code_33_overflow.txt

[source code] Android Development Tutorial 33 - Overflow

***** Tutorial Notes
** 33 - Overflow Menu
//Overview//
The overflow menu appears in the ActionBar as 3 stacked squares. The menu is included when you chose the Basic Activity template. By default, it has one item called settings. Try running the Activity before modifying it to see what happens when you click the overflow menu.
The goal here is to replace the default Setting menu with 3 coloritems, and change the display background color when you select one. 

//Tutorial//
NOTE: The overflow menu was not showing up in a new Basic activity, in Design and Preview, but is there in the emulator:
• It won’t show at all if you don’t have something in menu_main.xml.
• It won’t show up if the device has a hardware menu button.
• If you don't even get the App title in the preview, change the theme setting using the Editor tool bar.

NOTE: Bucky uses ActionBarActivity which is depreciated. Use AppCompatActivity instead. This also means that you can't select the Holo or Material themes that he does, without getting rendering errors. Don't worry the Overflow menu will be there when you run your app.

1. Start with a Basic Activity
	a. Open the context layout
	b. Delete hello world TextView
	c. Add a large text.
	d. Give the Layout and Id so you can reference.
2. Main_menu.xml has only the settings item by default.
	a. Delete it because we are not going to use it here.
	b. Add a <group>
	c. Add items with new ids
	d. Change the strings to string references
3. Main Activity
	a.  import android widget relative layout
	b. onOptionsItemSelected delete everything because we are not using the settings menu item
		i. get a reference to relative layout
		ii. use a switch to determine which item was selected
		iii. have default return to insure method returns something.

NOTE: If you didn't import Color you will get errors. Just use Alt-Enter to import it.


***** manifest.xml

***** MainActivity.java
package com.thenewboston.overflowmenu;

import android.graphics.Color;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.RelativeLayout;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        RelativeLayout main_view = (RelativeLayout)findViewById(R.id.main_view);
        switch (item.getItemId()){
            case R.id.menu_red:{
                if (item.isChecked())
                    item.setChecked(false);
                else
                    item.setChecked(true);
                main_view.setBackgroundColor(Color.RED);
                return true;
            }

            case R.id.menu_green:{
                if (item.isChecked())
                    item.setChecked(false);
                else
                    item.setChecked(true);
                main_view.setBackgroundColor(Color.GREEN);
                return true;
            }

            case R.id.menu_yellow:{
                if (item.isChecked())
                    item.setChecked(false);
                else
                    item.setChecked(true);
                main_view.setBackgroundColor(Color.YELLOW);
                return true;
            }

            default:
                return super.onOptionsItemSelected(item);
        }
    }
}

***** activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:context="com.thenewboston.overflowmenu.MainActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.AppBarLayout>

    <include layout="@layout/content_main" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|end"
        android:layout_margin="@dimen/fab_margin"
        android:src="@android:drawable/ic_dialog_email" />

</android.support.design.widget.CoordinatorLayout>

***** content_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.thenewboston.overflowmenu.MainActivity"
    tools:showIn="@layout/activity_main"
    android:id="@+id/main_view">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:text="Large Text"
        android:id="@+id/textView"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />
</RelativeLayout>

***** menu_main.xml
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context="com.thenewboston.overflowmenu.MainActivity">
    <group android:checkableBehavior="single">
        <item
            android:id="@+id/menu_red"
            android:orderInCategory="1"
            app:showAsAction="never"
            android:title="@string/red_string"/>

        <item
            android:id="@+id/menu_green"
            android:orderInCategory="2"
            app:showAsAction="never"
            android:title="@string/green_string"/>

        <item
            android:id="@+id/menu_yellow"
            android:orderInCategory="3"
            app:showAsAction="never"
            android:title="@string/yellow_string"/>
    </group>

</menu>

***** strings.xml
<resources>
    <string name="app_name">OverflowMenu</string>
    <string name="action_settings">Settings</string>

    <string name="red_string">Red</string>
    <string name="green_string">Green</string>
    <string name="yellow_string">Yellow</string>
</resources>