What can do

This is a library for easily calling Android methods in Qt.

To display a Toast in traditional Qt, you need the following code:

QJniObject javaString = QJniObject::fromString("Message");
QJniObject toast = QJniObject::callStaticObjectMethod("android/widget/Toast", "makeText",
                                                      "(Landroid/content/Context;Ljava/lang/CharSequence;I)Landroid/widget/Toast;",
                                                      QNativeInterface::QAndroidApplication::context().object(),
                                                      javaString.object(),
                                                      jint(0));
toast.callMethod<void>("show");

When using this library, just:

#define QT_ANDROID_API_AUTOUSE
#include <AndroidContext>
#include <android/widget/Toast>
auto toast = Toast::makeText(CONTEXT, QStringLiteral("Message"), 0);
toast.show();

How to use

Add the following to your CMake:

include(FetchContent)
FetchContent_Declare(androidapi
    GIT_REPOSITORY https://github.com/YJBeetle/QtAndroidAPI.git
    GIT_TAG origin/Qt6
    SOURCE_SUBDIR android-31
)
FetchContent_MakeAvailable(androidapi)

And add the link library after your target

target_link_libraries(${PROJECT_NAME} PRIVATE QtAndroidAPI)

Convenient Type Conversions

This library provides seamless implicit and explicit conversions between Qt data types and Java JNI types:

• String: QString $\leftrightarrow$ JString (Implicit conversion supported, or via .toString())
• Byte Array: QByteArray $\leftrightarrow$ JByteArray (Implicit conversion supported, or via .toByteArray())
• String List: QStringList $\leftrightarrow$ JObjectArray (Implicit conversion supported, or via .toStringList())
• Integer List: QList<int> $\leftrightarrow$ JIntArray (Implicit conversion supported, or via .toQList())
• Type Downcasting: Easily cast base objects to derived classes via obj.as<T>() (e.g. CONTEXT.as<Activity>()).

// String & ByteArray
QString msg = "Hello Qt";
Toast::makeText(CONTEXT, msg, 0).show(); // Auto converts to JString

QByteArray data = "binary data";
JByteArray jBytes = data;     // Auto converts to JByteArray
QByteArray recvData = jBytes; // Auto converts back to QByteArray

// Permissions / String Array
QStringList permissions = {"android.permission.CAMERA", "android.permission.READ_EXTERNAL_STORAGE"};
JObjectArray jPermissions = permissions; // Auto converts to Java String[]

// Downcasting
auto activity = CONTEXT.as<android::app::Activity>();