widgets: Import ToggleSwitch from the AOSP Settings app

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

app/src/main/java/com/wireguard/android/widgets/ToggleSwitch.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2013 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.wireguard.android.widgets;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.widget.Switch;
+
+public class ToggleSwitch extends Switch {
+
+    private ToggleSwitch.OnBeforeCheckedChangeListener mOnBeforeListener;
+
+    public static interface OnBeforeCheckedChangeListener {
+        public boolean onBeforeCheckedChanged(ToggleSwitch toggleSwitch, boolean checked);
+    }
+
+    public ToggleSwitch(Context context) {
+        super(context);
+    }
+
+    public ToggleSwitch(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public ToggleSwitch(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    public ToggleSwitch(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+    }
+
+    public void setOnBeforeCheckedChangeListener(OnBeforeCheckedChangeListener listener) {
+        mOnBeforeListener = listener;
+    }
+
+    @Override
+    public void setChecked(boolean checked) {
+        if (mOnBeforeListener != null
+                && mOnBeforeListener.onBeforeCheckedChanged(this, checked)) {
+            return;
+        }
+        super.setChecked(checked);
+    }
+
+    public void setCheckedInternal(boolean checked) {
+        super.setChecked(checked);
+    }
+}