invalid output position: invalid y\n");
+    return false;
+  }
+
+  return true;
+}
+
+static bool parse_float(float *dst, const char *str) {
+  char *end;
+  errno = 0;
+  float v = strtof(str, &end);
+  if (errno != 0 || end[0] != '\0' || str[0] == '\0') {
+    return false;
+  }
+  *dst = v;
+  return true;
+}
+
+static bool parse_transform(enum wl_output_transform *dst, const char *str) {
+  if (strcmp(str, "normal") == 0) {
+    *dst = WL_OUTPUT_TRANSFORM_NORMAL;
+  } else if (strcmp(str, "90") == 0) {
+    *dst = WL_OUTPUT_TRANSFORM_90;
+  } else if (strcmp(str, "180") == 0) {
+    *dst = WL_OUTPUT_TRANSFORM_180;
+  } else if (strcmp(str, "270") == 0) {
+    *dst = WL_OUTPUT_TRANSFORM_270;
+  } else if (strcmp(str, "flipped") == 0) {
+    *dst = WL_OUTPUT_TRANSFORM_FLIPPED;
+  } else if (strcmp(str, "flipped-90") == 0) {
+    *dst = WL_OUTPUT_TRANSFORM_FLIPPED_90;
+  } else if (strcmp(str, "flipped-180") == 0) {
+    *dst = WL_OUTPUT_TRANSFORM_FLIPPED_180;
+  } else if (strcmp(str, "flipped-270") == 0) {
+    *dst = WL_OUTPUT_TRANSFORM_FLIPPED_270;
+  } else {
+    return false;
+  }
+  return true;
+}
+
+static struct kanshi_profile_output *parse_profile_output(
+    struct kanshi_parser *parser) {
+  struct kanshi_profile_output *output = calloc(1, sizeof(*output));
+
+  if (!parser_expect_token(parser, KANSHI_TOKEN_STR)) {
+    return NULL;
+  }
+  output->name = strdup(parser->tok_str);
+
+  bool has_key = false;
+  enum kanshi_output_field key;
+  while (1) {
+    if (!parser_next_token(parser)) {
+      return NULL;
+    }
+
+    switch (parser->tok_type) {
+    case KANSHI_TOKEN_STR:
+      if (has_key) {
+        char *value = parser->tok_str;
+        switch (key) {
+        case KANSHI_OUTPUT_MODE:
+          if (!parse_mode(output, value)) {
+            return NULL;
+          }
+          break;
+        case KANSHI_OUTPUT_POSITION:
+          if (!parse_position(output, value)) {
+            return NULL;
+          }
+          break;
+        case KANSHI_OUTPUT_SCALE:
+          if (!parse_float(&output->scale, value)) {
+            fprintf(stderr, "invalid output scale\n");
+            return NULL;
+          }
+          break;
+        case KANSHI_OUTPUT_TRANSFORM:
+          if (!parse_transform(&output->transform, value)) {
+            fprintf(stderr, "invalid output transform\n");
+            return NULL;
+          }
+          break;
+        default:
+          assert(0);
+        }
+        has_key = false;
+        output->fields |= key;
+      } else {
+        has_key = true;
+        const char *key_str = parser->tok_str;
+        if (strcmp(key_str, "enable") == 0) {
+          output->enabled = true;
+          output->fields |= KANSHI_OUTPUT_ENABLED;
+          has_key = false;
+        } else if (strcmp(key_str, "disable") == 0) {
+          output->enabled = false;
+          output->fields |= KANSHI_OUTPUT_ENABLED;
+          has_key = false;
+        } else if (strcmp(key_str, "mode") == 0) {
+          key = KANSHI_OUTPUT_MODE;
+        } else if (strcmp(key_str, "position") == 0) {
+          key = KANSHI_OUTPUT_POSITION;
+        } else if (strcmp(key_str, "scale") == 0) {
+          key = KANSHI_OUTPUT_SCALE;
+        } else if (strcmp(key_str, "transform") == 0) {
+          key = KANSHI_OUTPUT_TRANSFORM;
+        } else {
+          fprintf(stderr,
+            "unknown directive '%s' in profile output '%s'\n",
+            key_str, output->name);
+          return NULL;
+        }
+      }
+      break;
+    case KANSHI_TOKEN_NEWLINE:
+      return output;
+    case KANSHI_TOKEN_COMMENT:
+      parser_ignore_line(parser);
+      return output;
+    default:
+      fprintf(stderr, "unexpected %s in output\n",
+        token_type_str(parser->tok_type));
+      return NULL;
+    }
+  }
+}
+
+static struct kanshi_profile_command *parse_profile_command(
+    struct kanshi_parser *parser) {
+  // Skip the 'exec' directive.
+  if (!parser_expect_token(parser, KANSHI_TOKEN_STR)) {
+    return NULL;
+  }
+
+  if (!parser_read_line(parser)) {
+    return NULL;
+  }
+
+  if (parser->tok_str_len <= 0) {
+    fprintf(stderr, "Ignoring empty command in config file on line %d\n",
+      parser->line);
+    return NULL;
+  }
+
+  struct kanshi_profile_command *command = calloc(1, sizeof(*command));
+  command->command = strdup(parser->tok_str);
+  return command;
+}
+
+static struct kanshi_profile *parse_profile(struct kanshi_parser *parser) {
+  struct kanshi_profile *profile = calloc(1, sizeof(*profile));
+  wl_list_init(&profile->outputs);
+  wl_list_init(&profile->commands);
+
+  // First parse an optional profile name
+  parser->tok_str_len = 0;
+  if (!parser_read_str(parser)) {
+    fprintf(stderr, "expected new profile, got %s\n",
+      token_type_str(parser->tok_type));
+    return NULL;
+  }
+  profile->name = (parser->tok_str_len == 0) ? NULL : strdup(parser->tok_str);
+
+  // Then parse the opening bracket
+  if (!parser_expect_token(parser, KANSHI_TOKEN_LBRACKET)) {
+    return NULL;
+  }
+
+  // Use the bracket position to generate a default profile name
+  if (profile->name == NULL) {
+    char generated_name[100];
+    int ret = snprintf(generated_name, sizeof(generated_name),
+        "<anonymous at line %d, col %d>", parser->line, parser->col);
+    if (ret >= 0) {
+      profile->name = strdup(generated_name);
+    } else {
+      profile->name = strdup("<anonymous>");
+    }
+  }
+
+  // Parse the profile commands until the closing bracket
+  while (1) {
+    if (!parser_next_token(parser)) {
+      return NULL;
+    }
+
+    switch (parser->tok_type) {
+    case KANSHI_TOKEN_RBRACKET:
+      return profile;
+    case KANSHI_TOKEN_STR:;
+      const char *directive = parser->tok_str;
+      if (strcmp(directive, "output") == 0) {
+        struct kanshi_profile_output *output =
+          parse_profile_output(parser);
+        if (output == NULL) {
+          return NULL;
+        }
+        // Store wildcard outputs at the end of the list
+        if (strcmp(output->name, "*") == 0) {
+          wl_list_insert(profile->outputs.prev, &output->link);
+        } else {
+          wl_list_insert(&profile->outputs, &output->link);
+        }
+      } else if (strcmp(directive, "exec") == 0) {
+        struct kanshi_profile_command *command =
+          parse_profile_command(parser);
+        if (command == NULL) {
+          return NULL;
+        }
+        // Insert commands at the end to preserve order
+        wl_list_insert(profile->commands.prev, &command->link);
+      } else {
+        fprintf(stderr, "unknown directive '%s' in profile '%s'\n",
+          directive, profile->name);
+        return NULL;
+      }
+      break;
+    case KANSHI_TOKEN_NEWLINE:
+      break; // No-op
+    case KANSHI_TOKEN_COMMENT:
+      parser_ignore_line(parser);
+      break; // No-op
+    default:
+      fprintf(stderr, "unexpected %s in profile '%s'\n",
+        token_type_str(parser->tok_type), profile->name);
+      return NULL;
+    }
+  }
+}
+
+static struct kanshi_config *_parse_config(struct kanshi_parser *parser) {
+  struct kanshi_config *config = calloc(1, sizeof(*config));
+  wl_list_init(&config->profiles);
+
+  while (1) {
+    int ch = parser_peek_char(parser);
+    if (ch < 0) {
+      return NULL;
+    } else if (ch == 0) {
+      return config;
+    } else if (ch == commentSign) {
+      parser_ignore_line(parser);
+      continue;
+    } else if (isspace(ch)) {
+      parser_read_char(parser);
+      continue;
+    }
+
+    struct kanshi_profile *profile = parse_profile(parser);
+    if (!profile) {
+      return NULL;
+    }
+
+    // Inset at the end to preserve ordering
+    wl_list_insert(config->profiles.prev, &profile->link);
+  }
+}
+
+struct kanshi_config *kanshi_parse_config(const char *path) {
+  FILE *f = fopen(path, "r");
+  if (f == NULL) {
+    return NULL;
+  }
+
+  struct kanshi_parser parser = {
+    .f = f,
+    .next = -1,
+    .line = 1,
+  };
+
+  struct kanshi_config *config = _parse_config(&parser);
+  fclose(f);
+  if (config == NULL) {
+    fprintf(stderr, "failed to parse config file: "
+      "error on line %d, column %d\n", parser.line, parser.col);
+    return NULL;
+  }
+
+  return config;
+}
+
+static const char *transform_to_string(enum wl_output_transform transform) {
+  switch (transform) {
+    case WL_OUTPUT_TRANSFORM_NORMAL:
+      return "normal";
+    case WL_OUTPUT_TRANSFORM_90:
+      return "90";
+    case WL_OUTPUT_TRANSFORM_180:
+      return "180";
+    case WL_OUTPUT_TRANSFORM_270:
+      return "270";
+    case WL_OUTPUT_TRANSFORM_FLIPPED:
+      return "flipped";
+    case WL_OUTPUT_TRANSFORM_FLIPPED_90:
+      return "flipped-90";
+    case WL_OUTPUT_TRANSFORM_FLIPPED_180:
+      return "flipped-180";
+    case WL_OUTPUT_TRANSFORM_FLIPPED_270:
+      return "flipped-270";
+  }
+  return NULL;
+}
+
+void kanshi_save_config(const char *path, struct kanshi_config *config) {
+  FILE *f = fopen(path, "w");
+  if (f == NULL) {
+    fprintf(stderr, "fopen: %s: %s\n", path, strerror(errno));
+    return;
+  }
+
+  fprintf(f, "# DO NOT EDIT - file autogenerated by wdisplays\n\n");
+
+  struct kanshi_profile *profile;
+  wl_list_for_each(profile, &config->profiles, link) {
+    fprintf(f, "{\n");
+    struct kanshi_profile_output *profile_output;
+    wl_list_for_each(profile_output, &profile->outputs, link) {
+      fprintf(f, "\toutput \"%s\"", profile_output->name);
+      if (profile_output->fields & KANSHI_OUTPUT_ENABLED) {
+        fprintf(f, " enable");
+        if (profile_output->fields & KANSHI_OUTPUT_MODE) {
+          fprintf(f, " mode %dx%d@%0.3fHz",
+              profile_output->mode.width, profile_output->mode.height,
+              profile_output->mode.refresh / 1000.f);
+        }
+        if (profile_output->fields & KANSHI_OUTPUT_POSITION) {
+          fprintf(f, " position %d,%d",
+              profile_output->position.x, profile_output->position.y);
+        }
+        if (profile_output->fields & KANSHI_OUTPUT_SCALE) {
+          fprintf(f, " scale %f", profile_output->scale);
+        }
+        if (profile_output->fields & KANSHI_OUTPUT_TRANSFORM) {
+          fprintf(f, " transform %s",
+              transform_to_string(profile_output->transform));
+        }
+      } else {
+        fprintf(f, " disable");
+      }
+      fprintf(f, "\n");
+    }
+    fprintf(f, "}\n\n");
+  }
+  fclose(f);
+}
+
+void kanshi_destroy_config(struct kanshi_config *config) {
+  struct kanshi_profile *profile, *tmp_profile;
+  wl_list_for_each_safe(profile, tmp_profile, &config->profiles, link) {
+    struct kanshi_profile_output *output, *tmp_output;
+    wl_list_for_each_safe(output, tmp_output, &profile->outputs, link) {
+      free(output->name);
+      wl_list_remove(&output->link);
+      free(output);
+    }
+    struct kanshi_profile_command *command, *tmp_command;
+    wl_list_for_each_safe(command, tmp_command, &profile->commands, link) {
+      free(command->command);
+      wl_list_remove(&command->link);
+      free(command);
+    }
+    wl_list_remove(&profile->link);
+    if (profile->name != NULL) {
+      free(profile->name);
+    }
+    free(profile);
+  }
+  free(config);
+}

src/wdisplays.h

@@ -28,8 +28,8 @@
  * https://github.com/emersion/kanshi/blob/38d27474b686fcc8324cc5e454741a49577c0988/include/config.h
  */
 
-#ifndef WDISPLAY_WDISPLAY_H
+#ifndef WDISPLAYS_WDISPLAYS_H
-#define WDISPLAY_WDISPLAY_H
+#define WDISPLAYS_WDISPLAYS_H
 
 #define HEADS_MAX 64
 #define HOVER_USECS (100 * 1000)
@@ -250,7 +250,6 @@ struct wd_state {
   struct wd_render_data render;
 };
 
-
 /*
  * Creates the application state structure.
  */