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 Lesser 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 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser 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.
21 * Modified by the GTK+ Team and others 1997-2000. See the AUTHORS
22 * file for a list of people on the GTK+ Team. See the ChangeLog
23 * files for a list of changes. These files are distributed with
24 * GTK+ at ftp://ftp.gtk.org/pub/gtk/.
31 #include "gtkvruler.h"
33 #include <glib/gprintf.h>
36 #define RULER_WIDTH 14
37 #define MINIMUM_INCR 5
38 #define MAXIMUM_SUBDIVIDE 5
39 #define MAXIMUM_SCALES 10
41 #define ROUND(x) ((int) ((x) + 0.5))
44 static void gtk_vruler_class_init (GtkVRulerClass *klass);
45 static void gtk_vruler_init (GtkVRuler *vruler);
46 static gint gtk_vruler_motion_notify (GtkWidget *widget,
47 GdkEventMotion *event);
48 static void gtk_vruler_draw_ticks (GtkRuler *ruler);
49 static void gtk_vruler_draw_pos (GtkRuler *ruler);
53 gtk_vruler_get_type (void)
55 static GType vruler_type = 0;
59 static const GTypeInfo vruler_info =
61 sizeof (GtkVRulerClass),
63 NULL, /* base_finalize */
64 (GClassInitFunc) gtk_vruler_class_init,
65 NULL, /* class_finalize */
66 NULL, /* class_data */
69 (GInstanceInitFunc) gtk_vruler_init,
72 vruler_type = g_type_register_static (GTK_TYPE_RULER, "GtkVRuler",
80 gtk_vruler_class_init (GtkVRulerClass *klass)
82 GtkWidgetClass *widget_class;
83 GtkRulerClass *ruler_class;
85 widget_class = (GtkWidgetClass*) klass;
86 ruler_class = (GtkRulerClass*) klass;
88 widget_class->motion_notify_event = gtk_vruler_motion_notify;
90 ruler_class->draw_ticks = gtk_vruler_draw_ticks;
91 ruler_class->draw_pos = gtk_vruler_draw_pos;
95 gtk_vruler_init (GtkVRuler *vruler)
99 widget = GTK_WIDGET (vruler);
100 widget->requisition.width = widget->style->xthickness * 2 + RULER_WIDTH;
101 widget->requisition.height = widget->style->ythickness * 2 + 1;
105 gtk_vruler_new (void)
107 return g_object_new (GTK_TYPE_VRULER, NULL);
112 gtk_vruler_motion_notify (GtkWidget *widget,
113 GdkEventMotion *event)
118 ruler = GTK_RULER (widget);
121 gdk_window_get_pointer (widget->window, NULL, &y, NULL);
125 ruler->position = ruler->lower + ((ruler->upper - ruler->lower) * y) / widget->allocation.height;
126 g_object_notify (G_OBJECT (ruler), "position");
128 /* Make sure the ruler has been allocated already */
129 if (ruler->backing_store != NULL)
130 gtk_ruler_draw_pos (ruler);
136 gtk_vruler_draw_ticks (GtkRuler *ruler)
144 gint length, ideal_length;
145 gdouble lower, upper; /* Upper and lower limits, in ruler units */
146 gdouble increment; /* Number of pixels per unit */
147 gint scale; /* Number of units per major unit */
149 gdouble start, end, cur;
156 PangoRectangle logical_rect, ink_rect;
158 if (!GTK_WIDGET_DRAWABLE (ruler))
161 widget = GTK_WIDGET (ruler);
163 xthickness = widget->style->xthickness;
164 ythickness = widget->style->ythickness;
166 layout = gtk_widget_create_pango_layout (widget, "012456789");
167 pango_layout_get_extents (layout, &ink_rect, &logical_rect);
169 digit_height = PANGO_PIXELS (ink_rect.height) + 2;
170 digit_offset = ink_rect.y;
172 width = widget->allocation.height;
173 height = widget->allocation.width - ythickness * 2;
175 gtk_paint_box (widget->style, ruler->backing_store,
176 GTK_STATE_NORMAL, GTK_SHADOW_OUT,
177 NULL, widget, "vruler",
179 widget->allocation.width, widget->allocation.height);
181 cr = gdk_drawable_create_cairo_context (ruler->backing_store);
182 gdk_cairo_set_source_color (cr, &widget->style->fg[widget->state]);
188 widget->allocation.height - 2 * ythickness);
190 upper = ruler->upper / ruler->metric->pixels_per_unit;
191 lower = ruler->lower / ruler->metric->pixels_per_unit;
193 if ((upper - lower) == 0)
195 increment = (gdouble) width / (upper - lower);
197 /* determine the scale
198 * use the maximum extents of the ruler to determine the largest
199 * possible number to be displayed. Calculate the height in pixels
200 * of this displayed text. Use this height to find a scale which
201 * leaves sufficient room for drawing the ruler.
203 scale = ceil (ruler->max_size / ruler->metric->pixels_per_unit);
204 g_snprintf (unit_str, sizeof (unit_str), "%d", scale);
205 text_height = strlen (unit_str) * digit_height + 1;
207 for (scale = 0; scale < MAXIMUM_SCALES; scale++)
208 if (ruler->metric->ruler_scale[scale] * fabs(increment) > 2 * text_height)
211 if (scale == MAXIMUM_SCALES)
212 scale = MAXIMUM_SCALES - 1;
214 /* drawing starts here */
216 for (i = MAXIMUM_SUBDIVIDE - 1; i >= 0; i--)
218 subd_incr = (gdouble) ruler->metric->ruler_scale[scale] /
219 (gdouble) ruler->metric->subdivide[i];
220 if (subd_incr * fabs(increment) <= MINIMUM_INCR)
223 /* Calculate the length of the tickmarks. Make sure that
224 * this length increases for each set of ticks
226 ideal_length = height / (i + 1) - 1;
227 if (ideal_length > ++length)
228 length = ideal_length;
232 start = floor (lower / subd_incr) * subd_incr;
233 end = ceil (upper / subd_incr) * subd_incr;
237 start = floor (upper / subd_incr) * subd_incr;
238 end = ceil (lower / subd_incr) * subd_incr;
241 for (cur = start; cur <= end; cur += subd_incr)
243 pos = ROUND ((cur - lower) * increment);
246 height + xthickness - length, pos,
252 g_snprintf (unit_str, sizeof (unit_str), "%d", (int) cur);
254 for (j = 0; j < (int) strlen (unit_str); j++)
256 pango_layout_set_text (layout, unit_str + j, 1);
257 pango_layout_get_extents (layout, NULL, &logical_rect);
260 gtk_paint_layout (widget->style,
261 ruler->backing_store,
262 GTK_WIDGET_STATE (widget),
268 pos + digit_height * j + 2 + PANGO_PIXELS (logical_rect.y - digit_offset),
278 g_object_unref (layout);
283 gtk_vruler_draw_pos (GtkRuler *ruler)
285 GtkWidget *widget = GTK_WIDGET (ruler);
288 gint bs_width, bs_height;
293 if (GTK_WIDGET_DRAWABLE (ruler))
295 xthickness = widget->style->xthickness;
296 ythickness = widget->style->ythickness;
297 width = widget->allocation.width - xthickness * 2;
298 height = widget->allocation.height;
300 bs_height = width / 2 + 2;
301 bs_height |= 1; /* make sure it's odd */
302 bs_width = bs_height / 2 + 1;
304 if ((bs_width > 0) && (bs_height > 0))
306 cairo_t *cr = gdk_drawable_create_cairo_context (widget->window);
308 /* If a backing store exists, restore the ruler */
309 if (ruler->backing_store)
310 gdk_draw_drawable (widget->window,
311 widget->style->black_gc,
312 ruler->backing_store,
313 ruler->xsrc, ruler->ysrc,
314 ruler->xsrc, ruler->ysrc,
315 bs_width, bs_height);
317 increment = (gdouble) height / (ruler->upper - ruler->lower);
319 x = (width + bs_width) / 2 + xthickness;
320 y = ROUND ((ruler->position - ruler->lower) * increment) + (ythickness - bs_height) / 2 - 1;
322 gdk_cairo_set_source_color (cr, &widget->style->fg[widget->state]);
324 cairo_move_to (cr, x, y);
325 cairo_line_to (cr, x + bs_width, y + bs_height / 2.);
326 cairo_line_to (cr, x, y + bs_height);