GTK+ Forums

flyjason · Familiar Face Joined: 04 Mar 2007 Posts: 19

Hi all,

I'm a novice in gtk+ programming; I should actually use it for doing a project. My project is based on ARToolKit which is a library for building Augmented Reality (AR) applications. In short, AR is the superimposition of virtual imagery on the real world. More information on ARToolKit can be found @ www.hitl.washington.edu/artoolkit/. So, I have to use GTK+ as interface tool and obviously integrate the interface with ARToolKit....something really unclear to me up till now :shock:. I'll be glad if somebody could comment on this as well.

Something I want to do is to display an image in a GtkImage widget after choosing which image to display via a combo box. For testing purposes, I've used a button (i.e. click on the button & display the image).

I'm trying the following code (on the button - onclick event), but it doesn't work :( :

Code: (Plaintext)
1 2 3	GtkWidget *img_objectdesign; img_objectdesign = gtk_image_new_from_file ("filename.jpg"); gtk_widget_show(img_objectdesign);

I use Glade to design the interface and I work on Windows.

Actually I obtained the following code on the web, so I modified it as above because on the interface window I put a GtkImage widget named as "img_objectdesign":

Code: (Plaintext)
1 2 3	GtkWidget *image; image = gtk_image_new_from_file ("filename.jpg"); gtk_widget_show(image);

I don't know if I'm doing the right thing or if something is missing, but one thing is for sure is that nothing's happening!! I click on the button and no image is displayed. :(

Can't understand something: I used Glade to make the interface, hence it generated some code automatically (creates callbacks.c, interface.c, etc). In Glade you can name your widgets. My question is that can you access a widget directly in your gtk+ code??

I mean can I put something like

Code: (Plaintext)
1	img_objectdesign = gtk_image_new_from_file ("filename.jpg");

directly (on a button event)?? ...and bearing to the fact that I named the GtkImage widget as "img_objectdesign" in Glade. But in doing so, I obtain compilation errors!! :(

So how do I use the widgets (name) directly in the gtk+ code??

I know I'm asking a lot of questions, but I hope you understand that I'm a beginner and many things are unclear to me unfortunately. :(
I don't even know if I'm formulating my questions well or if the questions are really questions? :?

Furthermore I'm really behind schedule in my project. Please help! :idea:

Micah Carrick · Posted: Tue Mar 06, 2007 9:09 pm Post subject:

flyjason · Familiar Face Joined: 04 Mar 2007 Posts: 19

Thank you for your help.

I'll post my application as it progresses.

In fact, the problem was how to reference widgets. I had a look at interface.c and saw the following line:

Code: (Plaintext)
1	/* Store pointers to all widgets, for use by lookup_widget(). */

So I pointed out that the lookup_widget() function was the key to access widgets.

So can I conclude that every widget is accessible via lookup_widget()??

I've used it but I don't really understand the parameter passing :(. I don't think I've mastered it and it would be nice if you could explain it to me and perhaps the concept of container as well. I feel it's important because of course I've got to have control over all the widgets.
:)