aboutsummaryrefslogtreecommitdiffstats
path: root/widgets/misc/e-canvas-utils.c
blob: 8189dc12404ef225b859552b96059d50afe40848 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
/*
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 *
 * Authors:
 *      Chris Lahey <clahey@ximian.com>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

#include "e-canvas-utils.h"

void
e_canvas_item_move_absolute (GnomeCanvasItem *item, gdouble dx, gdouble dy)
{
    cairo_matrix_t translate;

    g_return_if_fail (GNOME_IS_CANVAS_ITEM (item));

    cairo_matrix_init_translate (&translate, dx, dy);

    gnome_canvas_item_set_matrix (item, &translate);
}

static double
compute_offset (gint top, gint bottom, gint page_top, gint page_bottom)
{
    gint size = bottom - top;
    gint offset = 0;

    if (top <= page_top && bottom >= page_bottom)
        return 0;

    if (bottom > page_bottom)
        offset = (bottom - page_bottom);
    if (top < page_top + offset)
        offset = (top - page_top);

    if (top <= page_top + offset && bottom >= page_bottom + offset)
        return offset;

    if (top < page_top + size * 3 / 2 + offset)
        offset = top - (page_top + size * 3 / 2);
    if (bottom > page_bottom - size * 3 / 2 + offset)
        offset = bottom - (page_bottom - size * 3 / 2);
    if (top < page_top + size * 3 / 2 + offset)
        offset = top - ((page_top + page_bottom - (bottom - top)) / 2);

    return offset;
}

static void
e_canvas_show_area (GnomeCanvas *canvas, gdouble x1, gdouble y1, gdouble x2, gdouble y2)
{
    GtkAdjustment *h, *v;
    gint dx = 0, dy = 0;
    gdouble page_size;
    gdouble lower;
    gdouble upper;
    gdouble value;

    g_return_if_fail (canvas != NULL);
    g_return_if_fail (GNOME_IS_CANVAS (canvas));

    h = gtk_layout_get_hadjustment (GTK_LAYOUT (canvas));
    page_size = gtk_adjustment_get_page_size (h);
    lower = gtk_adjustment_get_lower (h);
    upper = gtk_adjustment_get_upper (h);
    value = gtk_adjustment_get_value (h);
    dx = compute_offset (x1, x2, value, value + page_size);
    if (dx)
        gtk_adjustment_set_value (h, CLAMP (value + dx, lower, upper - page_size));

    v = gtk_layout_get_vadjustment (GTK_LAYOUT (canvas));
    page_size = gtk_adjustment_get_page_size (v);
    lower = gtk_adjustment_get_lower (v);
    upper = gtk_adjustment_get_upper (v);
    value = gtk_adjustment_get_value (v);
    dy = compute_offset (y1, y2, value, value + page_size);
    if (dy)
        gtk_adjustment_set_value (v, CLAMP (value + dy, lower, upper - page_size));
}

void
e_canvas_item_show_area (GnomeCanvasItem *item, gdouble x1, gdouble y1, gdouble x2, gdouble y2)
{
    g_return_if_fail (item != NULL);
    g_return_if_fail (GNOME_IS_CANVAS_ITEM (item));

    gnome_canvas_item_i2w (item, &x1, &y1);
    gnome_canvas_item_i2w (item, &x2, &y2);

    e_canvas_show_area (item->canvas, x1, y1, x2, y2);
}

static gboolean
e_canvas_area_shown (GnomeCanvas *canvas, gdouble x1, gdouble y1, gdouble x2, gdouble y2)
{
    GtkAdjustment *h, *v;
    gint dx = 0, dy = 0;
    gdouble page_size;
    gdouble lower;
    gdouble upper;
    gdouble value;

    g_return_val_if_fail (canvas != NULL, FALSE);
    g_return_val_if_fail (GNOME_IS_CANVAS (canvas), FALSE);

    h = gtk_layout_get_hadjustment (GTK_LAYOUT (canvas));
    page_size = gtk_adjustment_get_page_size (h);
    lower = gtk_adjustment_get_lower (h);
    upper = gtk_adjustment_get_upper (h);
    value = gtk_adjustment_get_value (h);
    dx = compute_offset (x1, x2, value, value + page_size);
    if (CLAMP (value + dx, lower, upper - page_size) - value != 0)
        return FALSE;

    v = gtk_layout_get_vadjustment (GTK_LAYOUT (canvas));
    page_size = gtk_adjustment_get_page_size (v);
    lower = gtk_adjustment_get_lower (v);
    upper = gtk_adjustment_get_upper (v);
    value = gtk_adjustment_get_value (v);
    dy = compute_offset (y1, y2, value, value + page_size);
    if (CLAMP (value + dy, lower, upper - page_size) - value != 0)
        return FALSE;
    return TRUE;
}

gboolean
e_canvas_item_area_shown (GnomeCanvasItem *item, gdouble x1, gdouble y1, gdouble x2, gdouble y2)
{
    g_return_val_if_fail (item != NULL, FALSE);
    g_return_val_if_fail (GNOME_IS_CANVAS_ITEM (item), FALSE);

    gnome_canvas_item_i2w (item, &x1, &y1);
    gnome_canvas_item_i2w (item, &x2, &y2);

    return e_canvas_area_shown (item->canvas, x1, y1, x2, y2);
}

typedef struct {
    gdouble x1;
    gdouble y1;
    gdouble x2;
    gdouble y2;
    GnomeCanvas *canvas;
} DoubsAndCanvas;

static gboolean
show_area_timeout (gpointer data)
{
    DoubsAndCanvas *dac = data;

    e_canvas_show_area (dac->canvas, dac->x1, dac->y1, dac->x2, dac->y2);
    g_object_unref (dac->canvas);
    g_free (dac);
    return FALSE;
}

void
e_canvas_item_show_area_delayed (GnomeCanvasItem *item, gdouble x1, gdouble y1, gdouble x2, gdouble y2, gint delay)
{
    DoubsAndCanvas *dac;

    g_return_if_fail (item != NULL);
    g_return_if_fail (GNOME_IS_CANVAS_ITEM (item));

    gnome_canvas_item_i2w (item, &x1, &y1);
    gnome_canvas_item_i2w (item, &x2, &y2);

    dac = g_new (DoubsAndCanvas, 1);
    dac->x1 = x1;
    dac->y1 = y1;
    dac->x2 = x2;
    dac->y2 = y2;
    dac->canvas = item->canvas;
    g_object_ref (item->canvas);
    g_timeout_add (delay, show_area_timeout, dac);
}