Merge pull request #1491 from Consolatis/feature/fix_invisible_resize_area

src/ssd: allow invisible resize area across outputs

include/view.h

@@ -124,7 +124,7 @@ struct view {
 	struct wl_list link;
 
 	/*
-	 * The output that the view is displayed on. Specifically:
+	 * The primary output that the view is displayed on. Specifically:
 	 *
 	 *  - For floating views, this is the output nearest to the
 	 *    center of the view. It is computed automatically when the
@@ -139,6 +139,16 @@ struct view {
 	 * by calling view_set_output() beforehand.
 	 */
 	struct output *output;
+
+	/*
+	 * The outputs that the view is displayed on.
+	 * This is used to notify the foreign toplevel
+	 * implementation and to update the SSD invisible
+	 * resize area.
+	 * It is a bitset of output->scene_output->index.
+	 */
+	uint64_t outputs;
+
 	struct workspace *workspace;
 	struct wlr_surface *surface;
 	struct wlr_scene_tree *scene_tree;
@@ -460,6 +470,7 @@ void view_move_to_front(struct view *view);
 void view_move_to_back(struct view *view);
 struct view *view_get_root(struct view *view);
 void view_append_children(struct view *view, struct wl_array *children);
+bool view_on_output(struct view *view, struct output *output);
 
 /**
  * view_is_related() - determine if view and surface are owned by the

src/foreign.c

@@ -107,11 +107,10 @@ void
 foreign_toplevel_update_outputs(struct view *view)
 {
 	assert(view->toplevel.handle);
-	struct wlr_output_layout *layout = view->server->output_layout;
+
 	struct output *output;
 	wl_list_for_each(output, &view->server->outputs, link) {
-		if (output_is_usable(output) && wlr_output_layout_intersects(
-				layout, output->wlr_output, &view->current)) {
+		if (view_on_output(view, output)) {
 			wlr_foreign_toplevel_handle_v1_output_enter(
 				view->toplevel.handle, output->wlr_output);
 		} else {

src/ssd/ssd_extents.c

@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 
+#include <pixman.h>
 #include "common/mem.h"
 #include "common/scene-helpers.h"
 #include "labwc.h"
@@ -100,11 +101,6 @@ ssd_extents_update(struct ssd *ssd)
 	if (!view->output) {
 		return;
 	}
-	struct wlr_output_layout_output *l_output = wlr_output_layout_get(
-		view->server->output_layout, view->output->wlr_output);
-	if (!l_output) {
-		return;
-	}
 
 	struct theme *theme = view->server->theme;
 
@@ -127,10 +123,25 @@ ssd_extents_update(struct ssd *ssd)
 		-(theme->border_width + extended_area),
 		-(ssd->titlebar.height + theme->border_width + extended_area));
 
-	/* Convert usable area into layout coordinates */
-	struct wlr_box usable_area = view->output->usable_area;
-	usable_area.x += l_output->x;
-	usable_area.y += l_output->y;
+	/*
+	 * Convert all output usable areas that the
+	 * view is currently on into a pixman region
+	 */
+	int nrects;
+	pixman_region32_t usable;
+	pixman_region32_t intersection;
+	pixman_region32_init(&usable);
+	pixman_region32_init(&intersection);
+	struct output *output;
+	wl_list_for_each(output, &view->server->outputs, link) {
+		if (!view_on_output(view, output)) {
+			continue;
+		}
+		struct wlr_box usable_area =
+			output_usable_area_in_layout_coords(output);
+		pixman_region32_union_rect(&usable, &usable, usable_area.x,
+			usable_area.y, usable_area.width, usable_area.height);
+	}
 
 	/* Remember base layout coordinates */
 	int base_x, base_y;
@@ -176,11 +187,40 @@ ssd_extents_update(struct ssd *ssd)
 		part_box.height = target->height;
 
 		/* Constrain part to output->usable_area */
-		if (!wlr_box_intersection(&result_box, &part_box, &usable_area)) {
+		pixman_region32_clear(&intersection);
+		pixman_region32_intersect_rect(&intersection, &usable,
+			part_box.x, part_box.y, part_box.width, part_box.height);
+		const pixman_box32_t *inter_rects =
+			pixman_region32_rectangles(&intersection, &nrects);
+
+		if (nrects == 0) {
 			/* Not visible */
 			wlr_scene_node_set_enabled(part->node, false);
 			continue;
-		} else if (!part->node->enabled) {
+		}
+
+		/*
+		 * For each edge, the invisible grab area is resized
+		 * to not cover layer-shell clients such as panels.
+		 * However, only one resize operation is used per edge,
+		 * so if a window is in the unlikely position that it
+		 * is near a panel but also overspills onto another screen,
+		 * the invisible grab-area on the other screen would be
+		 * smaller than would normally be the case.
+		 *
+		 * Thus only use the first intersecting rect, this is
+		 * a compromise as it doesn't require us to create
+		 * multiple scene rects for a given extent edge
+		 * and still works in 95% of the cases.
+		 */
+		result_box = (struct wlr_box) {
+			.x = inter_rects[0].x1,
+			.y = inter_rects[0].y1,
+			.width = inter_rects[0].x2 - inter_rects[0].x1,
+			.height = inter_rects[0].y2 - inter_rects[0].y1
+		};
+
+		if (!part->node->enabled) {
 			wlr_scene_node_set_enabled(part->node, true);
 		}
 
@@ -204,6 +244,8 @@ ssd_extents_update(struct ssd *ssd)
 			wlr_scene_rect_set_size(rect, target->width, target->height);
 		}
 	}
+	pixman_region32_fini(&intersection);
+	pixman_region32_fini(&usable);
 }
 
 void

src/view.c

@@ -333,6 +333,34 @@ view_close(struct view *view)
 	}
 }
 
+static void
+view_update_outputs(struct view *view)
+{
+	struct output *output;
+	struct wlr_output_layout *layout = view->server->output_layout;
+
+	view->outputs = 0;
+	wl_list_for_each(output, &view->server->outputs, link) {
+		if (output_is_usable(output) && wlr_output_layout_intersects(
+				layout, output->wlr_output, &view->current)) {
+			view->outputs |= (1ull << output->scene_output->index);
+		}
+	}
+
+	if (view->toplevel.handle) {
+		foreign_toplevel_update_outputs(view);
+	}
+}
+
+bool
+view_on_output(struct view *view, struct output *output)
+{
+	assert(view);
+	assert(output);
+	return output->scene_output
+			&& (view->outputs & (1ull << output->scene_output->index));
+}
+
 void
 view_move(struct view *view, int x, int y)
 {
@@ -358,11 +386,9 @@ view_moved(struct view *view)
 	if (view_is_floating(view)) {
 		view_discover_output(view, NULL);
 	}
+	view_update_outputs(view);
 	ssd_update_geometry(view->ssd);
 	cursor_update_focus(view->server);
-	if (view->toplevel.handle) {
-		foreign_toplevel_update_outputs(view);
-	}
 	if (rc.resize_indicator && view->server->grabbed_view == view) {
 		resize_indicator_update(view);
 	}
@@ -1467,9 +1493,7 @@ view_adjust_for_layout_change(struct view *view)
 		}
 	}
 
-	if (view->toplevel.handle) {
-		foreign_toplevel_update_outputs(view);
-	}
+	view_update_outputs(view);
 }
 
 void