It relies on the following sequence of events, represented here by their callback method name:
1. `on_create`: The application is being created.
- You should build the UI at this time.
+ You should build the UI at this time and launch services.
-2. `on_start`: The app is starting or restarting, background activities may
+2. `on_resume`: The app enters the active state, it is in the foreground and interactive.
-3. `on_resume`: The app enters the active state, it is in the foreground.
-
-4. `on_pause`: The app leaves the active state and the foreground.
+3. `on_pause`: The app becomes inactive and it leaves the foreground.
It may still be visible in the background.
- It may then go back to `on_resume` or `on_stop`.
-5. `on_stop`: The app is completely hidden.
- It may then be destroyed (`on_destroy`) or go back to `on_start`.
+4. `on_stop`: The app is completely hidden.
+ It may then be destroyed (without warning) or go back to the active state with `on_restart`.
+
+5. `on_restart`: The app goes back to the inactive state.
+ You can revert what was done by `on_stop`.
-6. `on_destroy`: The app is being destroyed.
+![_app.nit_ life-cycle](doc/app-nit-lifecycle.png)
Life-cycle events related to saving and restoring the application state are provided by two special callback methods:
* `on_save_state`: The app may be destroyed soon, save its state for a future `on_restore_state`.
- More on how it can be done in the `app::data_store` section.
+ There is more on how it can be done in the `app::data_store` section.
* `on_restore_state`: The app is launching, restore its state from a previous `on_save_state`.
## Usage Example
-~~~
+~~~nitish
module my_module is
app_name "My App"
app_namespace "org.example.my_app"
* The mixin option (`-m module`) imports an additional module before compiling.
It can be used to load platform specific implementations of the _app.nit_ portable UI.
- ~~~
+ ~~~raw
# GNU/Linux version, using GTK
nitc calculator.nit -m linux
Continuing with the calculator example, it is adapted for Android by the module `android_calculator.nit`.
This module imports both `calculator` and `android`, it can then use Android specific code.
- ~~~
+ ~~~nitish
module android_calculator
import calculator