ruler.cpp revision c350508cfbe7720966a9b53c84388ab7e5f2e5ca
#define __SP_RULER_C__
/*
* Customized ruler class for inkscape
*
* Authors:
* Lauris Kaplinski <lauris@kaplinski.com>
* Frank Felfe <innerspace@iname.com>
* bulia byak <buliabyak@users.sf.net>
* Diederik van Lierop <mail@diedenrezi.nl>
*
* Copyright (C) 1999-2008 authors
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#include <cstring>
#include <cmath>
#include <cstdio>
#include "widget-sizes.h"
#include "desktop-widget.h"
#include "ruler.h"
#include "unit-constants.h"
#include "round.h"
#define MINIMUM_INCR 5
#define MAXIMUM_SUBDIVIDE 5
#define MAXIMUM_SCALES 10
#define UNUSED_PIXELS 2 // There appear to be two pixels that are not being used at each end of the ruler
static void sp_hruler_class_init (SPHRulerClass *klass);
static void sp_hruler_init (SPHRuler *hruler);
static gint sp_hruler_motion_notify (GtkWidget *widget, GdkEventMotion *event);
static void sp_hruler_draw_ticks (GtkRuler *ruler);
static void sp_hruler_draw_pos (GtkRuler *ruler);
static void sp_hruler_size_allocate (GtkWidget *widget, GtkAllocation *allocation);
static GtkWidgetClass *hruler_parent_class;
GtkType
sp_hruler_get_type (void)
{
static GtkType hruler_type = 0;
if (!hruler_type)
{
static const GtkTypeInfo hruler_info =
{
"SPHRuler",
sizeof (SPHRuler),
sizeof (SPHRulerClass),
(GtkClassInitFunc) sp_hruler_class_init,
(GtkObjectInitFunc) sp_hruler_init,
/* reserved_1 */ NULL,
/* reserved_2 */ NULL,
(GtkClassInitFunc) NULL,
};
hruler_type = gtk_type_unique (gtk_ruler_get_type (), &hruler_info);
}
return hruler_type;
}
static void
sp_hruler_class_init (SPHRulerClass *klass)
{
GtkWidgetClass *widget_class;
GtkRulerClass *ruler_class;
hruler_parent_class = (GtkWidgetClass *) gtk_type_class (GTK_TYPE_RULER);
widget_class = (GtkWidgetClass*) klass;
ruler_class = (GtkRulerClass*) klass;
widget_class->motion_notify_event = sp_hruler_motion_notify;
widget_class->size_allocate = sp_hruler_size_allocate;
ruler_class->draw_ticks = sp_hruler_draw_ticks;
ruler_class->draw_pos = sp_hruler_draw_pos;
}
static void
sp_hruler_init (SPHRuler *hruler)
{
GtkWidget *widget;
widget = GTK_WIDGET (hruler);
widget->requisition.width = widget->style->xthickness * 2 + 1;
widget->requisition.height = widget->style->ythickness * 2 + RULER_HEIGHT;
}
GtkWidget*
sp_hruler_new (void)
{
return GTK_WIDGET (gtk_type_new (sp_hruler_get_type ()));
}
static gint
sp_hruler_motion_notify (GtkWidget *widget,
GdkEventMotion *event)
{
GtkRuler *ruler;
g_return_val_if_fail (widget != NULL, FALSE);
g_return_val_if_fail (SP_IS_HRULER (widget), FALSE);
g_return_val_if_fail (event != NULL, FALSE);
ruler = GTK_RULER (widget);
double x = event->x; //Although event->x is double according to the docs, it only appears to return integers
ruler->position = ruler->lower + (ruler->upper - ruler->lower) * (x + UNUSED_PIXELS) / (widget->allocation.width + 2*UNUSED_PIXELS);
/* Make sure the ruler has been allocated already */
if (ruler->backing_store != NULL)
gtk_ruler_draw_pos (ruler);
return FALSE;
}
static void
sp_hruler_draw_ticks (GtkRuler *ruler)
{
GtkWidget *widget;
GdkGC *gc, *bg_gc;
PangoFontDescription *pango_desc;
PangoContext *pango_context;
PangoLayout *pango_layout;
gint i, tick_index;
gint width, height;
gint xthickness;
gint ythickness;
gint length, ideal_length;
double lower, upper; /* Upper and lower limits, in ruler units */
double increment; /* Number of pixels per unit */
gint scale; /* Number of units per major unit */
double subd_incr;
double start, end, cur;
gchar unit_str[32];
gint digit_height;
gint text_width;
gint pos;
g_return_if_fail (ruler != NULL);
g_return_if_fail (SP_IS_HRULER (ruler));
if (!GTK_WIDGET_DRAWABLE (ruler))
return;
widget = GTK_WIDGET (ruler);
gc = widget->style->fg_gc[GTK_STATE_NORMAL];
bg_gc = widget->style->bg_gc[GTK_STATE_NORMAL];
pango_desc = widget->style->font_desc;
// Create the pango layout
pango_context = gtk_widget_get_pango_context (widget);
pango_layout = pango_layout_new (pango_context);
PangoFontDescription *fs = pango_font_description_new ();
pango_font_description_set_size (fs, RULER_FONT_SIZE);
pango_layout_set_font_description (pango_layout, fs);
pango_font_description_free (fs);
digit_height = (int) floor (RULER_FONT_SIZE * RULER_FONT_VERTICAL_SPACING / PANGO_SCALE + 0.5);
xthickness = widget->style->xthickness;
ythickness = widget->style->ythickness;
width = widget->allocation.width; // in pixels; is apparently 2 pixels shorter than the canvas at each end
height = widget->allocation.height;// - ythickness * 2;
gtk_paint_box (widget->style, ruler->backing_store,
GTK_STATE_NORMAL, GTK_SHADOW_NONE,
NULL, widget, "hruler",
0, 0,
widget->allocation.width, widget->allocation.height);
upper = ruler->upper / ruler->metric->pixels_per_unit; // upper and lower are expressed in ruler units
lower = ruler->lower / ruler->metric->pixels_per_unit;
/* "pixels_per_unit" should be "points_per_unit". This is the size of the unit
* in 1/72nd's of an inch and has nothing to do with screen pixels */
if ((upper - lower) == 0)
return;
increment = (double) (width + 2*UNUSED_PIXELS) / (upper - lower); // screen pixels per ruler unit
/* determine the scale
* We calculate the text size as for the vruler instead of using
* text_width = gdk_string_width(font, unit_str), so that the result
* for the scale looks consistent with an accompanying vruler
*/
scale = (int)(ceil (ruler->max_size / ruler->metric->pixels_per_unit));
sprintf (unit_str, "%d", scale);
text_width = strlen (unit_str) * digit_height + 1;
for (scale = 0; scale < MAXIMUM_SCALES; scale++)
if (ruler->metric->ruler_scale[scale] * fabs(increment) > 2 * text_width)
break;
if (scale == MAXIMUM_SCALES)
scale = MAXIMUM_SCALES - 1;
/* drawing starts here */
length = 0;
for (i = MAXIMUM_SUBDIVIDE - 1; i >= 0; i--)
{
subd_incr = ruler->metric->ruler_scale[scale] /
ruler->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;
}
tick_index = 0;
cur = start; // location (in ruler units) of the first invisible tick at the left side of the canvas
while (cur <= end)
{
// due to the typical values for cur, lower and increment, pos will often end up to
// be e.g. 641.50000000000; rounding behaviour is not defined in such a case (see round.h)
// and jitter will be apparent (upon redrawing some of the lines on the ruler might jump a
// by a pixel, and jump back on the next redraw). This is suppressed by adding 1e-9 (that's only one nanopixel ;-))
pos = int(Inkscape::round((cur - lower) * increment + 1e-12)) - UNUSED_PIXELS;
gdk_draw_line (ruler->backing_store, gc,
pos, height + ythickness,
pos, height - length + ythickness);
/* draw label */
double label_spacing_px = (increment*(double)ruler->metric->ruler_scale[scale])/ruler->metric->subdivide[i];
if (i == 0 &&
(label_spacing_px > 6*digit_height || tick_index%2 == 0 || cur == 0) &&
(label_spacing_px > 3*digit_height || tick_index%4 == 0 || cur == 0))
{
if (fabs((int)cur) >= 2000 && (((int) cur)/1000)*1000 == ((int) cur))
sprintf (unit_str, "%dk", ((int) cur)/1000);
else
sprintf (unit_str, "%d", (int) cur);
pango_layout_set_text (pango_layout, unit_str, -1);
gdk_draw_layout (ruler->backing_store, gc,
pos + 2, 0, pango_layout);
}
/* Calculate cur from start rather than incrementing by subd_incr
* in each iteration. This is to avoid propagation of floating point
* errors in subd_incr.
*/
++tick_index;
cur = start + tick_index * subd_incr;
}
}
}
static void
sp_hruler_draw_pos (GtkRuler *ruler)
{
GtkWidget *widget;
GdkGC *gc;
int i;
gint x, y;
gint width, height;
gint bs_width, bs_height;
gint xthickness;
gint ythickness;
gfloat increment;
g_return_if_fail (ruler != NULL);
g_return_if_fail (SP_IS_HRULER (ruler));
if (GTK_WIDGET_DRAWABLE (ruler))
{
widget = GTK_WIDGET (ruler);
gc = widget->style->fg_gc[GTK_STATE_NORMAL];
xthickness = widget->style->xthickness;
ythickness = widget->style->ythickness;
width = widget->allocation.width; // in pixels; is apparently 2 pixels shorter than the canvas at each end
height = widget->allocation.height - ythickness * 2;
bs_width = height / 2;
bs_width |= 1; /* make sure it's odd */
bs_height = bs_width / 2 + 1;
if ((bs_width > 0) && (bs_height > 0))
{
/* If a backing store exists, restore the ruler */
if (ruler->backing_store && ruler->non_gr_exp_gc)
gdk_draw_pixmap (ruler->widget.window,
ruler->non_gr_exp_gc,
ruler->backing_store,
ruler->xsrc, ruler->ysrc,
ruler->xsrc, ruler->ysrc,
bs_width, bs_height);
increment = (gfloat) (width + 2*UNUSED_PIXELS) / (ruler->upper - ruler->lower);
// Calculate the coordinates (x, y, in pixels) of the tip of the triangle
x = int(Inkscape::round((ruler->position - ruler->lower) * increment + double(xthickness - bs_width) / 2.0) - UNUSED_PIXELS);
y = (height + bs_height) / 2 + ythickness;
for (i = 0; i < bs_height; i++)
gdk_draw_line (widget->window, gc,
x + i, y + i,
x + bs_width - 1 - i, y + i);
ruler->xsrc = x;
ruler->ysrc = y;
}
}
}
/**
* The hruler widget's size_allocate callback.
*/
static void
sp_hruler_size_allocate (GtkWidget *widget, GtkAllocation *allocation)
{
g_assert (widget != NULL);
g_assert (SP_IS_HRULER (widget));
// First call the default gtk_widget_size_allocate() method (which is being overridden here)
if (GTK_WIDGET_CLASS (hruler_parent_class)->size_allocate)
(* GTK_WIDGET_CLASS (hruler_parent_class)->size_allocate) (widget, allocation);
// Now the size of the ruler has changed, the ruler bounds (upper & lower) need to be updated
// For this we first need to obtain a pointer to the desktop, by walking up the tree of ancestors
GtkWidget *parent = gtk_widget_get_parent(widget);
do {
if (SP_IS_DESKTOP_WIDGET(parent)) {
// Now we've found the desktop widget we can have the ruler boundaries updated
sp_desktop_widget_update_hruler(SP_DESKTOP_WIDGET(parent));
// If the size of the ruler has increased, then a blank part is uncovered; therefore
// it must be redrawn
sp_hruler_draw_ticks(GTK_RULER(widget));
break;
}
parent = gtk_widget_get_parent(parent);
} while (parent != NULL);
}
// vruler
static void sp_vruler_class_init (SPVRulerClass *klass);
static void sp_vruler_init (SPVRuler *vruler);
static gint sp_vruler_motion_notify (GtkWidget *widget,
GdkEventMotion *event);
static void sp_vruler_draw_ticks (GtkRuler *ruler);
static void sp_vruler_draw_pos (GtkRuler *ruler);
static void sp_vruler_size_allocate (GtkWidget *widget, GtkAllocation *allocation);
static GtkWidgetClass *vruler_parent_class;
GtkType
sp_vruler_get_type (void)
{
static GtkType vruler_type = 0;
if (!vruler_type)
{
static const GtkTypeInfo vruler_info =
{
"SPVRuler",
sizeof (SPVRuler),
sizeof (SPVRulerClass),
(GtkClassInitFunc) sp_vruler_class_init,
(GtkObjectInitFunc) sp_vruler_init,
/* reserved_1 */ NULL,
/* reserved_2 */ NULL,
(GtkClassInitFunc) NULL,
};
vruler_type = gtk_type_unique (gtk_ruler_get_type (), &vruler_info);
}
return vruler_type;
}
static void
sp_vruler_class_init (SPVRulerClass *klass)
{
GtkWidgetClass *widget_class;
GtkRulerClass *ruler_class;
vruler_parent_class = (GtkWidgetClass *) gtk_type_class (GTK_TYPE_RULER);
widget_class = (GtkWidgetClass*) klass;
ruler_class = (GtkRulerClass*) klass;
widget_class->motion_notify_event = sp_vruler_motion_notify;
widget_class->size_allocate = sp_vruler_size_allocate;
ruler_class->draw_ticks = sp_vruler_draw_ticks;
ruler_class->draw_pos = sp_vruler_draw_pos;
}
static void
sp_vruler_init (SPVRuler *vruler)
{
GtkWidget *widget;
widget = GTK_WIDGET (vruler);
widget->requisition.width = widget->style->xthickness * 2 + RULER_WIDTH;
widget->requisition.height = widget->style->ythickness * 2 + 1;
}
GtkWidget*
sp_vruler_new (void)
{
return GTK_WIDGET (gtk_type_new (sp_vruler_get_type ()));
}
static gint
sp_vruler_motion_notify (GtkWidget *widget,
GdkEventMotion *event)
{
GtkRuler *ruler;
g_return_val_if_fail (widget != NULL, FALSE);
g_return_val_if_fail (SP_IS_VRULER (widget), FALSE);
g_return_val_if_fail (event != NULL, FALSE);
ruler = GTK_RULER (widget);
double y = event->y; //Although event->y is double according to the docs, it only appears to return integers
ruler->position = ruler->lower + (ruler->upper - ruler->lower) * (y + UNUSED_PIXELS) / (widget->allocation.height + 2*UNUSED_PIXELS);
/* Make sure the ruler has been allocated already */
if (ruler->backing_store != NULL)
gtk_ruler_draw_pos (ruler);
return FALSE;
}
static void
sp_vruler_draw_ticks (GtkRuler *ruler)
{
GtkWidget *widget;
GdkGC *gc, *bg_gc;
PangoFontDescription *pango_desc;
PangoContext *pango_context;
PangoLayout *pango_layout;
gint i, j, tick_index;
gint width, height;
gint xthickness;
gint ythickness;
gint length, ideal_length;
double lower, upper; /* Upper and lower limits, in ruler units */
double increment; /* Number of pixels per unit */
gint scale; /* Number of units per major unit */
double subd_incr;
double start, end, cur;
gchar unit_str[32];
gchar digit_str[2] = { '\0', '\0' };
gint digit_height;
gint text_height;
gint pos;
g_return_if_fail (ruler != NULL);
g_return_if_fail (SP_IS_VRULER (ruler));
if (!GTK_WIDGET_DRAWABLE (ruler))
return;
widget = GTK_WIDGET (ruler);
gc = widget->style->fg_gc[GTK_STATE_NORMAL];
bg_gc = widget->style->bg_gc[GTK_STATE_NORMAL];
pango_desc = widget->style->font_desc;
// Create the pango layout
pango_context = gtk_widget_get_pango_context (widget);
pango_layout = pango_layout_new (pango_context);
PangoFontDescription *fs = pango_font_description_new ();
pango_font_description_set_size (fs, RULER_FONT_SIZE);
pango_layout_set_font_description (pango_layout, fs);
pango_font_description_free (fs);
digit_height = (int) floor (RULER_FONT_SIZE * RULER_FONT_VERTICAL_SPACING / PANGO_SCALE + 0.5);
xthickness = widget->style->xthickness;
ythickness = widget->style->ythickness;
width = widget->allocation.height; //in pixels; is apparently 2 pixels shorter than the canvas at each end
height = widget->allocation.width;// - ythickness * 2;
gtk_paint_box (widget->style, ruler->backing_store,
GTK_STATE_NORMAL, GTK_SHADOW_NONE,
NULL, widget, "vruler",
0, 0,
widget->allocation.width, widget->allocation.height);
upper = ruler->upper / ruler->metric->pixels_per_unit; // upper and lower are expressed in ruler units
lower = ruler->lower / ruler->metric->pixels_per_unit;
/* "pixels_per_unit" should be "points_per_unit". This is the size of the unit
* in 1/72nd's of an inch and has nothing to do with screen pixels */
if ((upper - lower) == 0)
return;
increment = (double) (width + 2*UNUSED_PIXELS) / (upper - lower); // screen pixels per ruler unit
/* determine the scale
* 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 = (int)ceil (ruler->max_size / ruler->metric->pixels_per_unit);
sprintf (unit_str, "%d", scale);
text_height = strlen (unit_str) * digit_height + 1;
for (scale = 0; scale < MAXIMUM_SCALES; scale++)
if (ruler->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 = (double) ruler->metric->ruler_scale[scale] /
(double) ruler->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;
}
tick_index = 0;
cur = start; // location (in ruler units) of the first invisible tick at the top side of the canvas
while (cur < end) {
// due to the typical values for cur, lower and increment, pos will often end up to
// be e.g. 641.50000000000; rounding behaviour is not defined in such a case (see round.h)
// and jitter will be apparent (upon redrawing some of the lines on the ruler might jump a
// by a pixel, and jump back on the next redraw). This is suppressed by adding 1e-9 (that's only one nanopixel ;-))
pos = int(Inkscape::round((cur - lower) * increment + 1e-12)) - UNUSED_PIXELS;
gdk_draw_line (ruler->backing_store, gc,
height + xthickness - length, pos,
height + xthickness, pos);
/* draw label */
double label_spacing_px = fabs((increment*(double)ruler->metric->ruler_scale[scale])/ruler->metric->subdivide[i]);
if (i == 0 &&
(label_spacing_px > 6*digit_height || tick_index%2 == 0 || cur == 0) &&
(label_spacing_px > 3*digit_height || tick_index%4 == 0 || cur == 0))
{
if (fabs((int)cur) >= 2000 && (((int) cur)/1000)*1000 == ((int) cur))
sprintf (unit_str, "%dk", ((int) cur)/1000);
else
sprintf (unit_str, "%d", (int) cur);
for (j = 0; j < (int) strlen (unit_str); j++)
{
digit_str[0] = unit_str[j];
pango_layout_set_text (pango_layout, digit_str, 1);
gdk_draw_layout (ruler->backing_store, gc,
xthickness + 1,
pos + digit_height * (j) + 1,
pango_layout);
}
}
/* Calculate cur from start rather than incrementing by subd_incr
* in each iteration. This is to avoid propagation of floating point
* errors in subd_incr.
*/
++tick_index;
cur = start + tick_index * subd_incr;
}
}
}
static void
sp_vruler_draw_pos (GtkRuler *ruler)
{
GtkWidget *widget;
GdkGC *gc;
int i;
gint x, y;
gint width, height;
gint bs_width, bs_height;
gint xthickness;
gint ythickness;
gfloat increment;
g_return_if_fail (ruler != NULL);
g_return_if_fail (SP_IS_VRULER (ruler));
if (GTK_WIDGET_DRAWABLE (ruler))
{
widget = GTK_WIDGET (ruler);
gc = widget->style->fg_gc[GTK_STATE_NORMAL];
xthickness = widget->style->xthickness;
ythickness = widget->style->ythickness;
width = widget->allocation.width - xthickness * 2;
height = widget->allocation.height; // in pixels; is apparently 2 pixels shorter than the canvas at each end
bs_height = width / 2;
bs_height |= 1; /* make sure it's odd */
bs_width = bs_height / 2 + 1;
if ((bs_width > 0) && (bs_height > 0))
{
/* If a backing store exists, restore the ruler */
if (ruler->backing_store && ruler->non_gr_exp_gc)
gdk_draw_pixmap (ruler->widget.window,
ruler->non_gr_exp_gc,
ruler->backing_store,
ruler->xsrc, ruler->ysrc,
ruler->xsrc, ruler->ysrc,
bs_width, bs_height);
increment = (gfloat) (height + 2*UNUSED_PIXELS) / (ruler->upper - ruler->lower);
// Calculate the coordinates (x, y, in pixels) of the tip of the triangle
x = (width + bs_width) / 2 + xthickness;
y = int(Inkscape::round((ruler->position - ruler->lower) * increment + double(ythickness - bs_height) / 2.0) - UNUSED_PIXELS);
for (i = 0; i < bs_width; i++)
gdk_draw_line (widget->window, gc,
x + i, y + i,
x + i, y + bs_height - 1 - i);
ruler->xsrc = x;
ruler->ysrc = y;
}
}
}
/**
* The vruler widget's size_allocate callback.
*/
static void
sp_vruler_size_allocate (GtkWidget *widget, GtkAllocation *allocation)
{
g_assert (widget != NULL);
g_assert (SP_IS_VRULER (widget));
// First call the default gtk_widget_size_allocate() method (which is being overridden here)
if (GTK_WIDGET_CLASS (vruler_parent_class)->size_allocate)
(* GTK_WIDGET_CLASS (vruler_parent_class)->size_allocate) (widget, allocation);
// Now the size of the ruler has changed, the ruler bounds (upper & lower) need to be updated
// For this we first need to obtain a pointer to the desktop, by walking up the tree of ancestors
GtkWidget *parent = gtk_widget_get_parent(widget);
do {
if (SP_IS_DESKTOP_WIDGET(parent)) {
// Now we've found the desktop widget we can have the ruler boundaries updated
sp_desktop_widget_update_vruler(SP_DESKTOP_WIDGET(parent));
// If the size of the ruler has increased, then a blank part is uncovered; therefore
// it must be redrawn
sp_vruler_draw_ticks(GTK_RULER(widget));
break;
}
parent = gtk_widget_get_parent(parent);
} while (parent != NULL);
}
/// Ruler metrics.
static GtkRulerMetric const sp_ruler_metrics[] = {
// NOTE: the order of records in this struct must correspond to the SPMetric enum.
{"NONE", "", 1, { 1, 2, 5, 10, 25, 50, 100, 250, 500, 1000 }, { 1, 5, 10, 50, 100 }},
{"millimeters", "mm", PX_PER_MM, { 1, 2, 5, 10, 25, 50, 100, 250, 500, 1000 }, { 1, 5, 10, 50, 100 }},
{"centimeters", "cm", PX_PER_CM, { 1, 2, 5, 10, 25, 50, 100, 250, 500, 1000 }, { 1, 5, 10, 50, 100 }},
{"inches", "in", PX_PER_IN, { 1, 2, 4, 8, 16, 32, 64, 128, 256, 512 }, { 1, 2, 4, 8, 16 }},
{"feet", "ft", PX_PER_FT, { 1, 2, 5, 10, 25, 50, 100, 250, 500, 1000 }, { 1, 5, 10, 50, 100 }},
{"points", "pt", PX_PER_PT, { 1, 2, 5, 10, 25, 50, 100, 250, 500, 1000 }, { 1, 5, 10, 50, 100 }},
{"picas", "pc", PX_PER_PC, { 1, 2, 5, 10, 25, 50, 100, 250, 500, 1000 }, { 1, 5, 10, 50, 100 }},
{"pixels", "px", PX_PER_PX, { 1, 2, 5, 10, 25, 50, 100, 250, 500, 1000 }, { 1, 5, 10, 50, 100 }},
{"meters", "m", PX_PER_M, { 1, 2, 5, 10, 25, 50, 100, 250, 500, 1000 }, { 1, 5, 10, 50, 100 }},
};
void
sp_ruler_set_metric (GtkRuler *ruler,
SPMetric metric)
{
g_return_if_fail (ruler != NULL);
g_return_if_fail (GTK_IS_RULER (ruler));
g_return_if_fail((unsigned) metric < G_N_ELEMENTS(sp_ruler_metrics));
if (metric == 0)
return;
ruler->metric = const_cast<GtkRulerMetric *>(&sp_ruler_metrics[metric]);
if (GTK_WIDGET_DRAWABLE (ruler))
gtk_widget_queue_draw (GTK_WIDGET (ruler));
}