overlay: take into account <core><gap> for edge overlay

This also deduplicates get_edge_snap_box() in interactive.c and
view_get_edge_snap_box() in view.c.

include/labwc.h

@@ -429,7 +429,6 @@ void interactive_anchor_to_cursor(struct server *server, struct wlr_box *geo);
 void interactive_begin(struct view *view, enum input_mode mode, uint32_t edges);
 void interactive_finish(struct view *view);
 void interactive_cancel(struct view *view);
-/* Possibly returns VIEW_EDGE_CENTER if <topMaximize> is yes */
 enum view_edge edge_from_cursor(struct seat *seat, struct output **dest_output);
 
 void handle_tearing_new_object(struct wl_listener *listener, void *data);

include/view.h

@@ -501,6 +501,10 @@ bool view_contains_window_type(struct view *view, enum window_type window_type);
  */
 enum view_edge view_edge_invert(enum view_edge edge);
 
+/* If view is NULL, the size of SSD is not considered */
+struct wlr_box view_get_edge_snap_box(struct view *view, struct output *output,
+	enum view_edge edge);
+
 /**
  * view_is_focusable() - Check whether or not a view can be focused
  * @view: view to be checked

src/interactive.c

@@ -195,11 +195,7 @@ edge_from_cursor(struct seat *seat, struct output **dest_output)
 	} else if (cursor_x >= area->x + area->width - snap_range) {
 		return VIEW_EDGE_RIGHT;
 	} else if (cursor_y <= area->y + snap_range) {
-		if (rc.snap_top_maximize) {
+		return VIEW_EDGE_UP;
-			return VIEW_EDGE_CENTER;
-		} else {
-			return VIEW_EDGE_UP;
-		}
 	} else if (cursor_y >= area->y + area->height - snap_range) {
 		return VIEW_EDGE_DOWN;
 	} else {
@@ -223,7 +219,7 @@ snap_to_edge(struct view *view)
 	 * Don't store natural geometry here (it was
 	 * stored already in interactive_begin())
 	 */
-	if (edge == VIEW_EDGE_CENTER) {
+	if (edge == VIEW_EDGE_UP && rc.snap_top_maximize) {
 		/* <topMaximize> */
 		view_maximize(view, VIEW_AXIS_BOTH,
 			/*store_natural_geometry*/ false);

src/overlay.c

@@ -114,31 +114,13 @@ show_region_overlay(struct seat *seat, struct region *region)
 	show_overlay(seat, &seat->overlay.region_rect, &region->geo);
 }
 
-/* TODO: share logic with view_get_edge_snap_box() */
 static struct wlr_box get_edge_snap_box(enum view_edge edge, struct output *output)
 {
-	struct wlr_box box = output_usable_area_in_layout_coords(output);
+	if (edge == VIEW_EDGE_UP && rc.snap_top_maximize) {
-	switch (edge) {
+		return output_usable_area_in_layout_coords(output);
-	case VIEW_EDGE_RIGHT:
+	} else {
-		box.x += box.width / 2;
+		return view_get_edge_snap_box(NULL, output, edge);
-		/* fallthrough */
-	case VIEW_EDGE_LEFT:
-		box.width /= 2;
-		break;
-	case VIEW_EDGE_DOWN:
-		box.y += box.height / 2;
-		/* fallthrough */
-	case VIEW_EDGE_UP:
-		box.height /= 2;
-		break;
-	case VIEW_EDGE_CENTER:
-		/* <topMaximize> */
-		break;
-	default:
-		/* not reached */
-		assert(false);
 	}
-	return box;
 }
 
 static int

src/view.c

@@ -440,7 +440,7 @@ view_edge_invert(enum view_edge edge)
 	}
 }
 
-static struct wlr_box
+struct wlr_box
 view_get_edge_snap_box(struct view *view, struct output *output,
 		enum view_edge edge)
 {
@@ -469,14 +469,21 @@ view_get_edge_snap_box(struct view *view, struct output *output,
 		break;
 	}
 
-	struct border margin = ssd_get_margin(view->ssd);
 	struct wlr_box dst = {
-		.x = x_offset + usable.x + margin.left,
+		.x = x_offset + usable.x,
-		.y = y_offset + usable.y + margin.top,
+		.y = y_offset + usable.y,
-		.width = base_width - margin.left - margin.right,
+		.width = base_width,
-		.height = base_height - margin.top - margin.bottom,
+		.height = base_height,
 	};
 
+	if (view) {
+		struct border margin = ssd_get_margin(view->ssd);
+		dst.x += margin.left;
+		dst.y += margin.top;
+		dst.width -= margin.left + margin.right;
+		dst.height -= margin.top + margin.bottom;
+	}
+
 	return dst;
 }