Add the Allow Rotation setting to Launcher3.

This CL adds a Settings activity along with the code needed to provide
a "Allow Rotation" setting to all phones and tablets. This setting is
set to false for phones and true for tablets. On changing the setting
from unlocked to locked, the launcher (and the Settings activity)
will get locked to the orientation the user was in when he disabled
"Allow Rotation". This is consistent with how the natural rotation
feature of Android works.

Change-Id: I8a1c59d1fa0bb9262530cad96e0a9bdbab0d9344

4 files changed, 123 insertions, 10 deletions

diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 1aa446e31..da6430a73 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -221,7 +221,8 @@ public class Launcher extends Activity
     public static final String USER_HAS_MIGRATED = "launcher.user_migrated_from_old_data";
 
     /** The different states that Launcher can be in. */
-    enum State { NONE, WORKSPACE, APPS, APPS_SPRING_LOADED, WIDGETS, WIDGETS_SPRING_LOADED };
+    enum State { NONE, WORKSPACE, APPS, APPS_SPRING_LOADED, WIDGETS, WIDGETS_SPRING_LOADED }
+
     @Thunk State mState = State.WORKSPACE;
     @Thunk LauncherStateTransitionAnimation mStateTransitionAnimation;
 
@@ -405,6 +406,24 @@ public class Launcher extends Activity
 
     FocusIndicatorView mFocusHandler;
 
+    private boolean mRotationEnabled = false;
+    private boolean mPreferenceObserverRegistered = false;
+
+    final private SharedPreferences.OnSharedPreferenceChangeListener mSettingsObserver =
+            new SharedPreferences.OnSharedPreferenceChangeListener() {
+        @Override
+        public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
+            if (Utilities.ALLOW_ROTATION_PREFERENCE_KEY.equals(key)) {
+                if (mRotationEnabled = sharedPreferences.getBoolean(
+                        Utilities.ALLOW_ROTATION_PREFERENCE_KEY, false)) {
+                    unlockScreenOrientation(true);
+                } else {
+                    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_NOSENSOR);
+                }
+            }
+        }
+    };
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         if (DEBUG_STRICT_MODE) {
@@ -505,7 +524,19 @@ public class Launcher extends Activity
         IntentFilter filter = new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
         registerReceiver(mCloseSystemDialogsReceiver, filter);
 
-        // On large interfaces, we want the screen to auto-rotate based on the current orientation
+        mRotationEnabled = Utilities.isRotationAllowedForDevice(getApplicationContext());
+        // In case we are on a device with locked rotation, we should look at preferences to check
+        // if the user has specifically allowed rotation.
+        if (!mRotationEnabled) {
+            getSharedPreferences(LauncherFiles.ROTATION_PREF_FILE,
+                    Context.MODE_MULTI_PROCESS).registerOnSharedPreferenceChangeListener(
+                    mSettingsObserver);
+            mPreferenceObserverRegistered = true;
+            mRotationEnabled = Utilities.isAllowRotationPrefEnabled(getApplicationContext());
+        }
+
+        // On large interfaces, or on devices that a user has specifically enabled screen rotation,
+        // we want the screen to auto-rotate based on the current orientation
         unlockScreenOrientation(true);
 
         if (mLauncherCallbacks != null) {
@@ -1300,8 +1331,11 @@ public class Launcher extends Activity
     protected boolean hasSettings() {
         if (mLauncherCallbacks != null) {
             return mLauncherCallbacks.hasSettings();
+        } else {
+            // On devices with a locked orientation, we will at least have the allow rotation
+            // setting.
+            return !Utilities.isRotationAllowedForDevice(this);
         }
-        return false;
     }
 
     public void addToCustomContentPage(View customContent,
@@ -2083,6 +2117,13 @@ public class Launcher extends Activity
     public void onDestroy() {
         super.onDestroy();
 
+        if (mPreferenceObserverRegistered) {
+            getSharedPreferences(LauncherFiles.ROTATION_PREF_FILE,
+                    Context.MODE_MULTI_PROCESS).unregisterOnSharedPreferenceChangeListener(
+                    mSettingsObserver);
+            mPreferenceObserverRegistered = false;
+        }
+
         // Remove all pending runnables
         mHandler.removeMessages(ADVANCE_MSG);
         mHandler.removeMessages(0);
@@ -2865,6 +2906,8 @@ public class Launcher extends Activity
         if (LOGD) Log.d(TAG, "onClickSettingsButton");
         if (mLauncherCallbacks != null) {
             mLauncherCallbacks.onClickSettingsButton(v);
+        } else {
+            showSettingsActivity();
         }
     }
 
@@ -4472,7 +4515,7 @@ public class Launcher extends Activity
     }
 
     public void lockScreenOrientation() {
-        if (Utilities.isRotationEnabled(this)) {
+        if (mRotationEnabled) {
             if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR2) {
                 setRequestedOrientation(mapConfigurationOriActivityInfoOri(getResources()
                         .getConfiguration().orientation));
@@ -4481,8 +4524,9 @@ public class Launcher extends Activity
             }
         }
     }
+
     public void unlockScreenOrientation(boolean immediate) {
-        if (Utilities.isRotationEnabled(this)) {
+        if (mRotationEnabled) {
             if (immediate) {
                 setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED);
             } else {
@@ -4587,6 +4631,10 @@ public class Launcher extends Activity
         editor.apply();
     }
 
+    private void showSettingsActivity() {
+        startActivity(new Intent(this, SettingsActivity.class));
+    }
+
     /**
      * To be overridden by subclasses to indicate that there is an in-activity full-screen intro
      * screen that must be displayed and dismissed.
diff --git a/src/com/android/launcher3/LauncherFiles.java b/src/com/android/launcher3/LauncherFiles.java
index 03ec4bf7a..4aeaef0ad 100644
--- a/src/com/android/launcher3/LauncherFiles.java
+++ b/src/com/android/launcher3/LauncherFiles.java
@@ -27,6 +27,8 @@ public class LauncherFiles {
     public static final String WIDGET_PREVIEWS_DB = "widgetpreviews.db";
     public static final String APP_ICONS_DB = "app_icons.db";
 
+    public static final String ROTATION_PREF_FILE = "com.android.launcher3.rotation.prefs";
+
     public static final List<String> ALL_FILES = Collections.unmodifiableList(Arrays.asList(
             DEFAULT_WALLPAPER_THUMBNAIL,
             DEFAULT_WALLPAPER_THUMBNAIL_OLD,
@@ -37,7 +39,8 @@ public class LauncherFiles {
             WALLPAPER_IMAGES_DB,
             WIDGET_PREVIEWS_DB,
             MANAGED_USER_PREFERENCES_KEY,
-            APP_ICONS_DB));
+            APP_ICONS_DB,
+            ROTATION_PREF_FILE));
 
     // TODO: Delete these files on upgrade
     public static final List<String> OBSOLETE_FILES = Collections.unmodifiableList(Arrays.asList(
diff --git a/src/com/android/launcher3/SettingsActivity.java b/src/com/android/launcher3/SettingsActivity.java
new file mode 100644
index 000000000..a1da1b6fd
--- /dev/null
+++ b/src/com/android/launcher3/SettingsActivity.java
@@ -0,0 +1,53 @@
+/*
+ * 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.launcher3;
+
+import android.app.Activity;
+import android.content.Context;
+import android.os.Bundle;
+import android.preference.PreferenceFragment;
+
+/**
+ * Settings activity for Launcher. Currently implements the following setting:
+ * LockToPortrait
+ */
+public class SettingsActivity extends Activity {
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        // Display the fragment as the main content.
+        getFragmentManager().beginTransaction()
+                .replace(android.R.id.content, new LauncherSettingsFragment())
+                .commit();
+    }
+
+    /**
+     * This fragment shows the launcher preferences.
+     */
+    @SuppressWarnings("WeakerAccess")
+    public static class LauncherSettingsFragment extends PreferenceFragment {
+
+        @Override
+        public void onCreate(Bundle savedInstanceState) {
+            super.onCreate(savedInstanceState);
+            getPreferenceManager().setSharedPreferencesMode(Context.MODE_PRIVATE);
+            getPreferenceManager().setSharedPreferencesName(LauncherFiles.ROTATION_PREF_FILE);
+            addPreferencesFromResource(R.xml.launcher_preferences);
+        }
+    }
+}
diff --git a/src/com/android/launcher3/Utilities.java b/src/com/android/launcher3/Utilities.java
index 256eba020..a9cbf6970 100644
--- a/src/com/android/launcher3/Utilities.java
+++ b/src/com/android/launcher3/Utilities.java
@@ -25,6 +25,7 @@ import android.content.ActivityNotFoundException;
 import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
+import android.content.SharedPreferences;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
@@ -67,6 +68,7 @@ import java.util.regex.Pattern;
  * Various utilities shared amongst the Launcher's classes.
  */
 public final class Utilities {
+
     private static final String TAG = "Launcher.Utilities";
 
     private static int sIconWidth = -1;
@@ -93,6 +95,8 @@ public final class Utilities {
     static final String FORCE_ENABLE_ROTATION_PROPERTY = "launcher_force_rotate";
     public static boolean sForceEnableRotation = isPropertyEnabled(FORCE_ENABLE_ROTATION_PROPERTY);
 
+    public static final String ALLOW_ROTATION_PREFERENCE_KEY = "pref_allowRotation";
+
     /**
      * Returns a FastBitmapDrawable with the icon, accurately sized.
      */
@@ -114,10 +118,15 @@ public final class Utilities {
         return Log.isLoggable(propertyName, Log.VERBOSE);
     }
 
-    public static boolean isRotationEnabled(Context c) {
-        boolean enableRotation = sForceEnableRotation ||
-                c.getResources().getBoolean(R.bool.allow_rotation);
-        return enableRotation;
+    public static boolean isAllowRotationPrefEnabled(Context context) {
+        SharedPreferences sharedPrefs = context.getSharedPreferences(LauncherFiles.ROTATION_PREF_FILE,
+                Context.MODE_MULTI_PROCESS);
+        boolean allowRotationPref = sharedPrefs.getBoolean(ALLOW_ROTATION_PREFERENCE_KEY, false);
+        return sForceEnableRotation || allowRotationPref;
+    }
+
+    public static boolean isRotationAllowedForDevice(Context context) {
+        return sForceEnableRotation || context.getResources().getBoolean(R.bool.allow_rotation);
     }
 
     /**