gtk/demos/gtk-demo/spinbutton.c

/* Spin Button
 *
 * GtkSpinButton provides convenient ways to input data
 * that can be seen as a value in a range. The examples
 * here show that this does not necessarily mean numeric
 * values, and it can include custom formatting.
 */

#include <glib/gi18n.h>
#include <gtk/gtk.h>
#include <math.h>
#include <stdlib.h>

static gint
hex_spin_input (GtkSpinButton *spin_button,
                gdouble       *new_val)
{
  const gchar *buf;
  gchar *err;
  gdouble res;

  buf = gtk_spin_button_get_text (spin_button);
  res = strtol (buf, &err, 16);
  *new_val = res;
  if (*err)
    return GTK_INPUT_ERROR;
  else
    return TRUE;
}

static gint
hex_spin_output (GtkSpinButton *spin_button)
{
  GtkAdjustment *adjustment;
  gchar *buf;
  gint val;

  adjustment = gtk_spin_button_get_adjustment (spin_button);
  val = (gint) gtk_adjustment_get_value (adjustment);
  if (fabs (val) < 1e-5)
    buf = g_strdup ("0x00");
  else
    buf = g_strdup_printf ("0x%.2X", val);
  if (strcmp (buf, gtk_spin_button_get_text (spin_button)))
    gtk_spin_button_set_text (spin_button, buf);
  g_free (buf);

  return TRUE;
}

static gint
time_spin_input (GtkSpinButton *spin_button,
                 gdouble       *new_val)
{
  const gchar *text;
  gchar **str;
  gboolean found = FALSE;
  gint hours;
  gint minutes;
  gchar *endh;
  gchar *endm;

  text = gtk_spin_button_get_text (spin_button);
  str = g_strsplit (text, ":", 2);

  if (g_strv_length (str) == 2)
    {
      hours = strtol (str[0], &endh, 10);
      minutes = strtol (str[1], &endm, 10);
      if (!*endh && !*endm &&
          0 <= hours && hours < 24 &&
          0 <= minutes && minutes < 60)
        {
          *new_val = hours * 60 + minutes;
          found = TRUE;
        }
    }

  g_strfreev (str);

  if (!found)
    {
      *new_val = 0.0;
      return GTK_INPUT_ERROR;
    }

  return TRUE;
}

static gint
time_spin_output (GtkSpinButton *spin_button)
{
  GtkAdjustment *adjustment;
  gchar *buf;
  gdouble hours;
  gdouble minutes;

  adjustment = gtk_spin_button_get_adjustment (spin_button);
  hours = gtk_adjustment_get_value (adjustment) / 60.0;
  minutes = (hours - floor (hours)) * 60.0;
  buf = g_strdup_printf ("%02.0f:%02.0f", floor (hours), floor (minutes + 0.5));
  if (strcmp (buf, gtk_spin_button_get_text (spin_button)))
    gtk_spin_button_set_text (spin_button, buf);
  g_free (buf);

  return TRUE;
}

static gchar *month[12] = {
  "January",
  "February",
  "March",
  "April",
  "May",
  "June",
  "July",
  "August",
  "September",
  "October",
  "November",
  "December"
};

static gint
month_spin_input (GtkSpinButton *spin_button,
                  gdouble       *new_val)
{
  gint i;
  gchar *tmp1, *tmp2;
  gboolean found = FALSE;

  for (i = 1; i <= 12; i++)
    {
      tmp1 = g_ascii_strup (month[i - 1], -1);
      tmp2 = g_ascii_strup (gtk_spin_button_get_text (spin_button), -1);
      if (strstr (tmp1, tmp2) == tmp1)
        found = TRUE;
      g_free (tmp1);
      g_free (tmp2);
      if (found)
        break;
    }
  if (!found)
    {
      *new_val = 0.0;
      return GTK_INPUT_ERROR;
    }
  *new_val = (gdouble) i;

  return TRUE;
}

static gint
month_spin_output (GtkSpinButton *spin_button)
{
  GtkAdjustment *adjustment;
  gdouble value;
  gint i;

  adjustment = gtk_spin_button_get_adjustment (spin_button);
  value = gtk_adjustment_get_value (adjustment);
  for (i = 1; i <= 12; i++)
    if (fabs (value - (double)i) < 1e-5)
      {
        if (strcmp (month[i-1], gtk_spin_button_get_text (spin_button)))
          gtk_spin_button_set_text (spin_button, month[i-1]);
      }

  return TRUE;
}

static gboolean
value_to_label (GBinding     *binding,
                const GValue *from,
                GValue       *to,
                gpointer      user_data)
{
  g_value_take_string (to, g_strdup_printf ("%g", g_value_get_double (from)));
  return TRUE;
}

GtkWidget *
do_spinbutton (GtkWidget *do_widget)
{
  static GtkWidget *window;

  if (!window)
  {
    GtkBuilder *builder;
    GtkAdjustment *adj;
    GtkWidget *label;

    builder = gtk_builder_new_from_resource ("/spinbutton/spinbutton.ui");
    gtk_builder_add_callback_symbols (builder,
                                      "hex_spin_input", G_CALLBACK (hex_spin_input),
                                      "hex_spin_output", G_CALLBACK (hex_spin_output),
                                      "time_spin_input", G_CALLBACK (time_spin_input),
                                      "time_spin_output", G_CALLBACK (time_spin_output),
                                      "month_spin_input", G_CALLBACK (month_spin_input),
                                      "month_spin_output", G_CALLBACK (month_spin_output),
                                      NULL);
    gtk_builder_connect_signals (builder, NULL);
    window = GTK_WIDGET (gtk_builder_get_object (builder, "window"));
    gtk_window_set_display (GTK_WINDOW (window),
                            gtk_widget_get_display (do_widget));
    gtk_window_set_title (GTK_WINDOW (window), "Spin Buttons");
    gtk_window_set_resizable (GTK_WINDOW (window), FALSE);
    g_signal_connect (window, "destroy",
                      G_CALLBACK (gtk_widget_destroyed), &window);

    adj = GTK_ADJUSTMENT (gtk_builder_get_object (builder, "basic_adjustment"));
    label = GTK_WIDGET (gtk_builder_get_object (builder, "basic_label"));
    g_object_bind_property_full (adj, "value",
                                 label, "label",
                                 G_BINDING_SYNC_CREATE,
                                 value_to_label,
                                 NULL,
                                 NULL, NULL);
    adj = GTK_ADJUSTMENT (gtk_builder_get_object (builder, "hex_adjustment"));
    label = GTK_WIDGET (gtk_builder_get_object (builder, "hex_label"));
    g_object_bind_property_full (adj, "value",
                                 label, "label",
                                 G_BINDING_SYNC_CREATE,
                                 value_to_label,
                                 NULL,
                                 NULL, NULL);
    adj = GTK_ADJUSTMENT (gtk_builder_get_object (builder, "time_adjustment"));
    label = GTK_WIDGET (gtk_builder_get_object (builder, "time_label"));
    g_object_bind_property_full (adj, "value",
                                 label, "label",
                                 G_BINDING_SYNC_CREATE,
                                 value_to_label,
                                 NULL,
                                 NULL, NULL);
    adj = GTK_ADJUSTMENT (gtk_builder_get_object (builder, "month_adjustment"));
    label = GTK_WIDGET (gtk_builder_get_object (builder, "month_label"));
    g_object_bind_property_full (adj, "value",
                                 label, "label",
                                 G_BINDING_SYNC_CREATE,
                                 value_to_label,
                                 NULL,
                                 NULL, NULL);

    g_object_unref (builder);
  }

  if (!gtk_widget_get_visible (window))
    gtk_widget_show (window);
  else
    gtk_widget_destroy (window);

  return window;
}