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gimp/libgimpwidgets/gimpzoommodel.c

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/* LIBGIMP - The GIMP Library
* Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
*
* gimpzoommodel.c
* Copyright (C) 2005 David Odin <dindinx@gimp.org>
*
* 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.
*/
#include "config.h"
#include <math.h>
#include <gtk/gtk.h>
#include "libgimpbase/gimpbase.h"
#include "gimpwidgetstypes.h"
#include "gimpzoommodel.h"
#include "libgimp/libgimp-intl.h"
enum
{
PROP_0,
PROP_VALUE,
PROP_MINIMUM,
PROP_MAXIMUM
};
typedef struct _GimpZoomModelPrivate GimpZoomModelPrivate;
struct _GimpZoomModelPrivate
{
gdouble value;
gdouble minimum;
gdouble maximum;
};
#define GIMP_ZOOM_MODEL_GET_PRIVATE(obj) (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GIMP_TYPE_ZOOM_MODEL, GimpZoomModelPrivate))
static void gimp_zoom_model_set_property (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec);
static void gimp_zoom_model_get_property (GObject *object,
guint property_id,
GValue *value,
GParamSpec *pspec);
G_DEFINE_TYPE (GimpZoomModel, gimp_zoom_model, G_TYPE_OBJECT);
#define parent_class gimp_zoom_model_parent_class
static void
gimp_zoom_model_class_init (GimpZoomModelClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
parent_class = g_type_class_peek_parent (klass);
object_class->set_property = gimp_zoom_model_set_property;
object_class->get_property = gimp_zoom_model_get_property;
g_object_class_install_property (object_class, PROP_VALUE,
g_param_spec_double ("value",
"Value", NULL,
1.0 / 256.0, 256.0,
1.0,
G_PARAM_READWRITE|G_PARAM_CONSTRUCT));
g_object_class_install_property (object_class, PROP_MINIMUM,
g_param_spec_double ("minimum",
"Minimum", NULL,
1.0 / 256.0, 256.0,
1.0 / 256.0,
G_PARAM_READWRITE));
g_object_class_install_property (object_class, PROP_MAXIMUM,
g_param_spec_double ("maximum",
"Maximum", NULL,
1.0 / 256.0, 256.0,
256.0,
G_PARAM_READWRITE));
g_type_class_add_private (object_class, sizeof (GimpZoomModelPrivate));
}
static void
gimp_zoom_model_init (GimpZoomModel *model)
{
GimpZoomModelPrivate *priv = GIMP_ZOOM_MODEL_GET_PRIVATE (model);
priv->minimum = 1.0 / 256.0;
priv->maximum = 256.0;
}
static void
gimp_zoom_model_set_property (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec)
{
GimpZoomModelPrivate *priv = GIMP_ZOOM_MODEL_GET_PRIVATE (object);
switch (property_id)
{
case PROP_VALUE:
priv->value = g_value_get_double (value);
g_object_notify (object, "value");
break;
case PROP_MINIMUM:
priv->minimum = MIN (g_value_get_double (value), priv->maximum);
break;
case PROP_MAXIMUM:
priv->maximum = MAX (g_value_get_double (value), priv->minimum);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
break;
}
if (priv->value > priv->maximum || priv->value < priv->minimum)
{
priv->value = CLAMP (priv->value, priv->minimum, priv->maximum);
g_object_notify (object, "value");
}
}
static void
gimp_zoom_model_get_property (GObject *object,
guint property_id,
GValue *value,
GParamSpec *pspec)
{
GimpZoomModelPrivate *priv = GIMP_ZOOM_MODEL_GET_PRIVATE (object);
switch (property_id)
{
case PROP_VALUE:
g_value_set_double (value, priv->value);
break;
case PROP_MINIMUM:
g_value_set_double (value, priv->minimum);
break;
case PROP_MAXIMUM:
g_value_set_double (value, priv->maximum);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
break;
}
}
static void
gimp_zoom_model_zoom_in (GimpZoomModel *model)
{
GimpZoomModelPrivate *priv = GIMP_ZOOM_MODEL_GET_PRIVATE (model);
g_return_if_fail (GIMP_IS_ZOOM_MODEL (model));
if (priv->value < priv->maximum);
{
priv->value = gimp_zoom_model_zoom_step (GIMP_ZOOM_IN,
priv->value);
g_object_notify (G_OBJECT (model), "value");
}
}
static void
gimp_zoom_model_zoom_out (GimpZoomModel *model)
{
GimpZoomModelPrivate *priv = GIMP_ZOOM_MODEL_GET_PRIVATE (model);
g_return_if_fail (GIMP_IS_ZOOM_MODEL (model));
if (priv->value > priv->minimum)
{
priv->value = gimp_zoom_model_zoom_step (GIMP_ZOOM_OUT,
priv->value);
g_object_notify (G_OBJECT (model), "value");
}
}
static void
gimp_zoom_model_update_label (GimpZoomModel *model,
GParamSpec *pspec,
GtkLabel *label)
{
gint numerator;
gint denominator;
gchar *txt;
GimpZoomModelPrivate *priv = GIMP_ZOOM_MODEL_GET_PRIVATE (model);
g_return_if_fail (GIMP_IS_ZOOM_MODEL (model));
g_return_if_fail (GTK_IS_LABEL (label));
gimp_zoom_model_get_fraction (priv->value,
&numerator,
&denominator);
txt = g_strdup_printf (_("zoom factor %d:%d"), numerator, denominator);
gtk_label_set_text (label, txt);
g_free (txt);
}
void
gimp_zoom_model_get_fraction (gdouble zoom_factor,
gint *numerator,
gint *denominator)
{
gint p0, p1, p2;
gint q0, q1, q2;
gdouble remainder, next_cf;
gboolean swapped = FALSE;
g_return_if_fail (numerator != NULL && denominator != NULL);
/* make sure that zooming behaves symmetrically */
if (zoom_factor < 1.0)
{
zoom_factor = 1.0 / zoom_factor;
swapped = TRUE;
}
/* calculate the continued fraction for the desired zoom factor */
p0 = 1;
q0 = 0;
p1 = floor (zoom_factor);
q1 = 1;
remainder = zoom_factor - p1;
while (fabs (remainder) >= 0.0001 &&
fabs (((gdouble) p1 / q1) - zoom_factor) > 0.0001)
{
remainder = 1.0 / remainder;
next_cf = floor (remainder);
p2 = next_cf * p1 + p0;
q2 = next_cf * q1 + q0;
/* Numerator and Denominator are limited by 256 */
/* also absurd ratios like 170:171 are excluded */
if (p2 > 256 || q2 > 256 || (p2 > 1 && q2 > 1 && p2 * q2 > 200))
break;
/* remember the last two fractions */
p0 = p1;
p1 = p2;
q0 = q1;
q1 = q2;
remainder = remainder - next_cf;
}
zoom_factor = (gdouble) p1 / q1;
/* hard upper and lower bounds for zoom ratio */
if (zoom_factor > 256.0)
{
p1 = 256;
q1 = 1;
}
else if (zoom_factor < 1.0 / 256.0)
{
p1 = 1;
q1 = 256;
}
if (swapped)
{
*numerator = q1;
*denominator = p1;
}
else
{
*numerator = p1;
*denominator = q1;
}
}
gdouble
gimp_zoom_model_zoom_step (GimpZoomType zoom_type,
gdouble scale)
{
gint i, n_presets;
gdouble new_scale = 1.0;
/* This table is constructed to have fractions, that approximate
* sqrt(2)^k. This gives a smooth feeling regardless of the starting
* zoom level.
*
* Zooming in/out always jumps to a zoom step from the list above.
* However, we try to guarantee a certain size of the step, to
* avoid silly jumps from 101% to 100%.
* The factor 1.1 is chosen a bit arbitrary, but feels better
* than the geometric median of the zoom steps (2^(1/4)).
*/
#define ZOOM_MIN_STEP 1.1
gdouble presets[] = {
1.0 / 256, 1.0 / 180, 1.0 / 128, 1.0 / 90,
1.0 / 64, 1.0 / 45, 1.0 / 32, 1.0 / 23,
1.0 / 16, 1.0 / 11, 1.0 / 8, 2.0 / 11,
1.0 / 4, 1.0 / 3, 1.0 / 2, 2.0 / 3,
1.0,
3.0 / 2, 2.0, 3.0,
4.0, 11.0 / 2, 8.0, 11.0,
16.0, 23.0, 32.0, 45.0,
64.0, 90.0, 128.0, 180.0,
256.0,
};
n_presets = G_N_ELEMENTS (presets);
switch (zoom_type)
{
case GIMP_ZOOM_IN:
scale *= ZOOM_MIN_STEP;
new_scale = presets[n_presets-1];
for (i = n_presets - 1; i >= 0 && presets[i] > scale; i--)
new_scale = presets[i];
break;
case GIMP_ZOOM_OUT:
scale /= ZOOM_MIN_STEP;
new_scale = presets[0];
for (i = 0; i < n_presets && presets[i] < scale; i++)
new_scale = presets[i];
break;
case GIMP_ZOOM_TO:
new_scale = scale;
break;
}
return CLAMP (new_scale, 1.0/256.0, 256.0);
#undef ZOOM_MIN_STEP
}
/**
* gimp_zoom_model_new:
*
* Creates a new #GimpZoomModel.
*
* Return value: a new #GimpZoomModel.
*
* Since GIMP 2.4
**/
GimpZoomModel *
gimp_zoom_model_new (void)
{
GimpZoomModel *model;
model = g_object_new (GIMP_TYPE_ZOOM_MODEL,
"value", 1.0,
NULL);
return model;
}
/**
* gimp_zoom_widget_new:
*
* Creates a new widget to interact with the #GimpZoomModel.
* @model:
* @widget:
*
* Return value: a new #GtkWidget.
*
* Since GIMP 2.4
**/
GtkWidget *
gimp_zoom_widget_new (GimpZoomModel *model,
GimpZoomWidgetType widget)
{
GtkWidget *button;
GtkWidget *image;
GtkWidget *label;
gint numerator;
gint denominator;
gchar *txt;
GimpZoomModelPrivate *priv = GIMP_ZOOM_MODEL_GET_PRIVATE (model);
g_return_val_if_fail (GIMP_IS_ZOOM_MODEL (model), NULL);
switch (widget)
{
case GIMP_ZOOM_IN_BUTTON:
button = gtk_button_new ();
image = gtk_image_new_from_stock (GTK_STOCK_ZOOM_IN,
GTK_ICON_SIZE_SMALL_TOOLBAR);
gtk_container_add (GTK_CONTAINER (button), image);
gtk_widget_show (image);
g_signal_connect_swapped (button, "clicked",
G_CALLBACK (gimp_zoom_model_zoom_in),
model);
return button;
case GIMP_ZOOM_OUT_BUTTON:
button = gtk_button_new ();
image = gtk_image_new_from_stock (GTK_STOCK_ZOOM_OUT,
GTK_ICON_SIZE_SMALL_TOOLBAR);
gtk_container_add (GTK_CONTAINER (button), image);
gtk_widget_show (image);
g_signal_connect_swapped (button, "clicked",
G_CALLBACK (gimp_zoom_model_zoom_out),
model);
return button;
case GIMP_ZOOM_LABEL:
gimp_zoom_model_get_fraction (priv->value,
&numerator,
&denominator);
txt = g_strdup_printf (_("zoom factor %d:%d"), numerator, denominator);
label = gtk_label_new (txt);
g_free (txt);
gtk_misc_set_padding (GTK_MISC (label), 6, 6);
g_signal_connect (model, "notify::value",
G_CALLBACK (gimp_zoom_model_update_label),
label);
return label;
}
return NULL;
}
gdouble
gimp_zoom_model_get_factor (GimpZoomModel *model)
{
GimpZoomModelPrivate *priv = GIMP_ZOOM_MODEL_GET_PRIVATE (model);
g_return_val_if_fail (GIMP_IS_ZOOM_MODEL (model), 1.0);
return priv->value;
}
void
gimp_zoom_model_set_range (GimpZoomModel *model,
gdouble min,
gdouble max)
{
g_return_if_fail (min < max);
g_return_if_fail (min >= 1.0 / 256.0);
g_return_if_fail (max <= 256.0);
g_object_set (model, "minimum", min, "maximum", max, NULL);
}
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