input: implement xdg_toplevel interactive resize hints

include/sway/tree/container.h

@@ -219,6 +219,8 @@ void container_floating_resize_and_center(struct sway_container *con);
 
 void container_floating_set_default_size(struct sway_container *con);
 
+void container_set_resizing(struct sway_container *con, bool resizing);
+
 void container_set_floating(struct sway_container *container, bool enable);
 
 void container_set_geometry_from_content(struct sway_container *con);

include/sway/tree/view.h

@@ -43,6 +43,7 @@ struct sway_view_impl {
 	void (*set_activated)(struct sway_view *view, bool activated);
 	void (*set_tiled)(struct sway_view *view, bool tiled);
 	void (*set_fullscreen)(struct sway_view *view, bool fullscreen);
+	void (*set_resizing)(struct sway_view *view, bool resizing);
 	bool (*wants_floating)(struct sway_view *view);
 	void (*for_each_surface)(struct sway_view *view,
 		wlr_surface_iterator_func_t iterator, void *user_data);

sway/desktop/xdg_shell.c

@@ -185,6 +185,14 @@ static void set_fullscreen(struct sway_view *view, bool fullscreen) {
 	wlr_xdg_toplevel_set_fullscreen(surface, fullscreen);
 }
 
+static void set_resizing(struct sway_view *view, bool resizing) {
+	if (xdg_shell_view_from_view(view) == NULL) {
+		return;
+	}
+	struct wlr_xdg_surface *surface = view->wlr_xdg_surface;
+	wlr_xdg_toplevel_set_resizing(surface, resizing);
+}
+
 static bool wants_floating(struct sway_view *view) {
 	struct wlr_xdg_toplevel *toplevel = view->wlr_xdg_surface->toplevel;
 	struct wlr_xdg_toplevel_state *state = &toplevel->current;
@@ -260,6 +268,7 @@ static const struct sway_view_impl view_impl = {
 	.set_activated = set_activated,
 	.set_tiled = set_tiled,
 	.set_fullscreen = set_fullscreen,
+	.set_resizing = set_resizing,
 	.wants_floating = wants_floating,
 	.for_each_surface = for_each_surface,
 	.for_each_popup = for_each_popup,

sway/input/seatop_resize_floating.c

@@ -21,7 +21,12 @@ struct seatop_resize_floating_event {
 static void handle_button(struct sway_seat *seat, uint32_t time_msec,
 		struct wlr_input_device *device, uint32_t button,
 		enum wlr_button_state state) {
+	struct seatop_resize_floating_event *e = seat->seatop_data;
+	struct sway_container *con = e->con;
+
 	if (seat->cursor->pressed_button_count == 0) {
+		container_set_resizing(con, false);
+		arrange_container(con); // Send configure w/o resizing hint
 		seatop_begin_default(seat);
 	}
 }
@@ -170,6 +175,7 @@ void seatop_begin_resize_floating(struct sway_seat *seat,
 	seat->seatop_impl = &seatop_impl;
 	seat->seatop_data = e;
 
+	container_set_resizing(con, true);
 	container_raise_floating(con);
 
 	const char *image = edge == WLR_EDGE_NONE ?

sway/input/seatop_resize_tiling.c

@@ -4,6 +4,9 @@
 #include "sway/commands.h"
 #include "sway/input/cursor.h"
 #include "sway/input/seat.h"
+#include "sway/tree/arrange.h"
+#include "sway/tree/container.h"
+#include "sway/tree/view.h"
 
 struct seatop_resize_tiling_event {
 	struct sway_container *con;    // leaf container
@@ -12,17 +15,58 @@ struct seatop_resize_tiling_event {
 	struct sway_container *h_con;
 	struct sway_container *v_con;
 
+	// sibling con(s) that will be resized to accommodate
+	struct sway_container *h_sib;
+	struct sway_container *v_sib;
+
 	enum wlr_edges edge;
 	enum wlr_edges edge_x, edge_y;
 	double ref_lx, ref_ly;         // cursor's x/y at start of op
 	double h_con_orig_width;       // width of the horizontal ancestor at start
 	double v_con_orig_height;      // height of the vertical ancestor at start
 };
 
+static struct sway_container *container_get_resize_sibling(
+		struct sway_container *con, uint32_t edge) {
+	if (!con) {
+		return NULL;
+	}
+
+	list_t *siblings = container_get_siblings(con);
+	int index = container_sibling_index(con);
+	int offset = edge & (WLR_EDGE_TOP | WLR_EDGE_LEFT) ? -1 : 1;
+
+	if (siblings->length == 1) {
+		return NULL;
+	} else {
+		return siblings->items[index + offset];
+	}
+}
+
 static void handle_button(struct sway_seat *seat, uint32_t time_msec,
 		struct wlr_input_device *device, uint32_t button,
 		enum wlr_button_state state) {
+	struct seatop_resize_tiling_event *e = seat->seatop_data;
+
 	if (seat->cursor->pressed_button_count == 0) {
+		if (e->h_con) {
+			container_set_resizing(e->h_con, false);
+			container_set_resizing(e->h_sib, false);
+			if (e->h_con->parent) {
+				arrange_container(e->h_con->parent);
+			} else {
+				arrange_workspace(e->h_con->workspace);
+			}
+		}
+		if (e->v_con) {
+			container_set_resizing(e->v_con, false);
+			container_set_resizing(e->v_sib, false);
+			if (e->v_con->parent) {
+				arrange_container(e->v_con->parent);
+			} else {
+				arrange_workspace(e->v_con->workspace);
+			}
+		}
 		seatop_begin_default(seat);
 	}
 }
@@ -89,16 +133,22 @@ void seatop_begin_resize_tiling(struct sway_seat *seat,
 	if (edge & (WLR_EDGE_LEFT | WLR_EDGE_RIGHT)) {
 		e->edge_x = edge & (WLR_EDGE_LEFT | WLR_EDGE_RIGHT);
 		e->h_con = container_find_resize_parent(e->con, e->edge_x);
+		e->h_sib = container_get_resize_sibling(e->h_con, e->edge_x);
 
 		if (e->h_con) {
+			container_set_resizing(e->h_con, true);
+			container_set_resizing(e->h_sib, true);
 			e->h_con_orig_width = e->h_con->width;
 		}
 	}
 	if (edge & (WLR_EDGE_TOP | WLR_EDGE_BOTTOM)) {
 		e->edge_y = edge & (WLR_EDGE_TOP | WLR_EDGE_BOTTOM);
 		e->v_con = container_find_resize_parent(e->con, e->edge_y);
+		e->v_sib = container_get_resize_sibling(e->v_con, e->edge_y);
 
 		if (e->v_con) {
+			container_set_resizing(e->v_con, true);
+			container_set_resizing(e->v_sib, true);
 			e->v_con_orig_height = e->v_con->height;
 		}
 	}

sway/tree/container.c

@@ -746,6 +746,28 @@ void container_floating_set_default_size(struct sway_container *con) {
 	free(box);
 }
 
+
+/**
+ * Indicate to clients in this container that they are participating in (or
+ * have just finished) an interactive resize
+ */
+void container_set_resizing(struct sway_container *con, bool resizing) {
+	if (!con) {
+		return;
+	}
+
+	if (con->view) {
+		if (con->view->impl->set_resizing) {
+			con->view->impl->set_resizing(con->view, resizing);
+		}
+	} else {
+		for (int i = 0; i < con->children->length; ++i ) {
+			struct sway_container *child = con->children->items[i];
+			container_set_resizing(child, resizing);
+		}
+	}
+}
+
 void container_set_floating(struct sway_container *container, bool enable) {
 	if (container_is_floating(container) == enable) {
 		return;