Fix the vertical positioning of the text in collapsed notifications.

/*

 * Copyright (C) 2021 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.internal.widget;

import android.annotation.Nullable;

import android.content.Context;

import android.util.AttributeSet;

import android.view.View;

import android.widget.FrameLayout;

import android.widget.RemoteViews;

/**

 * This view will measure itself as having 0 size if all of its children are {@link #GONE}.

 * Otherwise it acts like a normal {@link FrameLayout}.

 */

@RemoteViews.RemoteView

public class NotificationVanishingFrameLayout extends FrameLayout {

    public NotificationVanishingFrameLayout(Context context) {

        this(context, null, 0, 0);

    }

    public NotificationVanishingFrameLayout(Context context, @Nullable AttributeSet attrs) {

        this(context, attrs, 0, 0);

    }

    public NotificationVanishingFrameLayout(Context context, @Nullable AttributeSet attrs,

            int defStyleAttr) {

        this(context, attrs, defStyleAttr, 0);

    }

    public NotificationVanishingFrameLayout(Context context, AttributeSet attrs, int defStyleAttr,

            int defStyleRes) {

        super(context, attrs, defStyleAttr, defStyleRes);

    }

    @Override

    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

        if (allChildrenGone()) {

            int zeroSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.EXACTLY);

            super.onMeasure(zeroSpec, zeroSpec);

        } else {

            super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        }

    }

    private boolean allChildrenGone() {

        final int childCount = getChildCount();

        for (int i = 0; i < childCount; i++) {

            final View child =  getChildAt(i);

            if (child != null && child.getVisibility() != GONE) {

                return false;

            }

        }

        return true;

    }

}

            android:orientation="vertical"

            >

            <com.android.internal.widget.NotificationVanishingFrameLayout

                android:layout_width="match_parent"

                android:layout_height="@dimen/notification_headerless_line_height"

                >

                <!-- This is the simplest way to keep this text vertically centered without using

                 gravity="center_vertical" which causes jumpiness in expansion animations. -->

                <include

                    layout="@layout/notification_template_text"

                    android:layout_width="match_parent"

                android:layout_height="@dimen/notification_headerless_line_height"

                    android:layout_height="@dimen/notification_text_height"

                    android:layout_gravity="center_vertical"

                    android:layout_marginTop="0dp"

                    />

            </com.android.internal.widget.NotificationVanishingFrameLayout>

            <include

                layout="@layout/notification_template_progress"