Android

Android TutorialAdding a FuseView to an Android ProjectAndroid 9-Patch ImagesAndroid Accessing SQLite databases using the ContentValues classAndroid Accounts and AccountManagerAndroid ACRAAndroid ActivityAndroid Activity RecognitionAndroid adb (Android Debug Bridge)Android adb shellAndroid AdMobAndroid AIDLAndroid AlarmManagerAndroid Android-x86 in VirtualBoxAndroid Animated AlertDialog BoxAndroid AnimatorsAndroid Annotation ProcessorAndroid Architecture ComponentsAndroid AsyncTaskAndroid AudioManagerAndroid AudioTrackAndroid AuthenticatorAndroid AutoCompleteTextViewAndroid Autosizing TextViewsAndroid Barcode and QR code readingAndroid Bitmap CacheAndroid Bluetooth and Bluetooth LE APIAndroid Bluetooth Low EnergyAndroid Bottom SheetsAndroid BottomNavigationViewAndroid BroadcastReceiverAndroid Building Backwards Compatible AppsAndroid ButterKnifeAndroid ButtonAndroid Callback URLAndroid Camera 2 APIAndroid Camera and GalleryAndroid Canvas drawing using SurfaceViewAndroid Capturing ScreenshotsAndroid CardViewAndroid Check Data ConnectionAndroid Check Internet ConnectivityAndroid CleverTapAndroid ColorsAndroid ConstraintLayoutAndroid ConstraintSetAndroid ContentProviderAndroid ContextAndroid CoordinatorLayout and BehaviorsAndroid Count Down TimerAndroid Crash Reporting ToolsAndroid Create Singleton Class for Toast MessageAndroid Creating Custom ViewsAndroid Creating Overlay (always-on-top) WindowsAndroid Creating Splash screenAndroid Custom FontsAndroid Dagger 2Android Data Binding LibraryAndroid Data Encryption/DecryptionAndroid Data Synchronization with Sync AdapterAndroid Date and Time PickersAndroid DayNight Theme (AppCompat v23.2 / API 14+)Android Define step value (increment) for custom RangeSeekBarAndroid Design PatternsAndroid Device Display MetricsAndroid DialogAndroid Displaying Google AdsAndroid Doze ModeAndroid DrawablesAndroid EditTextAndroid Email ValidationAndroid EmulatorAndroid Enhancing Alert DialogsAndroid ExceptionsAndroid ExoPlayerAndroid FastjsonAndroid fastlaneAndroid FileProviderAndroid FirebaseAndroid Firebase App IndexingAndroid Firebase Cloud MessagingAndroid Firebase Crash ReportingAndroid Firebase Realtime DataBaseAndroid FloatingActionButtonAndroid Formatting phone numbers with pattern.Android Formatting StringsAndroid FragmentsAndroid FrescoAndroid game developmentAndroid Gesture Detection



Android NDK

From WikiOD

How to log in ndk[edit | edit source]

First make sure you link against the logging library in your Android.mk file:

LOCAL_LDLIBS := -llog

Then use one of the following __android_log_print() calls:

#include <android/log.h>    
#define TAG "MY LOG"

__android_log_print(ANDROID_LOG_VERBOSE,    TAG, "The value of 1 + 1 is %d", 1 + 1)
__android_log_print(ANDROID_LOG_WARN,       TAG, "The value of 1 + 1 is %d", 1 + 1)
__android_log_print(ANDROID_LOG_DEBUG,      TAG, "The value of 1 + 1 is %d", 1 + 1)
__android_log_print(ANDROID_LOG_INFO,       TAG, "The value of 1 + 1 is %d", 1 + 1)
__android_log_print(ANDROID_LOG_ERROR,      TAG, "The value of 1 + 1 is %d", 1 + 1)

Or use those in a more convenient way by defining corresponding macros:

#define  LOGV(...)  __android_log_print(ANDROID_LOG_VERBOSE,    TAG, __VA_ARGS__)
#define  LOGW(...)  __android_log_print(ANDROID_LOG_WARN,       TAG, __VA_ARGS__)
#define  LOGD(...)  __android_log_print(ANDROID_LOG_DEBUG,      TAG, __VA_ARGS__)
#define  LOGI(...)  __android_log_print(ANDROID_LOG_INFO,       TAG, __VA_ARGS__)
#define  LOGE(...)  __android_log_print(ANDROID_LOG_ERROR,      TAG, __VA_ARGS__)

Example:

int x = 42;
LOGD("The value of x is %d", x);

Building native executables for Android[edit | edit source]

project/jni/main.c

#include <stdio.h>
#include <unistd.h>

int main(void) {
  printf("Hello world!\n");
  return 0;
}

project/jni/Android.mk

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE    := hello_world
LOCAL_SRC_FILES := main.c
include $(BUILD_EXECUTABLE)

project/jni/Application.mk

APP_ABI := all
APP_PLATFORM := android-21

If you want to support devices running Android versions lower than 5.0 (API 21), you need to compile your binary with APP_PLATFORM set to an older API, e.g. android-8. This is a consequence of Android 5.0 enforcing Position Independent Binaries (PIE), whereas older devices do not necessarily support PIEs. Therefore, you need to use either the PIE or the non-PIE, depending on the device version. If you want to use the binary from within your Android application, you need to check the API level and extract the correct binary.

APP_ABI can be changed to specific platforms such as armeabi to build the binary for those architectures only.

In the worst case, you will have both a PIE and a non-PIE binary for each architecture (about 14 different binaries using ndk-r10e).

To build the executable:

cd project
ndk-build

You will find the binaries at project/libs/<architecture>/hello_world. You can use them via ADB (push and chmod it with executable permission) or from your application (extract and chmod it with executable permission).

To determine the architecture of the CPU, retrieve the build property ro.product.cpu.abi for the primary architecture or ro.product.cpu.abilist (on newer devices) for a complete list of supported architectures. You can do this using the android.os.Build class from within your application or using getprop <name> via ADB.

How to clean the build[edit | edit source]

If you need to clean the build:

ndk*build clean

How to use a makefile other than Android.mk[edit | edit source]

ndk*build NDK_PROJECT_PATH=PROJECT_PATH APP_BUILD_SCRIPT=MyAndroid.mk

Credit:Stack_Overflow_Documentation