lib/android/nit_activity.nit

   1 # This file is part of NIT (http://www.nitlanguage.org).
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #     http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 # See the License for the specific language governing permissions and
  13 # limitations under the License.
  14
  15 # Some documentation of this module has been adapted from the
  16 # Android Open Source Project.
  17
  18 # Core implementation of `app.nit` on Android using a custom Java entry point
  19 #
  20 # This module is implemented in 3 languages:
  21 #
  22 # * The Java code, in `NitActivity.java` acts as the entry point registered
  23 #   to the Android OS. It relays most of the Android callbacks to C.
  24 #   In theory, there may be more than one instance of `NitActivity` alive at
  25 #   a given time. They hold a reference to the corresponding Nit `Activity`
  26 #   in the attribute `nitActivity`.
  27 #
  28 # * The C code is defined in the top part of this source file. It acts as a
  29 #   glue between Java and Nit by relaying calls between both languages.
  30 #   It keeps a global variables reference to the Java VM and the Nit `App`.
  31 #
  32 # * The Nit code defines the `Activity` class with the callbacks from Android.
  33 #   The callback methods should be redefined by user modules.
  34 #
  35 # The main is invoked when the native library is dynamically linked by
  36 # the Java virtual machine. For this reason, the main _must_ execute quickly,
  37 # on the main UI thread at least.
  38 module nit_activity is
  39         extra_java_files "NitActivity.java"
  40         android_activity "nit.app.NitActivity"
  41 end
  42
  43 import platform
  44 import log
  45 import activities
  46 import key_event
  47 import bundle
  48 import dalvik
  49
  50 in "C body" `{
  51
  52         #include <jni.h>
  53         #include <android/log.h>
  54
  55         // Nit's App running instance
  56         App global_app;
  57
  58         // Java VM that launched this program
  59         JavaVM *global_jvm;
  60
  61         // JNI callback on loading this program
  62         jint JNI_OnLoad(JavaVM *vm, void *reserved) {
  63                 // Set aside the Java VM
  64                 global_jvm = vm;
  65
  66                 // Invoke Nit system and main
  67                 main(0, NULL);
  68
  69                 return JNI_VERSION_1_2;
  70         }
  71
  72         /*
  73          * Implementations of NitActivity.java native methods
  74          */
  75
  76         JNIEXPORT jint JNICALL Java_nit_app_NitActivity_nitRegisterActivity
  77           (JNIEnv *env, jobject java_activity)
  78         {
  79                 Activity nit_activity = App_register_activity(global_app, java_activity);
  80                 Activity_incr_ref(nit_activity);
  81                 return (jint)(void*)nit_activity;
  82         }
  83
  84         JNIEXPORT void JNICALL Java_nit_app_NitActivity_nitOnCreate
  85           (JNIEnv *env, jobject java_activity, jint nit_activity, jobject saved_state)
  86         {
  87                 Activity_on_create((Activity)nit_activity, saved_state);
  88         }
  89
  90         JNIEXPORT void JNICALL Java_nit_app_NitActivity_nitOnStart
  91           (JNIEnv *env, jobject java_activity, jint nit_activity)
  92         {
  93                 Activity_on_start((Activity)nit_activity);
  94         }
  95
  96         JNIEXPORT void JNICALL Java_nit_app_NitActivity_nitOnRestart
  97           (JNIEnv *env, jobject java_activity, jint nit_activity)
  98         {
  99                 Activity_on_restart((Activity)nit_activity);
 100         }
 101
 102         JNIEXPORT void JNICALL Java_nit_app_NitActivity_nitOnResume
 103           (JNIEnv *env, jobject java_activity, jint nit_activity)
 104         {
 105                 Activity_on_resume((Activity)nit_activity);
 106         }
 107
 108         JNIEXPORT void JNICALL Java_nit_app_NitActivity_nitOnPause
 109           (JNIEnv *env, jobject java_activity, jint nit_activity)
 110         {
 111                 Activity_on_pause((Activity)nit_activity);
 112         }
 113
 114         JNIEXPORT void JNICALL Java_nit_app_NitActivity_nitOnStop
 115           (JNIEnv *env, jobject java_activity, jint nit_activity)
 116         {
 117                 Activity_on_stop((Activity)nit_activity);
 118         }
 119
 120         JNIEXPORT void JNICALL Java_nit_app_NitActivity_nitOnDestroy
 121           (JNIEnv *env, jobject java_activity, jint nit_activity)
 122         {
 123                 Activity_on_destroy((Activity)nit_activity);
 124         }
 125
 126         JNIEXPORT void JNICALL Java_nit_app_NitActivity_nitOnSaveInstanceState
 127           (JNIEnv *env, jobject java_activity, jint nit_activity, jobject saved_state)
 128         {
 129                 Activity_on_save_instance_state((Activity)nit_activity, saved_state);
 130         }
 131
 132         JNIEXPORT void JNICALL Java_nit_app_NitActivity_nitOnRestoreInstanceState
 133           (JNIEnv *env, jobject java_activity, jint nit_activity, jobject saved_state)
 134         {
 135                 Activity_on_restore_instance_state((Activity)nit_activity, saved_state);
 136         }
 137
 138         JNIEXPORT jboolean JNICALL Java_nit_app_NitActivity_nitOnBackPressed
 139           (JNIEnv *env, jobject java_activity, jint nit_activity)
 140         {
 141                 return (jboolean)Activity_on_back_pressed((Activity)nit_activity);
 142         }
 143
 144         JNIEXPORT jboolean JNICALL Java_nit_app_NitActivity_nitOnKeyDown
 145           (JNIEnv *env, jobject java_activity, jint nit_activity, jint keyCode, jobject event)
 146         {
 147                 return (jboolean)Activity_on_key_down((Activity)nit_activity, keyCode, event);
 148         }
 149
 150         JNIEXPORT jboolean JNICALL Java_nit_app_NitActivity_nitOnKeyLongPress
 151           (JNIEnv *env, jobject java_activity, jint nit_activity, jint keyCode, jobject event)
 152         {
 153                 return (jboolean)Activity_on_key_long_press((Activity)nit_activity, keyCode, event);
 154         }
 155
 156         JNIEXPORT jboolean JNICALL Java_nit_app_NitActivity_nitOnKeyMultiple
 157           (JNIEnv *env, jobject java_activity, jint nit_activity, jint keyCode, jint count, jobject event)
 158         {
 159                 return (jboolean)Activity_on_key_multiple((Activity)nit_activity, keyCode, count, event);
 160         }
 161
 162         JNIEXPORT jboolean JNICALL Java_nit_app_NitActivity_nitOnKeyUp
 163           (JNIEnv *env, jobject java_activity, jint nit_activity, jint keyCode, jobject event)
 164         {
 165                 return (jboolean)Activity_on_key_up((Activity)nit_activity, keyCode, event);
 166         }
 167 `}
 168
 169 # Wrapper to our Java `NitActivity`
 170 extern class NativeNitActivity in "Java" `{ nit.app.NitActivity `}
 171         super NativeActivity
 172 end
 173
 174 redef class Sys
 175         redef fun jvm `{ return global_jvm; `}
 176 end
 177
 178 redef class App
 179         # Known activities
 180         var activities = new Array[Activity]
 181
 182         # The main Java Activity of this application
 183         redef fun native_activity do return activities.first.native
 184
 185         redef fun setup do set_global_app
 186
 187         # Register app in C
 188         private fun set_global_app import register_activity,
 189         Activity.on_create, Activity.on_destroy,
 190         Activity.on_start, Activity.on_restart, Activity.on_stop,
 191         Activity.on_pause, Activity.on_resume,
 192         Activity.on_save_instance_state, Activity.on_restore_instance_state,
 193         Activity.on_back_pressed,
 194         Activity.on_key_down, Activity.on_key_long_press,
 195         Activity.on_key_multiple, Activity.on_key_up `{
 196                 App_incr_ref(self);
 197                 global_app = self;
 198         `}
 199
 200         # Create the Nit side to this new `native` Java activity, and return it to Java
 201         private fun register_activity(native: NativeNitActivity): Activity
 202         do
 203                 native = native.new_global_ref
 204                 var activity = new Activity(native)
 205                 activities.add activity
 206                 return activity
 207         end
 208 end
 209
 210 # An Android activity
 211 #
 212 # You must implement the callbacks (prefixed with `on_`) to follow the
 213 # standard Android life-cycle.
 214 class Activity
 215         # Native Java activity
 216         var native: NativeActivity
 217
 218         # Notification from Android, the activity is created
 219         #
 220         # Do your normal static set up here.
 221         #
 222         # If available, `save_state` contains the activity's previous state
 223         # as registered by `on_save_instance_state`.
 224         #
 225         # Followed by `on_start`.
 226         fun on_create(save_state: NativeBundle)
 227         do
 228                 app.on_create
 229                 app.on_restore_state
 230         end
 231
 232         # Notification from Android, the activity has been restarted
 233         #
 234         # Followed by `on_start`.
 235         fun on_restart do end
 236
 237         # Notification from Android, the activity has been started
 238         #
 239         # Followed by `on_resume` or `on_stop`.
 240         fun on_start do app.on_start
 241
 242         # Notification from Android, the activity has been resumed
 243         #
 244         # Followed by `on_pause`
 245         fun on_resume do app.on_resume
 246
 247         # Notification from Android, the activity has been paused
 248         #
 249         # Followed by `on_resume` or `on_stop`.
 250         fun on_pause do app.on_pause
 251
 252         # Notification from Android, the activity has been stopped
 253         #
 254         # Followed by `on_restart` or `on_destroy`.
 255         fun on_stop do app.on_stop
 256
 257         # Notification from Android, the activity is being destroyed
 258         #
 259         # Clean up and exit.
 260         fun on_destroy
 261         do
 262                 app.on_destroy
 263
 264                 native.delete_global_ref
 265                 app.activities.remove self
 266         end
 267
 268         # Notification from Android, the activity is being re-initialized from a `save_state`
 269         #
 270         # Occurs after `on_start`.
 271         fun on_restore_instance_state(save_state: NativeBundle) do end
 272
 273         # Notification from Android, the activity may be stopped, save state
 274         #
 275         # Occurs before `on_stop` and, without guarantee, before or after `on_pause`.
 276         fun on_save_instance_state(save_state: NativeBundle) do app.on_save_state
 277
 278         # Notification from Android, the system is running low on memory
 279         #
 280         # Try to reduce your memory use.
 281         fun on_low_memory do end
 282
 283         # Notification from Android, the current window of the activity has lost or gained focus
 284         fun on_window_focus_changed(has_focus: Bool) do end
 285
 286         # Notification from Android, the current device configuration has changed
 287         fun on_configuration_changed do end
 288
 289         # The back key has been pressed
 290         #
 291         # Return `true` if the event has been handled.
 292         fun on_back_pressed: Bool do return false
 293
 294         # A key has been pressed
 295         #
 296         # Return `true` if the event has been handled.
 297         fun on_key_down(key_code: Int, event: NativeKeyEvent): Bool do return false
 298
 299         # A key has been long pressed
 300         #
 301         # Return `true` if the event has been handled.
 302         fun on_key_long_press(key_code: Int, event: NativeKeyEvent): Bool do return false
 303
 304         # Multiple down/up pairs of the same key have occurred in a row
 305         #
 306         # Return `true` if the event has been handled.
 307         fun on_key_multiple(key_code, count: Int, event: NativeKeyEvent): Bool do return false
 308
 309         # A key has been released
 310         #
 311         # Return `true` if the event has been handled.
 312         fun on_key_up(key_code: Int, event: NativeKeyEvent): Bool do return false
 313 end
 314
 315 # Set up global data in C and leave it to Android to callback Java, which we relay to Nit
 316 app.setup