1 /* Copyright (C) 2016 Red Hat, Inc.
2  *
3  * This library is free software; you can redistribute it and/or
4  * modify it under the terms of the GNU Lesser General Public
5  * License as published by the Free Software Foundation; either
6  * version 2 of the License, or (at your option) any later version.
7  *
8  * This library is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * Lesser General Public License for more details.
12  *
13  * You should have received a copy of the GNU Lesser General Public
14  * License along with this library. If not, see <http://www.gnu.org/licenses/>.
15  */
16 
17 #include "config.h"
18 
19 #include "gdkpixbufutilsprivate.h"
20 
21 static GdkPixbuf *
load_from_stream(GdkPixbufLoader * loader,GInputStream * stream,GCancellable * cancellable,GError ** error)22 load_from_stream (GdkPixbufLoader  *loader,
23                   GInputStream     *stream,
24                   GCancellable     *cancellable,
25                   GError          **error)
26 {
27   GdkPixbuf *pixbuf;
28   gssize n_read;
29   guchar buffer[65536];
30   gboolean res;
31 
32   res = TRUE;
33   while (1)
34     {
35       n_read = g_input_stream_read (stream, buffer, sizeof (buffer), cancellable, error);
36       if (n_read < 0)
37         {
38           res = FALSE;
39           error = NULL; /* Ignore further errors */
40           break;
41         }
42 
43       if (n_read == 0)
44         break;
45 
46       if (!gdk_pixbuf_loader_write (loader, buffer, n_read, error))
47         {
48           res = FALSE;
49           error = NULL;
50           break;
51         }
52     }
53 
54   if (!gdk_pixbuf_loader_close (loader, error))
55     {
56       res = FALSE;
57       error = NULL;
58     }
59 
60   pixbuf = NULL;
61 
62   if (res)
63     {
64       pixbuf = gdk_pixbuf_loader_get_pixbuf (loader);
65       if (pixbuf)
66         g_object_ref (pixbuf);
67     }
68 
69   return pixbuf;
70 }
71 
72 static void
size_prepared_cb(GdkPixbufLoader * loader,gint width,gint height,gpointer data)73 size_prepared_cb (GdkPixbufLoader *loader,
74                   gint             width,
75                   gint             height,
76                   gpointer         data)
77 {
78   gdouble *scale = data;
79 
80   width = MAX (*scale * width, 1);
81   height = MAX (*scale * height, 1);
82 
83   gdk_pixbuf_loader_set_size (loader, width, height);
84 }
85 
86 /* Like gdk_pixbuf_new_from_stream_at_scale, but
87  * load the image at its original size times the
88  * given scale.
89  */
90 GdkPixbuf *
_gdk_pixbuf_new_from_stream_scaled(GInputStream * stream,gdouble scale,GCancellable * cancellable,GError ** error)91 _gdk_pixbuf_new_from_stream_scaled (GInputStream  *stream,
92                                     gdouble        scale,
93                                     GCancellable  *cancellable,
94                                     GError       **error)
95 {
96   GdkPixbufLoader *loader;
97   GdkPixbuf *pixbuf;
98 
99   loader = gdk_pixbuf_loader_new ();
100 
101   g_signal_connect (loader, "size-prepared",
102                     G_CALLBACK (size_prepared_cb), &scale);
103 
104   pixbuf = load_from_stream (loader, stream, cancellable, error);
105 
106   g_object_unref (loader);
107 
108   return pixbuf;
109 }
110 
111 /* Like gdk_pixbuf_new_from_resource_at_scale, but
112  * load the image at its original size times the
113  * given scale.
114  */
115 GdkPixbuf *
_gdk_pixbuf_new_from_resource_scaled(const gchar * resource_path,gdouble scale,GError ** error)116 _gdk_pixbuf_new_from_resource_scaled (const gchar  *resource_path,
117                                       gdouble       scale,
118                                       GError      **error)
119 {
120   GInputStream *stream;
121   GdkPixbuf *pixbuf;
122 
123   stream = g_resources_open_stream (resource_path, 0, error);
124   if (stream == NULL)
125     return NULL;
126 
127   pixbuf = _gdk_pixbuf_new_from_stream_scaled (stream, scale, NULL, error);
128   g_object_unref (stream);
129 
130   return pixbuf;
131 }
132 
133