Merge branch 'kanshi-config'

README.md

@@ -9,6 +9,7 @@ Compositors that are known to support the protocol are [Sway] and [Wayfire].
 The goal of this project is to allow precise adjustment of display settings in
 kiosks, digital signage, and other elaborate multi-monitor setups.
 
+
 ![Screenshot](wdisplays.png)
 
 # Installation
@@ -70,8 +71,16 @@ It's intended to be the Wayland equivalent of an xrandr GUI, like [ARandR].
 Sway, like i3, doesn't save any settings unless you put them in the config
 file. See man `sway-output`. If you want to have multiple configurations
 depending on the monitors connected, you'll need to use an external program
-like [kanshi] or [way-displays]. Integration with that and other external
-daemons is planned.
+like [kanshi] or [way-displays].
+
+When you apply a new change, the setting will be defaultly added to $HOME/.config/kanshi/config,
+if there is already a profile for the same monitors combination, the change will be applied on
+existing one.
+you can add kanshi autostart to your sway config:
+```
+exec kanshi
+exec_always kanshictl reload
+```
 
 ### How do I add support to my compositor?
 

meson.build

@@ -10,6 +10,7 @@ conf = configuration_data({
   'app_id': meson.project_name(),
   'version': meson.project_version(),
   'resource_prefix': '/' / '/'.join(meson.project_name().split('.')),
+  'WITH_KANSHI': get_option('kanshi').allowed(),
 })
 
 subdir('protocol')

meson_options.txt

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: CC0-1.0
+# SPDX-FileCopyrightText: NONE
+option('kanshi', type:'feature', description: 'Build support for saving config for the kanshi daemon')

protocol/wlr-output-management-unstable-v1.xml

@@ -39,7 +39,7 @@
     interface version number is reset.
   </description>
 
-  <interface name="zwlr_output_manager_v1" version="1">
+  <interface name="zwlr_output_manager_v1" version="2">
     <description summary="output device configuration manager">
       This interface is a manager that allows reading and writing the current
       output device configuration.
@@ -115,7 +115,7 @@
       </description>
     </request>
 
-    <event name="finished">
+    <event name="finished" type="destructor">
       <description summary="the compositor has finished with the manager">
         This event indicates that the compositor is done sending manager events.
         The compositor will destroy the object immediately after sending this
@@ -125,7 +125,7 @@
     </event>
   </interface>
 
-  <interface name="zwlr_output_head_v1" version="1">
+  <interface name="zwlr_output_head_v1" version="2">
     <description summary="output device">
       A head is an output device. The difference between a wl_output object and
       a head is that heads are advertised even if they are turned off. A head
@@ -257,9 +257,80 @@
         resources associated with it.
       </description>
     </event>
+
+    <!-- Version 2 additions -->
+    <event name="make" since="2">
+      <description summary="head manufacturer">
+        This event describes the manufacturer of the head.
+
+        This must report the same make as the wl_output interface does in its
+        geometry event.
+
+        Together with the model and serial_number events the purpose is to
+        allow clients to recognize heads from previous sessions and for example
+        load head-specific configurations back.
+
+        It is not guaranteed this event will be ever sent. A reason for that
+        can be that the compositor does not have information about the make of
+        the head or the definition of a make is not sensible in the current
+        setup, for example in a virtual session. Clients can still try to
+        identify the head by available information from other events but should
+        be aware that there is an increased risk of false positives.
+
+        It is not recommended to display the make string in UI to users. For
+        that the string provided by the description event should be preferred.
+      </description>
+      <arg name="make" type="string"/>
+    </event>
+
+    <event name="model" since="2">
+      <description summary="head model">
+        This event describes the model of the head.
+
+        This must report the same model as the wl_output interface does in its
+        geometry event.
+
+        Together with the make and serial_number events the purpose is to
+        allow clients to recognize heads from previous sessions and for example
+        load head-specific configurations back.
+
+        It is not guaranteed this event will be ever sent. A reason for that
+        can be that the compositor does not have information about the model of
+        the head or the definition of a model is not sensible in the current
+        setup, for example in a virtual session. Clients can still try to
+        identify the head by available information from other events but should
+        be aware that there is an increased risk of false positives.
+
+        It is not recommended to display the model string in UI to users. For
+        that the string provided by the description event should be preferred.
+      </description>
+      <arg name="model" type="string"/>
+    </event>
+
+    <event name="serial_number" since="2">
+      <description summary="head serial number">
+        This event describes the serial number of the head.
+
+        Together with the make and model events the purpose is to allow clients
+        to recognize heads from previous sessions and for example load head-
+        specific configurations back.
+
+        It is not guaranteed this event will be ever sent. A reason for that
+        can be that the compositor does not have information about the serial
+        number of the head or the definition of a serial number is not sensible
+        in the current setup. Clients can still try to identify the head by
+        available information from other events but should be aware that there
+        is an increased risk of false positives.
+
+        It is not recommended to display the serial_number string in UI to
+        users. For that the string provided by the description event should be
+        preferred.
+      </description>
+      <arg name="serial_number" type="string"/>
+    </event>
   </interface>
 
-  <interface name="zwlr_output_mode_v1" version="1">
+  <interface name="zwlr_output_mode_v1" version="2">
     <description summary="output mode">
       This object describes an output mode.
 
@@ -305,7 +376,7 @@
     </event>
   </interface>
 
-  <interface name="zwlr_output_configuration_v1" version="1">
+  <interface name="zwlr_output_configuration_v1" version="2">
     <description summary="output configuration">
       This object is used by the client to describe a full output configuration.
 
@@ -423,7 +494,7 @@
     </request>
   </interface>
 
-  <interface name="zwlr_output_configuration_head_v1" version="1">
+  <interface name="zwlr_output_configuration_head_v1" version="2">
     <description summary="head configuration">
       This object is used by the client to update a single head's configuration.
 

resources/wdisplays.gschema.xml

@@ -10,5 +10,8 @@
     <key name="show-overlay" type="b">
       <default>true</default>
     </key>
+    <key name="save-kanshi-config" type="b">
+      <default>false</default>
+    </key>
   </schema>
 </schemalist>

src/config.h.in

@@ -8,4 +8,7 @@
 #define WDISPLAYS_VERSION "@version@"
 #define WDISPLAYS_RESOURCE_PREFIX "@resource_prefix@"
 
+// Features
+#mesondefine WITH_KANSHI
+
 #endif

src/main.c

@@ -55,10 +55,12 @@ static gboolean send_apply(gpointer data) {
   struct wl_display *wl_display = gdk_wayland_display_get_wl_display(display);
   wd_apply_state(state, outputs, wl_display);
   state->apply_pending = FALSE;
+  state->apply_manual = false;
   return FALSE;
 }
 
-static void apply_state(struct wd_state *state) {
+static void apply_state(struct wd_state *state, bool manual) {
+  state->apply_manual = state->apply_manual || manual;
   gtk_stack_set_visible_child_name(GTK_STACK(state->header_stack), "title");
   if (!state->autoapply) {
     gtk_style_context_add_class(gtk_widget_get_style_context(state->spinner), "visible");
@@ -365,7 +367,7 @@ static void show_apply(struct wd_state *state) {
   const gchar *page = "title";
   if (has_changes(state)) {
     if (state->autoapply) {
-      apply_state(state);
+      apply_state(state, false);
     } else {
       page = "apply";
     }
@@ -469,6 +471,10 @@ void wd_ui_apply_done(struct wd_state *state, struct wl_list *outputs) {
 }
 
 void wd_ui_show_error(struct wd_state *state, const char *message) {
+  if (gtk_widget_in_destruction(gtk_widget_get_toplevel(state->info_bar))) {
+    fprintf(stderr, "%s\n", message);
+    return;
+  }
   gtk_label_set_text(GTK_LABEL(state->info_label), message);
   gtk_widget_show(state->info_bar);
   gtk_info_bar_set_revealed(GTK_INFO_BAR(state->info_bar), TRUE);
@@ -487,6 +493,9 @@ static void cleanup(GtkWidget *window, gpointer data) {
   g_object_unref(state->grabbing_cursor);
   g_object_unref(state->move_cursor);
   g_clear_object(&state->settings);
+#ifdef WITH_KANSHI
+  wd_save_kanshi_snapshot(state);
+#endif
   wd_state_destroy(state);
 }
 
@@ -899,7 +908,7 @@ static void cancel_changes(GSimpleAction *action, GVariant *param, gpointer data
 }
 
 static void apply_changes(GSimpleAction *action, GVariant *param, gpointer data) {
-  apply_state(data);
+  apply_state(data, true);
 }
 
 static void info_response(GtkInfoBar *info_bar, gint response_id, gpointer data) {
@@ -921,6 +930,11 @@ static void auto_apply_selected(GSimpleAction *action, GVariant *param, gpointer
   }
   state->autoapply = g_variant_get_boolean(param);
   g_simple_action_set_state(action, param);
+#ifdef WITH_KANSHI
+  if (!state->autoapply) {
+    wd_save_kanshi_snapshot(state);
+  }
+#endif
 }
 
 static gboolean redraw_canvas(GtkWidget *widget, GdkFrameClock *frame_clock, gpointer data) {
@@ -958,6 +972,18 @@ static void overlay_selected(GSimpleAction *action, GVariant *param, gpointer da
   }
 }
 
+#ifdef WITH_KANSHI
+static void save_kanshi_config_selected(GSimpleAction *action, GVariant *param, gpointer data) {
+  struct wd_state *state = data;
+  if (state->settings != NULL) {
+    g_settings_set_boolean(state->settings, "save-kanshi-config", g_variant_get_boolean(param));
+  }
+  state->save_kanshi_config = g_variant_get_boolean(param);
+  wd_drop_kanshi_snapshot(state);
+  g_simple_action_set_state(action, param);
+}
+#endif
+
 static void window_state_changed(GtkWidget *window, GdkEventWindowState *event,
     gpointer data) {
   struct wd_state *state = data;
@@ -1150,6 +1176,9 @@ static void activate(GtkApplication* app, gpointer user_data) {
     state->autoapply = g_settings_get_boolean(state->settings, "auto-apply");
     state->capture = g_settings_get_boolean(state->settings, "capture-screens");
     state->show_overlay = g_settings_get_boolean(state->settings, "show-overlay");
+#ifdef WITH_KANSHI
+    state->save_kanshi_config = g_settings_get_boolean(state->settings, "save-kanshi-config");
+#endif
   }
   if (startup->autoapply != -1) {
     state->autoapply = startup->autoapply;
@@ -1177,10 +1206,20 @@ static void activate(GtkApplication* app, gpointer user_data) {
   g_signal_connect(overlay_action, "change-state", G_CALLBACK(overlay_selected), state);
   g_action_map_add_action(G_ACTION_MAP(main_actions), G_ACTION(overlay_action));
 
+#ifdef WITH_KANSHI
+  action = g_simple_action_new_stateful("save-kanshi-config", NULL,
+      g_variant_new_boolean(state->save_kanshi_config));
+  g_signal_connect(action, "change-state", G_CALLBACK(save_kanshi_config_selected), state);
+  g_action_map_add_action(G_ACTION_MAP(main_actions), G_ACTION(action));
+#endif
+
   GMenu *main_menu = g_menu_new();
   g_menu_append(main_menu, "_Automatically Apply Changes", "app.auto-apply");
   g_menu_append(main_menu, "_Show Screen Contents", "app.capture-screens");
   g_menu_append(main_menu, "_Overlay Screen Names", "app.show-overlay");
+#ifdef WITH_KANSHI
+  g_menu_append(main_menu, "Save to _kanshi Config", "app.save-kanshi-config");
+#endif
   gtk_menu_button_set_menu_model(GTK_MENU_BUTTON(state->menu_button), G_MENU_MODEL(main_menu));
   gtk_menu_button_set_use_popover(GTK_MENU_BUTTON(state->menu_button), false);
 

src/meson.build

@@ -11,17 +11,23 @@ epoxy = dependency('epoxy')
 
 configure_file(input: 'config.h.in', output: 'config.h', configuration: conf)
 
+sources = [
+  'main.c',
+  'glviewport.c',
+  'headform.c',
+  'outputs.c',
+  'overlay.c',
+  'render.c',
+  resources,
+]
+
+if get_option('kanshi').allowed()
+  sources += 'store.c'
+endif
+
 executable(
   'wdisplays',
-  [
-    'main.c',
-    'glviewport.c',
-    'headform.c',
-    'outputs.c',
-    'overlay.c',
-    'render.c',
-    resources,
-  ],
+  sources,
   dependencies : [
     m_dep,
     rt_dep,

src/outputs.c

@@ -35,23 +35,60 @@ static void noop() {
 struct wd_pending_config {
   struct wd_state *state;
   struct wl_list *outputs;
+  struct wl_list link;
+  bool manual;
+  bool incomplete;
 };
 
-static void destroy_pending(struct wd_pending_config *pending) {
+static void destroy_outputs(struct wl_list *outputs) {
   struct wd_head_config *output, *tmp;
-  wl_list_for_each_safe(output, tmp, pending->outputs, link) {
+  wl_list_for_each_safe(output, tmp, outputs, link) {
     wl_list_remove(&output->link);
     free(output);
   }
-  free(pending->outputs);
+  free(outputs);
+}
+
+static void destroy_pending(struct wd_pending_config *pending) {
+  wl_list_remove(&pending->link);
+  if (pending->outputs != NULL) {
+    destroy_outputs(pending->outputs);
+  }
   free(pending);
 }
 
+#ifdef WITH_KANSHI
+void wd_drop_kanshi_snapshot(struct wd_state *state) {
+  if (state->kanshi_snapshot != NULL) {
+    destroy_outputs(state->kanshi_snapshot);
+    state->kanshi_snapshot = NULL;
+  }
+}
+
+void wd_save_kanshi_snapshot(struct wd_state *state) {
+  if (state->kanshi_snapshot != NULL) {
+    wd_store_config(state, state->kanshi_snapshot);
+    wd_drop_kanshi_snapshot(state);
+  }
+}
+#endif
+
 static void config_handle_succeeded(void *data,
     struct zwlr_output_configuration_v1 *config) {
   struct wd_pending_config *pending = data;
   zwlr_output_configuration_v1_destroy(config);
   wd_ui_apply_done(pending->state, pending->outputs);
+#ifdef WITH_KANSHI
+  if (pending->state->save_kanshi_config && !pending->incomplete) {
+    wd_drop_kanshi_snapshot(pending->state);
+    if (pending->manual) {
+      wd_store_config(pending->state, pending->outputs);
+    } else {
+      pending->state->kanshi_snapshot = pending->outputs;
+      pending->outputs = NULL;
+    }
+  }
+#endif
   destroy_pending(pending);
 }
 
@@ -90,6 +127,8 @@ void wd_apply_state(struct wd_state *state, struct wl_list *new_outputs,
   struct wd_pending_config *pending = calloc(1, sizeof(*pending));
   pending->state = state;
   pending->outputs = new_outputs;
+  pending->manual = state->apply_manual;
+  wl_list_insert(&state->pending_configs, &pending->link);
 
   zwlr_output_configuration_v1_add_listener(config, &config_listener, pending);
 
@@ -395,6 +434,9 @@ static void wd_head_destroy(struct wd_head *head) {
   zwlr_output_head_v1_destroy(head->wlr_head);
   free(head->name);
   free(head->description);
+  free(head->make);
+  free(head->model);
+  free(head->serial_number);
   free(head);
 }
 
@@ -420,6 +462,9 @@ static void mode_handle_preferred(void *data,
 static void mode_handle_finished(void *data,
     struct zwlr_output_mode_v1 *wlr_mode) {
   struct wd_mode *mode = data;
+#ifdef WITH_KANSHI
+  wd_save_kanshi_snapshot(mode->head->state);
+#endif
   if (mode->head->mode == mode) {
     mode->head->mode = NULL;
   }
@@ -517,10 +562,46 @@ static void head_handle_scale(void *data,
   wd_ui_reset_head(head, WD_FIELD_SCALE);
 }
 
+static void head_handle_make(void *data,
+    struct zwlr_output_head_v1 *wlr_head, const char *make) {
+  struct wd_head *head = data;
+  head->make = strdup(make);
+}
+
+static void head_handle_model(void *data,
+    struct zwlr_output_head_v1 *wlr_head, const char *model) {
+  struct wd_head *head = data;
+  head->model = strdup(model);
+}
+
+static void head_handle_serial_number(void *data,
+    struct zwlr_output_head_v1 *wlr_head, const char *serial_number) {
+  struct wd_head *head = data;
+  head->serial_number = strdup(serial_number);
+}
+
+static void remove_pending_head(struct wd_state *state, struct wd_head *head) {
+  struct wd_pending_config *pending;
+  wl_list_for_each(pending, &state->pending_configs, link) {
+    struct wd_head_config *output, *tmp;
+    wl_list_for_each_safe(output, tmp, pending->outputs, link) {
+      if (output->head == head) {
+        wl_list_remove(&output->link);
+        free(output);
+        pending->incomplete = true;
+      }
+    }
+  }
+}
+
 static void head_handle_finished(void *data,
     struct zwlr_output_head_v1 *wlr_head) {
   struct wd_head *head = data;
   struct wd_state *state = head->state;
+#ifdef WITH_KANSHI
+  wd_save_kanshi_snapshot(state);
+#endif
+  remove_pending_head(state, head);
   wl_list_remove(&head->link);
   wd_head_destroy(head);
 
@@ -548,12 +629,18 @@ static const struct zwlr_output_head_v1_listener head_listener = {
   .transform = head_handle_transform,
   .scale = head_handle_scale,
   .finished = head_handle_finished,
+  .make = head_handle_make,
+  .model = head_handle_model,
+  .serial_number = head_handle_serial_number,
 };
 
 static void output_manager_handle_head(void *data,
     struct zwlr_output_manager_v1 *manager,
     struct zwlr_output_head_v1 *wlr_head) {
   struct wd_state *state = data;
+#ifdef WITH_KANSHI
+  wd_save_kanshi_snapshot(state);
+#endif
 
   struct wd_head *head = calloc(1, sizeof(*head));
   head->state = state;
@@ -596,7 +683,7 @@ static void registry_handle_global(void *data, struct wl_registry *registry,
 
   if (strcmp(interface, zwlr_output_manager_v1_interface.name) == 0) {
     state->output_manager = wl_registry_bind(registry, name,
-        &zwlr_output_manager_v1_interface, 1);
+        &zwlr_output_manager_v1_interface, MIN(version, 2));
     zwlr_output_manager_v1_add_listener(state->output_manager,
         &output_manager_listener, state);
   } else if (strcmp(interface, zxdg_output_manager_v1_interface.name) == 0) {
@@ -737,6 +824,7 @@ struct wd_state *wd_state_create(void) {
   state->show_overlay = true;
   wl_list_init(&state->heads);
   wl_list_init(&state->outputs);
+  wl_list_init(&state->pending_configs);
   wl_list_init(&state->render.heads);
   return state;
 }

src/store.c

@@ -0,0 +1,673 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+// SPDX-FileCopyrightText: 2024-2025 Shaochang Tan
+// SPDX-FileCopyrightText: 2024-2025 Jason André Charles Gantner
+
+#include <errno.h>
+#include <fnmatch.h>
+#include <string.h>
+#include <wordexp.h>
+
+#include "wdisplays.h"
+
+#define INCLUDE_DEPTH_MAX 16
+
+struct kanshi_file {
+  char *path;
+  char *text;
+  GPtrArray *dirs;
+};
+
+struct kanshi_directive {
+  char *name;
+  GPtrArray *params;
+  GPtrArray *children;
+  size_t start, name_start, end;
+  size_t criteria_start, criteria_end;
+  struct kanshi_file *file;
+};
+
+struct kanshi_config {
+  GPtrArray *files;
+  GPtrArray *profiles;
+  GPtrArray *outputs;
+};
+
+struct kanshi_parser {
+  const char *text;
+  size_t pos;
+  int line;
+};
+
+static char *get_config_path(void) {
+  const char *env_path = g_getenv("WDISPLAYS_KANSHI_CONFIG");
+  if (env_path != NULL && env_path[0] != '\0') {
+    return g_strdup(env_path);
+  }
+
+  return g_build_filename(g_get_user_config_dir(), "kanshi", "config", NULL);
+}
+
+static void kanshi_directive_free(gpointer data) {
+  struct kanshi_directive *dir = data;
+  g_free(dir->name);
+  g_ptr_array_unref(dir->params);
+  if (dir->children != NULL) {
+    g_ptr_array_unref(dir->children);
+  }
+  g_free(dir);
+}
+
+static char peek(struct kanshi_parser *parser) {
+  return parser->text[parser->pos];
+}
+
+static void skip_blanks(struct kanshi_parser *parser) {
+  while (peek(parser) == ' ' || peek(parser) == '\t') {
+    parser->pos++;
+  }
+}
+
+static void next_line(struct kanshi_parser *parser) {
+  while (peek(parser) != '\0' && peek(parser) != '\n') {
+    parser->pos++;
+  }
+  if (peek(parser) == '\n') {
+    parser->pos++;
+    parser->line++;
+  }
+}
+
+static bool parse_error(struct kanshi_parser *parser, GError **error,
+    const char *message) {
+  g_set_error(error, G_IO_ERROR, G_IO_ERROR_INVALID_DATA,
+      "line %d: %s", parser->line, message);
+  return false;
+}
+
+static bool parse_word(struct kanshi_parser *parser, GString *word,
+    GError **error) {
+  char quote = peek(parser);
+  if (quote == '"' || quote == '\'') {
+    parser->pos++;
+  } else {
+    quote = '\0';
+  }
+  while (true) {
+    char c = peek(parser);
+    if (quote != '\0' && c == quote) {
+      parser->pos++;
+      return true;
+    }
+    if (c == '\0' || c == '\n') {
+      if (quote != '\0') {
+        return parse_error(parser, error, "unterminated quoted string");
+      }
+      return true;
+    }
+    if (quote == '\0' && (c == ' ' || c == '\t')) {
+      return true;
+    }
+    if (quote == '\0' && strchr("\"'{}", c) != NULL) {
+      return parse_error(parser, error, "unexpected character in word");
+    }
+    if (c == '\\' && quote != '\'') {
+      parser->pos++;
+      c = peek(parser);
+      if (c == '\0' || c == '\n') {
+        return parse_error(parser, error, "cannot escape a line break");
+      }
+    }
+    g_string_append_c(word, c);
+    parser->pos++;
+  }
+}
+
+static GPtrArray *parse_block(struct kanshi_parser *parser, bool nested,
+    GError **error);
+
+static struct kanshi_directive *parse_directive(struct kanshi_parser *parser,
+    GError **error) {
+  struct kanshi_directive *dir = g_new0(struct kanshi_directive, 1);
+  dir->params = g_ptr_array_new_with_free_func(g_free);
+  dir->name_start = parser->pos;
+  dir->start = parser->pos;
+  while (dir->start > 0 && (parser->text[dir->start - 1] == ' '
+        || parser->text[dir->start - 1] == '\t')) {
+    dir->start--;
+  }
+  if (dir->start > 0 && parser->text[dir->start - 1] != '\n') {
+    dir->start = dir->name_start;
+  }
+
+  g_autoptr(GString) word = g_string_new(NULL);
+  if (!parse_word(parser, word, error)) {
+    goto err;
+  }
+  dir->name = g_strdup(word->str);
+  skip_blanks(parser);
+
+  while (peek(parser) != '\0' && peek(parser) != '\n') {
+    if (peek(parser) == '{') {
+      parser->pos++;
+      skip_blanks(parser);
+      if (peek(parser) != '\n') {
+        parse_error(parser, error, "expected a line break after '{'");
+        goto err;
+      }
+      next_line(parser);
+      dir->children = parse_block(parser, true, error);
+      if (dir->children == NULL) {
+        goto err;
+      }
+      dir->end = parser->pos;
+      skip_blanks(parser);
+      if (peek(parser) != '\0' && peek(parser) != '\n') {
+        parser->pos = dir->end;
+        return dir;
+      }
+      break;
+    }
+    if (peek(parser) == '}') {
+      parse_error(parser, error, "unexpected '}'");
+      goto err;
+    }
+    size_t param_start = parser->pos;
+    g_string_truncate(word, 0);
+    if (!parse_word(parser, word, error)) {
+      goto err;
+    }
+    if (dir->params->len == 0) {
+      dir->criteria_start = param_start;
+      dir->criteria_end = parser->pos;
+    }
+    g_ptr_array_add(dir->params, g_strdup(word->str));
+    skip_blanks(parser);
+  }
+  next_line(parser);
+  dir->end = parser->pos;
+  return dir;
+
+err:
+  kanshi_directive_free(dir);
+  return NULL;
+}
+
+static GPtrArray *parse_block(struct kanshi_parser *parser, bool nested,
+    GError **error) {
+  GPtrArray *dirs = g_ptr_array_new_with_free_func(kanshi_directive_free);
+  while (true) {
+    skip_blanks(parser);
+    char c = peek(parser);
+    if (c == '\n' || c == '#') {
+      next_line(parser);
+    } else if (c == '\0') {
+      if (nested) {
+        parse_error(parser, error, "expected '}'");
+        break;
+      }
+      return dirs;
+    } else if (c == '}') {
+      if (!nested) {
+        parse_error(parser, error, "unexpected '}'");
+        break;
+      }
+      parser->pos++;
+      return dirs;
+    } else {
+      struct kanshi_directive *dir = parse_directive(parser, error);
+      if (dir == NULL) {
+        break;
+      }
+      g_ptr_array_add(dirs, dir);
+    }
+  }
+  g_ptr_array_unref(dirs);
+  return NULL;
+}
+
+static const char *find_param(struct kanshi_directive *dir, const char *key) {
+  for (guint i = 1; i + 1 < dir->params->len; i++) {
+    if (strcmp(g_ptr_array_index(dir->params, i), key) == 0) {
+      return g_ptr_array_index(dir->params, i + 1);
+    }
+  }
+  for (guint i = 0; dir->children != NULL && i < dir->children->len; i++) {
+    struct kanshi_directive *child = g_ptr_array_index(dir->children, i);
+    if (strcmp(child->name, key) == 0 && child->params->len > 0) {
+      return g_ptr_array_index(child->params, 0);
+    }
+  }
+  return NULL;
+}
+
+static bool is_output(struct kanshi_directive *dir) {
+  return strcmp(dir->name, "output") == 0 && dir->params->len > 0;
+}
+
+static char *head_identifier(struct wd_head *head) {
+  return g_strdup_printf("%s %s %s",
+      head->make != NULL ? head->make : "Unknown",
+      head->model != NULL ? head->model : "Unknown",
+      head->serial_number != NULL ? head->serial_number : "Unknown");
+}
+
+static bool criteria_match(const char *criteria, struct wd_head *head) {
+  g_autofree char *identifier = head_identifier(head);
+  return strcmp(criteria, "*") == 0 || strcmp(criteria, head->name) == 0
+    || fnmatch(criteria, identifier, 0) == 0;
+}
+
+static const char *resolve_alias(struct kanshi_config *config,
+    const char *criteria) {
+  if (criteria[0] != '$') {
+    return criteria;
+  }
+  for (guint i = 0; i < config->outputs->len; i++) {
+    struct kanshi_directive *dir = g_ptr_array_index(config->outputs, i);
+    const char *alias = find_param(dir, "alias");
+    if (alias != NULL && strcmp(alias, criteria) == 0) {
+      return g_ptr_array_index(dir->params, 0);
+    }
+  }
+  return NULL;
+}
+
+static bool match_profile(struct kanshi_config *config,
+    struct kanshi_directive *profile,
+    struct wd_head_config **heads, int num_heads,
+    struct kanshi_directive **matches) {
+  g_autoptr(GPtrArray) outputs = g_ptr_array_new();
+  for (guint i = 0; i < profile->children->len; i++) {
+    struct kanshi_directive *child = g_ptr_array_index(profile->children, i);
+    if (!is_output(child)) {
+      continue;
+    }
+    if (strcmp(g_ptr_array_index(child->params, 0), "*") == 0) {
+      g_ptr_array_add(outputs, child);
+    } else {
+      g_ptr_array_insert(outputs, 0, child);
+    }
+  }
+  if (outputs->len != (guint) num_heads) {
+    return false;
+  }
+
+  memset(matches, 0, num_heads * sizeof(*matches));
+  for (guint i = 0; i < outputs->len; i++) {
+    struct kanshi_directive *output = g_ptr_array_index(outputs, i);
+    const char *criteria = resolve_alias(config,
+        g_ptr_array_index(output->params, 0));
+    if (criteria == NULL) {
+      return false;
+    }
+    int j = 0;
+    while (j < num_heads
+        && (matches[j] != NULL || !criteria_match(criteria, heads[j]->head))) {
+      j++;
+    }
+    if (j == num_heads) {
+      return false;
+    }
+    matches[j] = output;
+  }
+  return true;
+}
+
+static void append_word(GString *str, const char *word) {
+  if (word[0] != '\0' && strpbrk(word, " \t\"'{}\\#") == NULL) {
+    g_string_append(str, word);
+    return;
+  }
+  g_string_append_c(str, '"');
+  for (const char *c = word; *c != '\0'; c++) {
+    if (*c == '"' || *c == '\\') {
+      g_string_append_c(str, '\\');
+    }
+    g_string_append_c(str, *c);
+  }
+  g_string_append_c(str, '"');
+}
+
+static void append_criteria(GString *str, struct wd_head_config **heads,
+    int num_heads, struct wd_head *head) {
+  g_autofree char *identifier = head_identifier(head);
+  bool usable = head->make != NULL || head->model != NULL
+    || head->serial_number != NULL;
+  if (identifier[0] == '$' || strchr(identifier, '\n') != NULL) {
+    usable = false;
+  }
+  for (int i = 0; usable && i < num_heads; i++) {
+    g_autofree char *other = head_identifier(heads[i]->head);
+    if (heads[i]->head != head && strcmp(identifier, other) == 0) {
+      usable = false;
+    }
+  }
+  if (!usable) {
+    append_word(str, head->name);
+    return;
+  }
+
+  g_autoptr(GString) pattern = g_string_new(NULL);
+  for (const char *c = identifier; *c != '\0'; c++) {
+    if (strchr("*?[\\", *c) != NULL) {
+      g_string_append_c(pattern, '\\');
+    }
+    g_string_append_c(pattern, *c);
+  }
+  append_word(str, pattern->str);
+}
+
+static const char *transform_name(enum wl_output_transform transform) {
+  switch (transform) {
+  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";
+  default:
+    return "normal";
+  }
+}
+
+static bool is_custom_mode(struct wd_head_config *output) {
+  struct wd_mode *mode;
+  wl_list_for_each(mode, &output->head->modes, link) {
+    if (mode->width == output->width && mode->height == output->height
+        && mode->refresh == output->refresh) {
+      return false;
+    }
+  }
+  return true;
+}
+
+static void format_scale(char *buf, size_t size, double scale) {
+  wl_fixed_t fixed = wl_fixed_from_double(scale);
+  scale = wl_fixed_to_double(fixed);
+  for (int digits = 0; digits <= 8; digits++) {
+    char format[8];
+    snprintf(format, sizeof(format), "%%.%df", digits);
+    g_ascii_formatd(buf, size, format, scale);
+    if (wl_fixed_from_double(g_ascii_strtod(buf, NULL)) == fixed) {
+      break;
+    }
+  }
+}
+
+static void append_settings(GString *str, struct wd_head_config *output,
+    const char *adaptive_sync) {
+  if (!output->enabled) {
+    g_string_append(str, " disable");
+  } else {
+    g_string_append(str, " enable mode ");
+    if (is_custom_mode(output)) {
+      g_string_append(str, "--custom ");
+    }
+    g_string_append_printf(str, "%dx%d", output->width, output->height);
+    if (output->refresh > 0) {
+      char refresh[G_ASCII_DTOSTR_BUF_SIZE];
+      g_ascii_formatd(refresh, sizeof(refresh), "%.3f", output->refresh / 1000.);
+      g_string_append_printf(str, "@%sHz", refresh);
+    }
+    char scale[G_ASCII_DTOSTR_BUF_SIZE];
+    format_scale(scale, sizeof(scale), output->scale);
+    g_string_append_printf(str, " position %d,%d scale %s transform %s",
+        output->x, output->y, scale, transform_name(output->transform));
+  }
+  if (adaptive_sync != NULL) {
+    g_string_append(str, " adaptive_sync ");
+    append_word(str, adaptive_sync);
+  }
+  g_string_append_c(str, '\n');
+}
+
+static void append_comments(GString *str, const char *text,
+    struct kanshi_directive *dir) {
+  const char *end = text + dir->end;
+  const char *line = strchr(text + dir->name_start, '\n');
+  while (line != NULL && ++line < end) {
+    const char *next = strchr(line, '\n');
+    if (line[strspn(line, " \t")] == '#') {
+      g_string_append_len(str, line, (next != NULL ? next + 1 : end) - line);
+    }
+    line = next;
+  }
+}
+
+static void rewrite_profile(GString *str, const char *text,
+    struct kanshi_directive *profile, struct wd_head_config **heads,
+    int num_heads, struct kanshi_directive **matches) {
+  size_t pos = 0;
+  for (guint i = 0; i < profile->children->len; i++) {
+    struct kanshi_directive *child = g_ptr_array_index(profile->children, i);
+    g_string_append_len(str, text + pos, child->start - pos);
+    pos = child->end;
+    if (!is_output(child)) {
+      g_string_append_len(str, text + child->start, child->end - child->start);
+      continue;
+    }
+    for (int j = 0; j < num_heads; j++) {
+      if (matches[j] == child) {
+        append_comments(str, text, child);
+        g_string_append_len(str, text + child->start,
+            child->name_start - child->start);
+        g_string_append(str, "output ");
+        g_string_append_len(str, text + child->criteria_start,
+            child->criteria_end - child->criteria_start);
+        append_settings(str, heads[j], find_param(child, "adaptive_sync"));
+      }
+    }
+  }
+  g_string_append(str, text + pos);
+}
+
+static void append_profile(GString *str, struct wd_head_config **heads,
+    int num_heads) {
+  if (str->len > 0 && str->str[str->len - 1] != '\n') {
+    g_string_append_c(str, '\n');
+  }
+  if (str->len > 0) {
+    g_string_append_c(str, '\n');
+  }
+  g_string_append(str, "profile {\n");
+  for (int i = 0; i < num_heads; i++) {
+    g_string_append(str, "\toutput ");
+    append_criteria(str, heads, num_heads, heads[i]->head);
+    append_settings(str, heads[i], NULL);
+  }
+  g_string_append(str, "}\n");
+}
+
+static void kanshi_file_free(gpointer data) {
+  struct kanshi_file *file = data;
+  g_free(file->path);
+  g_free(file->text);
+  if (file->dirs != NULL) {
+    g_ptr_array_unref(file->dirs);
+  }
+  g_free(file);
+}
+
+static bool load_file(struct kanshi_config *config, const char *path,
+    bool included, int depth, GError **error);
+
+static bool load_include(struct kanshi_config *config,
+    struct kanshi_directive *dir, int depth, GError **error) {
+  if (dir->params->len != 1) {
+    g_set_error(error, G_IO_ERROR, G_IO_ERROR_INVALID_DATA,
+        "%s: include expects exactly one path", dir->file->path);
+    return false;
+  }
+  const char *pattern = g_ptr_array_index(dir->params, 0);
+  wordexp_t words;
+  int ret = wordexp(pattern, &words, WRDE_NOCMD | WRDE_UNDEF);
+  if (ret != 0) {
+    if (ret == WRDE_NOSPACE) {
+      wordfree(&words);
+    }
+    g_set_error(error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+        "%s: cannot expand include %s", dir->file->path, pattern);
+    return false;
+  }
+  bool ok = true;
+  for (size_t i = 0; ok && i < words.we_wordc; i++) {
+    if (!g_path_is_absolute(words.we_wordv[i])) {
+      g_set_error(error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+          "%s: include %s is relative to the directory kanshi runs in",
+          dir->file->path, words.we_wordv[i]);
+      ok = false;
+    } else {
+      ok = load_file(config, words.we_wordv[i], true, depth + 1, error);
+    }
+  }
+  wordfree(&words);
+  return ok;
+}
+
+static bool load_file(struct kanshi_config *config, const char *path,
+    bool included, int depth, GError **error) {
+  if (depth > INCLUDE_DEPTH_MAX) {
+    g_set_error(error, G_IO_ERROR, G_IO_ERROR_TOO_MANY_LINKS,
+        "%s: includes nested too deeply", path);
+    return false;
+  }
+  struct kanshi_file *file = g_new0(struct kanshi_file, 1);
+  file->path = g_strdup(path);
+  g_ptr_array_add(config->files, file);
+  if (!g_file_get_contents(path, &file->text, NULL, error)) {
+    if (included || !g_error_matches(*error, G_FILE_ERROR, G_FILE_ERROR_NOENT)) {
+      return false;
+    }
+    g_clear_error(error);
+    file->text = g_strdup("");
+  }
+
+  struct kanshi_parser parser = { .text = file->text, .line = 1 };
+  file->dirs = parse_block(&parser, false, error);
+  if (file->dirs == NULL) {
+    g_prefix_error(error, "%s: ", path);
+    return false;
+  }
+  for (guint i = 0; i < file->dirs->len; i++) {
+    struct kanshi_directive *dir = g_ptr_array_index(file->dirs, i);
+    dir->file = file;
+    if (strcmp(dir->name, "profile") == 0 && dir->children != NULL) {
+      g_ptr_array_add(config->profiles, dir);
+    } else if (is_output(dir)) {
+      g_ptr_array_add(config->outputs, dir);
+    } else if (strcmp(dir->name, "include") == 0
+        && !load_include(config, dir, depth, error)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+static char *update_config(struct kanshi_config *config,
+    struct wl_list *outputs, struct kanshi_file **file, GError **error) {
+  struct wd_head_config *heads[HEADS_MAX];
+  int num_heads = 0;
+  struct wd_head_config *output;
+  wl_list_for_each_reverse(output, outputs, link) {
+    if (num_heads == HEADS_MAX) {
+      g_set_error(error, G_IO_ERROR, G_IO_ERROR_FAILED, "too many outputs");
+      return NULL;
+    }
+    heads[num_heads++] = output;
+  }
+  if (num_heads == 0) {
+    g_set_error(error, G_IO_ERROR, G_IO_ERROR_FAILED, "no outputs");
+    return NULL;
+  }
+
+  GString *str = g_string_new(NULL);
+  struct kanshi_directive *matches[HEADS_MAX];
+  for (guint i = 0; i < config->profiles->len; i++) {
+    struct kanshi_directive *profile = g_ptr_array_index(config->profiles, i);
+    if (match_profile(config, profile, heads, num_heads, matches)) {
+      *file = profile->file;
+      rewrite_profile(str, (*file)->text, profile, heads, num_heads, matches);
+      return g_string_free(str, FALSE);
+    }
+  }
+  *file = g_ptr_array_index(config->files, 0);
+  g_string_append(str, (*file)->text);
+  append_profile(str, heads, num_heads);
+  return g_string_free(str, FALSE);
+}
+
+static char *resolve_links(const char *path) {
+  char *current = g_strdup(path);
+  for (int i = 0; i < 40; i++) {
+    char *target = g_file_read_link(current, NULL);
+    if (target == NULL) {
+      break;
+    }
+    if (!g_path_is_absolute(target)) {
+      g_autofree char *dir = g_path_get_dirname(current);
+      g_autofree char *relative = target;
+      target = g_build_filename(dir, relative, NULL);
+    }
+    g_free(current);
+    current = target;
+  }
+  return current;
+}
+
+static bool write_config(const char *config_path, const char *contents,
+    GError **error) {
+  g_autofree char *path = resolve_links(config_path);
+  g_autofree char *dir = g_path_get_dirname(path);
+  if (g_mkdir_with_parents(dir, 0755) != 0) {
+    int err = errno;
+    g_set_error(error, G_FILE_ERROR, g_file_error_from_errno(err),
+        "%s: %s", dir, g_strerror(err));
+    return false;
+  }
+  return g_file_set_contents(path, contents, -1, error);
+}
+
+static void reload_kanshi(void) {
+  g_autofree char *kanshictl = g_find_program_in_path("kanshictl");
+  if (kanshictl == NULL) {
+    return;
+  }
+  char *argv[] = { kanshictl, "reload", NULL };
+  g_autoptr(GError) error = NULL;
+  if (!g_spawn_async(NULL, argv, NULL, 0, NULL, NULL, NULL, &error)) {
+    fprintf(stderr, "Failed to run kanshictl: %s\n", error->message);
+  }
+}
+
+void wd_store_config(struct wd_state *state, struct wl_list *outputs) {
+  g_autofree char *path = get_config_path();
+  g_autoptr(GPtrArray) files = g_ptr_array_new_with_free_func(kanshi_file_free);
+  g_autoptr(GPtrArray) profiles = g_ptr_array_new();
+  g_autoptr(GPtrArray) global_outputs = g_ptr_array_new();
+  struct kanshi_config config = { files, profiles, global_outputs };
+  struct kanshi_file *file = NULL;
+  g_autofree char *updated = NULL;
+  g_autoptr(GError) error = NULL;
+  if (!load_file(&config, path, false, 0, &error)) {
+    goto err;
+  }
+  updated = update_config(&config, outputs, &file, &error);
+  if (updated == NULL || !write_config(file->path, updated, &error)) {
+    goto err;
+  }
+  reload_kanshi();
+  return;
+
+err:;
+  g_autofree char *message = g_strdup_printf(
+      "Could not save the kanshi config: %s", error->message);
+  wd_ui_show_error(state, message);
+}

src/wdisplays.h

@@ -108,6 +108,7 @@ struct wd_head {
 
   uint32_t id;
   char *name, *description;
+  char *make, *model, *serial_number;
   int32_t phys_width, phys_height; // mm
   struct wl_list modes;
 
@@ -187,12 +188,16 @@ struct wd_state {
   struct wl_shm *shm;
   struct wl_list heads;
   struct wl_list outputs;
+  struct wl_list pending_configs;
   uint32_t serial;
 
   bool apply_pending;
+  bool apply_manual;
   bool autoapply;
   bool capture;
   bool show_overlay;
+  bool save_kanshi_config;
+  struct wl_list *kanshi_snapshot;
   double zoom;
 
   unsigned int apply_idle;
@@ -280,6 +285,19 @@ void wd_add_output_management_listener(struct wd_state *state, struct wl_display
  */
 void wd_apply_state(struct wd_state *state, struct wl_list *new_outputs, struct wl_display *display);
 
+#ifdef WITH_KANSHI
+/*
+ * Saves the layout of the last auto-apply to the kanshi config, unless it
+ * has been saved or dropped already.
+ */
+void wd_save_kanshi_snapshot(struct wd_state *state);
+
+/*
+ * Forgets the layout of the last auto-apply without saving it.
+ */
+void wd_drop_kanshi_snapshot(struct wd_state *state);
+#endif
+
 /*
  * Queues capture of the next frame of all screens.
  */
@@ -354,4 +372,14 @@ void wd_redraw_overlay(struct wd_output *output);
  */
 void wd_destroy_overlay(struct wd_output *output);
 
+// SPDX-SnippetBegin
+// SPDX-License-Identifier: MIT
+// SPDX-SnippetCopyrightText: 2024-2025 Jason André Charles Gantner
+#ifdef WITH_KANSHI
+/*
+ * Updates kanshi config
+ */
+void wd_store_config(struct wd_state *state, struct wl_list *outputs);
+#endif
+// SPDX-SnippetEnd
 #endif