GridLayoutManager - how to auto fit columns?
Asked 07 September, 2021
Viewed 3.1K times
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I have a RecyclerView with a GridLayoutManager that displays Card Views. I want the cards to rearrange according to the screen size (the Google Play app does this kind of thing with its app cards). Here is an example:

enter image description here

enter image description here

Here is how my app looks at the moment:

enter image description here

enter image description here

As you can see the cards just stretch and don't fit the empty space that is made from the orientation change. So how can I do this?

Code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Json;
using System.Threading;
using System.Threading.Tasks;
using Android.Media;
using Android.App;
using Android.Support.V4.App;
using Android.Support.V4.Content.Res;
using Android.Support.V4.Widget;
using Android.Support.V7.Widget;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Util;
using Android.Views;
using Android.Widget;
using Android.Net;
using Android.Views.Animations;
using Android.Graphics;
using Android.Graphics.Drawables;
using Newtonsoft.Json;
using *******.Adapters;
using *******.Models;

namespace *******.Fragments {
    public class Dashboard : GridLayoutBase {
        private ISharedPreferences pref;
        private SessionManager session;
        private string cookie;
        private DeviceModel deviceModel;
        private RecyclerView recyclerView;
        private RecyclerView.Adapter adapter;
//      private RecyclerView.LayoutManager layoutManager;
        private GridLayoutManager gridLayoutManager;
        private List<ItemData> itemData;
        private Bitmap lastPhotoBitmap;
        private Drawable lastPhotoDrawable;
        private static Activity activity;
        private ProgressDialog progressDialog;
        private TextView noData;
        private const string URL_DASHBOARD = "http://192.168.1.101/appapi/getdashboard";
        private const string URL_DATA = "http://192.168.1.101/appapi/getdata";

        public override void OnCreate(Bundle bundle) {
            base.OnCreate(bundle);

            activity = Activity;
            session = new SessionManager();
            pref = activity.GetSharedPreferences("UserSession", FileCreationMode.Private);
            cookie = pref.GetString("PHPSESSID", string.Empty);
        }

        public async override void OnStart() {
            base.OnStart();

            progressDialog = ProgressDialog.Show(activity, String.Empty, GetString(Resource.String.loading_text));
            progressDialog.Window.ClearFlags(WindowManagerFlags.DimBehind);

            await GetDevicesInfo();

            if (deviceModel.Error == "true" && deviceModel.ErrorType == "noSensors") {
                recyclerView.Visibility = ViewStates.Gone;
                noData.Visibility = ViewStates.Visible;

                progressDialog.Hide();

                return;
            } else {
                recyclerView.Visibility = ViewStates.Visible;
                noData.Visibility = ViewStates.Gone;

                await PopulateSensorStates();
            }

//          DisplayLastPhoto();

            adapter = new ViewAdapter(itemData);

            new System.Threading.Thread(new System.Threading.ThreadStart(() => {
                activity.RunOnUiThread(() => {
                    recyclerView.SetAdapter(adapter);
                });
            })).Start();

            progressDialog.Hide();
        }

        public async Task GetDevicesInfo() {
            var jsonFetcher = new JsonFetcher();
            JsonValue jsonDashboard = await jsonFetcher.FetchDataWithCookieAsync(URL_DASHBOARD, cookie);
            deviceModel = new DeviceModel();
            deviceModel = JsonConvert.DeserializeObject<DeviceModel>(jsonDashboard);
        }

        // Shows sensor states
        public async Task PopulateSensorStates() {
            itemData = new List<ItemData>();
            string lastValue = String.Empty;

            foreach (var sensor in this.deviceModel.Sensors) {
                var sensorImage = ResourcesCompat.GetDrawable(Resources, Resource.Drawable.smoke_red, null);

                switch (sensor.Type) {
                case "2":
                    var jsonFetcher = new JsonFetcher();
                    JsonValue jsonData = await jsonFetcher.FetchSensorDataAsync(URL_DATA, sensor.Id, "DESC", "1", cookie);
                    var deviceModel = new DeviceModel();
                    deviceModel = JsonConvert.DeserializeObject<DeviceModel>(jsonData);
                    lastValue = deviceModel.SensorData.Last().Value;
                    break;
                case "4":
                    await RenderLastCameraPhoto();
                    sensorImage = new BitmapDrawable(Resources, lastPhotoBitmap);
                    break;
                }

                itemData.Add(new ItemData() {
                    id = sensor.Id,
                    value = lastValue,
                    type = sensor.Type,
                    image = sensorImage,
                    title = sensor.Name.First().ToString().ToUpper() + sensor.Name.Substring(1).ToLower(),
                });
            }
        }

        // Shows the last camera photo
        public async Task RenderLastCameraPhoto() {
            if (deviceModel.Error == "true" && deviceModel.ErrorType == "noPhoto") {
                //TODO: Show a "No photo" picture
            } else {
                string url = deviceModel.LastPhotoLink;
                lastPhotoBitmap = await new ImageDownloader().GetImageBitmapFromUrlAsync(url, activity, 300, 300);
            }
        }

        public async void UpdateData(bool isSwipeRefresh) {
            await GetDevicesInfo();

            if (deviceModel.Error == "true" && deviceModel.ErrorType == "noSensors") {
                recyclerView.Visibility = ViewStates.Gone;
                noData.Visibility = ViewStates.Visible;

                return;
                } else {
                recyclerView.Visibility = ViewStates.Visible;
                noData.Visibility = ViewStates.Gone;

                await PopulateSensorStates();
            }

            adapter = new ViewAdapter(itemData);

            new System.Threading.Thread(new System.Threading.ThreadStart(() => {
                activity.RunOnUiThread(() => {
                    recyclerView.SetAdapter(adapter);
                });
            })).Start();

            adapter.NotifyDataSetChanged();
        }

        public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            View view = inflater.Inflate(Resource.Layout.Dashboard, container, false);
            noData = view.FindViewById<TextView>(Resource.Id.no_data_title);

            SwipeRefreshLayout swipeRefreshLayout = view.FindViewById<SwipeRefreshLayout>(Resource.Id.swipe_container);
            //          swipeRefreshLayout.SetColorSchemeResources(Color.LightBlue, Color.LightGreen, Color.Orange, Color.Red);

            // On refresh button press/swipe, updates the recycler view with new data
            swipeRefreshLayout.Refresh += (sender, e) => {
                UpdateData(true);

                swipeRefreshLayout.Refreshing = false;
            };

            var gridLayoutManager = new GridLayoutManager(activity, 2);

            recyclerView = view.FindViewById<RecyclerView>(Resource.Id.dashboard_recycler_view);
            recyclerView.HasFixedSize = true;
            recyclerView.SetLayoutManager(gridLayoutManager);
            recyclerView.SetItemAnimator(new DefaultItemAnimator());
            recyclerView.AddItemDecoration(new SpaceItemDecoration(15));

            return view;
        }

        public class ViewAdapter : RecyclerView.Adapter {
            private List<ItemData> itemData;
            public string sensorId;
            public string sensorType;
            private ImageView imageId;
            private TextView sensorValue;
            private TextView sensorTitle;

            public ViewAdapter(List<ItemData> itemData) {
                this.itemData = itemData;
            }

            public class ItemView : RecyclerView.ViewHolder {
                public View mainView { get; set; }

                public string id { get; set; }

                public string type { get; set; }

                public ImageView image { get; set; }

                //              public TextView value { get; set; }

                public TextView title { get; set; }

                public ItemView(View view) : base(view) {
                    mainView = view;
                }
            }

            public override RecyclerView.ViewHolder OnCreateViewHolder(ViewGroup parent, int viewType) {
                View itemLayoutView = LayoutInflater.From(parent.Context).Inflate(Resource.Layout.DashboardItems, null);
                CardView cardView = itemLayoutView.FindViewById<CardView>(Resource.Id.dashboard_card_view);
                imageId = itemLayoutView.FindViewById<ImageView>(Resource.Id.sensor_image);
//              sensorValue = itemLayoutView.FindViewById<TextView>(Resource.Id.sensor_value);
                sensorTitle = itemLayoutView.FindViewById<TextView>(Resource.Id.sensor_title);

                var viewHolder = new ItemView(itemLayoutView) {
                    id = sensorId,
                    type = sensorType,
                    image = imageId,
//                  value = sensorValue,
                    title = sensorTitle
                };

                return viewHolder;
            }

            public override void OnBindViewHolder(RecyclerView.ViewHolder viewHolder, int position) {
                ItemView itemHolder = viewHolder as ItemView;

                itemHolder.image.SetImageDrawable(itemData[position].image);

                if (itemData[position].type == "2") { // Temperature
                    itemHolder.title.Text = itemData[position].title + ": " + itemData[position].value;
                } else {
                    itemHolder.title.Text = itemData[position].title;
                }

                var bundle = new Bundle();
                var dualColumnList = new DualColumnList();
                var gallery = new Gallery();

                EventHandler clickUpdateViewEvent = ((sender, e) => {
                    bundle.PutString("id", itemData[position].id);
                    gallery.Arguments = bundle;
                    dualColumnList.Arguments = bundle;

                    if (itemData[position].type == "4") { // Camera
                        ((FragmentActivity)activity).ShowFragment(gallery, itemData[position].title, itemData[position].type, true);
                    } else {
                        ((FragmentActivity)activity).ShowFragment(dualColumnList, itemData[position].title, itemData[position].type, true);
                    }
                });

                itemHolder.image.Click += clickUpdateViewEvent;
//              itemHolder.value.Click += clickUpdateViewEvent;
                itemHolder.title.Click += clickUpdateViewEvent;
            }

            public override int ItemCount {
                get { return itemData.Count; }
            }
        }

        public class ItemData {
            public string id { get; set; }

            public string type { get; set; }

            public Drawable image { get; set; }

            public string value { get; set; }

            public string title { get; set; }
        }
    }
}

Fragment Layout:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.SwipeRefreshLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/swipe_container"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center_horizontal"
        android:weightSum="1">
        <RelativeLayout
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="0.9"
            android:scrollbars="vertical">
            <android.support.v7.widget.RecyclerView
                android:id="@+id/dashboard_recycler_view"
                android:layout_width="match_parent"
                android:layout_height="match_parent" />
            <TextView
                android:text="@string/no_data_text"
                android:id="@+id/no_data_title"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:textSize="30sp"
                android:gravity="center"
                android:layout_centerInParent="true" />
        </RelativeLayout>
    </LinearLayout>
</android.support.v4.widget.SwipeRefreshLayout>

Fragment Items Layout:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/dashboard_card_view"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:orientation="vertical"
        android:foreground="?android:attr/selectableItemBackground">
        <ImageView
            android:id="@+id/sensor_image"
            android:layout_width="120dp"
            android:layout_height="120dp"
            android:paddingTop="5dp"
            android:layout_alignParentTop="true" />
    <!--        <TextView
            android:id="@+id/sensor_value"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="30sp"
            android:layout_below="@id/sensor_image"
            android:gravity="center" />-->
        <TextView
            android:id="@+id/sensor_title"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textSize="23sp"
            android:layout_below="@id/sensor_image"
            android:gravity="center"
            android:layout_alignParentBottom="true" />
    </LinearLayout>
</android.support.v7.widget.CardView>

8 Answer