gtk/gtk/gtkvscale.c

132 lines
3.7 KiB
C

/* GTK - The GIMP Toolkit
* Copyright (C) 2001 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
* Modified by the GTK+ Team and others 1997-2000. See the AUTHORS
* file for a list of people on the GTK+ Team. See the ChangeLog
* files for a list of changes. These files are distributed with
* GTK+ at ftp://ftp.gtk.org/pub/gtk/.
*/
#include "config.h"
#include <math.h>
#include <stdlib.h>
#include "gtkvscale.h"
#include "gtkorientable.h"
/**
* SECTION:gtkvscale
* @Short_description: A vertical slider widget for selecting a value from a range
* @Title: GtkVScale
*
* The #GtkVScale widget is used to allow the user to select a value using
* a vertical slider. To create one, use gtk_hscale_new_with_range().
*
* The position to show the current value, and the number of decimal places
* shown can be set using the parent #GtkScale class's functions.
*/
G_DEFINE_TYPE (GtkVScale, gtk_vscale, GTK_TYPE_SCALE)
static void
gtk_vscale_class_init (GtkVScaleClass *class)
{
GtkRangeClass *range_class = GTK_RANGE_CLASS (class);
range_class->slider_detail = "vscale";
}
static void
gtk_vscale_init (GtkVScale *vscale)
{
gtk_orientable_set_orientation (GTK_ORIENTABLE (vscale),
GTK_ORIENTATION_VERTICAL);
}
/**
* gtk_vscale_new:
* @adjustment: the #GtkAdjustment which sets the range of the scale.
*
* Creates a new #GtkVScale.
*
* Returns: a new #GtkVScale.
*/
GtkWidget *
gtk_vscale_new (GtkAdjustment *adjustment)
{
g_return_val_if_fail (adjustment == NULL || GTK_IS_ADJUSTMENT (adjustment),
NULL);
return g_object_new (GTK_TYPE_VSCALE,
"adjustment", adjustment,
NULL);
}
/**
* gtk_vscale_new_with_range:
* @min: minimum value
* @max: maximum value
* @step: step increment (tick size) used with keyboard shortcuts
*
* Creates a new vertical scale widget that lets the user input a
* number between @min and @max (including @min and @max) with the
* increment @step. @step must be nonzero; it's the distance the
* slider moves when using the arrow keys to adjust the scale value.
*
* Note that the way in which the precision is derived works best if @step
* is a power of ten. If the resulting precision is not suitable for your
* needs, use gtk_scale_set_digits() to correct it.
*
* Return value: a new #GtkVScale
**/
GtkWidget *
gtk_vscale_new_with_range (gdouble min,
gdouble max,
gdouble step)
{
GtkObject *adj;
GtkScale *scale;
gint digits;
g_return_val_if_fail (min < max, NULL);
g_return_val_if_fail (step != 0.0, NULL);
adj = gtk_adjustment_new (min, min, max, step, 10 * step, 0);
if (fabs (step) >= 1.0 || step == 0.0)
{
digits = 0;
}
else
{
digits = abs ((gint) floor (log10 (fabs (step))));
if (digits > 5)
digits = 5;
}
scale = g_object_new (GTK_TYPE_VSCALE,
"adjustment", adj,
"digits", digits,
NULL);
return GTK_WIDGET (scale);
}