From 6bf3bb97f59282886e18b98ae38e8a67a1c3a91d Mon Sep 17 00:00:00 2001
From: ARDiDo <90479315+ARDiDo@users.noreply.github.com>
Date: Sun, 3 Oct 2021 13:33:38 -0400
Subject: [PATCH 1/3] implement basic drag and drop

---
 include/labwc.h |  5 +++++
 src/cursor.c    | 43 ++++++++++++++++++++++++++++++++++++++++++-
 src/output.c    | 23 +++++++++++++++++++++++
 3 files changed, 70 insertions(+), 1 deletion(-)

diff --git a/include/labwc.h b/include/labwc.h
index 2da1deb9..f9ad4227 100644
--- a/include/labwc.h
+++ b/include/labwc.h
@@ -61,6 +61,7 @@ struct seat {
 	struct wlr_keyboard_group *keyboard_group;
 	struct wlr_cursor *cursor;
 	struct wlr_xcursor_manager *xcursor_manager;
+	struct wlr_drag_icon *drag_icon;
 
 	/* if set, views cannot receive focus */
 	struct wlr_layer_surface_v1 *focused_layer;
@@ -81,6 +82,10 @@ struct seat {
 
 	struct wl_listener keyboard_key;
 	struct wl_listener keyboard_modifiers;
+
+	struct wl_listener request_start_drag;
+	struct wl_listener start_drag;
+	struct wl_listener destroy_drag;
 };
 
 struct server {
diff --git a/src/cursor.c b/src/cursor.c
index a6fae287..46d33ca1 100644
--- a/src/cursor.c
+++ b/src/cursor.c
@@ -57,6 +57,19 @@ request_set_primary_selection_notify(struct wl_listener *listener, void *data)
 		event->serial);
 }
 
+static void
+request_start_drag_notify(struct wl_listener *listener, void *data)
+{
+	struct seat *seat = wl_container_of(
+		listener, seat, request_start_drag);
+	struct wlr_seat_request_start_drag_event *event = data;
+	if (wlr_seat_validate_pointer_grab_serial(seat->seat, event->origin, event->serial)) {
+		wlr_seat_start_pointer_drag(seat->seat, event->drag, event->serial);
+	} else {
+		wlr_data_source_destroy(event->drag->source);
+	}
+}
+
 static void
 process_cursor_move(struct server *server, uint32_t time)
 {
@@ -190,7 +203,7 @@ process_cursor_motion(struct server *server, uint32_t time)
 		 * the pointer over a window.
 		 */
 		wlr_seat_pointer_notify_enter(wlr_seat, surface, sx, sy);
-		if (!focus_changed) {
+		if (!focus_changed || server->seat.drag_icon) {
 			/*
 			 * The enter event contains coordinates, so we only need
 			 * to notify on motion if the focus did not change.
@@ -206,6 +219,15 @@ process_cursor_motion(struct server *server, uint32_t time)
 	}
 }
 
+void
+start_drag(struct wl_listener *listener, void *data)
+{
+	struct seat *seat = wl_container_of(listener, seat, start_drag);
+	struct wlr_drag *wlr_drag = data;
+	seat->drag_icon = wlr_drag->icon;
+	wl_signal_add(&seat->drag_icon->events.destroy, &seat->destroy_drag);
+}
+
 static void
 cursor_motion(struct wl_listener *listener, void *data)
 {
@@ -228,6 +250,18 @@ cursor_motion(struct wl_listener *listener, void *data)
 	process_cursor_motion(seat->server, event->time_msec);
 }
 
+void
+destroy_drag(struct wl_listener *listener, void *data)
+{
+	struct seat *seat = wl_container_of(listener, seat, destroy_drag);
+
+	if (!seat->drag_icon) {
+		return;
+	}
+	seat->drag_icon = NULL;
+	desktop_focus_topmost_mapped_view(seat->server);
+}
+
 void
 cursor_motion_absolute(struct wl_listener *listener, void *data)
 {
@@ -442,6 +476,13 @@ cursor_init(struct seat *seat)
 	seat->request_set_selection.notify = request_set_selection_notify;
 	wl_signal_add(&seat->seat->events.request_set_selection,
 		&seat->request_set_selection);
+	seat->request_start_drag.notify = request_start_drag_notify;
+	wl_signal_add(&seat->seat->events.request_start_drag,
+		&seat->request_start_drag);
+	seat->start_drag.notify = start_drag;
+	wl_signal_add(&seat->seat->events.start_drag,
+		&seat->start_drag);
+	seat->destroy_drag.notify = destroy_drag;
 
 	seat->request_set_primary_selection.notify =
 		request_set_primary_selection_notify;
diff --git a/src/output.c b/src/output.c
index 78d90c6c..5a7c9319 100644
--- a/src/output.c
+++ b/src/output.c
@@ -179,6 +179,26 @@ render_surface_iterator(struct output *output, struct wlr_surface *surface,
 	render_texture(wlr_output, output_damage, texture, box, matrix);
 }
 
+void
+output_drag_icon_for_each_surface(struct output *output, struct seat *seat,
+		surface_iterator_func_t iterator, void *user_data)
+{
+	if (!seat->drag_icon || !seat->drag_icon->mapped) {
+		return;
+	}
+	output_surface_for_each_surface(output, seat->drag_icon->surface,
+			seat->cursor->x, seat->cursor->y, iterator, user_data);
+}
+
+static void
+render_drag_icon(struct output *output, pixman_region32_t *damage)
+{
+	struct render_data data = {
+		.damage = damage,
+	};
+	output_drag_icon_for_each_surface(output, &output->server->seat, render_surface_iterator, &data);
+}
+
 #if HAVE_XWAYLAND
 void
 output_unmanaged_for_each_surface(struct output *output,
@@ -290,6 +310,7 @@ output_for_each_surface(struct output *output, surface_iterator_func_t iterator,
 	output_layer_for_each_surface(output,
 		&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY],
 		iterator, user_data);
+	output_drag_icon_for_each_surface(output, &output->server->seat, iterator, user_data);
 }
 
 struct send_frame_done_data {
@@ -707,6 +728,8 @@ output_render(struct output *output, pixman_region32_t *damage)
 		render_osd(output, damage, output->server);
 	}
 
+	render_drag_icon(output, damage);
+
 	render_layer_toplevel(output, damage,
 		&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_TOP]);
 	render_layer_toplevel(output, damage,

From 565f0daee90bcc755d9a85debe8d090e3d93241a Mon Sep 17 00:00:00 2001
From: ARDiDo <90479315+ARDiDo@users.noreply.github.com>
Date: Sun, 3 Oct 2021 14:21:32 -0400
Subject: [PATCH 2/3] drag across monitor

---
 src/output.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/output.c b/src/output.c
index 5a7c9319..a4d0ded0 100644
--- a/src/output.c
+++ b/src/output.c
@@ -186,8 +186,11 @@ output_drag_icon_for_each_surface(struct output *output, struct seat *seat,
 	if (!seat->drag_icon || !seat->drag_icon->mapped) {
 		return;
 	}
+	double ox = seat->cursor->x, oy = seat->cursor->y;
+	wlr_output_layout_output_coords(output->server->output_layout,
+			output->wlr_output, &ox, &oy); 
 	output_surface_for_each_surface(output, seat->drag_icon->surface,
-			seat->cursor->x, seat->cursor->y, iterator, user_data);
+			ox, oy, iterator, user_data);
 }
 
 static void

From 6b9d3f4083b4acfc5f265065fb383a84a990e4d4 Mon Sep 17 00:00:00 2001
From: ARDiDo <90479315+ARDiDo@users.noreply.github.com>
Date: Sun, 3 Oct 2021 16:19:42 -0400
Subject: [PATCH 3/3] fix build errors

---
 src/xdg.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/xdg.c b/src/xdg.c
index 1eff1640..080cee42 100644
--- a/src/xdg.c
+++ b/src/xdg.c
@@ -35,7 +35,7 @@ has_ssd(struct view *view)
 	 * geometry.{x,y} seems to be greater than zero. We filter on that
 	 * on the assumption that this will remain true.
 	 */
-	if (view->xdg_surface->geometry.x || view->xdg_surface->geometry.y) {
+	if (view->xdg_surface->current.geometry.x || view->xdg_surface->current.geometry.y) {
 		return false;
 	}
 	return true;
@@ -57,7 +57,7 @@ handle_commit(struct wl_listener *listener, void *data)
 	view->padding.left = view->padding.right = size.x;
 
 	uint32_t serial = view->pending_move_resize.configure_serial;
-	if (serial > 0 && serial >= view->xdg_surface->configure_serial) {
+	if (serial > 0 && serial >= view->xdg_surface->current.configure_serial) {
 		if (view->pending_move_resize.update_x) {
 			view->x = view->pending_move_resize.x +
 				view->pending_move_resize.width - size.width;
@@ -66,7 +66,7 @@ handle_commit(struct wl_listener *listener, void *data)
 			view->y = view->pending_move_resize.y +
 				view->pending_move_resize.height - size.height;
 		}
-		if (serial == view->xdg_surface->configure_serial) {
+		if (serial == view->xdg_surface->current.configure_serial) {
 			view->pending_move_resize.configure_serial = 0;
 		}
 	}
@@ -258,8 +258,8 @@ position_xdg_toplevel_view(struct view *view)
 			output_usable_area_from_cursor_coords(view->server);
 		view->x = box.x;
 		view->y = box.y;
-		view->w = view->xdg_surface->geometry.width;
-		view->h = view->xdg_surface->geometry.height;
+		view->w = view->xdg_surface->current.geometry.width;
+		view->h = view->xdg_surface->current.geometry.height;
 		if (view->w && view->h) {
 			view_center(view);
 		}
@@ -272,8 +272,8 @@ position_xdg_toplevel_view(struct view *view)
 		assert(parent);
 		int center_x = parent->x + parent->w / 2;
 		int center_y = parent->y + parent->h / 2;
-		view->x = center_x - view->xdg_surface->geometry.width / 2;
-		view->y = center_y - view->xdg_surface->geometry.height / 2;
+		view->x = center_x - view->xdg_surface->current.geometry.width / 2;
+		view->y = center_y - view->xdg_surface->current.geometry.height / 2;
 	}
 	view->x += view->margin.left - view->padding.left;
 	view->y += view->margin.top - view->padding.top;