fix: stop self.dimen polution for inputcontainers

Without this fix, self.dimen is shared among all inputcontainers
intances, which breaks some of the UI rendering. All widget should
set/initialize their own self.dimen in self:init() method.

frontend/apps/reader/modules/readerconfig.lua

@@ -13,6 +13,7 @@ local ReaderConfig = InputContainer:new{
 }
 
 function ReaderConfig:init()
+    if not self.dimen then self.dimen = Geom:new{} end
     if Device:hasKeyboard() then
         self.key_events = {
             ShowConfigMenu = { { "AA" }, doc = "show config dialog" },

frontend/ui/widget/container/inputcontainer.lua

@@ -48,13 +48,12 @@ function InputContainer:_init()
         end
     end
     self.ges_events = new_ges_events
-
-    if not self.dimen then
-        self.dimen = Geom:new{}
-    end
 end
 
 function InputContainer:paintTo(bb, x, y)
+    if not self.dimen then
+        self.dimen = self[1]:getSize()
+    end
     self.dimen.x = x
     self.dimen.y = y
     if self[1] then

frontend/ui/widget/container/widgetcontainer.lua

@@ -7,14 +7,13 @@ WidgetContainer is a container for another Widget
 local WidgetContainer = Widget:new()
 
 function WidgetContainer:init()
-    if not self.dimen then
-        self.dimen = Geom:new{}
-    end
-    if not self.dimen.w then
-        self.dimen.w = self[1].getSize().w
-    end
-    if not self.dimen.h then
-        self.dimen.h = self[1].getSize().h
+    if self.dimen then
+        if not self.dimen.w then
+            self.dimen.w = self[1].getSize().w
+        end
+        if not self.dimen.h then
+            self.dimen.h = self[1].getSize().h
+        end
     end
 end
 

frontend/ui/widget/touchmenu.lua

@@ -274,6 +274,7 @@ local TouchMenu = InputContainer:new{
 }
 
 function TouchMenu:init()
+    if not self.dimen then self.dimen = Geom:new{} end
     self.show_parent = self.show_parent or self
     if not self.close_callback then
         self.close_callback = function()

frontend/ui/widget/widget.lua

@@ -31,8 +31,8 @@ definition.
 --]]
 function Widget:new(o)
     o = self:extend(o)
-    -- Both o._init and o.init are called on object create. But o._init is used
-    -- for base widget initialization (basic component used to build other
+    -- Both o._init and o.init are called on object creation. But o._init is
+    -- used for base widget initialization (basic component used to build other
     -- widgets). While o.init is for higher level widgets, for example Menu
     -- Widget
     if o._init then o:_init() end