ArcGIS Engine Developer Guide

BUILDING APPLICATIONS WITH C++ AND CONTROL WIDGETS
Although it might look like a new instance of
AoInitialize is created, it is a singleton object, so
this returns a pointer to the same AoInitialize
object created before.
// Start the application running
XtRealizeWidget(topLevel);
}
9. In the previous step you set up a callback to listen for window manager protocols
to close on command. Now implement the callback for when the application
is closed.
a. First give a forward declaration of the function. This is placed right after
the declaration for XtResizeWidget at the top of MapViewer.h.
extern "C" void XtResizeWidget(Widget, _XtDimension,
_XtDimension, _XtDimension);
void CloseAppCallback(Widget w, XtPointer client_data,
XtPointer call_data);
b. Write the function in MapViewer.cpp after FormSetup. Shut down and
uninitialize the ArcGIS Engine Developer Kit, then exit.
// Function called when WM_DELETE_WINDOW protocol is passed
void CloseAppCallback(Widget w, XtPointer client_data,
XtPointer call_data)
{
// Uninitialize the engine
{
IAoInitializePtr ipInit(CLSID_AoInitialize);
ipInit->Shutdown();
}
::AoUninitialize();
AoExit(0);
}
10. A final ArcGIS Engine C++ API call is required to turn the application over
to the X Toolkit Intrinsics, which handles passing events to the widgets. After
this call, the application code sits idle and waits for user-generated events.
This will end your main function.
int main(int argc, char* argv[])
{
…
FormSetup(argc, arcv, &app_context);
The GTK equivalent is gtk_main.
// Start the application running
XtAppMainLoop(app_context);
}
11. Compile the application by typing “make –f Makefile.SolarisMotif ” at the
command line.
12. Run the application by typing either “make –f Makefile.SolarisMotif run” or
“./MapViewer” at the command line. You will see an empty form titled
MapViewer.
364 • ArcGIS Engine Developer Guide