LatinIME: Fix back-arrow finishing activity

* When going to a sub setting menu and pressing the
  action bar up arrow instead of the device's back
  key, the settings are closed instead of going
  one level up as expected
* Call "onBackPressed" instead of "finish" to fix
  that
* For InputMethodSettings create a new flag to
  alter the behaviour for our use case but to keep
  existing behaviour for other callers

Test:
- Open the keyboard settings from Settings app
and navigate between menus ->
action bar back icon only goes one levelup
- Open keyboard settings directly from keyboard:
behaviour is the same, last "up" action takes you
back to where you came from

Change-Id: I4f01e80e7f35ddbd2af1baae899d689f1144a5a1

3 files changed, 12 insertions, 4 deletions

diff --git a/java/src/com/android/inputmethod/latin/settings/SettingsActivity.java b/java/src/com/android/inputmethod/latin/settings/SettingsActivity.java
index ac1657762..43467a05a 100644
--- a/java/src/com/android/inputmethod/latin/settings/SettingsActivity.java
+++ b/java/src/com/android/inputmethod/latin/settings/SettingsActivity.java
@@ -59,7 +59,7 @@ public final class SettingsActivity extends PreferenceActivity
     @Override
     public boolean onOptionsItemSelected(final MenuItem item) {
         if (mShowHomeAsUp && item.getItemId() == android.R.id.home) {
-            finish();
+            onBackPressed();
             return true;
         }
         return super.onOptionsItemSelected(item);
diff --git a/java/src/com/android/inputmethodcommon/InputMethodSettingsFragment.java b/java/src/com/android/inputmethodcommon/InputMethodSettingsFragment.java
index 8c5bae2cb..8d05f8383 100644
--- a/java/src/com/android/inputmethodcommon/InputMethodSettingsFragment.java
+++ b/java/src/com/android/inputmethodcommon/InputMethodSettingsFragment.java
@@ -34,6 +34,7 @@ public abstract class InputMethodSettingsFragment extends CustomPreferenceFragme
         super.onCreate(savedInstanceState);
         final Context context = getActivity();
         setPreferenceScreen(getPreferenceManager().createPreferenceScreen(context));
+        mSettings.setSpawnAsNewActivity(false);
         mSettings.init(context, getPreferenceScreen());
     }
 
diff --git a/java/src/com/android/inputmethodcommon/InputMethodSettingsImpl.java b/java/src/com/android/inputmethodcommon/InputMethodSettingsImpl.java
index cfa1a6596..e56c97578 100644
--- a/java/src/com/android/inputmethodcommon/InputMethodSettingsImpl.java
+++ b/java/src/com/android/inputmethodcommon/InputMethodSettingsImpl.java
@@ -40,6 +40,7 @@ import java.util.List;
     private Drawable mSubtypeEnablerIcon;
     private InputMethodManager mImm;
     private InputMethodInfo mImi;
+    private boolean mSpawnAsNewActivity = true;
 
     /**
      * Initialize internal states of this object.
@@ -55,9 +56,11 @@ import java.util.List;
         }
         final Intent intent = new Intent(Settings.ACTION_INPUT_METHOD_SUBTYPE_SETTINGS);
         intent.putExtra(Settings.EXTRA_INPUT_METHOD_ID, mImi.getId());
-        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK
-                | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED
-                | Intent.FLAG_ACTIVITY_CLEAR_TOP);
+        if (mSpawnAsNewActivity) {
+            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK
+                    | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED
+                    | Intent.FLAG_ACTIVITY_CLEAR_TOP);
+        }
         mSubtypeEnablerPreference = new Preference(context);
         mSubtypeEnablerPreference.setIntent(intent);
         prefScreen.addPreference(mSubtypeEnablerPreference);
@@ -176,4 +179,8 @@ import java.util.List;
             pref.setIcon(mSubtypeEnablerIcon);
         }
     }
+
+    public void setSpawnAsNewActivity(boolean spawnAsNew) {
+        mSpawnAsNewActivity = spawnAsNew;
+    }
 }