Add PreferenceUtils to registerOnActivityDestroyListener and unregisterOnActivityDestroyListener

app/src/main/java/com/hippo/preference/DialogPreference.java

@@ -27,6 +27,7 @@ import android.os.Build;
 import android.os.Bundle;
 import android.os.Parcelable;
 import android.preference.Preference;
+import android.preference.PreferenceManager;
 import android.support.annotation.DrawableRes;
 import android.support.annotation.StringRes;
 import android.support.v4.content.ContextCompat;
@@ -45,7 +46,8 @@ import com.hippo.ehviewer.R;
  * actual preference controls.
  */
 public abstract class DialogPreference extends Preference implements
-        DialogInterface.OnClickListener, DialogInterface.OnDismissListener {
+        DialogInterface.OnClickListener, DialogInterface.OnDismissListener,
+        PreferenceManager.OnActivityDestroyListener {
 
     private static final String KEY_SUPER = "super";
     private static final String KEY_IS_DIALOG_SHOWING = "is_dialog_showing";
@@ -272,6 +274,8 @@ public abstract class DialogPreference extends Preference implements
 
         onPrepareDialogBuilder(mBuilder);
 
+        PreferenceUtils.registerOnActivityDestroyListener(this, this);
+
         // Create the dialog
         final AlertDialog dialog = mDialog = mBuilder.create();
         if (state != null) {
@@ -336,6 +340,8 @@ public abstract class DialogPreference extends Preference implements
 
     @Override
     public void onDismiss(DialogInterface dialog) {
+        PreferenceUtils.unregisterOnActivityDestroyListener(this, this);
+
         mDialog = null;
         onDialogClosed(mWhichButtonClicked == DialogInterface.BUTTON_POSITIVE);
     }
@@ -359,6 +365,15 @@ public abstract class DialogPreference extends Preference implements
         return mDialog;
     }
 
+    @Override
+    public void onActivityDestroy() {
+        if (mDialog == null || !mDialog.isShowing()) {
+            return;
+        }
+
+        mDialog.dismiss();
+    }
+
     @Override
     protected Parcelable onSaveInstanceState() {
         final Parcelable superState = super.onSaveInstanceState();

app/src/main/java/com/hippo/preference/PreferenceUtils.java

@@ -0,0 +1,99 @@
+/*
+ * Copyright 2016 Hippo Seven
+ *
+ * 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.hippo.preference;
+
+import android.preference.Preference;
+import android.preference.PreferenceManager;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+public final class PreferenceUtils {
+    private PreferenceUtils() {}
+
+    private static final Method mRegisterOnActivityDestroyListener;
+    private static final Method mUnregisterOnActivityDestroyListener;
+
+    static {
+        Method method;
+        Class<?> clazz = PreferenceManager.class;
+
+        method = null;
+        try {
+            method = clazz.getDeclaredMethod("registerOnActivityDestroyListener",
+                    PreferenceManager.OnActivityDestroyListener.class);
+            if (null != method) {
+                method.setAccessible(true);
+            }
+        } catch (NoSuchMethodException e) {
+            e.printStackTrace();
+        }
+        mRegisterOnActivityDestroyListener = method;
+
+        method = null;
+        try {
+            method = clazz.getDeclaredMethod("unregisterOnActivityDestroyListener",
+                    PreferenceManager.OnActivityDestroyListener.class);
+            if (null != method) {
+                method.setAccessible(true);
+            }
+        } catch (NoSuchMethodException e) {
+            e.printStackTrace();
+        }
+        mUnregisterOnActivityDestroyListener = method;
+    }
+
+    @SuppressWarnings("TryWithIdenticalCatches")
+    public static void registerOnActivityDestroyListener(Preference preference,
+            PreferenceManager.OnActivityDestroyListener listener) {
+        if (null == mRegisterOnActivityDestroyListener || null == preference || null == listener) {
+            return;
+        }
+        PreferenceManager preferenceManager = preference.getPreferenceManager();
+        if (null == preferenceManager) {
+            return;
+        }
+
+        try {
+            mRegisterOnActivityDestroyListener.invoke(preferenceManager, listener);
+        } catch (IllegalAccessException e) {
+            e.printStackTrace();
+        } catch (InvocationTargetException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @SuppressWarnings("TryWithIdenticalCatches")
+    public static void unregisterOnActivityDestroyListener(Preference preference,
+            PreferenceManager.OnActivityDestroyListener listener) {
+        if (null == mUnregisterOnActivityDestroyListener || null == preference || null == listener) {
+            return;
+        }
+        PreferenceManager preferenceManager = preference.getPreferenceManager();
+        if (null == preferenceManager) {
+            return;
+        }
+
+        try {
+            mUnregisterOnActivityDestroyListener.invoke(preferenceManager, listener);
+        } catch (IllegalAccessException e) {
+            e.printStackTrace();
+        } catch (InvocationTargetException e) {
+            e.printStackTrace();
+        }
+    }
+}