CODEWITHSUNDEEP
javaandroid
Chud37
Chud37

Reputation: 5017

How to create Parcel In?

I have a class called MusicFile, its constructor is:

protected MusicFile(Parcel in) {
        Title = in.readString();
        Album = in.readString();
        Artist = in.readString();
        Path = in.readString();
        Genre = in.readString();
        Data = in.readString();
        artistID = in.readInt();
        if (in.readByte() == 0) {
            AlbumID = null;
        } else {
            AlbumID = in.readLong();
        }
        albumCover = in.readParcelable(Uri.class.getClassLoader());
    }

But now that I've made it to extend Parcelable, I cannot just create a new MusicFile like so:

MusicFile musicFile = new MusicFile();

Because it requires Parcel In.

How can I create a new Music file now? I've tried the following:

` Parcel parcel = New Parcel();

MusicFile musicFile = new MusicFile(parcel); `

However that doesnt seem to work. I get the following error: 'Parcel(long)' is not public in 'android.os.Parcel'. Cannot be accessed from outside package

What is the correct way to do this?

Upvotes: 0

Views: 2915

Answers (3)

JoseF
JoseF

Reputation: 1311

You can use Parcel.obtain() to get a Parcel. Don't forget to do

parcel.recycle()

after finishing using it.

Upvotes: 3

Arthur Attout
Arthur Attout

Reputation: 2916

You can extend Parcelableand leave your default constructor

import android.os.Parcel;
import android.os.Parcelable;


public class MusicFile implements Parcelable {

    private Integer id;
    private String title;
    ...

    public MusicFile(Integer id, String title) {
        this.id = id;
        this.title = title;
    }

    public MusicFile(){

    }

    protected MusicFile(Parcel in) {
        id = in.readByte() == 0x00 ? null : in.readInt();
        title = in.readString();
    }

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

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        if (id == null) {
            dest.writeByte((byte) (0x00));
        } else {
            dest.writeByte((byte) (0x01));
            dest.writeInt(id);
        }
        dest.writeString(title);
    }

    @SuppressWarnings("unused")
    public static final Parcelable.Creator<MusicFile> CREATOR = new Parcelable.Creator<MusicFile>() {
        @Override
        public MusicFile createFromParcel(Parcel in) {
            return new MusicFile(in);
        }

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

The class Parcel is handled by Android when you pass objects in bundles like bundle.addParcelableExtra(...). You should not attempt to handle these things on your own. When you call addParcelableExtra() Android uses these methods (writeToParcel, describeContents, etc.) to serialize your objects, but it is completely up to the framework. You should add these methods to help Android serialize your objects automatically (and save you from a lot of pain) but you keep your standards constructors, getters/setters, etc.

Upvotes: 1

Umair
Umair

Reputation: 6426

You need to create an empty constructor for parcelable. Your model should now look something like this:

 public static final Creator<MusicFile> CREATOR = new Creator<MusicFile>() {
    @Override
    public MusicFilecreateFromParcel(Parcel in) {
        return new MusicFile(in);
    }

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

// It's an empty constructor for parcelable 
private MusicFile() {

}

// This constructor is what parcel generates.
protected MusicFile(Parcel in) {
        Title = in.readString();
        Album = in.readString();
        Artist = in.readString();
        Path = in.readString();
        Genre = in.readString();
        Data = in.readString();
        artistID = in.readInt();
        if (in.readByte() == 0) {
            AlbumID = null;
        } else {
            AlbumID = in.readLong();
        }
        albumCover = in.readParcelable(Uri.class.getClassLoader());
    }

Upvotes: 0

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