Writing a Widget Using Cairo and GNU Smalltalk

Cairo is a powerful 2-dimensional graphics library designed to support a number of modern graphics techniques
including stroking, alpha blending and anti-aliasing. It supports multiple output formats, which allows
developers to use the same code to display graphics on the screen, print them to the printer or accelerate
them with OpenGL.

Here is a screenshot of a cairo clock :

After I got now through the creation of combo-boxes, I just want today explain the creation-process.

After I had some issues with the planned subject of the next guide, I switched - for an example - to glade and would like to show, how you can do RAD with glade and gnu-smalltalk. It's really easy and fast, and you won't blow up your source-code with the complete gui-creation stuff. As an example I picked a password-generator, because I frequently have to set passwords for different user etc. in the company I work for.

The thing I want to show today, is enhancing the little application with a toolbar, so let's dig into this...

(Most of the applications which have menus, also have a toolbar. And it is realy easy to set up.)

The nice thing, all toolbar entries should be connected to an existing callback-method in our application, which is reachable already by an menu-entry. A toolbar is only a shortcut to an entry in the menu. So, we only have to design the user-interface, no additional business-logic is needed.

Hello,

I took a look into the standard dialogs and the first I tried out was the AboutDialog. It's pretty easy to handle, all you have to do is to instantiate GTK.GtkAboutDialog and set several values for displaying, call run and destroy and that's all.

Let's enhance our about-method with an example: