ArcGIS Engine Developer Guide

C++ APPLICATION PROGRAMMING INTERFACE
Setting the size of a control widget
If you would like to set your control widget to have a specific size, you will need
to do this after the widget itself is created. Do not use XmNheight and
XmNwidth in the XtVaCreateWidget section. Due to internal limitations, that
will cause undetermined behavior in the controls. Instead, set the size of your
widget after it is created with a call to XtVaSetValues. For example, to set the
above mapControl to be 200x200, add the line:
XtVaSetValues(mapWidget, XmNheight, 200, XmNwidth, 200, NULL);
after the call to XtVaCreateWidget.
GTK PROGRAMMING
Getting started with GTK programming
GIMP Toolkit (GTK) widget ArcGIS controls have been provided for C++
developers. To use them, you must understand some basics of GTK programming.
This is not by any means a complete resource; the variety of GTK widgets and
their resources, which you have available to you as a programmer, are not discussed
here. However, this should give you a place to start figuring out the GTKspecific
bits of the C++ API and samples.
Seven steps of GTK programming
When writing a GTK program, there are seven steps that need to be done.
1. Initialize GTK.
2. Create the widgets.
3. Place the widgets.
4. Implement event listening and callback functions for widgets.
5. Show the widgets.
6. Begin the event handling loop.
7. Shut down the application.
To illustrate each of these steps, you will create a simple GTK application.
GTK Program: Simple PushButton
This application will be a single button that displays which button on the mouse
was used to click on the button widget. Start a new file that will be your program.
Here that file will be called pbExample.cpp.
To use GTK you will need to include the GTK header file: gtk/gtk.h. For the
display of the number of the button clicked, you will need to include iostream.
You will also need a main function. Set these up in your new file, so that it looks
like this:
#include
#include
int main(int argc, char* argv[])
{
return 0;
}
Chapter 4 • Developer environments • 241