1/*
2 * libjingle
3 * Copyright 2013, Google Inc.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 *  1. Redistributions of source code must retain the above copyright notice,
9 *     this list of conditions and the following disclaimer.
10 *  2. Redistributions in binary form must reproduce the above copyright notice,
11 *     this list of conditions and the following disclaimer in the documentation
12 *     and/or other materials provided with the distribution.
13 *  3. The name of the author may not be used to endorse or promote products
14 *     derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include "talk/app/webrtc/mediaconstraintsinterface.h"
29
30#include "talk/base/stringencode.h"
31
32namespace webrtc {
33
34const char MediaConstraintsInterface::kValueTrue[] = "true";
35const char MediaConstraintsInterface::kValueFalse[] = "false";
36
37// Set |value| to the value associated with the first appearance of |key|, or
38// return false if |key| is not found.
39bool MediaConstraintsInterface::Constraints::FindFirst(
40    const std::string& key, std::string* value) const {
41  for (Constraints::const_iterator iter = begin(); iter != end(); ++iter) {
42    if (iter->key == key) {
43      *value = iter->value;
44      return true;
45    }
46  }
47  return false;
48}
49
50// Find the highest-priority instance of the boolean-valued constraint) named by
51// |key| and return its value as |value|. |constraints| can be null.
52// If |mandatory_constraints| is non-null, it is incremented if the key appears
53// among the mandatory constraints.
54// Returns true if the key was found and has a valid boolean value.
55// If the key appears multiple times as an optional constraint, appearances
56// after the first are ignored.
57// Note: Because this uses FindFirst, repeated optional constraints whose
58// first instance has an unrecognized value are not handled precisely in
59// accordance with the specification.
60bool FindConstraint(const MediaConstraintsInterface* constraints,
61                    const std::string& key, bool* value,
62                    size_t* mandatory_constraints) {
63  std::string string_value;
64  if (!constraints) {
65    return false;
66  }
67  if (constraints->GetMandatory().FindFirst(key, &string_value)) {
68    if (mandatory_constraints)
69      ++*mandatory_constraints;
70    return talk_base::FromString(string_value, value);
71  }
72  if (constraints->GetOptional().FindFirst(key, &string_value)) {
73    return talk_base::FromString(string_value, value);
74  }
75  return false;
76}
77
78}  // namespace webrtc
79