ruler.cpp revision 0d4751e6a02aff68275f3114e880b4420adaf8f1
#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_ruler_common_draw_ticks (GtkRuler *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 GtkWidgetClass *hruler_parent_class;
GType
sp_hruler_get_type (void)
{
static GType hruler_type = 0;
if (!hruler_type)
{
static const GTypeInfo hruler_info = {
sizeof (SPHRulerClass),
NULL, NULL,
(GClassInitFunc) sp_hruler_class_init,
NULL, NULL,
sizeof (SPHRuler),
0,
(GInstanceInitFunc) sp_hruler_init,
NULL
};
hruler_type = g_type_register_static (gtk_ruler_get_type (), "SPHRuler", &hruler_info, (GTypeFlags)0);
}
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;
ruler_class->draw_ticks = sp_ruler_common_draw_ticks;
}
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 (g_object_new (sp_hruler_get_type (), NULL));
}
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
double pos = ruler->lower + (ruler->upper - ruler->lower) * (x + UNUSED_PIXELS) / (widget->allocation.width + 2*UNUSED_PIXELS);
gtk_ruler_set_range(ruler, ruler->lower, ruler->upper, pos, ruler->max_size);
return FALSE;
}
// 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_size_request (GtkWidget *widget, GtkRequisition *requisition);
static GtkWidgetClass *vruler_parent_class;
GType
sp_vruler_get_type (void)
{
static GType vruler_type = 0;
if (!vruler_type)
{
static const GTypeInfo vruler_info = {
sizeof (SPVRulerClass),
NULL, NULL,
(GClassInitFunc) sp_vruler_class_init,
NULL, NULL,
sizeof (SPVRuler),
0,
(GInstanceInitFunc) sp_vruler_init,
NULL
};
vruler_type = g_type_register_static (gtk_ruler_get_type (), "SPVRuler", &vruler_info, (GTypeFlags)0);
}
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_request = sp_vruler_size_request;
ruler_class->draw_ticks = sp_ruler_common_draw_ticks;
}
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;
g_object_set(G_OBJECT(vruler), "orientation", GTK_ORIENTATION_VERTICAL, NULL);
}
GtkWidget*
sp_vruler_new (void)
{
return GTK_WIDGET (g_object_new (sp_vruler_get_type (), NULL));
}
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
double pos = ruler->lower + (ruler->upper - ruler->lower) * (y + UNUSED_PIXELS) / (widget->allocation.height + 2*UNUSED_PIXELS);
gtk_ruler_set_range(ruler, ruler->lower, ruler->upper, pos, ruler->max_size);
return FALSE;
}
static void
sp_vruler_size_request (GtkWidget *widget, GtkRequisition *requisition)
{
requisition->width = widget->style->xthickness * 2 + RULER_WIDTH;
}
static void
sp_ruler_common_draw_ticks (GtkRuler *ruler)
{
GtkWidget *widget;
GdkGC *gc;
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_width, text_height;
gint text_dimension;
gint pos;
GtkOrientation orientation;
g_return_if_fail (ruler != NULL);
if (!gtk_widget_is_drawable (GTK_WIDGET (ruler)))
return;
g_object_get(G_OBJECT(ruler), "orientation", &orientation, NULL);
widget = GTK_WIDGET (ruler);
gc = widget->style->fg_gc[GTK_STATE_NORMAL];
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;
if (orientation == GTK_ORIENTATION_HORIZONTAL) {
width = widget->allocation.width; // in pixels; is apparently 2 pixels shorter than the canvas at each end
height = widget->allocation.height;
} else {
width = widget->allocation.height;
height = widget->allocation.width;
}
gtk_paint_box (widget->style, ruler->backing_store,
GTK_STATE_NORMAL, GTK_SHADOW_NONE, NULL, widget,
orientation == GTK_ORIENTATION_HORIZONTAL ? "hruler" : "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
* For vruler, 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.
* For hruler, 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_dimension = strlen (unit_str) * digit_height + 1;
for (scale = 0; scale < MAXIMUM_SCALES; scale++)
if (ruler->metric->ruler_scale[scale] * fabs(increment) > 2 * text_dimension)
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;
if (orientation == GTK_ORIENTATION_HORIZONTAL) {
gdk_draw_line (ruler->backing_store, gc,
pos, height + ythickness,
pos, height - length + ythickness);
} else {
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);
if (orientation == GTK_ORIENTATION_HORIZONTAL) {
pango_layout_set_text (pango_layout, unit_str, -1);
gdk_draw_layout (ruler->backing_store, gc,
pos + 2, 0, pango_layout);
} else {
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;
}
}
}
//TODO: warning: deprecated conversion from string constant to ‘gchar*’
//
//Turn out to be warnings that we should probably leave in place. The
// pointers/types used need to be read-only. So until we correct the using
// code, those warnings are actually desired. They say "Hey! Fix this". We
// definitely don't want to hide/ignore them. --JonCruz
// TODO address const/non-const gchar* issue:
/// 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_is_drawable (GTK_WIDGET (ruler)))
gtk_widget_queue_draw (GTK_WIDGET (ruler));
}