SnapToRegion: Add overlay while moving and pressing a modifier

include/labwc.h

@@ -156,6 +156,8 @@ struct seat {
 		struct wlr_scene_tree *icons;
 	} drag;
 
+	struct wlr_scene_rect *region_overlay;
+
 	struct wl_client *active_client_while_inhibited;
 	struct wl_list inputs;
 	struct wl_listener new_input;

include/regions.h

@@ -32,5 +32,7 @@ void regions_destroy(struct wl_list *regions);
 
 struct region *regions_from_cursor(struct server *server);
 struct region *regions_from_name(const char *region_name, struct output *output);
+void regions_show_overlay(struct view *view, struct seat *seat, struct region *region);
+void regions_hide_overlay(struct server *server, struct seat *seat);
 
 #endif /* __LABWC_REGIONS_H */

src/cursor.c

@@ -12,6 +12,7 @@
 #include "dnd.h"
 #include "labwc.h"
 #include "menu/menu.h"
+#include "regions.h"
 #include "resistance.h"
 #include "ssd.h"
 #include "view.h"
@@ -186,6 +187,20 @@ process_cursor_move(struct server *server, uint32_t time)
 	dy += server->grab_box.y;
 	resistance_move_apply(view, &dx, &dy);
 	view_move(view, dx, dy);
+
+	/* Region overlay */
+	if (!regions_available()) {
+		return;
+	}
+	struct wlr_keyboard *keyboard = &server->seat.keyboard_group->keyboard;
+	if (keyboard_any_modifiers_pressed(keyboard)) {
+		struct region *region = regions_from_cursor(server);
+		if (region) {
+			regions_show_overlay(view, &server->seat, region);
+		} else {
+			regions_hide_overlay(server, &server->seat);
+		}
+	}
 }
 
 static void

src/debug.c

@@ -110,10 +110,10 @@ get_special(struct server *server, struct wlr_scene_node *node)
 #endif
 	struct wlr_scene_tree *grand_parent =
 		node->parent ? node->parent->node.parent : NULL;
-	if (grand_parent == server->view_tree) {
+	if (grand_parent == server->view_tree && node->data) {
 		last_view = node_view_from_node(node);
 	}
-	if (node->parent == server->view_tree_always_on_top) {
+	if (node->parent == server->view_tree_always_on_top && node->data) {
 		last_view = node_view_from_node(node);
 	}
 	const char *view_part = get_view_part(last_view, node);

src/desktop.c

@@ -135,6 +135,10 @@ first_view(struct server *server)
 	struct wl_list *list_head =
 		&server->workspace_current->tree->children;
 	wl_list_for_each_reverse(node, list_head, link) {
+		if (!node->data) {
+			/* We found some non-view, most likely the region overlay */
+			continue;
+		}
 		struct view *view = node_view_from_node(node);
 		if (isfocusable(view)) {
 			return view;
@@ -200,6 +204,11 @@ desktop_cycle_view(struct server *server, struct view *start_view,
 			list_item = iter(list_item);
 		}
 		node = wl_container_of(list_item, node, link);
+		if (!node->data) {
+			/* We found some non-view, most likely the region overlay */
+			view = NULL;
+			continue;
+		}
 		view = node_view_from_node(node);
 		if (isfocusable(view)) {
 			return view;
@@ -218,6 +227,10 @@ topmost_mapped_view(struct server *server)
 	struct wlr_scene_node *node;
 	node_list = &server->workspace_current->tree->children;
 	wl_list_for_each_reverse(node, node_list, link) {
+		if (!node->data) {
+			/* We found some non-view, most likely the region overlay */
+			continue;
+		}
 		view = node_view_from_node(node);
 		if (view->mapped) {
 			return view;

src/interactive.c

@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 #include "labwc.h"
+#include "regions.h"
 #include "view.h"
 
 static int
@@ -141,6 +142,7 @@ interactive_finish(struct view *view)
 {
 	if (view->server->grabbed_view == view) {
 		enum input_mode mode = view->server->input_mode;
+		regions_hide_overlay(view->server, &view->server->seat);
 		view->server->input_mode = LAB_INPUT_STATE_PASSTHROUGH;
 		view->server->grabbed_view = NULL;
 		if (mode == LAB_INPUT_STATE_MOVE) {

src/keyboard.c

@@ -5,6 +5,7 @@
 #include "action.h"
 #include "key-state.h"
 #include "labwc.h"
+#include "regions.h"
 #include "workspaces.h"
 
 static bool should_cancel_cycling_on_next_key_release;
@@ -55,7 +56,8 @@ keyboard_modifiers_notify(struct wl_listener *listener, void *data)
 	struct wlr_keyboard_key_event *event = data;
 	struct wlr_keyboard *wlr_keyboard = keyboard->wlr_keyboard;
 
-	if (server->osd_state.cycle_view || seat->workspace_osd_shown_by_modifier) {
+	if (server->osd_state.cycle_view || server->grabbed_view
+			|| seat->workspace_osd_shown_by_modifier) {
 		if (event->state == WL_KEYBOARD_KEY_STATE_RELEASED
 				&& !keyboard_any_modifiers_pressed(wlr_keyboard))  {
 			if (server->osd_state.cycle_view) {
@@ -68,6 +70,9 @@ keyboard_modifiers_notify(struct wl_listener *listener, void *data)
 			if (seat->workspace_osd_shown_by_modifier) {
 				workspaces_osd_hide(seat);
 			}
+			if (server->grabbed_view) {
+				regions_hide_overlay(server, seat);
+			}
 		}
 	}
 	wlr_seat_keyboard_notify_modifiers(seat->seat, &wlr_keyboard->modifiers);

src/osd.c

@@ -66,6 +66,10 @@ get_osd_height(struct wl_list *node_list)
 	struct view *view;
 	struct wlr_scene_node *node;
 	wl_list_for_each(node, node_list, link) {
+		if (!node->data) {
+			/* We found some non-view, most likely the region overlay */
+			continue;
+		}
 		view = node_view_from_node(node);
 		if (!isfocusable(view)) {
 			continue;
@@ -215,6 +219,11 @@ preview_cycled_view(struct view *view)
 	osd_state->preview_node = &view->scene_tree->node;
 	osd_state->preview_anchor = lab_wlr_scene_get_prev_node(
 		osd_state->preview_node);
+	while (osd_state->preview_anchor && !osd_state->preview_anchor->data) {
+		/* Ignore non-view nodes */
+		osd_state->preview_anchor = lab_wlr_scene_get_prev_node(
+			osd_state->preview_anchor);
+	}
 
 	/* Store node enabled / minimized state and force-enable if disabled */
 	osd_state->preview_was_enabled = osd_state->preview_node->enabled;
@@ -288,6 +297,10 @@ render_osd(cairo_t *cairo, int w, int h, struct wl_list *node_list,
 
 	/* Draw text for each node */
 	wl_list_for_each_reverse(node, node_list, link) {
+		if (!node->data) {
+			/* We found some non-view, most likely the region overlay */
+			continue;
+		}
 		struct view *view = node_view_from_node(node);
 		if (!isfocusable(view)) {
 			continue;

src/regions.c

@@ -5,6 +5,7 @@
 #include <float.h>
 #include <math.h>
 #include <string.h>
+#include <wlr/render/pixman.h>
 #include <wlr/types/wlr_scene.h>
 #include <wlr/util/box.h>
 #include <wlr/util/log.h>
@@ -13,6 +14,7 @@
 #include "common/mem.h"
 #include "labwc.h"
 #include "regions.h"
+#include "view.h"
 
 bool
 regions_available(void)
@@ -23,7 +25,19 @@ regions_available(void)
 void
 regions_init(struct server *server, struct seat *seat)
 {
-	/* To be filled later */
+	assert(server);
+	assert(seat);
+
+	float *color;
+	float solid[4] = { 0.5, 0.5, 0.7, 1 };
+	float trans[4] = { 0.25, 0.25, 0.35, 0.5 };
+	if (wlr_renderer_is_pixman(server->renderer)) {
+		color = solid;
+	} else {
+		color = trans;
+	}
+	seat->region_overlay = wlr_scene_rect_create(&server->scene->tree, 0, 0, color);
+	wlr_scene_node_set_enabled(&seat->region_overlay->node, false);
 }
 
 struct region *
@@ -71,6 +85,44 @@ regions_from_cursor(struct server *server)
 	return closest_region;
 }
 
+void
+regions_show_overlay(struct view *view, struct seat *seat, struct region *region)
+{
+	assert(view);
+	assert(seat);
+	assert(region);
+	static struct region *old_region;
+
+	struct wlr_scene_rect *overlay = seat->region_overlay;
+	if (old_region != region) {
+		wlr_scene_rect_set_size(overlay, region->geo.width, region->geo.height);
+		wlr_scene_node_set_position(&overlay->node, region->geo.x, region->geo.y);
+		old_region = region;
+	}
+	if (overlay->node.parent != view->scene_tree->node.parent) {
+		wlr_scene_node_reparent(&overlay->node, view->scene_tree->node.parent);
+		wlr_scene_node_place_below(&overlay->node, &view->scene_tree->node);
+	}
+	if (!overlay->node.enabled) {
+		wlr_scene_node_set_enabled(&overlay->node, true);
+	}
+}
+
+void
+regions_hide_overlay(struct server *server, struct seat *seat)
+{
+	assert(server);
+	assert(seat);
+
+	struct wlr_scene_rect *overlay = seat->region_overlay;
+	if (overlay->node.enabled) {
+		wlr_scene_node_set_enabled(&overlay->node, false);
+	}
+	if (overlay->node.parent != &server->scene->tree) {
+		wlr_scene_node_reparent(&overlay->node, &server->scene->tree);
+	}
+}
+
 void
 regions_update(struct output *output)
 {

src/server.c

@@ -20,6 +20,7 @@
 #include "labwc.h"
 #include "layers.h"
 #include "menu/menu.h"
+#include "regions.h"
 #include "theme.h"
 #include "view.h"
 #include "workspaces.h"
@@ -388,6 +389,7 @@ server_init(struct server *server)
 		&server->output_power_manager_set_mode);
 
 	layers_init(server);
+	regions_init(server, &server->seat);
 
 #if HAVE_XWAYLAND
 	xwayland_server_init(server, compositor);