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         new_annotation app_files
  23 end
  24
  25 # App subclasses are cross-platform applications
  26 #
  27 # This class is refined by platform modules and so
  28 # App can be specialized directly in the user application code.
  29 class App
  30         super AppComponent
  31
  32         protected init do end
  33
  34         # Starts the internal setup of graphical and other stuff
  35         # Is called just before run
  36         fun setup do end
  37
  38         # Main entry point of your application
  39         fun run do end
  40 end
  41
  42 # An element of an application that is notified of the application life cycle
  43 #
  44 # Most users of _app.nit_ need only to implement `on_create` to setup the application.
  45 #
  46 # On mobile devices, the application can be stopped a anytime when another application takes the foreground.
  47 # Implement the callbacks `on_save_state` and `on_load_state` to keep the state of the application between execution,
  48 # for an illusion of continuous execution.
  49 abstract class AppComponent
  50
  51         # The application is being created
  52         #
  53         # You should build the UI at this time.
  54         fun on_create do end
  55
  56         # The application is starting or restarting, it is visible to the user
  57         fun on_start do end
  58
  59         # The application enters the active state, it is in the foreground and interactive
  60         fun on_resume do end
  61
  62         # The application leaves the active state but is still partially visible
  63         #
  64         # It may still be visible in the background.
  65         # It may then go back to `on_resume` or `on_stop`.
  66         fun on_pause do end
  67
  68         # The application is completely hidden from the user
  69         #
  70         # It may then be destroyed (`on_destroy`) or go back to `on_start`.
  71         fun on_stop do end
  72
  73         # The application is being destroyed
  74         fun on_destroy do end
  75
  76         # The application may be destroyed soon, save its state for a future `on_restore_state`
  77         fun on_save_state do end
  78
  79         # The application is launching, restore its state from a previous `on_save_state`
  80         fun on_restore_state do end
  81 end
  82
  83 # Print a warning
  84 fun print_warning(object: Object)
  85 do
  86         sys.stderr.write object.to_s
  87         sys.stderr.write "\n"
  88 end
  89
  90 # The running `App`
  91 fun app: App do return once new App
  92
  93 app.setup
  94 app.run