address some warnings, migrate user dictionary settings to androidx

app/src/main/java/org/dslul/openboard/inputmethod/event/Combiner.kt

@@ -17,7 +17,7 @@ interface Combiner {
      * @param event the event to combine with the existing state.
      * @return the resulting event.
      */
-    fun processEvent(previousEvents: ArrayList<Event>?, event: Event?): Event?
+    fun processEvent(previousEvents: ArrayList<Event>?, event: Event?): Event
 
     /**
      * Get the feedback that should be shown to the user for the current state of this combiner.

app/src/main/java/org/dslul/openboard/inputmethod/event/CombinerChain.kt

@@ -46,13 +46,13 @@ class CombinerChain(initialText: String?) {
      * new event. However it may never be null.
      */
     fun processEvent(previousEvents: ArrayList<Event>?,
-                     newEvent: Event?): Event? {
+                     newEvent: Event): Event {
         val modifiablePreviousEvents = ArrayList(previousEvents!!)
         var event = newEvent
         for (combiner in mCombiners) { // A combiner can never return more than one event; it can return several
 // code points, but they should be encapsulated within one event.
             event = combiner.processEvent(modifiablePreviousEvents, event)
-            if (event!!.isConsumed) { // If the event is consumed, then we don't pass it to subsequent combiners:
+            if (event.isConsumed) { // If the event is consumed, then we don't pass it to subsequent combiners:
 // they should not see it at all.
                 break
             }

app/src/main/java/org/dslul/openboard/inputmethod/event/DeadKeyCombiner.kt

@@ -188,11 +188,11 @@ class DeadKeyCombiner : Combiner {
     // TODO: make this a list of events instead
     val mDeadSequence = StringBuilder()
 
-    override fun processEvent(previousEvents: ArrayList<Event>?, event: Event?): Event? {
+    override fun processEvent(previousEvents: ArrayList<Event>?, event: Event?): Event {
         if (TextUtils.isEmpty(mDeadSequence)) { // No dead char is currently being tracked: this is the most common case.
             if (event!!.isDead) { // The event was a dead key. Start tracking it.
                 mDeadSequence.appendCodePoint(event.mCodePoint)
-                return Event.Companion.createConsumedEvent(event)
+                return Event.createConsumedEvent(event)
             }
             // Regular keystroke when not keeping track of a dead key. Simply said, there are
 // no dead keys at all in the current input, so this combiner has nothing to do and
@@ -201,8 +201,7 @@ class DeadKeyCombiner : Combiner {
         }
         if (Character.isWhitespace(event!!.mCodePoint)
                 || event.mCodePoint == mDeadSequence.codePointBefore(mDeadSequence.length)) { // When whitespace or twice the same dead key, we should output the dead sequence as is.
-            val resultEvent = createEventChainFromSequence(mDeadSequence.toString(),
+            val resultEvent = createEventChainFromSequence(mDeadSequence.toString(), event)
-                    event)
             mDeadSequence.setLength(0)
             return resultEvent
         }
@@ -211,13 +210,13 @@ class DeadKeyCombiner : Combiner {
                 val trimIndex = mDeadSequence.length - Character.charCount(
                         mDeadSequence.codePointBefore(mDeadSequence.length))
                 mDeadSequence.setLength(trimIndex)
-                return Event.Companion.createConsumedEvent(event)
+                return Event.createConsumedEvent(event)
             }
             return event
         }
         if (event.isDead) {
             mDeadSequence.appendCodePoint(event.mCodePoint)
-            return Event.Companion.createConsumedEvent(event)
+            return Event.createConsumedEvent(event)
         }
         // Combine normally.
         val sb = StringBuilder()
@@ -248,17 +247,16 @@ class DeadKeyCombiner : Combiner {
         get() = mDeadSequence
 
     companion object {
-        private fun createEventChainFromSequence(text: CharSequence,
+        private fun createEventChainFromSequence(text: CharSequence, originalEvent: Event): Event {
-                                                 originalEvent: Event?): Event? {
             var index = text.length
             if (index <= 0) {
                 return originalEvent
             }
-            var lastEvent: Event? = null
+            lateinit var lastEvent: Event
             do {
                 val codePoint = Character.codePointBefore(text, index)
-                lastEvent = Event.Companion.createHardwareKeypressEvent(codePoint,
+                lastEvent = Event.createHardwareKeypressEvent(codePoint,
-                        originalEvent!!.mKeyCode, lastEvent, false /* isKeyRepeat */)
+                        originalEvent.mKeyCode, lastEvent, false /* isKeyRepeat */)
                 index -= Character.charCount(codePoint)
             } while (index > 0)
             return lastEvent

app/src/main/java/org/dslul/openboard/inputmethod/latin/NgramContext.java

@@ -175,8 +175,7 @@ public class NgramContext {
                 }
             }
         }
-        final String[] contextStringArray = prevTermList.toArray(new String[prevTermList.size()]);
+        return prevTermList.toArray(new String[prevTermList.size()]);
-        return contextStringArray;
     }
 
     public boolean isValid() {
@@ -227,7 +226,7 @@ public class NgramContext {
     public int hashCode() {
         int hashValue = 0;
         for (final WordInfo wordInfo : mPrevWordsInfo) {
-            if (wordInfo == null || !WordInfo.EMPTY_WORD_INFO.equals(wordInfo)) {
+            if (!WordInfo.EMPTY_WORD_INFO.equals(wordInfo)) {
                 break;
             }
             hashValue ^= wordInfo.hashCode();
@@ -267,7 +266,7 @@ public class NgramContext {
 
     @Override
     public String toString() {
-        final StringBuffer builder = new StringBuffer();
+        final StringBuilder builder = new StringBuilder();
         for (int i = 0; i < mPrevWordsCount; i++) {
             final WordInfo wordInfo = mPrevWordsInfo[i];
             builder.append("PrevWord[");

app/src/main/java/org/dslul/openboard/inputmethod/latin/WordComposer.java

@@ -127,7 +127,7 @@ public final class WordComposer {
         refreshTypedWordCache();
     }
 
-    private final void refreshTypedWordCache() {
+    private void refreshTypedWordCache() {
         mTypedWordCache = mCombinerChain.getComposingWordWithCombiningFeedback();
         mCodePointSize = Character.codePointCount(mTypedWordCache, 0, mTypedWordCache.length());
     }
@@ -144,7 +144,7 @@ public final class WordComposer {
         return size() == 1;
     }
 
-    public final boolean isComposingWord() {
+    public boolean isComposingWord() {
         return size() > 0;
     }
 

app/src/main/java/org/dslul/openboard/inputmethod/latin/userdictionary/UserDictionaryAddWordContents.java

@@ -83,15 +83,13 @@ public class UserDictionaryAddWordContents {
             // it's too long to be edited.
             mWordEditText.setSelection(mWordEditText.getText().length());
         }
-        final String shortcut;
         if (UserDictionarySettings.IS_SHORTCUT_API_SUPPORTED) {
-            shortcut = args.getString(EXTRA_SHORTCUT);
+            final String shortcut = args.getString(EXTRA_SHORTCUT);
             if (null != shortcut && null != mShortcutEditText) {
                 mShortcutEditText.setText(shortcut);
             }
             mOldShortcut = args.getString(EXTRA_SHORTCUT);
         } else {
-            shortcut = null;
             mOldShortcut = null;
         }
         mMode = args.getInt(EXTRA_MODE); // default return value for #getInt() is 0 = MODE_EDIT

app/src/main/java/org/dslul/openboard/inputmethod/latin/userdictionary/UserDictionaryList.java

@@ -22,9 +22,6 @@ import android.content.Intent;
 import android.database.Cursor;
 import android.os.Build;
 import android.os.Bundle;
-import android.preference.Preference;
-import android.preference.PreferenceFragment;
-import android.preference.PreferenceGroup;
 import android.provider.UserDictionary;
 import android.text.TextUtils;
 import android.view.inputmethod.InputMethodInfo;
@@ -32,6 +29,9 @@ import android.view.inputmethod.InputMethodManager;
 import android.view.inputmethod.InputMethodSubtype;
 
 import androidx.annotation.Nullable;
+import androidx.preference.Preference;
+import androidx.preference.PreferenceFragmentCompat;
+import androidx.preference.PreferenceGroup;
 
 import org.dslul.openboard.inputmethod.latin.R;
 import org.dslul.openboard.inputmethod.latin.common.LocaleUtils;
@@ -44,18 +44,17 @@ import java.util.TreeSet;
 // packages/apps/Settings/src/com/android/settings/inputmethod/UserDictionaryList.java
 // in order to deal with some devices that have issues with the user dictionary handling
 
-public class UserDictionaryList extends PreferenceFragment {
+public class UserDictionaryList extends PreferenceFragmentCompat {
 
     public static final String USER_DICTIONARY_SETTINGS_INTENT_ACTION =
             "android.settings.USER_DICTIONARY_SETTINGS";
 
     @Override
-    public void onCreate(final Bundle icicle) {
+    public void onCreatePreferences(@Nullable Bundle bundle, @Nullable String s) {
-        super.onCreate(icicle);
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
             getPreferenceManager().setStorageDeviceProtected();
         }
-        setPreferenceScreen(getPreferenceManager().createPreferenceScreen(getActivity()));
+        setPreferenceScreen(getPreferenceManager().createPreferenceScreen(requireContext()));
     }
 
     public static TreeSet<String> getUserDictionaryLocalesSet(final Activity activity) {
@@ -115,10 +114,12 @@ public class UserDictionaryList extends PreferenceFragment {
      * @param userDictGroup The group to put the settings in.
      */
     protected void createUserDictSettings(final PreferenceGroup userDictGroup) {
-        final Activity activity = getActivity();
         userDictGroup.removeAll();
-        final TreeSet<String> localeSet =
+        final TreeSet<String> localeSet = UserDictionaryList.getUserDictionaryLocalesSet(requireActivity());
-                UserDictionaryList.getUserDictionaryLocalesSet(activity);
+        if (localeSet == null) {
+            userDictGroup.addPreference(createUserDictionaryPreference(null));
+            return;
+        }
 
         if (localeSet.size() > 1) {
             // Have an "All languages" entry in the languages list if there are two or more active
@@ -141,7 +142,7 @@ public class UserDictionaryList extends PreferenceFragment {
      * @return The corresponding preference.
      */
     protected Preference createUserDictionaryPreference(@Nullable final String localeString) {
-        final Preference newPref = new Preference(getActivity());
+        final Preference newPref = new Preference(requireContext());
         final Intent intent = new Intent(USER_DICTIONARY_SETTINGS_INTENT_ACTION);
         if (null == localeString) {
             newPref.setTitle(Locale.getDefault().getDisplayName());

app/src/main/java/org/dslul/openboard/inputmethod/latin/userdictionary/UserDictionarySettings.java

@@ -159,7 +159,7 @@ public class UserDictionarySettings extends ListFragment {
     public void onResume() {
         super.onResume();
         ListAdapter adapter = getListView().getAdapter();
-        if (adapter != null && adapter instanceof MyAdapter) {
+        if (adapter instanceof MyAdapter) {
             // The list view is forced refreshed here. This allows the changes done 
             // in UserDictionaryAddWordFragment (update/delete/insert) to be seen when 
             // user goes back to this view. 
@@ -292,28 +292,24 @@ public class UserDictionarySettings extends ListFragment {
     private static class MyAdapter extends SimpleCursorAdapter implements SectionIndexer {
         private AlphabetIndexer mIndexer;
 
-        private ViewBinder mViewBinder = new ViewBinder() {
+        private final ViewBinder mViewBinder = (v, c, columnIndex) -> {
-
+            if (!IS_SHORTCUT_API_SUPPORTED) {
-            @Override
+                // just let SimpleCursorAdapter set the view values
-            public boolean setViewValue(final View v, final Cursor c, final int columnIndex) {
-                if (!IS_SHORTCUT_API_SUPPORTED) {
-                    // just let SimpleCursorAdapter set the view values
-                    return false;
-                }
-                if (columnIndex == INDEX_SHORTCUT) {
-                    final String shortcut = c.getString(INDEX_SHORTCUT);
-                    if (TextUtils.isEmpty(shortcut)) {
-                        v.setVisibility(View.GONE);
-                    } else {
-                        ((TextView)v).setText(shortcut);
-                        v.setVisibility(View.VISIBLE);
-                    }
-                    v.invalidate();
-                    return true;
-                }
-
                 return false;
             }
+            if (columnIndex == INDEX_SHORTCUT) {
+                final String shortcut = c.getString(INDEX_SHORTCUT);
+                if (TextUtils.isEmpty(shortcut)) {
+                    v.setVisibility(View.GONE);
+                } else {
+                    ((TextView)v).setText(shortcut);
+                    v.setVisibility(View.VISIBLE);
+                }
+                v.invalidate();
+                return true;
+            }
+
+            return false;
         };
 
         public MyAdapter(final Context context, final int layout, final Cursor c,