Using the Qt SCXML Compiler (qscxmlc)
The qscxmlc
tool reads an .scxml file and produces C++ source and header files, containing a class that implements a state machine as defined in SCXML.
Usage
The qscxmlc
tool is invoked automatically if the project is linked against the scxml
library in the project file, and the .scxml
file to use is specified using the special build directives STATECHARTS
or qt6_add_statecharts.
When using cmake:
find_package(Qt6 COMPONENTS Scxml REQUIRED)
target_link_libraries(mytarget PRIVATE Qt6::Scxml)
qt6_add_statecharts(mytarget
MyStatemachine.scxml
)
When using qmake:
QT += scxml
STATECHARTS = MyStatemachine.scxml
With above definitions, qmake
or cmake
invokes qscxmlc
to generate MyStatemachine.h and MyStatemachine.cpp, and adds them appropriately to the project as headers and sources.
By default, the name of the generated class that implements the state machine corresponds with the name attribute of the <scxml>
root element.
Command-Line Options
The qscxmlc
tool supports the following command-line options, which can be specified using the QSCXMLC_ARGUMENTS
variable in the project file:
Option | Description |
---|---|
--namespace <namespace> | Put the generated class(es) in the specified namespace. You can use the QSCXMLC_NAMESPACE variable to specify this in your project file. |
-o <base/out/name> | The base name of the output files. This can include a path. If none is specified, the basename of the input file is used. |
--header <header/out> | The name of the output header file. If none is specified, .h is added to the base name. |
--impl <cpp/out> | The name of the output header file. If none is specified, .cpp is added to the base name. |
--classname <StateMachineClassName> | The class name of the generated state machine. If none is specified, the value of the name attribute of the <scxml> tag is taken. If that attribute is not specified either, the basename (excluding path) is taken from the input file name. |
--statemethods | Generate extra accessor and signal methods for states. This way you can connect to state changes with plain QObject::connect() and directly call a method to find out if a state is currently active. |