#define __SP_RULER_C__

#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;

sp_hruler_get_type (void)

{

//TODO: switch to GObject

// GtkType and such calls were deprecated a while back with the

// introduction of GObject as a separate layer, with GType instead. --JonCruz

static GtkType hruler_type = 0;

if (!hruler_type)

{

static const GtkTypeInfo hruler_info =

{

(gchar*) "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

if ((upper - lower) == 0)

return;

increment = (double) (width + 2*UNUSED_PIXELS) / (upper - lower); // screen pixels per ruler unit

/* determine the scale

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

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

++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;

}

}

}

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);

}

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;

sp_vruler_get_type (void)

{

//TODO: switch to GObject

// GtkType and such calls were deprecated a while back with the

// introduction of GObject as a separate layer, with GType instead. --JonCruz

static GtkType vruler_type = 0;

if (!vruler_type)

{

static const GtkTypeInfo vruler_info =

{

(gchar*) "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

if ((upper - lower) == 0)

return;

increment = (double) (width + 2*UNUSED_PIXELS) / (upper - lower); // screen pixels per ruler unit

/* determine the scale

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

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

++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;

}

}

}

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);

}

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 }},

};

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));

}