feat: add "AutoPlace" action

The AutoPlace action will apply placement_find_best() to an active view,
moving it to a position on its output that will minimize overlap with
other views.

docs/labwc-actions.5.scd

@@ -219,6 +219,10 @@ Actions are used in menus and keyboard/mouse bindings.
 	*output_name* The name of virtual output. If not supplied, will remove the
 	last virtual output added.
 
+*<action name="AutoPlace" />*
+	Use the automatic placement policy to move the active window to a
+	position on its output that will minimize overlap with other windows.
+
 *<action name="None" />*
 	If used as the only action for a binding: clear an earlier defined binding.
 

docs/rc.xml.all

@@ -457,6 +457,10 @@
         <action name="MoveTo" x="0" y="0" />
         <action name="ToggleAlwaysOnBottom"/>
       </windowRule>
+      <windowRule identifier="org.qutebrowser.qutebrowser">
+        <action name="ResizeTo" width="1024" y="800" />
+        <action name="AutoPlace"/>
+      </windowRule>
     </windowRules>
   -->
 

src/action.c

@@ -16,6 +16,7 @@
 #include "debug.h"
 #include "labwc.h"
 #include "menu/menu.h"
+#include "placement.h"
 #include "regions.h"
 #include "ssd.h"
 #include "view.h"
@@ -100,6 +101,7 @@ enum action_type {
 	ACTION_TYPE_FOR_EACH,
 	ACTION_TYPE_VIRTUAL_OUTPUT_ADD,
 	ACTION_TYPE_VIRTUAL_OUTPUT_REMOVE,
+	ACTION_TYPE_AUTO_PLACE,
 };
 
 const char *action_names[] = {
@@ -146,6 +148,7 @@ const char *action_names[] = {
 	"ForEach",
 	"VirtualOutputAdd",
 	"VirtualOutputRemove",
+	"AutoPlace",
 	NULL
 };
 
@@ -940,6 +943,14 @@ actions_run(struct view *activator, struct server *server,
 				output_remove_virtual(server, output_name);
 			}
 			break;
+		case ACTION_TYPE_AUTO_PLACE:
+			if (view) {
+				int x = 0, y = 0;
+				if (placement_find_best(view, &x, &y)) {
+					view_move(view, x, y);
+				}
+			}
+			break;
 		case ACTION_TYPE_INVALID:
 			wlr_log(WLR_ERROR, "Not executing unknown action");
 			break;