From 1a2cf776af55d3f8279ee2f14814bd94100f9739 Mon Sep 17 00:00:00 2001
From: Ahmed El-Helw <ahmedre@fb.com>
Date: Fri, 11 Dec 2015 11:36:20 -0800
Subject: [PATCH] Support custom fonts for flat React rendering.

Summary:
Custom fonts weren't supported before, now they are when using flat
rendering in React.

Differential Revision: D2740489
---
 .../react/flat/FlatUIImplementation.java      |  9 ++--
 .../facebook/react/flat/TypefaceCache.java    | 44 +++++++++++++++++--
 2 files changed, 43 insertions(+), 10 deletions(-)

diff --git a/ReactAndroid/src/main/java/com/facebook/react/flat/FlatUIImplementation.java b/ReactAndroid/src/main/java/com/facebook/react/flat/FlatUIImplementation.java
index c17de9be7..ffe105c27 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/flat/FlatUIImplementation.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/flat/FlatUIImplementation.java
@@ -9,20 +9,16 @@
 
 package com.facebook.react.flat;
 
+import javax.annotation.Nullable;
+
 import java.util.ArrayList;
 import java.util.List;
 
-import javax.annotation.Nullable;
-
-import com.facebook.csslayout.CSSNode;
 import com.facebook.react.bridge.ReactApplicationContext;
 import com.facebook.react.bridge.ReadableArray;
 import com.facebook.react.uimanager.CatalystStylesDiffMap;
-import com.facebook.react.uimanager.NativeViewHierarchyManager;
 import com.facebook.react.uimanager.ReactShadowNode;
-import com.facebook.react.uimanager.ThemedReactContext;
 import com.facebook.react.uimanager.UIImplementation;
-import com.facebook.react.uimanager.UIViewOperationQueue;
 import com.facebook.react.uimanager.ViewManager;
 import com.facebook.react.uimanager.ViewManagerRegistry;
 import com.facebook.react.uimanager.events.EventDispatcher;
@@ -45,6 +41,7 @@ public class FlatUIImplementation extends UIImplementation {
     viewManagers.add(new RCTTextManager());
     viewManagers.add(new RCTRawTextManager());
     viewManagers.add(new RCTVirtualTextManager());
+    TypefaceCache.setAssetManager(reactContext.getAssets());
 
     ViewManagerRegistry viewManagerRegistry = new ViewManagerRegistry(viewManagers);
     FlatNativeViewHierarchyManager nativeViewHierarchyManager = new FlatNativeViewHierarchyManager(
diff --git a/ReactAndroid/src/main/java/com/facebook/react/flat/TypefaceCache.java b/ReactAndroid/src/main/java/com/facebook/react/flat/TypefaceCache.java
index 9c023782e..b5e2d63b8 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/flat/TypefaceCache.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/flat/TypefaceCache.java
@@ -9,10 +9,15 @@
 
 package com.facebook.react.flat;
 
+import javax.annotation.Nullable;
+
 import java.util.HashMap;
 
+import android.content.res.AssetManager;
 import android.graphics.Typeface;
 
+import com.facebook.infer.annotation.Assertions;
+
 /**
  * TypefaceCache provides methods to resolve typeface from font family, or existing typeface
  * with a different style.
@@ -24,9 +29,20 @@ import android.graphics.Typeface;
   private static final HashMap<String, Typeface[]> FONTFAMILY_CACHE = new HashMap<>();
   private static final HashMap<Typeface, Typeface[]> TYPEFACE_CACHE = new HashMap<>();
 
-  /**
-   * Returns a Typeface for a given a FontFamily and style.
-   */
+  private static final String[] EXTENSIONS = {
+      "",
+      "_bold",
+      "_italic",
+      "_bold_italic"};
+  private static final String[] FILE_EXTENSIONS = {".ttf", ".otf"};
+  private static final String FONTS_ASSET_PATH = "fonts/";
+
+  @Nullable private static AssetManager sAssetManager = null;
+
+  public static void setAssetManager(AssetManager assetManager) {
+    sAssetManager = assetManager;
+  }
+
   public static Typeface getTypeface(String fontFamily, int style) {
     Typeface[] cache = FONTFAMILY_CACHE.get(fontFamily);
     if (cache == null) {
@@ -38,12 +54,32 @@ import android.graphics.Typeface;
       return cache[style];
     }
 
-    Typeface typeface = Typeface.create(fontFamily, style);
+    Typeface typeface = createTypeface(fontFamily, style);
     cache[style] = typeface;
     TYPEFACE_CACHE.put(typeface, cache);
     return typeface;
   }
 
+  private static Typeface createTypeface(String fontFamilyName, int style) {
+    String extension = EXTENSIONS[style];
+    StringBuilder fileNameBuffer = new StringBuilder(32)
+        .append(FONTS_ASSET_PATH)
+        .append(fontFamilyName)
+        .append(extension);
+    int length = fileNameBuffer.length();
+    for (String fileExtension : FILE_EXTENSIONS) {
+      String fileName = fileNameBuffer.append(fileExtension).toString();
+      try {
+        return Typeface.createFromAsset(sAssetManager, fileName);
+      } catch (RuntimeException e) {
+        // unfortunately Typeface.createFromAsset throws an exception instead of returning null
+        // if the typeface doesn't exist
+        fileNameBuffer.setLength(length);
+      }
+    }
+    return Assertions.assumeNotNull(Typeface.create(fontFamilyName, style));
+  }
+
   /**
    * Returns a derivative of a given Typeface with a different style.
    */