Send update dispatcher though FFI

resources/custom_modules/cffi_example/README.md

@@ -7,6 +7,9 @@ Most language can implement the required functions and constants (C, C++, Rust,
 Go, Python, ...), meaning you can develop custom modules using your language of
 choice, as long as there's GTK bindings.
 
+Symbols to implement are documented in the
+[waybar_cffi_module.h](waybar_cffi_module.h) file.
+
 # Usage
 
 ## Building this module

resources/custom_modules/cffi_example/main.c

@@ -19,7 +19,8 @@ void onclicked(GtkButton* button) {
 // You must
 const size_t wbcffi_version = 1;
 
-void* wbcffi_init(GtkContainer* root, const struct wbcffi_config_entry* config_entries,
+void* wbcffi_init(GtkContainer* root_widget, void (*trigger_update)(void*),
+                  void* trigger_update_arg, const struct wbcffi_config_entry* config_entries,
                   size_t config_entries_len) {
   printf("cffi_example: init config:\n");
   for (size_t i = 0; i < config_entries_len; i++) {
@@ -28,7 +29,7 @@ void* wbcffi_init(GtkContainer* root, const struct wbcffi_config_entry* config_e
 
   // Allocate the instance object
   Instance* inst = malloc(sizeof(Instance));
-  inst->root = root;
+  inst->root = root_widget;
 
   // Add a container for displaying the next widgets
   inst->container = GTK_BOX(gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 5));
@@ -51,13 +52,18 @@ void* wbcffi_init(GtkContainer* root, const struct wbcffi_config_entry* config_e
   printf("cffi_example inst=%p: init success ! (%d total instances)\n", inst, ++instance_count);
   return inst;
 }
+
 void wbcffi_deinit(void* instance) {
   printf("cffi_example inst=%p: free memory\n", instance);
   free(instance);
 }
+
+void wbcffi_update(void* instance) { printf("cffi_example inst=%p: Update request\n", instance); }
+
 void wbcffi_refresh(void* instance, int signal) {
   printf("cffi_example inst=%p: Received refresh signal %d\n", instance, signal);
 }
+
 void wbcffi_doaction(void* instance, const char* name) {
   printf("cffi_example inst=%p: doAction(%s)\n", instance, name);
 }

resources/custom_modules/cffi_example/waybar_cffi_module.h

@@ -23,12 +23,16 @@ struct wbcffi_config_entry {
 /// MANDATORY CFFI function
 ///
 /// @param root_widget        Root GTK widget instantiated by Waybar
+/// @param trigger_update     Call this function with trigger_update_arg as argument to trigger
+///                           wbcffi_update() on the next GTK main event loop iteration
+/// @param trigger_update_arg Argument for trigger_update call
 /// @param config_entries     Flat representation of the module JSON config. The data only available
 ///                           during wbcffi_init call.
 /// @param config_entries_len Number of entries in `config_entries`
 ///
 /// @return A untyped pointer to module data, NULL if the module failed to load.
-void* wbcffi_init(GtkContainer* root_widget, const struct wbcffi_config_entry* config_entries,
+void* wbcffi_init(GtkContainer* root_widget, const void (*trigger_update)(void*),
+                  void* trigger_update_arg, const struct wbcffi_config_entry* config_entries,
                   size_t config_entries_len);
 
 /// Module deinit/delete function, called when Waybar is closed or when the module is removed
@@ -38,8 +42,15 @@ void* wbcffi_init(GtkContainer* root_widget, const struct wbcffi_config_entry* c
 /// @param instance Module instance data (as returned by `wbcffi_init`)
 void wbcffi_deinit(void* instance);
 
-/// When Waybar receives a POSIX signal, it forwards the signal to each module, calling this
-/// function
+/// Called from the GTK main event loop, to update the UI
+///
+/// Optional CFFI function
+///
+/// @param instance Module instance data (as returned by `wbcffi_init`)
+/// @param action_name Action name
+void wbcffi_update(void* instance);
+
+/// Called when Waybar receives a POSIX signal and forwards it to each module
 ///
 /// Optional CFFI function
 ///
@@ -47,12 +58,14 @@ void wbcffi_deinit(void* instance);
 /// @param signal Signal ID
 void wbcffi_refresh(void* instance, int signal);
 
+/// Called on module action (see
+/// https://github.com/Alexays/Waybar/wiki/Configuration#module-actions-config)
 ///
 /// Optional CFFI function
 ///
 /// @param instance Module instance data (as returned by `wbcffi_init`)
-/// @param name Action name
-void wbcffi_doaction(void* instance, const char* name);
+/// @param action_name Action name
+void wbcffi_doaction(void* instance, const char* action_name);
 
 #ifdef __cplusplus
 }