1 files changed, 111 insertions, 0 deletions
diff --git a/src/com/android/tv/util/TvTrackInfoUtils.java b/src/com/android/tv/util/TvTrackInfoUtils.java
new file mode 100644
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--- /dev/null
+++ b/src/com/android/tv/util/TvTrackInfoUtils.java
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.tv.util;
+
+import android.media.tv.TvTrackInfo;
+
+import java.util.Comparator;
+import java.util.List;
+
+/**
+ * Static utilities for {@link TvTrackInfo}.
+ */
+public class TvTrackInfoUtils {
+
+    /**
+     * Compares how closely two {@link android.media.tv.TvTrackInfo}s match {@code language}, {@code
+     * channelCount} and {@code id} in that precedence.
+     *
+     * @param id           The track id to match.
+     * @param language     The language to match.
+     * @param channelCount The channel count to match.
+     * @return -1 if lhs is a worse match, 0 if lhs and rhs match equally and 1 if lhs is a better
+     * match.
+     */
+    public static Comparator<TvTrackInfo> createComparator(final String id, final String language,
+            final int channelCount) {
+        return new Comparator<TvTrackInfo>() {
+
+            @Override
+            public int compare(TvTrackInfo lhs, TvTrackInfo rhs) {
+                if (lhs == rhs) {
+                    return 0;
+                }
+                if (lhs == null) {
+                    return -1;
+                }
+                if (rhs == null) {
+                    return 1;
+                }
+                boolean rhsLangMatch = Utils.isEqualLanguage(rhs.getLanguage(), language);
+                boolean lhsLangMatch = Utils.isEqualLanguage(lhs.getLanguage(), language);
+                if (rhsLangMatch) {
+                    if (lhsLangMatch) {
+                        boolean rhsCountMatch = rhs.getAudioChannelCount() == channelCount;
+                        boolean lhsCountMatch = lhs.getAudioChannelCount() == channelCount;
+                        if (rhsCountMatch) {
+                            if (lhsCountMatch) {
+                                boolean rhsIdMatch = rhs.getId().equals(id);
+                                boolean lhsIdMatch = lhs.getId().equals(id);
+                                if (rhsIdMatch) {
+                                    return lhsIdMatch ? 0 : -1;
+                                } else {
+                                    return lhsIdMatch ? 1 : 0;
+                                }
+
+                            } else {
+                                return -1;
+                            }
+                        } else {
+                            return lhsCountMatch ? 1 : 0;
+                        }
+                    } else {
+                        return -1;
+                    }
+                } else {
+                    return lhsLangMatch ? 1 : 0;
+                }
+            }
+        };
+    }
+
+    /**
+     * Selects the  best TvTrackInfo available or the first if none matches.
+     *
+     * @param tracks       The tracks to choose from
+     * @param id           The track id to match.
+     * @param language     The language to match.
+     * @param channelCount The channel count to match.
+     * @return the best matching track or the first one if none matches.
+     */
+    public static TvTrackInfo getBestTrackInfo(List<TvTrackInfo> tracks, String id, String language,
+            int channelCount) {
+        if (tracks == null) {
+            return null;
+        }
+        Comparator<TvTrackInfo> comparator = createComparator(id, language, channelCount);
+        TvTrackInfo best = null;
+        for (TvTrackInfo track : tracks) {
+            if (comparator.compare(track, best) > 0) {
+                best = track;
+            }
+        }
+        return best;
+    }
+
+    private TvTrackInfoUtils() {
+    }
+}