Create feature factory interface & initial impl.

Creates the abstract class FeatureFactory and an AOSP implementation
called Factory.

Also creates a static library for generating logtags since we need to use the code generated
by the logtags in multiple packages now.

BUG: 27751878
Change-Id: I88d826333642d3efc252134c4facb7b1ca014f32
(cherry picked from commit 867bb9c07ab332fd9be67d1eeee3db796d9e0ffa)

Android.mk

 LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 
+LOCAL_SRC_FILES := \
+        $(call all-logtags-files-under, src)
+
+LOCAL_MODULE := settings-logtags
+
+include $(BUILD_STATIC_JAVA_LIBRARY)
+
+# Build the Settings APK
+include $(CLEAR_VARS)
+
 LOCAL_JAVA_LIBRARIES := bouncycastle core-oj telephony-common ims-common
 LOCAL_STATIC_JAVA_LIBRARIES := \
     android-support-v4 \
@@ -9,13 +19,13 @@ LOCAL_STATIC_JAVA_LIBRARIES := \
     android-support-v7-preference \
     android-support-v7-appcompat \
     android-support-v14-preference \
-    jsr305
+    jsr305 \
+    settings-logtags
 
 LOCAL_MODULE_TAGS := optional
 
 LOCAL_SRC_FILES := \
-        $(call all-java-files-under, src) \
-        src/com/android/settings/EventLogTags.logtags
+        $(call all-java-files-under, src)
 
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res \
     frameworks/support/v7/preference/res \

proguard.flags

@@ -17,6 +17,7 @@
 -keep class com.android.settings.users.*
 -keep class com.android.settings.nfc.*
 -keep class com.android.settings.notification.*
+-keep class com.android.settings.overlay.FeatureFactoryImpl
 -keep class com.android.settings.accessibility.*FragmentForSetupWizard
 -keep class com.android.settings.display.*FragmentForSetupWizard
 

res/values/config.xml

@@ -38,4 +38,6 @@
     <!-- When true enable color temperature setting. -->
     <bool name="config_enableColorTemperature">false</bool>
 
+    <!-- Fully-qualified class name for the implementation of the FeatureFactory to be instantiated. -->
+    <string name="config_featureFactory" translatable="false">com.android.settings.overlay.FeatureFactoryImpl</string>
 </resources>

src/com/android/settings/SettingsActivity.java

@@ -102,6 +102,7 @@ import com.android.settings.notification.ZenModePrioritySettings;
 import com.android.settings.notification.ZenModeScheduleRuleSettings;
 import com.android.settings.notification.ZenModeSettings;
 import com.android.settings.notification.ZenModeVisualInterruptionSettings;
+import com.android.settings.overlay.FeatureFactory;
 import com.android.settings.print.PrintJobSettingsFragment;
 import com.android.settings.print.PrintSettingsFragment;
 import com.android.settings.search.DynamicIndexableContentMonitor;
@@ -681,6 +682,9 @@ public class SettingsActivity extends SettingsDrawerActivity
             }
         }
 
+        // Will remove this line before submitting.
+        FeatureFactory.getFactory(this).createToastController().makeToast(this);
+
         if (DEBUG_TIMING) Log.d(LOG_TAG, "onCreate took " + (System.currentTimeMillis() - startTime)
                 + " ms");
     }

src/com/android/settings/overlay/FeatureFactory.java

+/*
+ * Copyright (C) 2016 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.settings.overlay;
+
+import android.content.Context;
+import android.text.TextUtils;
+import android.util.Log;
+
+import com.android.settings.R;
+
+/**
+ * Abstract class for creating feature controllers. Allows OEM implementations to define their own
+ * factories with their own controllers containing whatever code is needed to implement
+ * the features. To provide a factory implementation, implementors should override
+ * {@link R.string#config_featureFactory} in their override.
+ */
+public abstract class FeatureFactory {
+    private static final String LOG_TAG = "FeatureFactory";
+    private static final boolean DEBUG = false;
+
+    private static FeatureFactory sFactory;
+
+    /**
+     * Returns a factory for creating feature controllers. Creates the factory if it does not
+     * already exist. Uses the value of {@link R.string#config_featureFactory} to instantiate
+     * a factory implementation.
+     */
+    public static FeatureFactory getFactory(Context context) {
+        if (sFactory != null) {
+            return sFactory;
+        }
+
+        if (DEBUG) Log.d(LOG_TAG, "getFactory");
+        final String clsName = context.getString(R.string.config_featureFactory);
+        if (TextUtils.isEmpty(clsName)) {
+            throw new UnsupportedOperationException("No feature factory configured");
+        }
+        try {
+            sFactory = (FeatureFactory) context.getClassLoader().loadClass(clsName).newInstance();
+        } catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) {
+            throw new FactoryNotFoundException(e);
+        }
+
+        if (DEBUG) Log.d(LOG_TAG, "started " + sFactory.getClass().getSimpleName());
+        return sFactory;
+    }
+
+    /**
+     * Creates stub controller that makes {@link android.widget.Toast}s.
+     * Will be removed before submitting.
+     */
+    public abstract ToastController createToastController();
+
+    public static class FactoryNotFoundException extends RuntimeException {
+        public FactoryNotFoundException(Throwable throwable) {
+            super("Unable to create factory. Did you misconfigure Proguard?", throwable);
+        }
+    }
+}

src/com/android/settings/overlay/FeatureFactoryImpl.java

+/*
+ * Copyright (C) 2016 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.settings.overlay;
+
+import android.content.Context;
+import android.widget.Toast;
+
+/**
+ * {@link FeatureFactory} implementation for AOSP Settings.
+ */
+public class FeatureFactoryImpl extends FeatureFactory {
+    @Override
+    public ToastController createToastController() {
+        return new ToastController() {
+            @Override
+            public void makeToast(Context context) {
+                Toast.makeText(context, "Here's a piece of AOSP toast", Toast.LENGTH_LONG).show();
+            }
+        };
+    }
+}

src/com/android/settings/overlay/ToastController.java

+package com.android.settings.overlay;
+
+import android.content.Context;
+
+/**
+ * Will be removed before submitting. Just a proof of concept for review.
+ */
+public interface ToastController {
+    void makeToast(Context context);
+}