move: Check if grid is enabled before activating edges on drag

plugins/grid/grid.cpp

@@ -102,8 +102,16 @@ class wayfire_grid : public wf::plugin_interface_t, public wf::per_output_tracke
                 return false;
             });
         }
+
+        wf::get_core().connect(&grid_request_signal_cb);
     }
 
+    wf::signal::connection_t<wf::grid::grid_request_signal> grid_request_signal_cb =
+        [=] (wf::grid::grid_request_signal *ev)
+    {
+        ev->carried_out = true;
+    };
+
     void handle_new_output(wf::output_t *output) override
     {
         output->connect(&on_workarea_changed);

plugins/grid/wayfire/plugins/grid.hpp

@@ -8,6 +8,18 @@ namespace wf
 {
 namespace grid
 {
+/**
+ * name: request
+ * on: core
+ * when: Emitted before move renders a grid indicator and sets the slot.
+ * carried_out: true if a plugin can handle move request to grid.
+ */
+struct grid_request_signal
+{
+    /* True if a plugin handled this signal */
+    bool carried_out = false;
+};
+
 /**
  * The slot where a view can be placed with grid.
  * BL = bottom-left, TR = top-right, etc.

plugins/single_plugins/move.cpp

@@ -490,7 +490,16 @@ class wayfire_move : public wf::per_output_plugin_instance_t,
             slot.preview = nullptr;
         }
 
-        slot.slot_id = new_slot_id;
+        wf::grid::grid_request_signal grid_signal;
+        wf::get_core().emit(&grid_signal);
+
+        if (grid_signal.carried_out || (new_slot_id == wf::grid::slot_t::SLOT_CENTER))
+        {
+            slot.slot_id = new_slot_id;
+        } else
+        {
+            slot.slot_id = new_slot_id = wf::grid::slot_t::SLOT_NONE;
+        }
 
         /* Show a preview overlay */
         if (new_slot_id)