GTK gossip: gtkspinbutton

Gtkspinbutton is a component that allows the user to adjust the value. It has an up or down arrow and is pressed, you can set the upper and lower limits of the input values, the number of small numbers, and the value of increment by pressing the arrow, however, the actually token of the gtkspinbutton is derived from the gtkentry:

Gtkwidget


+ ---- Gtkentry


+ ---- Gtkspinbutton

You can use the gtk_spin_button_new () function to add a gtkspinbutton:

Gtkwidget * gtk_spin_button_new (

Gtkadjustment * adjustment, gdouble climb_rate, guint digits );

Climb_rate is the acceleration of changes in the numeric value when the value is set to press the hour, for a 0.0 to 1.0 setting, digits is a small number that sets the metric value. This function also requires a gtkadjustment, this object is used to control the threshold, upper and lower limit, and increment value of a number:

Gtkobject * gtk_adjustment_new (gdouble value, // Initial Value


Gdouble lower, // lower bound value


Gdouble upper, // upper bound value


Gdouble step_increment, // increment Value


Gdouble page_increment, // does not define the gtkspinbutton identifier


Gdouble page_size );
// Does not define the gtkspinbutton callback

Gtkadjustment can also be used in other Widgets. page_increment is the number of terminal increments when Pagedown and Pageup are pressed,
Page_size is the size that the component can display, but for gtkspinbutton, the parameter step_increment is intentionally defined.

You can also use
Gtk_spin_button_new_with_range (). You can directly specify the minimum value, maximum value, and increment value. This function automatically produces gtkadjustment:

Gtkwidget * gtk_spin_button_new_with_range (gdouble min,



Gdouble Max,



Gdouble step );

In
Gtkhbox
And gtkvbox


You have used gtkspinbutton.
The gtk_spin_button_new_with_range () function is used to create a gtkspinbutton. In this example, modify the example of the parameter to create a gtkadjustment and use it.
Create a gtk_spin_button_new () function:

• Gtk_spin_button_demo.c

#include <gtk/gtk.h>

void value_changed_callback(GtkSpinButton *spinButton, gpointer data) {
    gdouble value = gtk_spin_button_get_value(spinButton);
    GString *text = g_string_new("");
    g_string_sprintf(text, "%.2f", value);
    gtk_label_set_text(GTK_LABEL(data), text->str);
}

int main(int argc, char *argv[]) {
    GtkWidget *window;
    GtkWidget *spinButton;
    GtkObject *adjustment;
    GtkWidget *label;
    GtkWidget *hbox;

    gtk_init(&argc, &argv);

    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title(GTK_WINDOW(window), "GtkSpinButton");
    gtk_window_set_default_size(GTK_WINDOW(window), 250, 50);

    adjustment = gtk_adjustment_new(0.0, 0.0, 100.0, 0.05, 0.0, 0.0);
    spinButton = gtk_spin_button_new(GTK_ADJUSTMENT(adjustment), 0.01, 2);
    label = gtk_label_new("0.00");
    hbox = gtk_hbox_new(TRUE, 5);

    gtk_box_pack_start(GTK_BOX(hbox), spinButton, TRUE, TRUE, 5);
    gtk_box_pack_start(GTK_BOX(hbox), label, TRUE, TRUE, 5);
    gtk_container_add(GTK_CONTAINER(window), hbox);

    g_signal_connect(GTK_OBJECT(spinButton), "value_changed",
                     G_CALLBACK(value_changed_callback), label);
    g_signal_connect(GTK_OBJECT(window), "destroy",
                     G_CALLBACK(gtk_main_quit), NULL);

    gtk_widget_show_all(window);

    gtk_main();

    return 0;
}

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