Optimize default drawer scripts

main/calendar-menu.lua

@@ -21,6 +21,10 @@ function on_drawer_open()
 
     have_permission = true
 
+    if #events == #drawer:items() then
+        return
+    end
+
     lines = map(events, function(it)
         local date = fmt.colored(os.date("%d.%m", it.begin), it.color)
         return date..fmt.space(4)..it.title

main/contacts-menu.lua

@@ -22,6 +22,10 @@ function on_drawer_open()
         sort_by_name(phone:contacts())
     )
 
+    if #contacts == #drawer:items() then
+        return
+    end
+
     names = map(contacts, function(it) return it.name end)
     keys = map(contacts, function(it) return it.lookup_key end)
 

samples/apps-menu.lua

@@ -0,0 +1,26 @@
+-- name = "Apps menu"
+-- type = "drawer"
+-- testing = "true"
+
+function on_drawer_open()
+    apps_tab = apps:list()
+    debug:toast("called")
+
+    -- Do not update if the list of the apps is not changed
+    if #apps_tab ~= #drawer:items() then
+        update()
+    end
+end
+
+function update()
+    names_tab = map(function(it) return apps:name(it) end, apps_tab)
+    apps:request_icons(apps_tab)
+end
+
+function on_icons_ready(icons_tab)
+    drawer:show_list(names_tab, icons_tab, nil, true)
+end
+
+function on_click(idx)
+    apps:launch(apps_tab[idx])
+end