gtk2/gtk/gtkruler.c
2010-07-13 19:40:49 +02:00

941 lines
27 KiB
C

/* GTK - The GIMP Toolkit
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
*
* 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 <string.h>
#include "gtkorientable.h"
#include "gtkruler.h"
#include "gtkprivate.h"
#include "gtkintl.h"
#define RULER_WIDTH 14
#define MINIMUM_INCR 5
#define MAXIMUM_SUBDIVIDE 5
#define MAXIMUM_SCALES 10
#define ROUND(x) ((int) ((x) + 0.5))
struct _GtkRulerPriv
{
GtkOrientation orientation;
GtkRulerMetric *metric;
GdkGC *non_gr_exp_gc;
GdkPixmap *backing_store;
gint slider_size;
gint xsrc;
gint ysrc;
gdouble lower; /* The upper limit of the ruler (in points) */
gdouble max_size; /* The maximum size of the ruler */
gdouble position; /* The position of the mark on the ruler */
gdouble upper; /* The lower limit of the ruler */
};
enum {
PROP_0,
PROP_ORIENTATION,
PROP_LOWER,
PROP_UPPER,
PROP_POSITION,
PROP_MAX_SIZE,
PROP_METRIC
};
static void gtk_ruler_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec);
static void gtk_ruler_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec);
static void gtk_ruler_realize (GtkWidget *widget);
static void gtk_ruler_unrealize (GtkWidget *widget);
static void gtk_ruler_size_request (GtkWidget *widget,
GtkRequisition *requisition);
static void gtk_ruler_size_allocate (GtkWidget *widget,
GtkAllocation *allocation);
static gboolean gtk_ruler_motion_notify (GtkWidget *widget,
GdkEventMotion *event);
static gboolean gtk_ruler_expose (GtkWidget *widget,
GdkEventExpose *event);
static void gtk_ruler_make_pixmap (GtkRuler *ruler);
static void gtk_ruler_real_draw_ticks (GtkRuler *ruler);
static void gtk_ruler_real_draw_pos (GtkRuler *ruler);
static const GtkRulerMetric ruler_metrics[] =
{
{ "Pixel", "Pi", 1.0, { 1, 2, 5, 10, 25, 50, 100, 250, 500, 1000 }, { 1, 5, 10, 50, 100 }},
{ "Inches", "In", 72.0, { 1, 2, 4, 8, 16, 32, 64, 128, 256, 512 }, { 1, 2, 4, 8, 16 }},
{ "Centimeters", "Cn", 28.35, { 1, 2, 5, 10, 25, 50, 100, 250, 500, 1000 }, { 1, 5, 10, 50, 100 }},
};
G_DEFINE_TYPE_WITH_CODE (GtkRuler, gtk_ruler, GTK_TYPE_WIDGET,
G_IMPLEMENT_INTERFACE (GTK_TYPE_ORIENTABLE,
NULL))
static void
gtk_ruler_class_init (GtkRulerClass *class)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (class);
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
gobject_class->set_property = gtk_ruler_set_property;
gobject_class->get_property = gtk_ruler_get_property;
widget_class->realize = gtk_ruler_realize;
widget_class->unrealize = gtk_ruler_unrealize;
widget_class->size_request = gtk_ruler_size_request;
widget_class->size_allocate = gtk_ruler_size_allocate;
widget_class->motion_notify_event = gtk_ruler_motion_notify;
widget_class->expose_event = gtk_ruler_expose;
class->draw_ticks = gtk_ruler_real_draw_ticks;
class->draw_pos = gtk_ruler_real_draw_pos;
g_object_class_override_property (gobject_class,
PROP_ORIENTATION,
"orientation");
g_object_class_install_property (gobject_class,
PROP_LOWER,
g_param_spec_double ("lower",
P_("Lower"),
P_("Lower limit of ruler"),
-G_MAXDOUBLE,
G_MAXDOUBLE,
0.0,
GTK_PARAM_READWRITE));
g_object_class_install_property (gobject_class,
PROP_UPPER,
g_param_spec_double ("upper",
P_("Upper"),
P_("Upper limit of ruler"),
-G_MAXDOUBLE,
G_MAXDOUBLE,
0.0,
GTK_PARAM_READWRITE));
g_object_class_install_property (gobject_class,
PROP_POSITION,
g_param_spec_double ("position",
P_("Position"),
P_("Position of mark on the ruler"),
-G_MAXDOUBLE,
G_MAXDOUBLE,
0.0,
GTK_PARAM_READWRITE));
g_object_class_install_property (gobject_class,
PROP_MAX_SIZE,
g_param_spec_double ("max-size",
P_("Max Size"),
P_("Maximum size of the ruler"),
-G_MAXDOUBLE,
G_MAXDOUBLE,
0.0,
GTK_PARAM_READWRITE));
/**
* GtkRuler:metric:
*
* The metric used for the ruler.
*
* Since: 2.8
*/
g_object_class_install_property (gobject_class,
PROP_METRIC,
g_param_spec_enum ("metric",
P_("Metric"),
P_("The metric used for the ruler"),
GTK_TYPE_METRIC_TYPE,
GTK_PIXELS,
GTK_PARAM_READWRITE));
g_type_class_add_private (gobject_class, sizeof (GtkRulerPriv));
}
static void
gtk_ruler_init (GtkRuler *ruler)
{
GtkWidget *widget = GTK_WIDGET (ruler);
GtkRulerPriv *priv;
ruler->priv = G_TYPE_INSTANCE_GET_PRIVATE (ruler,
GTK_TYPE_RULER,
GtkRulerPriv);
priv = ruler->priv;
priv->orientation = GTK_ORIENTATION_HORIZONTAL;
widget->requisition.width = widget->style->xthickness * 2 + 1;
widget->requisition.height = widget->style->ythickness * 2 + RULER_WIDTH;
priv->backing_store = NULL;
priv->xsrc = 0;
priv->ysrc = 0;
priv->slider_size = 0;
priv->lower = 0;
priv->upper = 0;
priv->position = 0;
priv->max_size = 0;
gtk_ruler_set_metric (ruler, GTK_PIXELS);
}
static void
gtk_ruler_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GtkRuler *ruler = GTK_RULER (object);
GtkRulerPriv *priv = ruler->priv;
switch (prop_id)
{
case PROP_ORIENTATION:
priv->orientation = g_value_get_enum (value);
gtk_widget_queue_resize (GTK_WIDGET (ruler));
break;
case PROP_LOWER:
gtk_ruler_set_range (ruler, g_value_get_double (value), priv->upper,
priv->position, priv->max_size);
break;
case PROP_UPPER:
gtk_ruler_set_range (ruler, priv->lower, g_value_get_double (value),
priv->position, priv->max_size);
break;
case PROP_POSITION:
gtk_ruler_set_range (ruler, priv->lower, priv->upper,
g_value_get_double (value), priv->max_size);
break;
case PROP_MAX_SIZE:
gtk_ruler_set_range (ruler, priv->lower, priv->upper,
priv->position, g_value_get_double (value));
break;
case PROP_METRIC:
gtk_ruler_set_metric (ruler, g_value_get_enum (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_ruler_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GtkRuler *ruler = GTK_RULER (object);
GtkRulerPriv *priv = ruler->priv;
switch (prop_id)
{
case PROP_ORIENTATION:
g_value_set_enum (value, priv->orientation);
break;
case PROP_LOWER:
g_value_set_double (value, priv->lower);
break;
case PROP_UPPER:
g_value_set_double (value, priv->upper);
break;
case PROP_POSITION:
g_value_set_double (value, priv->position);
break;
case PROP_MAX_SIZE:
g_value_set_double (value, priv->max_size);
break;
case PROP_METRIC:
g_value_set_enum (value, gtk_ruler_get_metric (ruler));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
/**
* gtk_ruler_new:
* @orientation: the ruler's orientation.
*
* Creates a new #GtkRuler with the given orientation.
*
* Return value: a new #GtkRuler.
*
* Since: 3.0
**/
GtkWidget *
gtk_ruler_new (GtkOrientation orientation)
{
return g_object_new (GTK_TYPE_RULER,
"orientation", orientation,
NULL);
}
void
gtk_ruler_set_metric (GtkRuler *ruler,
GtkMetricType metric)
{
GtkRulerPriv *priv;
g_return_if_fail (GTK_IS_RULER (ruler));
priv = ruler->priv;
priv->metric = (GtkRulerMetric *) &ruler_metrics[metric];
if (gtk_widget_is_drawable (GTK_WIDGET (ruler)))
gtk_widget_queue_draw (GTK_WIDGET (ruler));
g_object_notify (G_OBJECT (ruler), "metric");
}
/**
* gtk_ruler_get_metric:
* @ruler: a #GtkRuler
*
* Gets the units used for a #GtkRuler. See gtk_ruler_set_metric().
*
* Return value: the units currently used for @ruler
**/
GtkMetricType
gtk_ruler_get_metric (GtkRuler *ruler)
{
GtkRulerPriv *priv;
gint i;
g_return_val_if_fail (GTK_IS_RULER (ruler), 0);
priv = ruler->priv;
for (i = 0; i < G_N_ELEMENTS (ruler_metrics); i++)
if (priv->metric == &ruler_metrics[i])
return i;
g_assert_not_reached ();
return 0;
}
/**
* gtk_ruler_set_range:
* @ruler: the gtkruler
* @lower: the lower limit of the ruler
* @upper: the upper limit of the ruler
* @position: the mark on the ruler
* @max_size: the maximum size of the ruler used when calculating the space to
* leave for the text
*
* This sets the range of the ruler.
*/
void
gtk_ruler_set_range (GtkRuler *ruler,
gdouble lower,
gdouble upper,
gdouble position,
gdouble max_size)
{
GtkRulerPriv *priv;
g_return_if_fail (GTK_IS_RULER (ruler));
priv = ruler->priv;
g_object_freeze_notify (G_OBJECT (ruler));
if (priv->lower != lower)
{
priv->lower = lower;
g_object_notify (G_OBJECT (ruler), "lower");
}
if (priv->upper != upper)
{
priv->upper = upper;
g_object_notify (G_OBJECT (ruler), "upper");
}
if (priv->position != position)
{
priv->position = position;
g_object_notify (G_OBJECT (ruler), "position");
}
if (priv->max_size != max_size)
{
priv->max_size = max_size;
g_object_notify (G_OBJECT (ruler), "max-size");
}
g_object_thaw_notify (G_OBJECT (ruler));
if (gtk_widget_is_drawable (GTK_WIDGET (ruler)))
gtk_widget_queue_draw (GTK_WIDGET (ruler));
}
/**
* gtk_ruler_get_range:
* @ruler: a #GtkRuler
* @lower: (allow-none): location to store lower limit of the ruler, or %NULL
* @upper: (allow-none): location to store upper limit of the ruler, or %NULL
* @position: (allow-none): location to store the current position of the mark on the ruler, or %NULL
* @max_size: location to store the maximum size of the ruler used when calculating
* the space to leave for the text, or %NULL.
*
* Retrieves values indicating the range and current position of a #GtkRuler.
* See gtk_ruler_set_range().
**/
void
gtk_ruler_get_range (GtkRuler *ruler,
gdouble *lower,
gdouble *upper,
gdouble *position,
gdouble *max_size)
{
GtkRulerPriv *priv;
g_return_if_fail (GTK_IS_RULER (ruler));
priv = ruler->priv;
if (lower)
*lower = priv->lower;
if (upper)
*upper = priv->upper;
if (position)
*position = priv->position;
if (max_size)
*max_size = priv->max_size;
}
void
gtk_ruler_draw_ticks (GtkRuler *ruler)
{
g_return_if_fail (GTK_IS_RULER (ruler));
if (GTK_RULER_GET_CLASS (ruler)->draw_ticks)
GTK_RULER_GET_CLASS (ruler)->draw_ticks (ruler);
}
void
gtk_ruler_draw_pos (GtkRuler *ruler)
{
g_return_if_fail (GTK_IS_RULER (ruler));
if (GTK_RULER_GET_CLASS (ruler)->draw_pos)
GTK_RULER_GET_CLASS (ruler)->draw_pos (ruler);
}
static void
gtk_ruler_realize (GtkWidget *widget)
{
GtkRuler *ruler;
GdkWindowAttr attributes;
gint attributes_mask;
ruler = GTK_RULER (widget);
gtk_widget_set_realized (widget, TRUE);
attributes.window_type = GDK_WINDOW_CHILD;
attributes.x = widget->allocation.x;
attributes.y = widget->allocation.y;
attributes.width = widget->allocation.width;
attributes.height = widget->allocation.height;
attributes.wclass = GDK_INPUT_OUTPUT;
attributes.visual = gtk_widget_get_visual (widget);
attributes.colormap = gtk_widget_get_colormap (widget);
attributes.event_mask = gtk_widget_get_events (widget);
attributes.event_mask |= (GDK_EXPOSURE_MASK |
GDK_POINTER_MOTION_MASK |
GDK_POINTER_MOTION_HINT_MASK);
attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL | GDK_WA_COLORMAP;
widget->window = gdk_window_new (gtk_widget_get_parent_window (widget), &attributes, attributes_mask);
gdk_window_set_user_data (widget->window, ruler);
widget->style = gtk_style_attach (widget->style, widget->window);
gtk_style_set_background (widget->style, widget->window, GTK_STATE_ACTIVE);
gtk_ruler_make_pixmap (ruler);
}
static void
gtk_ruler_unrealize (GtkWidget *widget)
{
GtkRuler *ruler = GTK_RULER (widget);
GtkRulerPriv *priv = ruler->priv;
if (priv->backing_store)
{
g_object_unref (priv->backing_store);
priv->backing_store = NULL;
}
if (priv->non_gr_exp_gc)
{
g_object_unref (priv->non_gr_exp_gc);
priv->non_gr_exp_gc = NULL;
}
GTK_WIDGET_CLASS (gtk_ruler_parent_class)->unrealize (widget);
}
static void
gtk_ruler_size_request (GtkWidget *widget,
GtkRequisition *requisition)
{
GtkRuler *ruler = GTK_RULER (widget);
GtkRulerPriv *priv = ruler->priv;
if (priv->orientation == GTK_ORIENTATION_HORIZONTAL)
{
requisition->width = widget->style->xthickness * 2 + 1;
requisition->height = widget->style->ythickness * 2 + RULER_WIDTH;
}
else
{
requisition->width = widget->style->xthickness * 2 + RULER_WIDTH;
requisition->height = widget->style->ythickness * 2 + 1;
}
}
static void
gtk_ruler_size_allocate (GtkWidget *widget,
GtkAllocation *allocation)
{
GtkRuler *ruler = GTK_RULER (widget);
widget->allocation = *allocation;
if (gtk_widget_get_realized (widget))
{
gdk_window_move_resize (widget->window,
allocation->x, allocation->y,
allocation->width, allocation->height);
gtk_ruler_make_pixmap (ruler);
}
}
static gboolean
gtk_ruler_motion_notify (GtkWidget *widget,
GdkEventMotion *event)
{
GtkRuler *ruler = GTK_RULER (widget);
GtkRulerPriv *priv = ruler->priv;
gint x;
gint y;
gdk_event_request_motions (event);
x = event->x;
y = event->y;
if (priv->orientation == GTK_ORIENTATION_HORIZONTAL)
priv->position = priv->lower + ((priv->upper - priv->lower) * x) / widget->allocation.width;
else
priv->position = priv->lower + ((priv->upper - priv->lower) * y) / widget->allocation.height;
g_object_notify (G_OBJECT (ruler), "position");
/* Make sure the ruler has been allocated already */
if (priv->backing_store != NULL)
gtk_ruler_draw_pos (ruler);
return FALSE;
}
static gboolean
gtk_ruler_expose (GtkWidget *widget,
GdkEventExpose *event)
{
if (gtk_widget_is_drawable (widget))
{
GtkRuler *ruler = GTK_RULER (widget);
GtkRulerPriv *priv = ruler->priv;
gtk_ruler_draw_ticks (ruler);
gdk_draw_drawable (widget->window,
priv->non_gr_exp_gc,
priv->backing_store,
0, 0, 0, 0,
widget->allocation.width,
widget->allocation.height);
gtk_ruler_draw_pos (ruler);
}
return FALSE;
}
static void
gtk_ruler_make_pixmap (GtkRuler *ruler)
{
GtkRulerPriv *priv = ruler->priv;
GtkWidget *widget;
gint width;
gint height;
widget = GTK_WIDGET (ruler);
if (priv->backing_store)
{
gdk_drawable_get_size (priv->backing_store, &width, &height);
if ((width == widget->allocation.width) &&
(height == widget->allocation.height))
return;
g_object_unref (priv->backing_store);
}
priv->backing_store = gdk_pixmap_new (widget->window,
widget->allocation.width,
widget->allocation.height,
-1);
priv->xsrc = 0;
priv->ysrc = 0;
if (!priv->non_gr_exp_gc)
{
priv->non_gr_exp_gc = gdk_gc_new (widget->window);
gdk_gc_set_exposures (priv->non_gr_exp_gc, FALSE);
}
}
static void
gtk_ruler_real_draw_ticks (GtkRuler *ruler)
{
GtkWidget *widget = GTK_WIDGET (ruler);
GtkRulerPriv *priv = ruler->priv;
cairo_t *cr;
gint i, j;
gint width, height;
gint xthickness;
gint ythickness;
gint length, ideal_length;
gdouble lower, upper; /* Upper and lower limits, in ruler units */
gdouble increment; /* Number of pixels per unit */
gint scale; /* Number of units per major unit */
gdouble subd_incr;
gdouble start, end, cur;
gchar unit_str[32];
gint digit_height;
gint digit_offset;
gint text_width;
gint text_height;
gint pos;
PangoLayout *layout;
PangoRectangle logical_rect, ink_rect;
if (!gtk_widget_is_drawable (widget))
return;
xthickness = widget->style->xthickness;
ythickness = widget->style->ythickness;
layout = gtk_widget_create_pango_layout (widget, "012456789");
pango_layout_get_extents (layout, &ink_rect, &logical_rect);
digit_height = PANGO_PIXELS (ink_rect.height) + 2;
digit_offset = ink_rect.y;
if (priv->orientation == GTK_ORIENTATION_HORIZONTAL)
{
width = widget->allocation.width;
height = widget->allocation.height - ythickness * 2;
}
else
{
width = widget->allocation.height;
height = widget->allocation.width - ythickness * 2;
}
#define DETAILE(private) (priv->orientation == GTK_ORIENTATION_HORIZONTAL ? "hruler" : "vruler");
gtk_paint_box (widget->style, priv->backing_store,
GTK_STATE_NORMAL, GTK_SHADOW_OUT,
NULL, widget,
priv->orientation == GTK_ORIENTATION_HORIZONTAL ?
"hruler" : "vruler",
0, 0,
widget->allocation.width, widget->allocation.height);
cr = gdk_cairo_create (priv->backing_store);
gdk_cairo_set_source_color (cr, &widget->style->fg[widget->state]);
if (priv->orientation == GTK_ORIENTATION_HORIZONTAL)
{
cairo_rectangle (cr,
xthickness,
height + ythickness,
widget->allocation.width - 2 * xthickness,
1);
}
else
{
cairo_rectangle (cr,
height + xthickness,
ythickness,
1,
widget->allocation.height - 2 * ythickness);
}
upper = priv->upper / priv->metric->pixels_per_unit;
lower = priv->lower / priv->metric->pixels_per_unit;
if ((upper - lower) == 0)
goto out;
increment = (gdouble) width / (upper - lower);
/* determine the scale H
* We calculate the text size as for the vruler, so that the result
* for the scale looks consistent with an accompanying vruler
*/
/* determine the scale V
* use the maximum extents of the ruler to determine the largest
* possible number to be displayed. Calculate the height in pixels
* of this displayed text. Use this height to find a scale which
* leaves sufficient room for drawing the ruler.
*/
scale = ceil (priv->max_size / priv->metric->pixels_per_unit);
g_snprintf (unit_str, sizeof (unit_str), "%d", scale);
if (priv->orientation == GTK_ORIENTATION_HORIZONTAL)
{
text_width = strlen (unit_str) * digit_height + 1;
for (scale = 0; scale < MAXIMUM_SCALES; scale++)
if (priv->metric->ruler_scale[scale] * fabs(increment) > 2 * text_width)
break;
}
else
{
text_height = strlen (unit_str) * digit_height + 1;
for (scale = 0; scale < MAXIMUM_SCALES; scale++)
if (priv->metric->ruler_scale[scale] * fabs(increment) > 2 * text_height)
break;
}
if (scale == MAXIMUM_SCALES)
scale = MAXIMUM_SCALES - 1;
/* drawing starts here */
length = 0;
for (i = MAXIMUM_SUBDIVIDE - 1; i >= 0; i--)
{
subd_incr = (gdouble) priv->metric->ruler_scale[scale] /
(gdouble) priv->metric->subdivide[i];
if (subd_incr * fabs(increment) <= MINIMUM_INCR)
continue;
/* Calculate the length of the tickmarks. Make sure that
* this length increases for each set of ticks
*/
ideal_length = height / (i + 1) - 1;
if (ideal_length > ++length)
length = ideal_length;
if (lower < upper)
{
start = floor (lower / subd_incr) * subd_incr;
end = ceil (upper / subd_incr) * subd_incr;
}
else
{
start = floor (upper / subd_incr) * subd_incr;
end = ceil (lower / subd_incr) * subd_incr;
}
for (cur = start; cur <= end; cur += subd_incr)
{
pos = ROUND ((cur - lower) * increment);
if (priv->orientation == GTK_ORIENTATION_HORIZONTAL)
{
cairo_rectangle (cr,
pos, height + ythickness - length,
1, length);
}
else
{
cairo_rectangle (cr,
height + xthickness - length, pos,
length, 1);
}
/* draw label */
if (i == 0)
{
g_snprintf (unit_str, sizeof (unit_str), "%d", (int) cur);
if (priv->orientation == GTK_ORIENTATION_HORIZONTAL)
{
pango_layout_set_text (layout, unit_str, -1);
pango_layout_get_extents (layout, &logical_rect, NULL);
gtk_paint_layout (widget->style,
priv->backing_store,
gtk_widget_get_state (widget),
FALSE,
NULL,
widget,
"hruler",
pos + 2, ythickness + PANGO_PIXELS (logical_rect.y - digit_offset),
layout);
}
else
{
for (j = 0; j < (int) strlen (unit_str); j++)
{
pango_layout_set_text (layout, unit_str + j, 1);
pango_layout_get_extents (layout, NULL, &logical_rect);
gtk_paint_layout (widget->style,
priv->backing_store,
gtk_widget_get_state (widget),
FALSE,
NULL,
widget,
"vruler",
xthickness + 1,
pos + digit_height * j + 2 + PANGO_PIXELS (logical_rect.y - digit_offset),
layout);
}
}
}
}
}
cairo_fill (cr);
out:
cairo_destroy (cr);
g_object_unref (layout);
}
static void
gtk_ruler_real_draw_pos (GtkRuler *ruler)
{
GtkWidget *widget = GTK_WIDGET (ruler);
GtkRulerPriv *priv = ruler->priv;
gint x, y;
gint width, height;
gint bs_width, bs_height;
gint xthickness;
gint ythickness;
gdouble increment;
if (gtk_widget_is_drawable (widget))
{
xthickness = widget->style->xthickness;
ythickness = widget->style->ythickness;
width = widget->allocation.width;
height = widget->allocation.height;
if (priv->orientation == GTK_ORIENTATION_HORIZONTAL)
{
height -= ythickness * 2;
bs_width = height / 2 + 2;
bs_width |= 1; /* make sure it's odd */
bs_height = bs_width / 2 + 1;
}
else
{
width -= xthickness * 2;
bs_height = width / 2 + 2;
bs_height |= 1; /* make sure it's odd */
bs_width = bs_height / 2 + 1;
}
if ((bs_width > 0) && (bs_height > 0))
{
cairo_t *cr = gdk_cairo_create (widget->window);
/* If a backing store exists, restore the ruler */
if (priv->backing_store)
gdk_draw_drawable (widget->window,
widget->style->black_gc,
priv->backing_store,
priv->xsrc, priv->ysrc,
priv->xsrc, priv->ysrc,
bs_width, bs_height);
if (priv->orientation == GTK_ORIENTATION_HORIZONTAL)
{
increment = (gdouble) width / (priv->upper - priv->lower);
x = ROUND ((priv->position - priv->lower) * increment) + (xthickness - bs_width) / 2 - 1;
y = (height + bs_height) / 2 + ythickness;
}
else
{
increment = (gdouble) height / (priv->upper - priv->lower);
x = (width + bs_width) / 2 + xthickness;
y = ROUND ((priv->position - priv->lower) * increment) + (ythickness - bs_height) / 2 - 1;
}
gdk_cairo_set_source_color (cr, &widget->style->fg[widget->state]);
cairo_move_to (cr, x, y);
if (priv->orientation == GTK_ORIENTATION_HORIZONTAL)
{
cairo_line_to (cr, x + bs_width / 2.0, y + bs_height);
cairo_line_to (cr, x + bs_width, y);
}
else
{
cairo_line_to (cr, x + bs_width, y + bs_height / 2.0);
cairo_line_to (cr, x, y + bs_height);
}
cairo_fill (cr);
cairo_destroy (cr);
priv->xsrc = x;
priv->ysrc = y;
}
}
}