a

 Button btnFadeIn,btnFadeOut,btnFadeCross,btnBlink,
            btnZoomIn, btnZoomOut, btnMove, btnRotate,
            btnSlideDown,btnSlideUp,btnTogether,btnSequential;

    Context context;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setPointer();
    }

    private void setPointer()
    {
        this.context=this;
        btnFadeIn=(Button)findViewById(R.id.btnFadeIn);
        btnFadeIn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(context,FadeInActivity.class));
            }
        });
        btnFadeOut=(Button)findViewById(R.id.btnFadeOut);
        btnFadeOut.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(context,FadeOutActivity.class));
            }
        });
        btnFadeCross=(Button)findViewById(R.id.btnFadeCross);
        btnFadeCross.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(context,CrossActivity.class));
            }
        });
        btnBlink=(Button)findViewById(R.id.btnBlink);
        btnBlink.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(context,BlinkActivity.class));
            }
        });
        btnZoomIn=(Button)findViewById(R.id.btnZoomIn);
        btnZoomIn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(context,ZoomInActivity.class));
            }
        });
        btnZoomOut=(Button)findViewById(R.id.btnZoomOut);
        btnZoomOut.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(context,ZoomOutActivity.class));
            }
        });
        btnRotate=(Button)findViewById(R.id.btnRotate);
        btnRotate.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(context,RotateActivity.class));
            }
        });
        btnMove=(Button)findViewById(R.id.btnMove);
        btnMove.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(context,MoveActivity.class));
            }
        });
        btnSlideDown=(Button)findViewById(R.id.btnSlideDown);
        btnSlideDown.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(context,SlideDownActivity.class));
            }
        });
        btnSlideUp=(Button)findViewById(R.id.btnSlideUp);
        btnSlideUp.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(context,SlideAsideActivity.class));
            }
        });
        btnTogether=(Button)findViewById(R.id.btnTogether);
        btnTogether.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(context,TogetherActivity.class));
            }
        });
        btnSequential=(Button)findViewById(R.id.btnSequential);
        btnSequential.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(context,SequentialActivity.class));
            }
        });
    }