LayoutTransitionActivity.java

package com.luciofm.devfest.anime;

import android.app.Activity;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;

import butterknife.InjectView;
import butterknife.Views;

public class LayoutTransitionActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_layout_transition);

        if (savedInstanceState == null) {
            getFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .commit();
        }
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {

        @InjectView(R.id.container)
        LinearLayout container;

        public PlaceholderFragment() {
        }

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setHasOptionsMenu(true);
        }

        @Override
        public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
            getActivity().getMenuInflater().inflate(R.menu.layout_transition, menu);
            super.onCreateOptionsMenu(menu, inflater);
        }

        @Override
        public boolean onOptionsItemSelected(MenuItem item) {
            if (item.getItemId() == R.id.action_add_text) {
                addView(newTextView());
            } else if (item.getItemId() == R.id.action_add_button) {
                addView(newButton());
            }
            return super.onOptionsItemSelected(item);
        }

        private void addView(View view) {
            container.addView(view, 0);
        }

        private Button newButton() {
            Button button = new Button(getActivity());
            button.setText(getString(R.string.one_button));
            ViewGroup.MarginLayoutParams params = new ViewGroup.MarginLayoutParams(
                    ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
            button.setLayoutParams(params);
            button.setOnClickListener(clickListener);
            return button;
        }

        private TextView newTextView() {
            TextView textView = new TextView(getActivity());
            textView.setText("Um texto");
            ViewGroup.MarginLayoutParams params = new ViewGroup.MarginLayoutParams(
                    ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
            params.bottomMargin = params.topMargin = getResources().getDimensionPixelSize(R.dimen.text_margin);
            textView.setClickable(true);
            textView.setLayoutParams(params);
            textView.setOnClickListener(clickListener);
            return textView;
        }

        View.OnClickListener clickListener = new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                container.removeView(v);
            }
        };

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_layout_transition, container, false);
            Views.inject(this, rootView);
            return rootView;
        }
    }

}