1 /*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "filter/ConfigFilter.h"
18
19 #include "androidfw/ConfigDescription.h"
20 #include "androidfw/ResourceTypes.h"
21
22 using ::android::ConfigDescription;
23
24 namespace aapt {
25
AddConfig(ConfigDescription config)26 void AxisConfigFilter::AddConfig(ConfigDescription config) {
27 uint32_t diff_mask = ConfigDescription::DefaultConfig().diff(config);
28
29 // Ignore the version
30 diff_mask &= ~android::ResTable_config::CONFIG_VERSION;
31
32 // Ignore any densities. Those are best handled in --preferred-density
33 if ((diff_mask & android::ResTable_config::CONFIG_DENSITY) != 0) {
34 config.density = 0;
35 diff_mask &= ~android::ResTable_config::CONFIG_DENSITY;
36 }
37
38 configs_.insert(std::make_pair(config, diff_mask));
39 config_mask_ |= diff_mask;
40 }
41
42 // Returns true if the locale script of the config should be considered matching
43 // the locale script of entry.
44 //
45 // If both the scripts are empty, the scripts are considered matching for
46 // backward compatibility reasons.
47 //
48 // If only one script is empty, we try to compute it based on the provided
49 // language and country. If we could not compute it, we assume it's either a
50 // new language we don't know about, or a private use language. We return true
51 // since we don't know any better and they might as well be a match.
52 //
53 // Finally, when we have two scripts (one of which could be computed), we return
54 // true if and only if they are an exact match.
ScriptsMatch(const ConfigDescription & config,const ConfigDescription & entry)55 static bool ScriptsMatch(const ConfigDescription& config, const ConfigDescription& entry) {
56 const char* config_script = config.localeScript;
57 const char* entry_script = entry.localeScript;
58 if (config_script[0] == '\0' && entry_script[0] == '\0') {
59 return true; // both scripts are empty. We match for backward compatibility reasons.
60 }
61
62 char script_buffer[sizeof(config.localeScript)];
63 if (config_script[0] == '\0') {
64 android::localeDataComputeScript(script_buffer, config.language, config.country);
65 if (script_buffer[0] == '\0') { // We can't compute the script, so we match.
66 return true;
67 }
68 config_script = script_buffer;
69 } else if (entry_script[0] == '\0') {
70 android::localeDataComputeScript(script_buffer, entry.language, entry.country);
71 if (script_buffer[0] == '\0') { // We can't compute the script, so we match.
72 return true;
73 }
74 entry_script = script_buffer;
75 }
76 return memcmp(config_script, entry_script, sizeof(config.localeScript)) == 0;
77 }
78
Match(const ConfigDescription & config) const79 bool AxisConfigFilter::Match(const ConfigDescription& config) const {
80 const uint32_t mask = ConfigDescription::DefaultConfig().diff(config);
81 if ((config_mask_ & mask) == 0) {
82 // The two configurations don't have any common axis.
83 return true;
84 }
85
86 uint32_t matched_axis = 0;
87 for (const auto& entry : configs_) {
88 const ConfigDescription& target = entry.first;
89 const uint32_t diff_mask = entry.second;
90 uint32_t diff = target.diff(config);
91 if ((diff & diff_mask) == 0) {
92 // Mark the axis that was matched.
93 matched_axis |= diff_mask;
94 } else if ((diff & diff_mask) == android::ResTable_config::CONFIG_LOCALE) {
95 // If the locales differ, but the languages are the same and
96 // the locale we are matching only has a language specified,
97 // we match.
98 //
99 // Exception: we won't match if a script is specified for at least
100 // one of the locales and it's different from the other locale's
101 // script. (We will compute the other script if at least one of the
102 // scripts were explicitly set. In cases we can't compute an script,
103 // we match.)
104 if (config.language[0] != '\0' && config.country[0] == '\0' &&
105 config.localeVariant[0] == '\0' && config.language[0] == entry.first.language[0] &&
106 config.language[1] == entry.first.language[1] && ScriptsMatch(config, entry.first)) {
107 matched_axis |= android::ResTable_config::CONFIG_LOCALE;
108 }
109 } else if ((diff & diff_mask) ==
110 android::ResTable_config::CONFIG_SMALLEST_SCREEN_SIZE) {
111 // Special case if the smallest screen width doesn't match. We check that
112 // the
113 // config being matched has a smaller screen width than the filter
114 // specified.
115 if (config.smallestScreenWidthDp != 0 &&
116 config.smallestScreenWidthDp < target.smallestScreenWidthDp) {
117 matched_axis |= android::ResTable_config::CONFIG_SMALLEST_SCREEN_SIZE;
118 }
119 }
120 }
121 return matched_axis == (config_mask_ & mask);
122 }
123
124 } // namespace aapt
125