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Android Animations and Transitions The Transitions Framework Transitioning Back and Forth

Tefo Temba Kebitseng
Tefo Temba Kebitseng
6,049 Points
Posted by Tefo Temba Kebitseng
Tefo Temba Kebitseng
6,049 Points

Animation and Transitions : challenge task 4 of 4 Finally, fix the onButtonClicked() method so that the mTransitionManag

public void onButtonClicked(View view) { if (mCurrentScene == mScene2) { mCurrentScene = mScene1; } else { mCurrentScene = mScene2; }
mTransitionManager.transitionTo(mCurrentScene); }

I added line 18 to the code so that the onButtonClicked method is fixed to be able to transition to the current scene.I followed the example from the tutorial and still get error: java.lang.NullPointerException (Look around MainActivity.java line 18)

MainActivity.java 
public class MainActivity extends Activity {

    protected TransitionManager mTransitionManager;
    protected Scene mScene1;
    protected Scene mScene2;
    protected Scene mCurrentScene;
    protected TransitionSet mForwardSet;
    protected TransitionSet mBackwardSet;

    // Some code omitted for brevity 
    public void onButtonClicked(View view) {
        if (mCurrentScene == mScene2) {
            mCurrentScene = mScene1;
        }
        else {
            mCurrentScene = mScene2;
        }        
      mTransitionManager.transitionTo(mCurrentScene);
    }

    protected void setupTransitions() {
        // These methods are setting up scenes and transitions sets like in the video
        initScenes();
        initSets();       
        // Start here!      
      TransitionManager mTransitionManager = new TransitionManager();

      mTransitionManager.setTransition(mScene1,mScene2, mForwardSet);
      mTransitionManager.setTransition(mScene2,mScene1, mBackwardSet);  
      mScene1.enter();
    }
}
Justice Munyanyi
Justice Munyanyi
14,165 Points

I used same line of code and it was accepted. Can't see even any typo.