widget: Mutualize all set_widget implementation to behave the same

Now always call both check_widget and make_widget_from_value. This
should make it a lot less confusing when randomly trying to create
a widget as all ways to do it slowly converge toward an unified
one.

lib/awful/widget/only_on_screen.lua

@@ -51,13 +51,7 @@ end
 -- @property widget
 -- @tparam widget widget The widget
 
-function only_on_screen:set_widget(widget)
+only_on_screen.set_widget = base.set_widget_common
-    if widget then
-        base.check_widget(widget)
-    end
-    self._private.widget = widget
-    self:emit_signal("widget::layout_changed")
-end
 
 function only_on_screen:get_widget()
     return self._private.widget

lib/wibox/container/arcchart.lua

@@ -192,13 +192,7 @@ end
 -- @property widget
 -- @tparam widget widget The widget
 
-function arcchart:set_widget(widget)
+arcchart.set_widget = base.set_widget_common
-    if widget then
-        base.check_widget(widget)
-    end
-    self._private.widget = widget
-    self:emit_signal("widget::layout_changed")
-end
 
 function arcchart:get_children()
     return {self._private.widget}

lib/wibox/container/background.lua

@@ -218,13 +218,7 @@ end
 -- @tparam widget widget The widget to be disaplayed inside of the background
 --  area
 
-function background:set_widget(widget)
+background.set_widget = base.set_widget_common
-    if widget then
-        base.check_widget(widget)
-    end
-    self._private.widget = widget
-    self:emit_signal("widget::layout_changed")
-end
 
 function background:get_widget()
     return self._private.widget

lib/wibox/container/constraint.lua

@@ -42,10 +42,7 @@ end
 -- @property widget
 -- @tparam widget widget The widget
 
-function constraint:set_widget(widget)
+constraint.set_widget = base.set_widget_common
-    self._private.widget = widget
-    self:emit_signal("widget::layout_changed")
-end
 
 function constraint:get_widget()
     return self._private.widget

lib/wibox/container/margin.lua

@@ -73,13 +73,7 @@ end
 -- @property widget
 -- @tparam widget widget The widget
 
-function margin:set_widget(widget)
+margin.set_widget = base.set_widget_common
-    if widget then
-        base.check_widget(widget)
-    end
-    self._private.widget = widget
-    self:emit_signal("widget::layout_changed")
-end
 
 function margin:get_widget()
     return self._private.widget

lib/wibox/container/mirror.lua

@@ -49,13 +49,7 @@ end
 -- @property widget
 -- @tparam widget widget The widget
 
-function mirror:set_widget(widget)
+mirror.set_widget = base.set_widget_common
-    if widget then
-        base.check_widget(widget)
-    end
-    self._private.widget = widget
-    self:emit_signal("widget::layout_changed")
-end
 
 function mirror:get_widget()
     return self._private.widget

lib/wibox/container/place.lua

@@ -61,13 +61,11 @@ function place:fit(context, width, height)
         and height or h
 end
 
-function place:set_widget(widget)
+--- The widget to be placed.
-    if widget then
+-- @property widget
-        base.check_widget(widget)
+-- @tparam widget widget The widget
-    end
+
-    self._private.widget = widget
+place.set_widget = base.set_widget_common
-    self:emit_signal("widget::layout_changed")
-end
 
 function place:get_widget()
     return self._private.widget

lib/wibox/container/radialprogressbar.lua

@@ -129,13 +129,7 @@ end
 -- @property widget
 -- @tparam widget widget The widget
 
-function radialprogressbar:set_widget(widget)
+radialprogressbar.set_widget = base.set_widget_common
-    if widget then
-        base.check_widget(widget)
-    end
-    self._private.widget = widget
-    self:emit_signal("widget::layout_changed")
-end
 
 function radialprogressbar:get_children()
     return {self._private.widget}

lib/wibox/container/rotate.lua

@@ -62,13 +62,7 @@ end
 -- @property widget
 -- @tparam widget widget The widget
 
-function rotate:set_widget(widget)
+rotate.set_widget = base.set_widget_common
-    if widget then
-        base.check_widget(widget)
-    end
-    self._private.widget = widget
-    self:emit_signal("widget::layout_changed")
-end
 
 function rotate:get_widget()
     return self._private.widget

lib/wibox/container/scroll.lua

@@ -277,10 +277,14 @@ function scroll:set_widget(widget)
     if widget == self._private.widget then
         return
     end
-    if widget then
+
-        base.check_widget(widget)
+    local w = base.make_widget_from_value(widget)
+
+    if w then
+        base.check_widget(w)
     end
-    self._private.widget = widget
+
+    self._private.widget = w
     self:emit_signal("widget::layout_changed")
     self:emit_signal("widget::redraw_needed")
 end

lib/wibox/layout/fixed.lua

@@ -70,8 +70,9 @@ function fixed:add(...)
     local args = { n=select('#', ...), ... }
     assert(args.n > 0, "need at least one widget to add")
     for i=1, args.n do
-        base.check_widget(args[i])
+        local w = base.make_widget_from_value(args[i])
-        table.insert(self._private.widgets, args[i])
+        base.check_widget(w)
+        table.insert(self._private.widgets, w)
     end
     self:emit_signal("widget::layout_changed")
 end

lib/wibox/layout/grid.lua

@@ -293,10 +293,9 @@ function grid:add(...)
     assert(args.n > 0, "need at least one widget to add")
     local row, column
     for i=1, args.n do
-        local w = args[i]
         -- Get the next empty coordinate to insert the widget
         row, column = self:get_next_empty(row, column)
-        self:add_widget_at(w, row, column, 1, 1)
+        self:add_widget_at(args[i], row, column, 1, 1)
     end
 end
 
@@ -317,6 +316,7 @@ function grid:add_widget_at(child, row, col, row_span, col_span)
     col_span = (col_span and col_span > 0) and col_span or 1
 
     -- check if the object is a widget
+    child = base.make_widget_from_value(child)
     base.check_widget(child)
 
     -- test if the new widget superpose with existing ones

lib/wibox/layout/manual.lua

@@ -102,9 +102,16 @@ function manual_layout:layout(context, width, height)
 end
 
 function manual_layout:add(...)
-    local wdgs = {...}
+    local wdgs = {}
     local old_count = #self._private.widgets
-    gtable.merge(self._private.widgets, {...})
+
+    for _, v in ipairs {...} do
+        local w = base.make_widget_from_value(v)
+        base.check_widget(w)
+        table.insert(wdgs, w)
+    end
+
+    gtable.merge(self._private.widgets, wdgs)
 
     -- Add the points
     for k, v in ipairs(wdgs) do
@@ -166,7 +173,7 @@ function manual_layout:add_at(widget, point)
     end
 
     self._private.pos[#self._private.widgets+1] = point
-    self:add(widget)
+    self:add(base.make_widget_from_value(widget))
 end
 
 --- Move a widget (by index).

lib/wibox/layout/ratio.lua

@@ -355,8 +355,9 @@ function ratio:add(...)
     local args = { n=select('#', ...), ... }
     assert(args.n > 0, "need at least one widget to add")
     for i=1, args.n do
-        base.check_widget(args[i])
+        local w = base.make_widget_from_value(args[i])
-        table.insert(self._private.widgets, args[i])
+        base.check_widget(w)
+        table.insert(self._private.widgets, w)
     end
 
     normalize(self)

lib/wibox/widget/base.lua

@@ -155,6 +155,24 @@ function base.widget:get_all_children()
     return ret
 end
 
+--- Common implementation of the `:set_widget()` method exposed by many
+-- other widgets.
+--
+-- Use this if your widget has no custom logic when setting the widget.
+--
+-- @usage
+--   rawset(my_custom_widget, "set_widget", wibox.widget.base.set_widget_common)
+function base.set_widget_common(self, widget)
+    local w = widget and base.make_widget_from_value(widget)
+
+    if w then
+        base.check_widget(w)
+    end
+
+    self._private.widget = w
+    self:emit_signal("widget::layout_changed")
+end
+
 --- Emit a signal and ensure all parent widgets in the hierarchies also
 -- forward the signal. This is useful to track signals when there is a dynamic
 -- set of containers and layouts wrapping the widget.