Programming with GTK v3

vmelkon · 11-14-2022, 02:24 PM

Is it possible to position controls, such as LABELS, EDITBOX, COMBOBOX, CHECKBOXES, BUTTONS manually?
Or must we use gtk_box_new() and gtk_box_pack_start()

Example:
This code just creates a window with a button on it.
The button is not visible because something is wrong.

I have similar code done in Qt.
Qt has functions to establish a parent------child relationship.
So, I can create a window
create a button
make the button a child of the window,
then I can change the position and size of the button and the coordinate is with respect to the {0,0} of the client area of the window.

Qt has some box and autopositioning functions. But it feels like I don’t have control and besides, sometimes, I want to do something custom.

Code:

static void OnActivate(GtkApplication *app)
{
	//Create a new window
	GtkWidget *pTheWindow=gtk_application_window_new(app);

	gtk_window_set_title(GTK_WINDOW(pTheWindow), "www.lucidarme.me");

	gtk_window_resize((GtkWindow *)pTheWindow, 500, 700);

	//Create a new button
	GtkWidget *button=gtk_button_new_with_label("Hello, World!");
	//When the button is clicked, close the window passed as an argument
	g_signal_connect_swapped(button, "clicked", G_CALLBACK(gtk_window_close), pTheWindow);

	//gtk_window_set_child(GTK_WINDOW(window), button);
	gtk_window_set_attached_to(GTK_WINDOW(button), pTheWindow);

	gtk_window_present(GTK_WINDOW(pTheWindow));

	gtk_window_move(GTK_WINDOW(pTheWindow), 10, 10);
	gtk_window_move(GTK_WINDOW(button), 10, 10);
	gtk_window_resize(GTK_WINDOW(button), 100, 22);


	//gtk_window_set_default_geometry(GtkWindow *window, gint width, gint height);
	//gtk_window_move(GtkWindow *window, gint x, gint y);
	//gtk_window_resize((GtkWindow *)pTheLabel, 100, 22);

}

int main(int argc, char *argv[])
{
	//Create a new application
	GtkApplication *app;
	int status;


	app=gtk_application_new("com.example.GtkApplication", G_APPLICATION_FLAGS_NONE);
	g_signal_connect(app, "activate", G_CALLBACK(OnActivate), NULL);
	status=g_application_run(G_APPLICATION(app), argc, argv);
	g_object_unref(app);

	return status;
}

EdGr · 11-14-2022, 03:00 PM

You have to pack the button into a container like GtkBox or GtkGrid. The container controls the positioning of its children.
Ed

vmelkon · 11-15-2022, 09:21 AM

Quote:

Originally Posted by EdGr

You have to pack the button into a container like GtkBox or GtkGrid. The container controls the positioning of its children.
Ed

Alright but it seems to have a mind of its own. I can’t scale and position my BUTTON?
What if I want a button that is 10 x 10 pixels?

Code:

static void OnActivate(GtkApplication *app)
{
	GtkWidget *vbox;

	//Create a new window
	GtkWidget *pTheWindow=gtk_application_window_new(app);

	gtk_window_set_title(GTK_WINDOW(pTheWindow), "www.lucidarme.me");

	gtk_window_resize((GtkWindow *)pTheWindow, 500, 700);

	//Create a new button
	GtkWidget *button=gtk_button_new_with_label("Hello, World!");
	//When the button is clicked, close the window passed as an argument
	g_signal_connect_swapped(button, "clicked", G_CALLBACK(gtk_window_close), pTheWindow);

	//I think this is part of GTK v4.0
	//gtk_window_set_child(GTK_WINDOW(window), button);

	//This does not work
	//gtk_window_set_attached_to(GTK_WINDOW(button), pTheWindow);

	vbox=gtk_box_new(GTK_ORIENTATION_VERTICAL, 10);
	//gtk_box_pack_start(GTK_BOX(vbox), label, 0, 0, 0);
	gtk_box_pack_start(GTK_BOX(vbox), button, 0, 0, 0);
	gtk_container_add(GTK_CONTAINER(pTheWindow), vbox);

	gtk_window_present(GTK_WINDOW(pTheWindow));
	gtk_widget_show_all(pTheWindow);

	gtk_window_move(GTK_WINDOW(pTheWindow), 10, 10);
	gtk_window_move(GTK_WINDOW(button), 10, 10);
	gtk_window_resize(GTK_WINDOW(button), 100, 22);


	//gtk_window_set_default_geometry(GtkWindow *window, gint width, gint height);
	//gtk_window_move(GtkWindow *window, gint x, gint y);
	//gtk_window_resize((GtkWindow *)pTheLabel, 100, 22);

}

EdGr · 11-15-2022, 10:08 AM

GTK determines the widget's size and position from the theme, font, DPI settings, etc. This is a nontrivial amount of logic.

The application can choose its own image sizes. GTK will adjust the layout to accommodate images.
Ed

teckk · 11-15-2022, 04:22 PM

Couple of examples from my snippets.

bclickgtk3.c

Code:

#include <gtk/gtk.h>

void button_clicked(GtkWidget *widget, gpointer data) {    
    g_print("clicked gtk3\n");
}

int main(int argc, char *argv[]) 
{
    GtkWidget *window;
    GtkWidget *halign;
    GtkWidget *btn;

    gtk_init(&argc, &argv);

    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title(GTK_WINDOW(window), "GtkButton");
    gtk_window_set_default_size(GTK_WINDOW(window), 300, 200);
    gtk_container_set_border_width(GTK_CONTAINER(window), 15);
    gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);

    btn = gtk_button_new_with_label("Click");
    gtk_widget_set_halign(btn, GTK_ALIGN_START);
    gtk_widget_set_valign(btn, GTK_ALIGN_START);
    gtk_widget_set_size_request(btn, 70, 30);
    
    gtk_container_add(GTK_CONTAINER(window), btn);

    g_signal_connect(G_OBJECT(btn), "clicked", G_CALLBACK(button_clicked), NULL);

    g_signal_connect(G_OBJECT(window), "destroy", G_CALLBACK(gtk_main_quit), NULL);

    gtk_widget_show_all(window);

    gtk_main();

    return 0;
}

//gcc bclickgtk3.c -o bclickgtk3 $(pkg-config --cflags --libs gtk+-3.0)

corner.c

Code:

#include <gtk/gtk.h>

int main(int argc, char *argv[]) 
{
    GtkWidget *window;
    GtkWidget *okBtn;
    GtkWidget *clsBtn;

    GtkWidget *vbox;
    GtkWidget *hbox;
    GtkWidget *halign;
    GtkWidget *valign;

    gtk_init(&argc, &argv);

    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
    gtk_window_set_default_size(GTK_WINDOW(window), 350, 200);
    gtk_window_set_title(GTK_WINDOW(window), "Corner buttons");
    gtk_container_set_border_width(GTK_CONTAINER(window), 10);

    vbox = gtk_vbox_new(FALSE, 5);

    valign = gtk_alignment_new(0, 1, 0, 0);
    gtk_container_add(GTK_CONTAINER(vbox), valign);
    gtk_container_add(GTK_CONTAINER(window), vbox);

    hbox = gtk_hbox_new(TRUE, 3);

    okBtn = gtk_button_new_with_label("OK");
    gtk_widget_set_size_request(okBtn, 70, 30);
    gtk_container_add(GTK_CONTAINER(hbox), okBtn);
    clsBtn = gtk_button_new_with_label("Close");
    gtk_container_add(GTK_CONTAINER(hbox), clsBtn);

    halign = gtk_alignment_new(1, 0, 0, 0);
    gtk_container_add(GTK_CONTAINER(halign), hbox);

    gtk_box_pack_start(GTK_BOX(vbox), halign, FALSE, FALSE, 0);

    g_signal_connect(G_OBJECT(window), "destroy",
        G_CALLBACK(gtk_main_quit), G_OBJECT(window));

    gtk_widget_show_all(window);

    gtk_main();

    return 0;
}

fixed.c

Code:

//Fixed Buttons

#include <gtk/gtk.h>

int main(int argc, char *argv[]) 
{    
    GtkWidget *window;
    GtkWidget *fixed;

    GtkWidget *btn1;
    GtkWidget *btn2;
    GtkWidget *btn3;
    GtkWidget *btn4;
    GtkWidget *btn5;

    gtk_init(&argc, &argv);

    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title(GTK_WINDOW(window), "GtkFixed");
    gtk_window_set_default_size(GTK_WINDOW(window), 400, 400);
    gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);

    fixed = gtk_fixed_new();
    gtk_container_add(GTK_CONTAINER(window), fixed);

    btn1 = gtk_button_new_with_label("Button1");
    gtk_fixed_put(GTK_FIXED(fixed), btn1, 15, 15);
    gtk_widget_set_size_request(btn1, 200, 30);

    btn2 = gtk_button_new_with_label("Button2");
    gtk_fixed_put(GTK_FIXED(fixed), btn2, 100, 60);
    gtk_widget_set_size_request(btn2, 80, 50);

    btn3 = gtk_button_new_with_label("Run");
    gtk_fixed_put(GTK_FIXED(fixed), btn3, 15, 180);
    gtk_widget_set_size_request(btn3, 40, 30);
    
    btn4 = gtk_button_new_with_label("Save");
    gtk_fixed_put(GTK_FIXED(fixed), btn4, 100, 180);
    gtk_widget_set_size_request(btn3, 80, 40);
    
    btn5 = gtk_button_new_with_label("Quit");
    gtk_fixed_put(GTK_FIXED(fixed), btn5, 195, 180);
    gtk_widget_set_size_request(btn3, 40, 60);

    g_signal_connect(G_OBJECT(window), "destroy", 
        G_CALLBACK(gtk_main_quit), NULL);

    gtk_widget_show_all(window);

    gtk_main();

    return 0;
}

//gcc fixed.c -o fixed $(pkg-config --cflags --libs gtk+-3.0)