VKAccessTokenTracker.java

//
//  Copyright (c) 2015 VK.com
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//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
//  FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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package com.vk.sdk;

import com.android.annotations.Nullable;

/**
 * Use this class for track access token changes.
 * <p/>
 * See example usage:
 * <pre>
 * <code>VKAccessTokenTracker vkAccessTokenTracker = new VKAccessTokenTracker() {
 *  @Override
 *   public void onVKAccessTokenChanged(VKAccessToken oldToken, VKAccessToken newToken) {
 *       if (newToken == null) {
 *           Toast.makeText(Application.this, "AccessToken invalidated", Toast.LENGTH_LONG).show();
 *       }
 *   }
 * };
 * </code>
 * </pre>
 */
public abstract class VKAccessTokenTracker {

    private boolean isTracking = false;

    /**
     * This method will be call only from main thread
     *
     * @param oldToken Token before changes
     * @param newToken Actual token after changes
     */
    public abstract void onVKAccessTokenChanged(@Nullable VKAccessToken oldToken, @Nullable VKAccessToken newToken);

    public boolean isTracking() {
        return isTracking;
    }

    public void startTracking() {
        VKSdk.addVKTokenTracker(this);
        isTracking = true;
    }

    public void stopTracking() {
        VKSdk.removeVKTokenTracker(this);
        isTracking = false;
    }
}