Merge "Dump theme inheritance information in UnsupportedOperationException"

core/java/android/content/res/AssetManager.java

@@ -791,6 +791,21 @@ public final class AssetManager implements AutoCloseable {
         }
     }
 
+    /**
+     * To get the parent theme resource id according to the parameter theme resource id.
+     * @param resId theme resource id.
+     * @return the parent theme resource id.
+     * @hide
+     */
+    @StyleRes
+    int getParentThemeIdentifier(@StyleRes int resId) {
+        synchronized (this) {
+            ensureValidLocked();
+            // name is checked in JNI.
+            return nativeGetParentThemeIdentifier(mObject, resId);
+        }
+    }
+
     /**
      * Enable resource resolution logging to track the steps taken to resolve the last resource
      * entry retrieved. Stores the configuration and package names for each step.
@@ -1600,6 +1615,8 @@ public final class AssetManager implements AutoCloseable {
     private static native void nativeThemeDump(long ptr, long themePtr, int priority, String tag,
             String prefix);
     static native @NativeConfig int nativeThemeGetChangingConfigurations(long themePtr);
+    @StyleRes
+    private static native int nativeGetParentThemeIdentifier(long ptr, @StyleRes int styleId);
 
     // AssetInputStream related native methods.
     private static native void nativeAssetDestroy(long assetPtr);

core/java/android/content/res/Resources.java

@@ -1508,6 +1508,12 @@ public class Resources {
      * retrieve XML attributes with style and theme information applied.
      */
     public final class Theme {
+        /**
+         * To trace parent themes needs to prevent a cycle situation.
+         * e.x. A's parent is B, B's parent is C, and C's parent is A.
+         */
+        private static final int MAX_NUMBER_OF_TRACING_PARENT_THEME = 100;
+
         private final Object mLock = new Object();
 
         @GuardedBy("mLock")
@@ -1801,6 +1807,13 @@ public class Resources {
             }
         }
 
+        @StyleRes
+        /*package*/ int getParentThemeIdentifier(@StyleRes int resId) {
+            synchronized (mLock) {
+                return mThemeImpl.getParentThemeIdentifier(resId);
+            }
+        }
+
         /**
          * @hide
          */
@@ -1948,8 +1961,27 @@ public class Resources {
         public String toString() {
             final StringBuilder sb = new StringBuilder();
             sb.append('{');
-            sb.append("id=0x").append(Integer.toHexString(getAppliedStyleResId())).append(", ");
-            sb.append("themes=").append(Arrays.deepToString(getTheme()));
+            int themeResId = getAppliedStyleResId();
+            int i = 0;
+            sb.append("InheritanceMap=[");
+            while (themeResId > 0) {
+                if (i > MAX_NUMBER_OF_TRACING_PARENT_THEME) {
+                    sb.append(",...");
+                    break;
+                }
+
+                if (i > 0) {
+                    sb.append(", ");
+                }
+                sb.append("id=0x").append(Integer.toHexString(themeResId));
+                sb.append(getResourcePackageName(themeResId))
+                        .append(":").append(getResourceTypeName(themeResId))
+                        .append("/").append(getResourceEntryName(themeResId));
+
+                i++;
+                themeResId = getParentThemeIdentifier(themeResId);
+            }
+            sb.append("], Themes=").append(Arrays.deepToString(getTheme()));
             sb.append('}');
             return sb.toString();
         }

core/java/android/content/res/ResourcesImpl.java

@@ -1310,6 +1310,14 @@ public class ResourcesImpl {
             return mThemeResId;
         }
 
+        @StyleRes
+        /*package*/ int getParentThemeIdentifier(@StyleRes int resId) {
+            if (resId > 0) {
+                return mAssets.getParentThemeIdentifier(resId);
+            }
+            return 0;
+        }
+
         void applyStyle(int resId, boolean force) {
             mAssets.applyStyleToTheme(mTheme, resId, force);
             mThemeResId = resId;

core/jni/android_util_AssetManager.cpp

@@ -881,6 +881,12 @@ static jint NativeGetResourceArray(JNIEnv* env, jclass /*clazz*/, jlong ptr, jin
   return static_cast<jint>(bag->entry_count);
 }
 
+static jint NativeGetParentThemeIdentifier(JNIEnv* env, jclass /*clazz*/, jlong ptr, jint resid) {
+  ScopedLock<AssetManager2> assetmanager(AssetManagerFromLong(ptr));
+  const auto parentThemeResId = assetmanager->GetParentThemeResourceId(resid);
+  return parentThemeResId.value_or(0);
+}
+
 static jint NativeGetResourceIdentifier(JNIEnv* env, jclass /*clazz*/, jlong ptr, jstring name,
                                         jstring def_type, jstring def_package) {
   ScopedUtfChars name_utf8(env, name);
@@ -1464,6 +1470,8 @@ static const JNINativeMethod gAssetManagerMethods[] = {
     {"nativeGetResourceIntArray", "(JI)[I", (void*)NativeGetResourceIntArray},
     {"nativeGetResourceArraySize", "(JI)I", (void*)NativeGetResourceArraySize},
     {"nativeGetResourceArray", "(JI[I)I", (void*)NativeGetResourceArray},
+    {"nativeGetParentThemeIdentifier", "(JI)I",
+     (void*)NativeGetParentThemeIdentifier},
 
     // AssetManager resource name/ID methods.
     {"nativeGetResourceIdentifier", "(JLjava/lang/String;Ljava/lang/String;Ljava/lang/String;)I",

libs/androidfw/AssetManager2.cpp

@@ -902,6 +902,27 @@ std::string AssetManager2::GetLastResourceResolution() const {
   return log_stream.str();
 }
 
+base::expected<uint32_t, NullOrIOError> AssetManager2::GetParentThemeResourceId(uint32_t resid)
+const {
+  auto entry = FindEntry(resid, 0u /* density_override */,
+                         false /* stop_at_first_match */,
+                         false /* ignore_configuration */);
+  if (!entry.has_value()) {
+    return base::unexpected(entry.error());
+  }
+
+  auto entry_map = std::get_if<incfs::verified_map_ptr<ResTable_map_entry>>(&entry->entry);
+  if (entry_map == nullptr) {
+    // Not a bag, nothing to do.
+    return base::unexpected(std::nullopt);
+  }
+
+  auto map = *entry_map;
+  const uint32_t parent_resid = dtohl(map->parent.ident);
+
+  return parent_resid;
+}
+
 base::expected<AssetManager2::ResourceName, NullOrIOError> AssetManager2::GetResourceName(
     uint32_t resid) const {
   auto result = FindEntry(resid, 0u /* density_override */, true /* stop_at_first_match */,

libs/androidfw/include/androidfw/AssetManager2.h

@@ -192,6 +192,12 @@ class AssetManager2 {
   std::unique_ptr<Asset> OpenNonAsset(const std::string& filename, ApkAssetsCookie cookie,
                                       Asset::AccessMode mode) const;
 
+  // Returns the resource id of parent style of the specified theme.
+  //
+  // Returns a null error if the name is missing/corrupt, or an I/O error if reading resource data
+  // failed.
+  base::expected<uint32_t, NullOrIOError> GetParentThemeResourceId(uint32_t resid) const;
+
   // Returns the resource name of the specified resource ID.
   //
   // Utf8 strings are preferred, and only if they are unavailable are the Utf16 variants populated.