Add a sample for an EmojiCompat implementation.

emojicompat/AssetEmojiCompatConfig.java

@@ -0,0 +1,88 @@
+
+import android.content.res.AssetManager;
+import android.support.annotation.NonNull;
+import android.support.text.emoji.EmojiCompat;
+import android.support.text.emoji.MetadataRepo;
+import android.util.Log;
+import android.support.v4.util.Preconditions;
+
+/**
+ * A simple implementation of EmojiCompat.Config using typeface assets.
+ * Based on:
+ * https://android.googlesource.com/platform/frameworks/support/+/master/emoji/bundled/src/main/java/android/support/text/emoji/bundled/BundledEmojiCompatConfig.java
+ * Changes are marked with comments. Formatting and other simple changes are not always marked.
+ */
+public class AssetEmojiCompatConfig extends EmojiCompat.Config {
+
+    /**
+     * Create a new configuration for this EmojiCompat
+     * @param assetName The file name/path of the requested font
+     * @param context Context instance
+     */
+    public AssetEmojiCompatConfig(@NonNull Context context,
+                                  // NEW
+                                  @NonNull String assetName) {
+        // This one is oviously new
+        super(new AssetMetadataLoader(context, assetName));
+    }
+
+    /**
+     * This is the MetadataLoader. Derived from BundledMetadataLoader but with
+     * the addition of a custom asset name.
+     */
+    private static class AssetMetadataLoader implements EmojiCompat.MetadataRepoLoader{
+        private final Context mContext;
+        // NEW
+        private final String assetName;
+
+        private AssetMetadataLoader(@NonNull Context context, 
+                                    // NEW
+                                    String assetName) {
+            this.mContext = context;
+            // NEW
+            this.assetName = assetName;
+        }
+
+
+        // Copied from BundledEmojiCompatConfig
+        @Override
+        @RequiresApi(19)
+        public void load(@NonNull EmojiCompat.MetadataRepoLoaderCallback loaderCallback) {
+            Preconditions.checkNotNull(loaderCallback, "loaderCallback cannot be null");
+            final InitRunnable runnable = new InitRunnable(mContext, loaderCallback, assetName);
+            final Thread thread = new Thread(runnable);
+            thread.setDaemon(false);
+            thread.start();
+        }
+    }
+
+    @RequiresApi(19)
+    private static class InitRunnable implements Runnable {
+        // The font name is assigned in the constructor.
+        private final String FONT_NAME;
+        // Slightly different variable names
+        private final EmojiCompat.MetadataRepoLoaderCallback loaderCallback;
+        private final Context context;
+
+        private InitRunnable(final Context context,
+                             final EmojiCompat.MetadataRepoLoaderCallback loaderCallback,
+                             // NEW parameter
+                             final String FONT_NAME) {
+            this.context = context;
+            this.loaderCallback = loaderCallback;
+            this.FONT_NAME = FONT_NAME;
+        }
+        
+        // This has been copied from BundledEmojiCompatConfig
+        @Override
+        public void run() {
+            try {
+                final AssetManager assetManager = context.getAssets();
+                final MetadataRepo resourceIndex = MetadataRepo.create(mgr, FONT_NAME);
+                loaderCallback.onLoaded(resourceIndex);
+            } catch (Throwable t) {
+                loaderCallback.onFailed(t);
+            }
+        }
+    }
+}