xdg-shell: add support for v4

This adds a configure_bounds event to let the client know of the
preferred maximum window geometry size.

include/wlr/types/wlr_xdg_shell.h

@@ -137,10 +137,18 @@ struct wlr_xdg_toplevel_state {
 	uint32_t min_width, min_height;
 };
 
+enum wlr_xdg_toplevel_configure_field {
+	WLR_XDG_TOPLEVEL_CONFIGURE_BOUNDS = 1 << 0,
+};
+
 struct wlr_xdg_toplevel_configure {
+	uint32_t fields; // enum wlr_xdg_toplevel_configure_field
 	bool maximized, fullscreen, resizing, activated;
 	uint32_t tiled; // enum wlr_edges
 	uint32_t width, height;
+	struct {
+		uint32_t width, height;
+	} bounds;
 };
 
 struct wlr_xdg_toplevel_requested {
@@ -376,6 +384,13 @@ uint32_t wlr_xdg_toplevel_set_resizing(struct wlr_xdg_toplevel *toplevel,
 uint32_t wlr_xdg_toplevel_set_tiled(struct wlr_xdg_toplevel *toplevel,
 		uint32_t tiled_edges);
 
+/**
+ * Configure the recommended bounds for the client's window geometry size.
+ * Returns the associated configure serial.
+ */
+uint32_t wlr_xdg_toplevel_set_bounds(struct wlr_xdg_toplevel *toplevel,
+		int32_t width, int32_t height);
+
 /**
  * Request that this toplevel closes.
  */

types/xdg_shell/wlr_xdg_shell.c

@@ -3,7 +3,7 @@
 #include "types/wlr_xdg_shell.h"
 #include "util/signal.h"
 
-#define WM_BASE_VERSION 3
+#define WM_BASE_VERSION 4
 
 static const struct xdg_wm_base_interface xdg_shell_impl;
 

types/xdg_shell/wlr_xdg_toplevel.c

@@ -31,6 +31,14 @@ struct wlr_xdg_toplevel_configure *send_xdg_toplevel_configure(
 	}
 	*configure = toplevel->scheduled;
 
+	uint32_t version = wl_resource_get_version(toplevel->resource);
+
+	if ((configure->fields & WLR_XDG_TOPLEVEL_CONFIGURE_BOUNDS) &&
+			version >= XDG_TOPLEVEL_CONFIGURE_BOUNDS_SINCE_VERSION) {
+		xdg_toplevel_send_configure_bounds(toplevel->resource,
+			configure->bounds.width, configure->bounds.height);
+	}
+
 	size_t nstates = 0;
 	uint32_t states[32];
 	if (configure->maximized) {
@@ -46,8 +54,7 @@ struct wlr_xdg_toplevel_configure *send_xdg_toplevel_configure(
 		states[nstates++] = XDG_TOPLEVEL_STATE_ACTIVATED;
 	}
 	if (configure->tiled) {
-		if (wl_resource_get_version(toplevel->resource) >=
-				XDG_TOPLEVEL_STATE_TILED_LEFT_SINCE_VERSION) {
+		if (version >= XDG_TOPLEVEL_STATE_TILED_LEFT_SINCE_VERSION) {
 			const struct {
 				enum wlr_edges edge;
 				enum xdg_toplevel_state state;
@@ -79,6 +86,8 @@ struct wlr_xdg_toplevel_configure *send_xdg_toplevel_configure(
 	xdg_toplevel_send_configure(toplevel->resource,
 		width, height, &wl_states);
 
+	toplevel->scheduled.fields = 0;
+
 	return configure;
 }
 
@@ -501,3 +510,14 @@ uint32_t wlr_xdg_toplevel_set_tiled(struct wlr_xdg_toplevel *toplevel,
 	toplevel->scheduled.tiled = tiled;
 	return wlr_xdg_surface_schedule_configure(toplevel->base);
 }
+
+uint32_t wlr_xdg_toplevel_set_bounds(struct wlr_xdg_toplevel *toplevel,
+		int32_t width, int32_t height) {
+	assert(toplevel->base->client->shell->version >=
+		XDG_TOPLEVEL_CONFIGURE_BOUNDS_SINCE_VERSION);
+	assert(width >= 0 && height >= 0);
+	toplevel->scheduled.fields |= WLR_XDG_TOPLEVEL_CONFIGURE_BOUNDS;
+	toplevel->scheduled.bounds.width = width;
+	toplevel->scheduled.bounds.height = height;
+	return wlr_xdg_surface_schedule_configure(toplevel->base);
+}