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/.
29 #include <glib/gprintf.h>
32 #include "gtkhruler.h"
35 #define RULER_HEIGHT 14
36 #define MINIMUM_INCR 5
37 #define MAXIMUM_SUBDIVIDE 5
38 #define MAXIMUM_SCALES 10
40 #define ROUND(x) ((int) ((x) + 0.5))
43 static void gtk_hruler_class_init (GtkHRulerClass *klass);
44 static void gtk_hruler_init (GtkHRuler *hruler);
45 static gint gtk_hruler_motion_notify (GtkWidget *widget,
46 GdkEventMotion *event);
47 static void gtk_hruler_draw_ticks (GtkRuler *ruler);
48 static void gtk_hruler_draw_pos (GtkRuler *ruler);
52 gtk_hruler_get_type (void)
54 static GType hruler_type = 0;
58 static const GTypeInfo hruler_info =
60 sizeof (GtkHRulerClass),
62 NULL, /* base_finalize */
63 (GClassInitFunc) gtk_hruler_class_init,
64 NULL, /* class_finalize */
65 NULL, /* class_data */
68 (GInstanceInitFunc) gtk_hruler_init,
71 hruler_type = g_type_register_static (GTK_TYPE_RULER, "GtkHRuler",
79 gtk_hruler_class_init (GtkHRulerClass *klass)
81 GtkWidgetClass *widget_class;
82 GtkRulerClass *ruler_class;
84 widget_class = (GtkWidgetClass*) klass;
85 ruler_class = (GtkRulerClass*) klass;
87 widget_class->motion_notify_event = gtk_hruler_motion_notify;
89 ruler_class->draw_ticks = gtk_hruler_draw_ticks;
90 ruler_class->draw_pos = gtk_hruler_draw_pos;
94 gtk_hruler_init (GtkHRuler *hruler)
98 widget = GTK_WIDGET (hruler);
99 widget->requisition.width = widget->style->xthickness * 2 + 1;
100 widget->requisition.height = widget->style->ythickness * 2 + RULER_HEIGHT;
105 gtk_hruler_new (void)
107 return g_object_new (GTK_TYPE_HRULER, NULL);
111 gtk_hruler_motion_notify (GtkWidget *widget,
112 GdkEventMotion *event)
117 ruler = GTK_RULER (widget);
120 gdk_window_get_pointer (widget->window, &x, NULL, NULL);
124 ruler->position = ruler->lower + ((ruler->upper - ruler->lower) * x) / widget->allocation.width;
125 g_object_notify (G_OBJECT (ruler), "position");
127 /* Make sure the ruler has been allocated already */
128 if (ruler->backing_store != NULL)
129 gtk_ruler_draw_pos (ruler);
135 gtk_hruler_draw_ticks (GtkRuler *ruler)
143 gint length, ideal_length;
144 gdouble lower, upper; /* Upper and lower limits, in ruler units */
145 gdouble increment; /* Number of pixels per unit */
146 gint scale; /* Number of units per major unit */
148 gdouble start, end, cur;
155 PangoRectangle logical_rect, ink_rect;
157 if (!GTK_WIDGET_DRAWABLE (ruler))
160 widget = GTK_WIDGET (ruler);
162 xthickness = widget->style->xthickness;
163 ythickness = widget->style->ythickness;
165 layout = gtk_widget_create_pango_layout (widget, "012456789");
166 pango_layout_get_extents (layout, &ink_rect, &logical_rect);
168 digit_height = PANGO_PIXELS (ink_rect.height) + 2;
169 digit_offset = ink_rect.y;
171 width = widget->allocation.width;
172 height = widget->allocation.height - ythickness * 2;
174 gtk_paint_box (widget->style, ruler->backing_store,
175 GTK_STATE_NORMAL, GTK_SHADOW_OUT,
176 NULL, widget, "hruler",
178 widget->allocation.width, widget->allocation.height);
180 cr = gdk_drawable_create_cairo_context (ruler->backing_store);
181 gdk_cairo_set_source_color (cr, &widget->style->fg[widget->state]);
186 widget->allocation.width - 2 * xthickness,
189 upper = ruler->upper / ruler->metric->pixels_per_unit;
190 lower = ruler->lower / ruler->metric->pixels_per_unit;
192 if ((upper - lower) == 0)
194 increment = (gdouble) width / (upper - lower);
196 /* determine the scale
197 * We calculate the text size as for the vruler instead of using
198 * text_width = gdk_string_width(font, unit_str), so that the result
199 * for the scale looks consistent with an accompanying vruler
201 scale = ceil (ruler->max_size / ruler->metric->pixels_per_unit);
202 g_snprintf (unit_str, sizeof (unit_str), "%d", scale);
203 text_width = strlen (unit_str) * digit_height + 1;
205 for (scale = 0; scale < MAXIMUM_SCALES; scale++)
206 if (ruler->metric->ruler_scale[scale] * fabs(increment) > 2 * text_width)
209 if (scale == MAXIMUM_SCALES)
210 scale = MAXIMUM_SCALES - 1;
212 /* drawing starts here */
214 for (i = MAXIMUM_SUBDIVIDE - 1; i >= 0; i--)
216 subd_incr = (gdouble) ruler->metric->ruler_scale[scale] /
217 (gdouble) ruler->metric->subdivide[i];
218 if (subd_incr * fabs(increment) <= MINIMUM_INCR)
221 /* Calculate the length of the tickmarks. Make sure that
222 * this length increases for each set of ticks
224 ideal_length = height / (i + 1) - 1;
225 if (ideal_length > ++length)
226 length = ideal_length;
230 start = floor (lower / subd_incr) * subd_incr;
231 end = ceil (upper / subd_incr) * subd_incr;
235 start = floor (upper / subd_incr) * subd_incr;
236 end = ceil (lower / subd_incr) * subd_incr;
240 for (cur = start; cur <= end; cur += subd_incr)
242 pos = ROUND ((cur - lower) * increment);
245 pos, height + ythickness - length,
251 g_snprintf (unit_str, sizeof (unit_str), "%d", (int) cur);
253 pango_layout_set_text (layout, unit_str, -1);
254 pango_layout_get_extents (layout, &logical_rect, NULL);
256 gtk_paint_layout (widget->style,
257 ruler->backing_store,
258 GTK_WIDGET_STATE (widget),
263 pos + 2, ythickness + PANGO_PIXELS (logical_rect.y - digit_offset),
272 g_object_unref (layout);
276 gtk_hruler_draw_pos (GtkRuler *ruler)
278 GtkWidget *widget = GTK_WIDGET (ruler);
281 gint bs_width, bs_height;
286 if (GTK_WIDGET_DRAWABLE (ruler))
288 xthickness = widget->style->xthickness;
289 ythickness = widget->style->ythickness;
290 width = widget->allocation.width;
291 height = widget->allocation.height - ythickness * 2;
293 bs_width = height / 2 + 2;
294 bs_width |= 1; /* make sure it's odd */
295 bs_height = bs_width / 2 + 1;
297 if ((bs_width > 0) && (bs_height > 0))
299 cairo_t *cr = gdk_drawable_create_cairo_context (widget->window);
301 /* If a backing store exists, restore the ruler */
302 if (ruler->backing_store)
303 gdk_draw_drawable (widget->window,
304 widget->style->black_gc,
305 ruler->backing_store,
306 ruler->xsrc, ruler->ysrc,
307 ruler->xsrc, ruler->ysrc,
308 bs_width, bs_height);
310 increment = (gdouble) width / (ruler->upper - ruler->lower);
312 x = ROUND ((ruler->position - ruler->lower) * increment) + (xthickness - bs_width) / 2 - 1;
313 y = (height + bs_height) / 2 + ythickness;
315 gdk_cairo_set_source_color (cr, &widget->style->fg[widget->state]);
317 cairo_move_to (cr, x, y);
318 cairo_line_to (cr, x + bs_width / 2., y + bs_height);
319 cairo_line_to (cr, x + bs_width, y);