path: root/files/patches/sway_background_covered.diff

diff --git a/include/ipc.h b/include/ipc.h
index ff011750..e417b421 100644
--- a/include/ipc.h
+++ b/include/ipc.h
@@ -29,9 +29,10 @@ enum ipc_command_type {
 	IPC_EVENT_MODE = ((1<<31) | 2),
 	IPC_EVENT_WINDOW = ((1<<31) | 3),
 	IPC_EVENT_BARCONFIG_UPDATE = ((1<<31) | 4),
-	IPC_EVENT_BINDING = ((1<<31) | 5),
-	IPC_EVENT_SHUTDOWN = ((1<<31) | 6),
-	IPC_EVENT_TICK = ((1<<31) | 7),
+	IPC_EVENT_BACKGROUND_COVERED = ((1<<31) | 5),
+	IPC_EVENT_BINDING = ((1<<31) | 6),
+	IPC_EVENT_SHUTDOWN = ((1<<31) | 7),
+	IPC_EVENT_TICK = ((1<<31) | 8),
 
 	// sway-specific event types
 	IPC_EVENT_BAR_STATE_UPDATE = ((1<<31) | 20),
diff --git a/include/sway/ipc-server.h b/include/sway/ipc-server.h
index d4c00942..41e00679 100644
--- a/include/sway/ipc-server.h
+++ b/include/sway/ipc-server.h
@@ -17,6 +17,7 @@ void ipc_event_workspace(struct sway_workspace *old,
 void ipc_event_window(struct sway_container *window, const char *change);
 void ipc_event_barconfig_update(struct bar_config *bar);
 void ipc_event_bar_state_update(struct bar_config *bar);
+void ipc_event_background_covered(struct sway_output *output, bool covered);
 void ipc_event_mode(const char *mode, bool pango);
 void ipc_event_shutdown(const char *reason);
 void ipc_event_binding(struct sway_binding *binding);
diff --git a/include/sway/output.h b/include/sway/output.h
index 4584ea45..83e3cd7f 100644
--- a/include/sway/output.h
+++ b/include/sway/output.h
@@ -53,6 +53,8 @@ struct sway_output {
 	bool enabled;
 	list_t *workspaces;
 
+	bool background_covered;
+
 	struct sway_output_state current;
 
 	struct wl_listener layout_destroy;
diff --git a/include/sway/tree/workspace.h b/include/sway/tree/workspace.h
index 58bde20c..1fcd5017 100644
--- a/include/sway/tree/workspace.h
+++ b/include/sway/tree/workspace.h
@@ -40,6 +40,9 @@ struct sway_workspace {
 	enum sway_container_layout layout;
 	enum sway_container_layout prev_split_layout;
 
+	bool background_covered;
+	bool pending_background_check;
+
 	struct side_gaps current_gaps;
 	int gaps_inner;
 	struct side_gaps gaps_outer;
@@ -47,6 +50,7 @@ struct sway_workspace {
 	struct sway_output *output; // NULL if no outputs are connected
 	list_t *floating;           // struct sway_container
 	list_t *tiling;             // struct sway_container
+	list_t *sorted;             // struct sway_container
 	list_t *output_priority;
 	bool urgent;
 
@@ -89,6 +93,8 @@ bool workspace_is_visible(struct sway_workspace *ws);
 
 bool workspace_is_empty(struct sway_workspace *ws);
 
+void workspace_check_background_covered(struct sway_workspace *ws);
+
 void workspace_output_raise_priority(struct sway_workspace *workspace,
 		struct sway_output *old_output, struct sway_output *new_output);
 
diff --git a/sway/desktop/transaction.c b/sway/desktop/transaction.c
index 8f12832a..9869c934 100644
--- a/sway/desktop/transaction.c
+++ b/sway/desktop/transaction.c
@@ -702,30 +702,60 @@ static void transaction_apply(struct sway_transaction *transaction) {
 				"(%.1f frames if 60Hz)", transaction, ms, ms / (1000.0f / 60));
 	}
 
+	struct sway_transaction_instruction *instruction;
+	struct sway_node *node;
+	struct sway_workspace *ws = NULL;
+
 	// Apply the instruction state to the node's current state
 	for (int i = 0; i < transaction->instructions->length; ++i) {
-		struct sway_transaction_instruction *instruction =
-			transaction->instructions->items[i];
-		struct sway_node *node = instruction->node;
+		instruction = transaction->instructions->items[i];
+		node = instruction->node;
 
 		switch (node->type) {
 		case N_ROOT:
+			ws = NULL;
 			break;
 		case N_OUTPUT:
 			apply_output_state(node->sway_output, &instruction->output_state);
+			ws = node->sway_output->current.active_workspace;
 			break;
 		case N_WORKSPACE:
 			apply_workspace_state(node->sway_workspace,
 					&instruction->workspace_state);
+			ws = node->sway_workspace;
 			break;
 		case N_CONTAINER:
 			apply_container_state(node->sway_container,
 					&instruction->container_state);
+			ws = node->sway_container->current.workspace;
 			break;
 		}
 
+		if (ws) ws->pending_background_check = true;
+
 		node->instruction = NULL;
 	}
+
+	for (int i = 0; i < transaction->instructions->length; ++i) {
+		instruction = transaction->instructions->items[i];
+		node = instruction->node;
+
+		switch (node->type) {
+		case N_ROOT:
+			continue;
+		case N_OUTPUT:
+			ws = node->sway_output->current.active_workspace;
+			break;
+		case N_WORKSPACE:
+			ws = node->sway_workspace;
+			break;
+		case N_CONTAINER:
+			ws = node->sway_container->current.workspace;
+			break;
+		}
+
+		if (ws) workspace_check_background_covered(ws);
+	}
 }
 
 static void transaction_commit_pending(void);
diff --git a/sway/ipc-json.c b/sway/ipc-json.c
index 571338a4..f9bdcfae 100644
--- a/sway/ipc-json.c
+++ b/sway/ipc-json.c
@@ -16,6 +16,7 @@
 #include "sway/tree/view.h"
 #include "sway/tree/workspace.h"
 #include "sway/output.h"
+#include "sway/layers.h"
 #include "sway/input/input-manager.h"
 #include "sway/input/cursor.h"
 #include "sway/input/seat.h"
@@ -360,6 +361,9 @@ static void ipc_json_describe_enabled_output(struct sway_output *output,
 	json_object_object_add(object, "current_workspace",
 			json_object_new_string(ws->name));
 
+	json_object_object_add(object, "covered",
+			json_object_new_boolean(ws->background_covered));
+
 	json_object *modes_array = json_object_new_array();
 	struct wlr_output_mode *mode;
 	wl_list_for_each(mode, &wlr_output->modes, link) {
diff --git a/sway/ipc-server.c b/sway/ipc-server.c
index 7f353c0e..f3093505 100644
--- a/sway/ipc-server.c
+++ b/sway/ipc-server.c
@@ -362,6 +362,20 @@ void ipc_event_bar_state_update(struct bar_config *bar) {
 	json_object_put(json);
 }
 
+void ipc_event_background_covered(struct sway_output *output, bool covered) {
+	if (!ipc_has_event_listeners(IPC_EVENT_BACKGROUND_COVERED)) {
+		return;
+	}
+	sway_log(SWAY_DEBUG, "Sending background_covered event");
+
+	json_object *json = json_object_new_object();
+	json_object_object_add(json, "output", json_object_new_string(output->wlr_output->name));
+	json_object_object_add(json, "covered", json_object_new_boolean(covered));
+	const char *json_string = json_object_to_json_string(json);
+	ipc_send_event(json_string, IPC_EVENT_BACKGROUND_COVERED);
+	json_object_put(json);
+}
+
 void ipc_event_mode(const char *mode, bool pango) {
 	if (!ipc_has_event_listeners(IPC_EVENT_MODE)) {
 		return;
@@ -744,6 +758,8 @@ void ipc_client_handle_command(struct ipc_client *client, uint32_t payload_lengt
 				client->subscribed_events |= event_mask(IPC_EVENT_BARCONFIG_UPDATE);
 			} else if (strcmp(event_type, "bar_state_update") == 0) {
 				client->subscribed_events |= event_mask(IPC_EVENT_BAR_STATE_UPDATE);
+			} else if (strcmp(event_type, "background_covered") == 0) {
+				client->subscribed_events |= event_mask(IPC_EVENT_BACKGROUND_COVERED);
 			} else if (strcmp(event_type, "mode") == 0) {
 				client->subscribed_events |= event_mask(IPC_EVENT_MODE);
 			} else if (strcmp(event_type, "shutdown") == 0) {
diff --git a/sway/tree/output.c b/sway/tree/output.c
index 44b941ca..9004c3cb 100644
--- a/sway/tree/output.c
+++ b/sway/tree/output.c
@@ -142,6 +142,7 @@ struct sway_output *output_create(struct wlr_output *wlr_output) {
 
 	output->workspaces = create_list();
 	output->current.workspaces = create_list();
+	output->background_covered = false;
 
 	return output;
 }
diff --git a/sway/tree/workspace.c b/sway/tree/workspace.c
index f8709a4c..1234c1cd 100644
--- a/sway/tree/workspace.c
+++ b/sway/tree/workspace.c
@@ -88,8 +88,12 @@ struct sway_workspace *workspace_create(struct sway_output *output,
 	ws->layout = output_get_default_layout(output);
 	ws->floating = create_list();
 	ws->tiling = create_list();
+	ws->sorted = create_list();
 	ws->output_priority = create_list();
 
+	ws->background_covered = false;
+	ws->pending_background_check = true;
+
 	ws->gaps_outer = config->gaps_outer;
 	ws->gaps_inner = config->gaps_inner;
 	if (name) {
@@ -153,6 +157,7 @@ void workspace_destroy(struct sway_workspace *workspace) {
 	list_free_items_and_destroy(workspace->output_priority);
 	list_free(workspace->floating);
 	list_free(workspace->tiling);
+	list_free(workspace->sorted);
 	list_free(workspace->current.floating);
 	list_free(workspace->current.tiling);
 	free(workspace);
@@ -616,6 +621,75 @@ bool workspace_is_empty(struct sway_workspace *ws) {
 	return true;
 }
 
+static bool x_covered_at_y(list_t *containers, double y, double x, double width)
+{
+	double end = x + width;
+	double extent = x;
+	for (int i = 0; i < containers->length; ++i) {
+		struct sway_container *n = containers->items[i];
+		if (!(n->current.y <= y && n->current.y + n->current.height >= y)) {
+			continue;
+		}
+		if (n->current.x > extent) return false;
+		x = n->current.x + n->current.width;
+		if (x >= end) return true;
+		if (x > extent) extent = x;
+	}
+	return false;
+}
+
+static int containers_x_compare(const void *a, const void *b) {
+	return (*(struct sway_container **)a)->current.x - (*(struct sway_container **)b)->current.x;
+}
+
+#define TERMINAL_APP_ID "kitty"
+
+static void add_con_and_or_children_to_list(list_t *result, list_t *list)
+{
+	struct sway_container *con;
+	for (int i = 0; i < list->length; ++i) {
+		con = list->items[i];
+		if (con->current.children) {
+			add_con_and_or_children_to_list(result, con->current.children);
+			if (con->current.layout != L_NONE) return;
+		}
+		if (!con->view || !con->view->wlr_xdg_toplevel) continue; // Hack.
+		const char *app_id = view_get_app_id(con->view);
+		if (app_id == NULL || strcmp(app_id, TERMINAL_APP_ID) != 0) {
+			list_add(result, con);
+		}
+	}
+}
+
+void workspace_check_background_covered(struct sway_workspace *ws) {
+	if (!ws->output || !ws->pending_background_check) return;
+	ws->sorted->length = 0;
+	add_con_and_or_children_to_list(ws->sorted, ws->tiling);
+	add_con_and_or_children_to_list(ws->sorted, ws->floating);
+	list_stable_sort(ws->sorted, containers_x_compare);
+	ws->background_covered = ws->sorted->length > 0;
+	struct sway_container *con;
+	for (int i = 0; i < ws->sorted->length; ++i) {
+		con = ws->sorted->items[i];
+		double y = con->current.y - 1.0;
+		if (y < ws->y) y = ws->y;
+		double span = con->current.y + con->current.height + 1.0;
+		if (span > ws->y + ws->height) span = ws->y + ws->height;
+		bool top = x_covered_at_y(ws->sorted, y, ws->x, ws->width);
+		if (!top || !x_covered_at_y(ws->sorted, span, ws->x, ws->width)) {
+			ws->background_covered = false;
+			break;
+		}
+	}
+	if (ws == ws->output->current.active_workspace) {
+		if (ws->background_covered != ws->output->background_covered) {
+			ws->output->background_covered = ws->background_covered;
+			ipc_event_background_covered(ws->output, ws->output->background_covered);
+		}
+		ws->pending_background_check = false;
+	}
+}
+
 static int find_output(const void *id1, const void *id2) {
 	return strcmp(id1, id2);
 }