1 /* GTK - The GIMP Toolkit
2 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
14 * You should have received a copy of the GNU Library General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
22 #include "gtkvruler.h"
25 #define RULER_WIDTH 14
26 #define MINIMUM_INCR 5
27 #define MAXIMUM_SUBDIVIDE 5
28 #define MAXIMUM_SCALES 10
30 #define ROUND(x) ((int) ((x) + 0.5))
33 static void gtk_vruler_class_init (GtkVRulerClass *klass);
34 static void gtk_vruler_init (GtkVRuler *vruler);
35 static gint gtk_vruler_motion_notify (GtkWidget *widget,
36 GdkEventMotion *event);
37 static void gtk_vruler_draw_ticks (GtkRuler *ruler);
38 static void gtk_vruler_draw_pos (GtkRuler *ruler);
42 gtk_vruler_get_type (void)
44 static guint vruler_type = 0;
48 GtkTypeInfo vruler_info =
52 sizeof (GtkVRulerClass),
53 (GtkClassInitFunc) gtk_vruler_class_init,
54 (GtkObjectInitFunc) gtk_vruler_init,
55 /* reversed_1 */ NULL,
56 /* reversed_2 */ NULL,
57 (GtkClassInitFunc) NULL,
60 vruler_type = gtk_type_unique (gtk_ruler_get_type (), &vruler_info);
67 gtk_vruler_class_init (GtkVRulerClass *klass)
69 GtkWidgetClass *widget_class;
70 GtkRulerClass *ruler_class;
72 widget_class = (GtkWidgetClass*) klass;
73 ruler_class = (GtkRulerClass*) klass;
75 widget_class->motion_notify_event = gtk_vruler_motion_notify;
77 ruler_class->draw_ticks = gtk_vruler_draw_ticks;
78 ruler_class->draw_pos = gtk_vruler_draw_pos;
82 gtk_vruler_init (GtkVRuler *vruler)
86 widget = GTK_WIDGET (vruler);
87 widget->requisition.width = widget->style->klass->xthickness * 2 + RULER_WIDTH;
88 widget->requisition.height = widget->style->klass->ythickness * 2 + 1;
94 return GTK_WIDGET (gtk_type_new (gtk_vruler_get_type ()));
99 gtk_vruler_motion_notify (GtkWidget *widget,
100 GdkEventMotion *event)
105 g_return_val_if_fail (widget != NULL, FALSE);
106 g_return_val_if_fail (GTK_IS_VRULER (widget), FALSE);
107 g_return_val_if_fail (event != NULL, FALSE);
109 ruler = GTK_RULER (widget);
112 gdk_window_get_pointer (widget->window, NULL, &y, NULL);
116 ruler->position = ruler->lower + ((ruler->upper - ruler->lower) * y) / widget->allocation.height;
118 /* Make sure the ruler has been allocated already */
119 if (ruler->backing_store != NULL)
120 gtk_ruler_draw_pos (ruler);
126 gtk_vruler_draw_ticks (GtkRuler *ruler)
135 gint length, ideal_length;
136 gfloat lower, upper; /* Upper and lower limits, in ruler units */
137 gfloat increment; /* Number of pixels per unit */
138 gint scale; /* Number of units per major unit */
140 gfloat start, end, cur;
142 gchar digit_str[2] = { '\0', '\0' };
147 g_return_if_fail (ruler != NULL);
148 g_return_if_fail (GTK_IS_VRULER (ruler));
150 if (!GTK_WIDGET_DRAWABLE (ruler))
153 widget = GTK_WIDGET (ruler);
155 gc = widget->style->fg_gc[GTK_STATE_NORMAL];
156 bg_gc = widget->style->bg_gc[GTK_STATE_NORMAL];
157 font = widget->style->font;
158 xthickness = widget->style->klass->xthickness;
159 ythickness = widget->style->klass->ythickness;
160 digit_height = font->ascent; /* assume descent == 0 ? */
162 width = widget->allocation.height;
163 height = widget->allocation.width - ythickness * 2;
165 gdk_draw_line (ruler->backing_store, gc,
169 widget->allocation.height - ythickness);
171 upper = ruler->upper / ruler->metric->pixels_per_unit;
172 lower = ruler->lower / ruler->metric->pixels_per_unit;
174 if ((upper - lower) == 0)
176 increment = (gfloat) width / (upper - lower);
178 /* determine the scale
179 * use the maximum extents of the ruler to determine the largest
180 * possible number to be displayed. Calculate the height in pixels
181 * of this displayed text. Use this height to find a scale which
182 * leaves sufficient room for drawing the ruler.
184 scale = ceil (ruler->max_size / ruler->metric->pixels_per_unit);
185 sprintf (unit_str, "%d", scale);
186 text_height = strlen (unit_str) * digit_height + 1;
188 for (scale = 0; scale < MAXIMUM_SCALES; scale++)
189 if (ruler->metric->ruler_scale[scale] * fabs(increment) > 2 * text_height)
192 if (scale == MAXIMUM_SCALES)
193 scale = MAXIMUM_SCALES - 1;
195 /* drawing starts here */
197 for (i = MAXIMUM_SUBDIVIDE - 1; i >= 0; i--)
199 subd_incr = (gfloat) ruler->metric->ruler_scale[scale] /
200 (gfloat) ruler->metric->subdivide[i];
201 if (subd_incr * fabs(increment) <= MINIMUM_INCR)
204 /* Calculate the length of the tickmarks. Make sure that
205 * this length increases for each set of ticks
207 ideal_length = height / (i + 1) - 1;
208 if (ideal_length > ++length)
209 length = ideal_length;
213 start = floor (lower / subd_incr) * subd_incr;
214 end = ceil (upper / subd_incr) * subd_incr;
218 start = floor (upper / subd_incr) * subd_incr;
219 end = ceil (lower / subd_incr) * subd_incr;
222 for (cur = start; cur <= end; cur += subd_incr)
224 pos = ROUND ((cur - lower) * increment);
226 gdk_draw_line (ruler->backing_store, gc,
227 height + xthickness - length, pos,
228 height + xthickness, pos);
233 sprintf (unit_str, "%d", (int) cur);
234 for (j = 0; j < (int) strlen (unit_str); j++)
236 digit_str[0] = unit_str[j];
237 gdk_draw_rectangle (ruler->backing_store,
240 pos + digit_height * j + 1,
241 gdk_string_width(font, digit_str),
243 gdk_draw_string (ruler->backing_store, font, gc,
245 pos + digit_height * (j + 1) + 1,
255 gtk_vruler_draw_pos (GtkRuler *ruler)
262 gint bs_width, bs_height;
267 g_return_if_fail (ruler != NULL);
268 g_return_if_fail (GTK_IS_VRULER (ruler));
270 if (GTK_WIDGET_DRAWABLE (ruler))
272 widget = GTK_WIDGET (ruler);
274 gc = widget->style->fg_gc[GTK_STATE_NORMAL];
275 xthickness = widget->style->klass->xthickness;
276 ythickness = widget->style->klass->ythickness;
277 width = widget->allocation.width - xthickness * 2;
278 height = widget->allocation.height;
280 bs_height = width / 2;
281 bs_height |= 1; /* make sure it's odd */
282 bs_width = bs_height / 2 + 1;
284 if ((bs_width > 0) && (bs_height > 0))
286 /* If a backing store exists, restore the ruler */
287 if (ruler->backing_store && ruler->non_gr_exp_gc)
288 gdk_draw_pixmap (ruler->widget.window,
289 ruler->non_gr_exp_gc,
290 ruler->backing_store,
291 ruler->xsrc, ruler->ysrc,
292 ruler->xsrc, ruler->ysrc,
293 bs_width, bs_height);
295 increment = (gfloat) height / (ruler->upper - ruler->lower);
297 x = (width + bs_width) / 2 + xthickness;
298 y = ROUND ((ruler->position - ruler->lower) * increment) + (ythickness - bs_height) / 2 - 1;
300 for (i = 0; i < bs_width; i++)
301 gdk_draw_line (widget->window, gc,
303 x + i, y + bs_height - 1 - i);