Refactor choose lock password scrolling

Replace the negative margin + inset background hack with a overriding
call to requestRectangleOnScreen, which will also make a best effort
to show all the password requirements if there are multiple of them.

Bug: 38236574
Test: Added ScrollToParentEditTextTest
Change-Id: Id570652b64434b2d0b25c231540375d93884aaa9

src/com/android/settings/widget/ScrollToParentEditText.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2017 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.android.settings.widget;
+
+import android.content.Context;
+import android.graphics.Rect;
+import android.util.AttributeSet;
+import android.view.View;
+import android.view.ViewParent;
+import android.widget.EditText;
+
+/**
+ * An EditText that, instead of scrolling to itself when focused, will request scrolling to its
+ * parent. This is used in ChooseLockPassword to do make a best effort for not hiding the error
+ * messages for why the password is invalid under the keyboard.
+ */
+public class ScrollToParentEditText extends EditText {
+
+    private Rect mRect = new Rect();
+
+    public ScrollToParentEditText(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    @Override
+    public boolean requestRectangleOnScreen(Rect rectangle, boolean immediate) {
+        ViewParent parent = getParent();
+        if (parent instanceof View) {
+            // Request the entire parent view to be shown, which in ChooseLockPassword's case,
+            // will include messages for why the password is invalid (if any).
+            ((View) parent).getDrawingRect(mRect);
+            return ((View) parent).requestRectangleOnScreen(mRect, immediate);
+        } else {
+            return super.requestRectangleOnScreen(rectangle, immediate);
+        }
+    }
+}