BarActivity.java

package com.halzhang.android.examples.bar;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;

public class BarActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Window window = getWindow();
        window.setFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS, WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
        window.setFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION, WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION);
        window.getDecorView().setOnSystemUiVisibilityChangeListener(new View.OnSystemUiVisibilityChangeListener() {
            @Override
            public void onSystemUiVisibilityChange(int visibility) {
                if (visibility == View.SYSTEM_UI_FLAG_VISIBLE) {
                    View view = findViewById(R.id.title_panel);
                    Animation animation = AnimationUtils.loadAnimation(getApplicationContext(), R.anim.push_down_in);
                    view.setAnimation(animation);
                    view.setVisibility(View.VISIBLE);
                    animation.start();
                }
            }
        });
        setContentView(R.layout.activity_bar);
        findViewById(R.id.bar).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                hideBar();
            }
        });
    }

    private void hideBar() {

        View view = findViewById(R.id.title_panel);
        Animation animation = AnimationUtils.loadAnimation(this, R.anim.push_up_out);
        view.setAnimation(animation);
        view.setVisibility(View.GONE);
        animation.start();
        animation.setAnimationListener(new Animation.AnimationListener() {
            @Override
            public void onAnimationStart(Animation animation) {

            }

            @Override
            public void onAnimationEnd(Animation animation) {
                View decorView = getWindow().getDecorView();
                // Hide the status bar.
                int uiOptions = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_FULLSCREEN;
                decorView.setSystemUiVisibility(uiOptions);
            }

            @Override
            public void onAnimationRepeat(Animation animation) {

            }
        });
    }

    private void showBar() {
        View decorView = getWindow().getDecorView();
        int uiOptions = View.SYSTEM_UI_FLAG_VISIBLE;
        decorView.setSystemUiVisibility(uiOptions);
    }
}