lib/app/app_base.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Copyright 2011-2014 Alexis Laferrière <alexis.laf@xymus.net>
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 # Base of the _app.nit_ framework, defines `App`
  18 module app_base is
  19         new_annotation app_name
  20         new_annotation app_namespace
  21         new_annotation app_version
  22 end
  23
  24 # App subclasses are cross-platform applications
  25 #
  26 # This class is refined by platform modules and so
  27 # App can be specialized directly in the user application code.
  28 class App
  29         super AppComponent
  30
  31         protected init do end
  32
  33         # Starts the internal setup of graphical and other stuff
  34         # Is called just before run
  35         fun setup do end
  36
  37         # Main entry point of your application
  38         fun run do end
  39 end
  40
  41 # An element of an application that is notified of the application life cycle
  42 #
  43 # Most users of _app.nit_ need only to implement `on_create` to setup the application.
  44 #
  45 # On mobile devices, the application can be stopped a anytime when another application takes the foreground.
  46 # Implement the callbacks `on_save_state` and `on_load_state` to keep the state of the application between execution,
  47 # for an illusion of continuous execution.
  48 abstract class AppComponent
  49
  50         # The application is being created
  51         #
  52         # You should build the UI at this time.
  53         fun on_create do end
  54
  55         # The application is starting or restarting, it is visible to the user
  56         fun on_start do end
  57
  58         # The application enters the active state, it is in the foreground and interactive
  59         fun on_resume do end
  60
  61         # The application leaves the active state but is still partially visible
  62         #
  63         # It may still be visible in the background.
  64         # It may then go back to `on_resume` or `on_stop`.
  65         fun on_pause do end
  66
  67         # The application is completely hidden from the user
  68         #
  69         # It may then be destroyed (`on_destroy`) or go back to `on_start`.
  70         fun on_stop do end
  71
  72         # The application is being destroyed
  73         fun on_destroy do end
  74
  75         # The application may be destroyed soon, save its state for a future `on_restore_state`
  76         fun on_save_state do end
  77
  78         # The application is launching, restore its state from a previous `on_save_state`
  79         fun on_restore_state do end
  80 end
  81
  82 # Print a warning
  83 fun print_warning(object: Object)
  84 do
  85         sys.stderr.write object.to_s
  86         sys.stderr.write "\n"
  87 end
  88
  89 # The running `App`
  90 fun app: App do return once new App
  91
  92 app.setup
  93 app.run