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
|
/* -*- Mode: Vala; indent-tabs-mode: nil; tab-width: 4 -*-
*
* Copyright (C) 2012 Canonical Ltd
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 3 as
* published by the Free Software Foundation.
*
* 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Authors: Michael Terry <michael.terry@canonical.com>
*/
public class FadingLabel : Gtk.Label
{
private Cairo.Surface cached_surface;
public FadingLabel (string text)
{
Object (label: text);
}
public override void get_preferred_width (out int minimum, out int natural)
{
base.get_preferred_width (out minimum, out natural);
minimum = 0;
}
public override void get_preferred_width_for_height (int height, out int minimum, out int natural)
{
base.get_preferred_width_for_height (height, out minimum, out natural);
minimum = 0;
}
public override void size_allocate (Gtk.Allocation allocation)
{
base.size_allocate (allocation);
cached_surface = null;
}
private Cairo.Surface make_surface (Cairo.Context orig_c)
{
int w, h;
get_layout ().get_pixel_size (out w, out h);
var bw = get_allocated_width ();
var bh = get_allocated_height ();
var surface = new Cairo.Surface.similar (orig_c.get_target (), Cairo.Content.COLOR_ALPHA, bw, bh);
var c = new Cairo.Context (surface);
if (w > bw)
{
c.push_group ();
base.draw (c);
c.pop_group_to_source ();
var mask = new Cairo.Pattern.linear (0, 0, bw, 0);
mask.add_color_stop_rgba (1.0 - 27.0 / bw, 1.0, 1.0, 1.0, 1.0);
mask.add_color_stop_rgba (1.0 - 21.6 / bw, 1.0, 1.0, 1.0, 0.5);
mask.add_color_stop_rgba (1.0, 1.0, 1.0, 1.0, 0.0);
c.mask (mask);
}
else
base.draw (c);
return surface;
}
public override bool draw (Cairo.Context c)
{
if (cached_surface == null)
cached_surface = make_surface (c);
c.set_source_surface (cached_surface, 0, 0);
c.paint ();
return false;
}
}
|
