[UX] Make the reader bottom menu compatible with key navigation (#3785)

* [toggleswitch] Add support for key navigation to this widget

Add the onFocus an onUnfocus event handler
add a new function that just circle the switch if not touch event is
detected

* Add key navigation to the readermenu

The shortcut is still Alt-gr on sdl, to be defined on Kindle

* Remove the old method of handling the Press key.

Now the event is handled by the main widget who implement focusmanager
and then dispatched to the currently focused item.
Modify the fine font tuning only for non touch-devices

See : https://github.com/koreader/koreader/pull/3785#issuecomment-375306466

plugins/coverbrowser.koplugin/covermenu.lua

@@ -1,5 +1,6 @@
 local Device = require("device")
 local DocumentRegistry = require("document/documentregistry")
+local Event = require("ui/event")
 local FileManagerBookInfo = require("apps/filemanager/filemanagerbookinfo")
 local ImageViewer = require("ui/widget/imageviewer")
 local Menu = require("ui/widget/menu")
@@ -93,7 +94,7 @@ function CoverMenu:updateItems(select_number)
             -- reset focus manager accordingly
             self.selected = { x = 1, y = select_number }
             -- set focus to requested menu item
-            self.item_group[select_number]:onFocus()
+            self:getFocusItem():handleEvent(Event:new("Focus"))
             -- This will not work with our MosaicMenu, as a MosaicMenuItem is
             -- not a direct child of item_group (which contains VerticalSpans
             -- and HorizontalGroup...)

plugins/coverbrowser.koplugin/listmenu.lua

@@ -146,11 +146,6 @@ function ListMenuItem:init()
             },
         }
     end
-    if Device:hasKeys() then
-        self.active_key_events = {
-            Select = { {"Press"}, doc = "chose selected item" },
-        }
-    end
 
     -- We now build the minimal widget container that won't change after udpate()
 
@@ -654,13 +649,11 @@ end
 -- As done in MenuItem
 function ListMenuItem:onFocus()
     self._underline_container.color = Blitbuffer.COLOR_BLACK
-    self.key_events = self.active_key_events
     return true
 end
 
 function ListMenuItem:onUnfocus()
     self._underline_container.color = Blitbuffer.COLOR_WHITE
-    self.key_events = {}
     return true
 end
 

plugins/coverbrowser.koplugin/mosaicmenu.lua

@@ -334,11 +334,6 @@ function MosaicMenuItem:init()
             },
         }
     end
-    if Device:hasKeys() then
-        self.active_key_events = {
-            Select = { {"Press"}, doc = "chose selected item" },
-        }
-    end
 
     -- We now build the minimal widget container that won't change after udpate()
 
@@ -642,13 +637,11 @@ end
 -- As done in MenuItem
 function MosaicMenuItem:onFocus()
     self._underline_container.color = Blitbuffer.COLOR_BLACK
-    self.key_events = self.active_key_events
     return true
 end
 
 function MosaicMenuItem:onUnfocus()
     self._underline_container.color = Blitbuffer.COLOR_WHITE
-    self.key_events = {}
     return true
 end