Android Class Parcelable with Arraylist

Android Class Parcelable with ArrayList

If you need to pass an ArrayList between activities, then I'd go with implementing Parcelable also, as there is no other way around I guess.
However I don't think you will need that much of getters and setters. Here is your Question class which implements Parcelable:

public class Question implements Parcelable {
    public String id;
    public String text;
    public String image;
    public ArrayList<Choice> choices;

    /**
     * Constructs a Question from values
     */
    public Question (String id, String text, String image, ArrayList<Choice> choices) {
        this.id = id;
        this.text = text;
        this.image = image;
        this.choices = choices;
    }

    /**
     * Constructs a Question from a Parcel
     * @param parcel Source Parcel
     */
    public Question (Parcel parcel) {
        this.id = parcel.readString();
        this.text = parcel.readString();
        this.image = parcel.readString();
        this.choices = parcel.readArrayList(null);
    }

    @Override
    public int describeContents() {
        return 0;
    }

    // Required method to write to Parcel
    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(id);
        dest.writeString(text);
        dest.writeString(image);
        dest.writeList(choices);
    }

    // Method to recreate a Question from a Parcel
    public static Creator<Question> CREATOR = new Creator<Question>() {

        @Override
        public Question createFromParcel(Parcel source) {
            return new Question(source);
        }

        @Override
        public Question[] newArray(int size) {
            return new Question[size];
        }

    };
}

Making data class with ArrayList inside Parcelable

Use the following within your Constructor:

parcel.createStringArrayList()

and within writeToParcel:

parcel.writeStringList(this.mTest)

Just a side node: If you're using Android Studio, just let it generate the Parcelable with the Parcelable code generator Plugin.

ArrayListArrayListString in Parcelable object kotlin

You can't directly create Parcelable for List of List directly, so one solution is to make one subclass of your desired List as Parcelable and take it as you final list type. How? check out below :

Let's first create our internal List of String class like below :

class StringList() : ArrayList<String>(), Parcelable {
    constructor(source: Parcel) : this() {
        source.createStringArrayList()
    }

    override fun describeContents() = 0

    override fun writeToParcel(dest: Parcel, flags: Int) {
        dest.writeStringList(this@StringList)
    }

    companion object {
        @JvmField
        val CREATOR: Parcelable.Creator<StringList> = object : Parcelable.Creator<StringList> {
            override fun createFromParcel(source: Parcel): StringList = StringList(source)
            override fun newArray(size: Int): Array<StringList?> = arrayOfNulls(size)
        }
    }
}

What we've done here is created our ArrayList<String> parcelable so that we can use it at any endpoint.

So final data class would be having following implementation :

data class Foo(@SerializedName("bar") val bar: List<StringList>) : Parcelable {
    constructor(source: Parcel) : this(
        source.createTypedArrayList(StringList.CREATOR)
    )

    override fun describeContents() = 0

    override fun writeToParcel(dest: Parcel, flags: Int) = with(dest) {
        writeTypedList(bar)
    }

    companion object {
       @JvmField
       val CREATOR: Parcelable.Creator<Foo> = object : Parcelable.Creator<Foo> {
            override fun createFromParcel(source: Parcel): Foo = Foo(source)
            override fun newArray(size: Int): Array<Foo?> = arrayOfNulls(size)
       }
    }
}

Note: It's simple implementation based on O.P., you can make any customization based on your requirement.

How to make generic arraylist parcelable in Android?

I have given up implementing AList as a Parcelable. However, since AList is ArrayList-like, I can treat it exactly as an ArrayList when I need to write AList<T> to Parcel.

For example, I have a AList<Tag> Tags declared in Food class. So in protected Food(Parcel in), I can write:

    ArrayList<Tag> tags = new ArrayList<>();
    in.readTypedList(tags, Tag.CREATOR);
    Tags = new AList<>(tags);

Of course, I have implemented Tag as a Parcelable. And I can have such writeToParcel:

@Override
public void writeToParcel(Parcel dest, int flags) {
    dest.writeString(Name);
    dest.writeString(ImagePath);
    dest.writeTypedList(Tags.ToArrayList());
    dest.writeString(Note);
    dest.writeByte((byte) (IsFavorite ? 1 : 0));
    if (DateAdded == null) {
        dest.writeByte((byte) 0);
    } else {
        dest.writeByte((byte) 1);
        dest.writeLong(DateAdded);
    }
}

My source code for Food class is here.

how to read Int arraylist in parcelable in android

So to create a parcelable class.

Firstly, Add add plugin to the gradle

plugins {
    .
    .
    id 'kotlin-parcelize'
}

Then, create a class and use annotations to parcelize the data

@Parcelize
class PostCardsListData(

    @SerializedName("arrDescriptionsTags")
    var arrDescriptionsTags: ArrayList<String>? = null,

    @SerializedName("priceDetail")
    var priceDetail: ArrayList<Int?>? = null

) : Parcelable 

To read/write data you just need to create an object of this class and use the dot operator to access the list.

In the activity/fragment/viewModel class

private var listData = PostCardsListData()

//read data

private var priceList : ArrayList<Int> = ArrayList()
if(listData.priceDetail != null){
    priceList.addAll(listData.priceDetail)
}

how to properly implement Parcelable with an ArrayListParcelable?

You almost got it !

You just need to do :

public void writeToParcel(Parcel out, int flags) {
    out.writeString(_mac);
    out.writeString(_pan);
    out.writeInt(_band);
    out.writeSerializable(_lqis);
    out.writeTypedList(_devices);
}

private ZigBeeNetwork(Parcel in) {
    _mac = in.readString();
    _pan = in.readString();
    _band = in.readInt();
    _lqis = (ArrayList<Integer>) in.readSerializable();
    in.readTypedList(_devices, ZigBeeDev.CREATOR);
}

That's all!

For your list of Integer, you can also do :

out.writeList(_lqis);
_lqis = new ArrayList<>();
in.readList(_lqis Integer.class.getClassLoader());

It should work.

How to implement Parcelable on my class which contains an ArrayListString?

I'm using Java instead of Kotlin but I think this problem can handled by a same solution.

I often use:

• parcel.createStringArrayList() instead of parcel.readArrayList(null)
• parcel.writeStringList(transactionImages) instead of parcel.writeList(transactionImages)

Making ArrayList of custom objects parcelable

Use writeTypedList and readTypedList.

parcel.writeTypedList(yourList);

and

parcel.readTypedList(yourList, YourParcelable.CREATOR);

Notice how you pass in the CREATOR as an argument for reading the list back.

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