Saving state on configuration changes for a custom view.

CustomView.java

package com.operator.android;

import android.content.Context;
import android.os.Parcel;
import android.os.Parcelable;
import android.view.View;

/**
 * A custom {@link View} that demonstrates how to save/restore instance state.
 */
public class CustomView extends View {

    private boolean someState;

    public CustomView(Context context) {
        super(context);
    }

    public boolean isSomeState() {
        return someState;
    }

    public void setSomeState(boolean someState) {
        this.someState = someState;
    }

    @Override protected Parcelable onSaveInstanceState() {
        final Parcelable superState = super.onSaveInstanceState();
        final CustomViewSavedState customViewSavedState = new CustomViewSavedState(superState);
        customViewSavedState.someState = this.someState;
        return customViewSavedState;
    }

    @Override protected void onRestoreInstanceState(Parcelable state) {
        final CustomViewSavedState customViewSavedState = (CustomViewSavedState) state;
        setSomeState(customViewSavedState.someState);
        super.onRestoreInstanceState(customViewSavedState.getSuperState());
    }

    private static class CustomViewSavedState extends BaseSavedState {

        boolean someState;

        public static final Parcelable.Creator<CustomViewSavedState> CREATOR = new Creator<CustomViewSavedState>() {
            @Override public CustomViewSavedState createFromParcel(Parcel source) {
                return new CustomViewSavedState(source);
            }

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

        public CustomViewSavedState(Parcelable superState) {
            super(superState);
        }

        private CustomViewSavedState(Parcel source) {
            super(source);
            someState = source.readInt() == 1;
        }

        @Override public void writeToParcel(Parcel out, int flags) {
            super.writeToParcel(out, flags);
            out.writeInt(someState ? 1 : 0);
        }
    }

}