cosmic-workspaces: abstract transaction-addon

This allows to use it for a future ext-workspace implementation.
It is also more generalized so can be used for other protocol
implementation in the future in case the protocols require some
kind of transaction management.

include/protocols/cosmic-workspaces-internal.h

@@ -16,43 +16,6 @@ enum pending_change {
 	CW_PENDING_WS_REMOVE     = 1 << 3,
 };
 
-struct transaction {
-	uint32_t change;
-	struct wl_list link;
-};
-
-struct transaction_workspace {
-	struct transaction base;
-	struct lab_cosmic_workspace *workspace;
-};
-
-struct transaction_group {
-	struct transaction base;
-	struct lab_cosmic_workspace_group *group;
-	char *new_workspace_name;
-};
-
-struct session_context {
-	int ref_count;
-	struct wl_list transactions;
-};
-
-struct wl_resource_addon {
-	struct session_context *ctx;
-	void *data;
-};
-
-struct wl_resource_addon *resource_addon_create(struct session_context *ctx);
-
-void transaction_add_workspace_ev(struct lab_cosmic_workspace *ws,
-	struct wl_resource *resource, enum pending_change change);
-
-void transaction_add_workspace_group_ev(struct lab_cosmic_workspace_group *group,
-	struct wl_resource *resource, enum pending_change change,
-	const char *new_workspace_name);
-
-void resource_addon_destroy(struct wl_resource_addon *addon);
-
 void group_output_send_initial_state(struct lab_cosmic_workspace_group *group,
 	struct wl_resource *group_resource);
 

include/protocols/transaction-addon.h

@@ -0,0 +1,84 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef LABWC_PROTOCOLS_TRANSACTION_ADDON_H
+#define LABWC_PROTOCOLS_TRANSACTION_ADDON_H
+
+#include <wayland-server-core.h>
+
+struct lab_transaction_op {
+	uint32_t change;
+	void *src;
+	void *data;
+
+	struct {
+		struct wl_signal destroy;
+	} events;
+
+	// Private
+	struct wl_list link;
+};
+
+struct lab_transaction_session_context {
+	int ref_count;
+	struct wl_list transaction_ops;
+};
+
+struct lab_wl_resource_addon {
+	struct lab_transaction_session_context *ctx;
+	void *data;
+};
+
+/*
+ * Creates a new addon which can be attached to a wl_resource via
+ * wl_resource_set_user_data() and retrieved via wl_resource_get_user_data().
+ *
+ * Usually the ctx argument should be addon->ctx of the parent wl_resource.
+ * If it is NULL it will be created automatically which can be used for top
+ * level wl_resources (when a client binds a wl_global from the registry).
+ *
+ * The context refcount is increased by one after this call.
+ */
+struct lab_wl_resource_addon *lab_resource_addon_create(
+	struct lab_transaction_session_context *ctx);
+
+/*
+ * A generic transaction operation attached to
+ * a session context transaction operation list.
+ *
+ * All arguments other than the context are user defined.
+ * Use of an enum for pending_change is suggested.
+ *
+ * The client is responsible for eventually freeing the data
+ * passed in the void *src and *data arguments by listening
+ * to the events.destroy signal. The transaction operations can be
+ * looped through by using lab_transaction_for_each(trans_op, ctx).
+ */
+struct lab_transaction_op *lab_transaction_op_add(
+	struct lab_transaction_session_context *ctx,
+	uint32_t pending_change, void *src, void *data);
+
+/*
+ * Removes the transaction operation from the ctx list and frees it.
+ *
+ * Does *not* free any passed in src or data arguments.
+ * Use the events.destroy signal for that if necessary.
+ */
+void lab_transaction_op_destroy(struct lab_transaction_op *transaction_op);
+
+/*
+ * Destroys the addon.
+ *
+ * The context refcount is decreased by one. If it reaches
+ * zero the context will be free'd alongside the addon itself.
+ * If the context is destroyed all pending transaction operations
+ * are destroyed as well.
+ */
+void lab_resource_addon_destroy(struct lab_wl_resource_addon *addon);
+
+/* Convinience wrappers for looping through the pending transaction ops of a ctx */
+#define lab_transaction_for_each(transaction_op, ctx) \
+	wl_list_for_each(transaction_op, &(ctx)->transaction_ops, link)
+
+#define lab_transaction_for_each_safe(trans_op, trans_op_tmp, ctx) \
+	wl_list_for_each_safe(trans_op, trans_op_tmp, &(ctx)->transaction_ops, link)
+
+#endif /* LABWC_PROTOCOLS_TRANSACTIONS_ADDON_H */