[JAVA] Customize how to divide the contents of Recyclerview

Introduction

In some cases, the layout of the contents of Recyclerview is divided into two, below that is further divided into four, and no, there is no need to divide below this four divisions! In that way, I want to divide the contents of the recyclerview in various ways!

like this!

References

About RecyclerView http://qiita.com/Yuki_Yamada/items/ec8b6c1ff0c9d74c2a53 About setSpan (how many items are divided) https://stackoverflow.com/questions/32366412/gridlayoutmanager-setspansizelookup-creating-blank-cells About Viewtype http://woshidan.hatenablog.com/entry/2015/11/02/083000

Library settings

build.gradle

compile 'com.android.support:recyclerview-v7:25.3.1'

Please add.

Implementation

This time, the contents of xml described in the three layout files are applied to the recyclerview. Then, the layout file is described below.

layout1.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <TextView
        android:layout_margin="1dp"
        android:text="1"
        android:background="@color/colorAccent"
        android:gravity="center"
        android:layout_width="match_parent"
        android:layout_height="50dp" />
</LinearLayout>

layout2.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <TextView
        android:layout_margin="1dp"
        android:text="2"
        android:background="@color/colorPrimaryDark"
        android:gravity="center"
        android:layout_width="match_parent"
        android:layout_height="100dp" />
</LinearLayout>

layout3.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <TextView
        android:layout_margin="1dp"
        android:text="3"
        android:background="@color/colorPrimary"
        android:gravity="center"
        android:layout_width="match_parent"
        android:layout_height="200dp" />
</LinearLayout>

Next, let's set the Recyclerview as usual. First, prepare a Recyclerview (Recyclerview cannot have child elements)

recyclerview.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">
    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerview"
        android:scrollbars="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
</LinearLayout>

Next, connect Recyclerview with layout1.xml, layout2.xml, and layout3.xml by adapter.

custom_recyclerview_adapter.java

package my package;

import android.app.Activity;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class custom_recyclerview_adapter extends RecyclerView.Adapter<custom_recyclerview_adapter.ViewHolder>{
    private Activity mactivity;
    private int item_count;

    public custom_recyclerview_adapter(Activity mactivity,int item_count) {
        this.mactivity = mactivity;
        this.item_count = item_count;
    }

    @Override
    public custom_recyclerview_adapter.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {

        View view;
        final custom_recyclerview_adapter.ViewHolder viewHold;

        /******important******/
        switch(i) {//Here, branch from the viewType of the layout to the layout you want to apply.
            case 0:
                view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.layout1, viewGroup, false);
                viewHold = new custom_recyclerview_adapter.ViewHolder(view,i);
                //Equipped with click listener
                view.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        int position = viewHold.getAdapterPosition(); //Get position
                        Log.d("test",String.valueOf(position));//Return what number you pressed
                    }
                });
                return viewHold;
            case 1:
                view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.layout2, viewGroup, false);
                viewHold = new custom_recyclerview_adapter.ViewHolder(view,i);
                //Equipped with click listener
                view.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        int position = viewHold.getAdapterPosition(); //Get position
                        Log.d("test",String.valueOf(position));//Return what number you pressed
                    }
                });
                return viewHold;
            case 2:
                view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.layout3, viewGroup, false);
                viewHold = new custom_recyclerview_adapter.ViewHolder(view,i);
                //Equipped with click listener
                view.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        int position = viewHold.getAdapterPosition(); //Get position
                        Log.d("test",String.valueOf(position));//Return what number you pressed
                    }
                });
                return viewHold;
        }
        /*************/
        return null;
    }

    @Override//Make changes to the view here
    public void onBindViewHolder(custom_recyclerview_adapter.ViewHolder viewHolder, int i) {
        //Data display
        if(0 <= i && i <= 3) {
            //viewHolder.title1.setText(test[i] + "Mr.");
        }
        else if(4 <= i && i <= 7){// creates second view
            //viewHolder.title2.setText("hello");
        }
        else{// creates third view
            //viewHolder.title3.setText("test");
        }
    }

    @Override
    public int getItemCount() {
        return item_count;
    }

    /******important*******/
    @Override
    public int getItemViewType(int position) {//position is the position of the item in the recyclerview
        if(0 <= position && position <= 3) {//Viewtype 0th to 3rd contents of recyclerview"0"Set to
            return 0;
        }
        else if(4 <= position && position <= 7){//Viewtype the 4th to 7th contents of recyclerview"1"Set to
            return 1;
        }
        else{//Other view types"2"Set to
            return 2;
        }
    }
    /*****************/

    public class ViewHolder extends RecyclerView.ViewHolder{
        /*TextView title1;
        TextView title2;
        TextView title3;*/
        public ViewHolder(View view,int i) {
            super(view);
            /*title1 = (TextView)view.findViewById(R.id.textsample);
            title2 = (TextView)view.findViewById(R.id.textsample1);
            title3 = (TextView)view.findViewById(R.id.textsample2);*/
        }
    }
}

You can set ViewType for each position with getItemViewType. You can think of ViewType as a flag.

The actors are now complete. Let's implement it! !!

MainActivity.java

package jp.app.oomae.hisaki.recyclerview_custom_layout_sample;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.recyclerview);

        RecyclerView recyclerView = (RecyclerView)findViewById(R.id.recyclerview);
        recyclerView.setHasFixedSize(true);//Processing performance improves when the view size is fixed
        /*****************************************important*****************************************************/
        GridLayoutManager gridLayoutManagerVertical = new GridLayoutManager(this, 4, LinearLayoutManager.VERTICAL,false);
        gridLayoutManagerVertical.setSpanSizeLookup(new Custom_Spansize(4, 2 ,1));
        recyclerView.setLayoutManager(gridLayoutManagerVertical);
        /*************************************************************************************************/
        custom_recyclerview_adapter adapter = new custom_recyclerview_adapter(this,20);//Make 20 items
        recyclerView.setAdapter(adapter);
    }
}

However, if nothing is done, an error will occur. The Span inside the Recyclerview is not set. Describe the following file.

Custom_Spansize.java

package my package;

import android.support.v7.widget.GridLayoutManager;

public class Custom_Spansize extends GridLayoutManager.SpanSizeLookup{
    private int spanCnt1, spanCnt2 , spanCnt3;

    public Custom_Spansize(int spanCnt1, int spanCnt2,int spanCnt3) {
        super();
        this.spanCnt1 = spanCnt1;
        this.spanCnt2 = spanCnt2;
        this.spanCnt3 = spanCnt3;
    }

    @Override
    public int getSpanSize(int position) {
        int result;
        if(position >= 0 && position <= 3){
            result = spanCnt1;
        }
        else if(position >= 4 && position <= 7){
            result = spanCnt2;
        }
        else {
            result = spanCnt3;
        }
        return result;
    }
}

This completes the implementation.

application

MainActivity.java

        GridLayoutManager gridLayoutManagerVertical = new GridLayoutManager(this, 4, LinearLayoutManager.VERTICAL,false);
        gridLayoutManagerVertical.setSpanSizeLookup(new Custom_Spansize(4, 2 ,1));

Change the span interval here.

         GridLayoutManager gridLayoutManagerVertical = new GridLayoutManager(this, 4,LinearLayoutManager.VERTICAL,false);

4 here is the highest number of spans.

         gridLayoutManagerVertical.setSpanSizeLookup(new Custom_Spansize(4, 2 ,1));

Change the interval with the argument here. The idea is

--First argument: 4 ÷ 4 = 1 --Second argument: 4 ÷ 2 = 2 --Third argument: 4 ÷ 1 = 4

GridLayoutManager second argument ÷ Custom_Spansize argument = span The result of the division is Span.

This is the end. We look forward to hearing from you.

This code

https://github.com/hisakioomae/recyclerview_custom_layout_sample