Add divider between dashboard tiles

    <!-- Dashboard tile image margin start / end -->

    <dimen name="dashboard_tile_image_margin">24dp</dimen>

    <dimen name="dashboard_tile_divider_offset">8dp</dimen>

    <!-- Dashboard chevron tile size -->

    <dimen name="dashboard_tile_chevron_size">16dp</dimen>

/*

 * Copyright (C) 2016 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.dashboard;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.drawable.Drawable;

import android.support.v4.view.ViewCompat;

import android.support.v7.widget.RecyclerView;

import android.support.v7.widget.RecyclerView.State;

import android.support.v7.widget.RecyclerView.ViewHolder;

import android.util.TypedValue;

import android.view.View;

import com.android.settings.R;

public class DashboardDecorator extends RecyclerView.ItemDecoration {

    private final Context mContext;

    private final Drawable mDivider;

    public DashboardDecorator(Context context) {

        mContext = context;

        TypedValue value = new TypedValue();

        mContext.getTheme().resolveAttribute(android.R.attr.listDivider, value, true);

        mDivider = mContext.getDrawable(value.resourceId);

    }

    @Override

    public void onDrawOver(Canvas c, RecyclerView parent, State state) {

        final int childCount = parent.getChildCount();

        for (int i = 1; i < childCount; i++) {

            final View child = parent.getChildAt(i);

            final ViewHolder holder = parent.getChildViewHolder(child);

            if (holder.getItemViewType() == R.layout.dashboard_tile && parent.getChildViewHolder(parent.getChildAt(i - 1)).getItemViewType()

                        != R.layout.dashboard_category) {

                int top = getChildTop(child);

                int left = getChildLeft(child);

                mDivider.setBounds(left, top, child.getRight(),

                        top + mDivider.getIntrinsicHeight());

                mDivider.draw(c);

            }

            if (holder.getItemViewType() == R.layout.dashboard_category) {

                if (parent.getChildViewHolder(parent.getChildAt(i - 1)).getItemViewType()

                        != R.layout.dashboard_tile) {

                    continue;

                }

            } else if (holder.getItemViewType() != R.layout.condition_card) {

                continue;

            }

            int top = getChildTop(child);

            mDivider.setBounds(child.getLeft(), top, child.getRight(),

                    top + mDivider.getIntrinsicHeight());

            mDivider.draw(c);

        }

    }

    private int getChildTop(View child) {

        final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child

                .getLayoutParams();

        return child.getTop() + params.topMargin + Math.round(ViewCompat.getTranslationY(child));

    }

    private int getChildLeft(View child) {

        final int margin = mContext.getResources().getDimensionPixelSize(R.dimen.dashboard_tile_image_size)

            + mContext.getResources().getDimensionPixelSize(R.dimen.dashboard_tile_image_margin_start)

            + mContext.getResources().getDimensionPixelSize(R.dimen.dashboard_tile_image_margin_end)

            - mContext.getResources().getDimensionPixelSize(R.dimen.dashboard_tile_divider_offset);

        return child.getLeft() + margin;

    }

}