fix issue when rotating screen while keyboard is showing on some newer android versions

see https://github.com/Helium314/openboard/pull/33#issuecomment-1650487463
based on commits
  4d464ec07d
  6ae09365a5
  6c752d8eca

app/src/main/java/org/dslul/openboard/inputmethod/keyboard/KeyboardSwitcher.java

@@ -25,6 +25,8 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.inputmethod.EditorInfo;
 
+import androidx.annotation.NonNull;
+
 import org.dslul.openboard.inputmethod.event.Event;
 import org.dslul.openboard.inputmethod.keyboard.KeyboardLayoutSet.KeyboardLayoutSetException;
 import org.dslul.openboard.inputmethod.keyboard.clipboard.ClipboardHistoryView;
@@ -93,23 +95,24 @@ public final class KeyboardSwitcher implements KeyboardState.SwitchActions {
         mIsHardwareAcceleratedDrawingEnabled = mLatinIME.enableHardwareAcceleration();
     }
 
-    public void updateKeyboardTheme() {
+    public void updateKeyboardTheme(@NonNull Context displayContext) {
         final boolean themeUpdated = updateKeyboardThemeAndContextThemeWrapper(
-                mLatinIME, KeyboardTheme.getKeyboardTheme(mLatinIME /* context */));
+                displayContext, KeyboardTheme.getKeyboardTheme(displayContext /* context */));
         if (themeUpdated && mKeyboardView != null) {
-            mLatinIME.setInputView(onCreateInputView(mIsHardwareAcceleratedDrawingEnabled));
+            mLatinIME.setInputView(onCreateInputView(displayContext, mIsHardwareAcceleratedDrawingEnabled));
         }
     }
 
-    public void forceUpdateKeyboardTheme() {
+    public void forceUpdateKeyboardTheme(@NonNull Context displayContext) {
-        mLatinIME.setInputView(onCreateInputView(mIsHardwareAcceleratedDrawingEnabled));
+        mLatinIME.setInputView(onCreateInputView(displayContext, mIsHardwareAcceleratedDrawingEnabled));
     }
 
     private boolean updateKeyboardThemeAndContextThemeWrapper(final Context context,
             final KeyboardTheme keyboardTheme) {
         final boolean nightModeChanged = (mCurrentUiMode & Configuration.UI_MODE_NIGHT_MASK)
                 != (context.getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK);
-        if (mThemeContext == null || !keyboardTheme.equals(mKeyboardTheme) || nightModeChanged) {
+        if (mThemeContext == null || !keyboardTheme.equals(mKeyboardTheme) || nightModeChanged
+                || !mThemeContext.getResources().equals(context.getResources())) {
             mKeyboardTheme = keyboardTheme;
             mThemeContext = new ContextThemeWrapper(context, keyboardTheme.mStyleId);
             mCurrentUiMode = context.getResources().getConfiguration().uiMode;
@@ -530,13 +533,14 @@ public final class KeyboardSwitcher implements KeyboardState.SwitchActions {
         }
     }
 
-    public View onCreateInputView(final boolean isHardwareAcceleratedDrawingEnabled) {
+    public View onCreateInputView(@NonNull Context displayContext,
+                                  final boolean isHardwareAcceleratedDrawingEnabled) {
         if (mKeyboardView != null) {
             mKeyboardView.closing();
         }
 
         updateKeyboardThemeAndContextThemeWrapper(
-                mLatinIME, KeyboardTheme.getKeyboardTheme(mLatinIME /* context */));
+                displayContext, KeyboardTheme.getKeyboardTheme(displayContext /* context */));
         mCurrentInputView = (InputView)LayoutInflater.from(mThemeContext).inflate(
                 R.layout.input_view, null);
         mMainKeyboardFrame = mCurrentInputView.findViewById(R.id.main_keyboard_frame);

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

@@ -98,11 +98,14 @@ import java.util.Locale;
 import java.util.concurrent.TimeUnit;
 
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 import static org.dslul.openboard.inputmethod.latin.common.Constants.ImeOption.FORCE_ASCII;
 import static org.dslul.openboard.inputmethod.latin.common.Constants.ImeOption.NO_MICROPHONE;
 import static org.dslul.openboard.inputmethod.latin.common.Constants.ImeOption.NO_MICROPHONE_COMPAT;
 
+import androidx.annotation.NonNull;
+
 /**
  * Input method implementation for Qwerty'ish keyboard.
  */
@@ -163,6 +166,9 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
     // {@link #onEvaluateInputViewShown()}.
     private boolean mIsExecutingStartShowingInputView;
 
+    // Used for re-initialize keyboard layout after onConfigurationChange.
+    @Nullable private Context mDisplayContext;
+
     // Object for reacting to adding/removing a dictionary pack.
     private final BroadcastReceiver mDictionaryPackInstallReceiver =
             new DictionaryPackInstallBroadcastReceiver(this);
@@ -620,10 +626,11 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
         DebugFlags.init(DeviceProtectedUtils.getSharedPreferences(this));
         RichInputMethodManager.init(this);
         mRichImm = RichInputMethodManager.getInstance();
-        KeyboardSwitcher.init(this);
         AudioAndHapticFeedbackManager.init(this);
         AccessibilityUtils.init(this);
         mStatsUtilsManager.onCreate(this /* context */, mDictionaryFacilitator);
+        mDisplayContext = getDisplayContext();
+        KeyboardSwitcher.init(this);
         super.onCreate();
 
         mClipboardHistoryManager.onCreate();
@@ -816,14 +823,46 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
             }
         }
         // KeyboardSwitcher will check by itself if theme update is necessary
-        mKeyboardSwitcher.updateKeyboardTheme();
+        mKeyboardSwitcher.updateKeyboardTheme(getDisplayContext());
         super.onConfigurationChanged(conf);
     }
 
+    @Override
+    public void onInitializeInterface() {
+        mDisplayContext = getDisplayContext();
+        mKeyboardSwitcher.updateKeyboardTheme(mDisplayContext);
+    }
+
+    /**
+     * Returns the context object whose resources are adjusted to match the metrics of the display.
+     *
+     * Note that before {@link android.os.Build.VERSION_CODES#KITKAT}, there is no way to support
+     * multi-display scenarios, so the context object will just return the IME context itself.
+     *
+     * With initiating multi-display APIs from {@link android.os.Build.VERSION_CODES#KITKAT}, the
+     * context object has to return with re-creating the display context according the metrics
+     * of the display in runtime.
+     *
+     * Starts from {@link android.os.Build.VERSION_CODES#S_V2}, the returning context object has
+     * became to IME context self since it ends up capable of updating its resources internally.
+     */
+    private @NonNull Context getDisplayContext() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S_V2) {
+            // IME context sources is now managed by WindowProviderService from Android 12L.
+            return this;
+        }
+        // An issue in Q that non-activity components Resources / DisplayMetrics in
+        // Context doesn't well updated when the IME window moving to external display.
+        // Currently we do a workaround is to create new display context directly and re-init
+        // keyboard layout with this context.
+        final WindowManager wm = (WindowManager) getSystemService(Context.WINDOW_SERVICE);
+        return createDisplayContext(wm.getDefaultDisplay());
+    }
+
     @Override
     public View onCreateInputView() {
         StatsUtils.onCreateInputView();
-        return mKeyboardSwitcher.onCreateInputView(mIsHardwareAcceleratedDrawingEnabled);
+        return mKeyboardSwitcher.onCreateInputView(getDisplayContext(), mIsHardwareAcceleratedDrawingEnabled);
     }
 
     @Override
@@ -906,7 +945,7 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
         mGestureConsumer = GestureConsumer.NULL_GESTURE_CONSUMER;
         mRichImm.refreshSubtypeCaches();
         final KeyboardSwitcher switcher = mKeyboardSwitcher;
-        switcher.updateKeyboardTheme();
+        switcher.updateKeyboardTheme(mDisplayContext);
         final MainKeyboardView mainKeyboardView = switcher.getMainKeyboardView();
         // If we are starting input in a different text field from before, we'll have to reload
         // settings, so currentSettingsValues can't be final.

app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/AppearanceSettingsFragment.kt

@@ -81,7 +81,8 @@ class AppearanceSettingsFragment : SubScreenFragment(), Preference.OnPreferenceC
     override fun onPause() {
         super.onPause()
         if (needsReload)
-            KeyboardSwitcher.getInstance().forceUpdateKeyboardTheme()
+            // todo: is this the correct "displayContext? if not it may cause weird rare issues on some android versions
+            KeyboardSwitcher.getInstance().forceUpdateKeyboardTheme(activity)
         needsReload = false
     }