Add a placement to try empty area only. Minor bug fixing.

README.md

@@ -97,7 +97,7 @@ For `new_placement_cb` the arguments are:
 The callback places the new client by changing its geometry and client data.
 Note that after the callback machi will validate the geometry and fit into the areas.
 So no need to set the `.area`, `.lu`, or `.rd` field of the client data in the callback.
-See `placement.empty_then_fair` in `layout.lua` for an example.
+See `placement.empty` in `layout.lua` for an example.
 
 ## The layout editor and commands
 

layout.lua

@@ -493,7 +493,7 @@ end
 
 module.placement = {}
 
-function module.placement.empty_then_fair(c, instance, areas, geometry)
+local function empty_then_maybe_fair(c, instance, areas, geometry, do_fair)
     local area_client_count = {}
     for _, oc in ipairs(c.screen.tiled_clients) do
         local cd = instance.client_data[oc]
@@ -521,8 +521,11 @@ function module.placement.empty_then_fair(c, instance, areas, geometry)
             end
         end
     end
-    instance.client_data[c].lu = choice
-    instance.client_data[c].rd = choice
+    if choice_client_count > 1 and not do_fair then
+        return
+    end
+    instance.client_data[c].lu = nil
+    instance.client_data[c].rd = nil
     instance.client_data[c].area = choice
     geometry.x = areas[choice].x
     geometry.y = areas[choice].y
@@ -530,4 +533,12 @@ function module.placement.empty_then_fair(c, instance, areas, geometry)
     geometry.height = areas[choice].height
 end
 
+function module.placement.empty(c, instance, areas, geometry)
+    empty_then_maybe_fair(c, instance, areas, geometry, false)
+end
+
+function module.placement.empty_then_fair(c, instance, areas, geometry)
+    empty_then_maybe_fair(c, instance, areas, geometry, true)
+end
+
 return module