diff options
Diffstat (limited to 'src/corelib/kernel/qjniobject.cpp')
| -rw-r--r-- | src/corelib/kernel/qjniobject.cpp | 52 |
1 files changed, 33 insertions, 19 deletions
diff --git a/src/corelib/kernel/qjniobject.cpp b/src/corelib/kernel/qjniobject.cpp index 8244a4390f..d5b0cd5663 100644 --- a/src/corelib/kernel/qjniobject.cpp +++ b/src/corelib/kernel/qjniobject.cpp @@ -34,19 +34,10 @@ using namespace Qt::StringLiterals; \sa QJniEnvironment - \section1 General Notes - - \list - \li Class names need to be fully-qualified, for example: \c "java/lang/String". - \li Method signatures are written as \c "(ArgumentsTypes)ReturnType", see \l {JNI Types}. - \li All object types are returned as a QJniObject. - \endlist - \section1 Method Signatures QJniObject provides convenience functions that will use the correct signature based on the - provided template types. For functions that only return and take \l {JNI types}, the - signature can be generate at compile time: + provided or deduced template arguments. \code jint x = QJniObject::callMethod<jint>("getSize"); @@ -54,13 +45,11 @@ using namespace Qt::StringLiterals; jint ret = jString1.callMethod<jint>("compareToIgnoreCase", jString2.object<jstring>()); \endcode - These functions are variadic templates, and the compiler will deduce the template arguments - from the actual argument types. In many situations, only the return type needs to be provided - explicitly. - - For functions that take other argument types, you need to supply the signature yourself. It is - important that the signature matches the function you want to call. The example below - demonstrates how to call different static functions: + These functions are variadic templates, and the compiler will deduce the + signature from the actual argument types. Only the return type needs to be + provided explicitly. QJniObject can deduce the signature string for + functions that take \l {JNI types}, and for types that have been declared + with the QtJniTypes type mapping. \code // Java class @@ -73,6 +62,31 @@ using namespace Qt::StringLiterals; } \endcode + \code + // C++ code + Q_DECLARE_JNI_CLASS(TestClass, "org/qtproject/qt/TestClass") + + // ... + using namespace QtJniTypes; + TestClass testClass = TestClass::callStaticMethod<TestClass>("create"); + \endcode + + This allows working with arbitrary Java and Android types in C++ code, without having to + create JNI signature strings explicitly. + + \section2 Explicit JNI Signatures + + It is possible to supply the signature yourself. In that case, it is important + that the signature matches the function you want to call. + + \list + \li Class names need to be fully-qualified, for example: \c "java/lang/String". + \li Method signatures are written as \c "(ArgumentsTypes)ReturnType", see \l {JNI Types}. + \li All object types are returned as a QJniObject. + \endlist + + The example below demonstrates how to call different static functions: + The signature structure is \c "(ArgumentsTypes)ReturnType". Array types in the signature must have the \c {[} prefix, and the fully-qualified \c Object type names must have the \c L prefix and the \c ; suffix. The signature for the \c create function is @@ -105,9 +119,9 @@ using namespace Qt::StringLiterals; // C++ code QJniObject string1 = QJniObject::fromString("String1"); QJniObject string2 = QJniObject::fromString("String2"); - QJniObject stringArray = QJniObject::callStaticObjectMethod<jstringArray>( + QJniObject stringArray = QJniObject::callStaticObjectMethod<jobjectArray>( "org/qtproject/qt/TestClass", - "stringArray" + "stringArray", string1.object<jstring>(), string2.object<jstring>()); \endcode |