#define __SP_RULER_C__

/*
 * Customized ruler class for inkscape
 *
 * Authors:
 *   Lauris Kaplinski <lauris@kaplinski.com>
 *   Frank Felfe <innerspace@iname.com>
 *
 * Copyright (C) 1999-2002 authors
 *
 * Released under GNU GPL, read the file 'COPYING' for more information
 */

#include <math.h>
#include <stdio.h>
#include <string.h>
#include "widget-sizes.h"
#include "ruler.h"

#define MINIMUM_INCR          5
#define MAXIMUM_SUBDIVIDE     5
#define MAXIMUM_SCALES        10

#define ROUND(x) ((int) ((x) + 0.5))


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);


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;

  widget_class = (GtkWidgetClass*) klass;
  ruler_class = (GtkRulerClass*) klass;

  widget_class->motion_notify_event = sp_hruler_motion_notify;

  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;
  gint x;

  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);

  if (event->is_hint)
    gdk_window_get_pointer (widget->window, &x, NULL, NULL);
  else
    x = (int)event->x;

  ruler->position = ruler->lower + ((ruler->upper - ruler->lower) * x) / widget->allocation.width;

  /*  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;
  gint width, height;
  gint xthickness;
  gint ythickness;
  gint length, ideal_length;
  gfloat lower, upper;		/* Upper and lower limits, in ruler units */
  gfloat increment;		/* Number of pixels per unit */
  gint scale;			/* Number of units per major unit */
  gfloat subd_incr;
  gfloat 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;
  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;
  lower = ruler->lower / ruler->metric->pixels_per_unit;

  if ((upper - lower) == 0) 
    return;
  increment = (gfloat) width / (upper - lower);

  /* 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 = (gfloat) ruler->metric->ruler_scale[scale] / 
	          (gfloat) 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;
	}

  
      for (cur = start; cur <= end; cur += subd_incr)
	{
	  pos = ROUND ((cur - lower) * increment);

	  gdk_draw_line (ruler->backing_store, gc,
			 pos, height + ythickness, 
			 pos, height - length + ythickness);

	  /* draw label */
	  if (i == 0)
	    {
	      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);
	    }
	}
    }
}

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;
      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 / (ruler->upper - ruler->lower);

	  x = ROUND ((ruler->position - ruler->lower) * increment) + (xthickness - bs_width) / 2 - 1;
	  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;
	}
    }
}





// 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);


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;

  widget_class = (GtkWidgetClass*) klass;
  ruler_class = (GtkRulerClass*) klass;

  widget_class->motion_notify_event = sp_vruler_motion_notify;

  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;
  gint y;

  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);

  if (event->is_hint)
    gdk_window_get_pointer (widget->window, NULL, &y, NULL);
  else
    y = (int)event->y;

  ruler->position = ruler->lower + ((ruler->upper - ruler->lower) * y) / widget->allocation.height;

  /*  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;
  gint width, height;
  gint xthickness;
  gint ythickness;
  gint length, ideal_length;
  gfloat lower, upper;		/* Upper and lower limits, in ruler units */
  gfloat increment;		/* Number of pixels per unit */
  gint scale;			/* Number of units per major unit */
  gfloat subd_incr;
  gfloat 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;
  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;
  lower = ruler->lower / ruler->metric->pixels_per_unit;

  if ((upper - lower) == 0)
    return;
  increment = (gfloat) width / (upper - lower);

  /* 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 = (gfloat) ruler->metric->ruler_scale[scale] / 
	          (gfloat) 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;
	}

        
      for (cur = start; cur <= end; cur += subd_incr)
	{
	  pos = ROUND ((cur - lower) * increment);

	  gdk_draw_line (ruler->backing_store, gc,
			 height + xthickness - length, pos,
			 height + xthickness, pos);

	  /* draw label */
	  if (i == 0)
	    {

	      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); 
		}
	    }
	}
    }
}

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;

      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 / (ruler->upper - ruler->lower);

	  x = (width + bs_width) / 2 + xthickness;
	  y = ROUND ((ruler->position - ruler->lower) * increment) + (ythickness - bs_height) / 2 - 1;

	  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;
	}
    }
}


void
sp_ruler_set_metric (GtkRuler *ruler,
		     SPMetric  metric)
{
  g_return_if_fail (ruler != NULL);
  g_return_if_fail (GTK_IS_RULER (ruler));

  ruler->metric = (GtkRulerMetric *) &sp_ruler_metrics[metric];

  if (GTK_WIDGET_DRAWABLE (ruler))
    gtk_widget_queue_draw (GTK_WIDGET (ruler));
}

