BottomBar

What?

A custom view component that mimics the new Material Design Bottom Navigation pattern.

Does it work on my Grandpa Gary's HTC Dream?

Nope. The current minSDK version is API level 11 (Honeycomb).

Your uncle Bob's Galaxy S Mini will probably be supported in the future though.

Gimme that Gradle sweetness, pls?

compile 'com.roughike:bottom-bar:1.3.9'

Maven:

<dependency>
  <groupId>com.roughike</groupId>
  <artifactId>bottom-bar</artifactId>
  <version>1.3.9</version>
  <type>pom</type>
</dependency>

How?

You can add items by specifying an array of items or by xml menu resources.

Creating the icons

The icons must be fully opaque, solid color, 24dp and with no padding. For example, with Android Asset Studio Generic Icon generator, select "TRIM" and make sure the padding is 0dp. Here's what your icons should look like:

Adding items from menu resource

res/menu/bottombar_menu.xml:

<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:id="@+id/bottomBarItemOne"
        android:icon="@drawable/ic_recents"
        android:title="Recents" />
        ...
</menu>

MainActivity.java

public class MainActivity extends AppCompatActivity {
    private BottomBar mBottomBar;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mBottomBar = BottomBar.attach(this, savedInstanceState);
        mBottomBar.setItems(R.menu.bottombar_menu);
        mBottomBar.setOnMenuTabClickListener(new OnMenuTabClickListener() {
            @Override
            public void onMenuTabSelected(@IdRes int menuItemId) {
                if (menuItemId == R.id.bottomBarItemOne) {
                    // The user selected item number one.
                }
            }

            @Override
            public void onMenuTabReSelected(@IdRes int menuItemId) {
                if (menuItemId == R.id.bottomBarItemOne) {
                    // The user reselected item number one, scroll your content to top.
                }
            }
        });
        
        // Setting colors for different tabs when there's more than three of them.
        // You can set colors for tabs in three different ways as shown below.
        mBottomBar.mapColorForTab(0, ContextCompat.getColor(this, R.color.colorAccent));
        mBottomBar.mapColorForTab(1, 0xFF5D4037);
        mBottomBar.mapColorForTab(2, "#7B1FA2");
        mBottomBar.mapColorForTab(3, "#FF5252");
        mBottomBar.mapColorForTab(4, "#FF9800");
    }
    
    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        
        // Necessary to restore the BottomBar's state, otherwise we would
        // lose the current tab on orientation change.
        mBottomBar.onSaveInstanceState(outState);
    }
}

Badges

You can easily add badges for showing an unread message count or new items / whatever you like.

// Make a Badge for the first tab, with red background color and a value of "13".
BottomBarBadge unreadMessages = mBottomBar.makeBadgeForTabAt(0, "#FF0000", 13);

// Control the badge's visibility
unreadMessages.show();
unreadMessages.hide();

// Change the displayed count for this badge.
unreadMessages.setCount(4);

// Change the show / hide animation duration.
unreadMessages.setAnimationDuration(200);

// If you want the badge be shown always after unselecting the tab that contains it.
unreadMessages.setAutoShowAfterUnSelection(true);

// If you don't want this badge to be hidden after selecting the tab contains it.
unreadMessages.setAutoShowAfterUnSelection(false);

Customization

// Disable the left bar on tablets and behave exactly the same on mobile and tablets instead.
mBottomBar.noTabletGoodness();

// Show all titles even when there's more than three tabs.
mBottomBar.useFixedMode();

// Use the dark theme.
mBottomBar.useDarkTheme();

// Set the color for the active tab. Ignored on mobile when there are more than three tabs.
mBottomBar.setActiveTabColor("#009688");

// Use custom text appearance in tab titles.
mBottomBar.setTextAppearance(R.style.MyTextAppearance);

// Use custom typeface that's located at the "/src/main/assets" directory. If using with
// custom text appearance, set the text appearance first.
mBottomBar.setTypeFace("MyFont.ttf");

What about hiding it automatically on scroll?

Easy-peasy!

MainActivity.java:

// Instead of attach(), use attachShy():
mBottomBar = BottomBar.attachShy((CoordinatorLayout) findViewById(R.id.myCoordinator), 
    findViewById(R.id.myScrollingContent), savedInstanceState);

activity_main.xml:

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/myCoordinator"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true">

    <android.support.v4.widget.NestedScrollView
        android:id="@+id/myScrollingContent"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <!-- Your loooong scrolling content here -->

    </android.support.v4.widget.NestedScrollView>

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

I don't want to set items from a menu resource!

That's alright, you can also do it the hard way if you like living on the edge.

mBottomBar.setItems(
  new BottomBarTab(R.drawable.ic_recents, "Recents"),
  new BottomBarTab(R.drawable.ic_favorites, "Favorites"),
  new BottomBarTab(R.drawable.ic_nearby, "Nearby")
);

// Listen for tab changes
mBottomBar.setOnTabClickListener(new OnTabClickListener() {
    @Override
    public void onTabSelected(int position) {
        // The user selected a tab at the specified position
    }

    @Override
    public void onTabReSelected(int position) {
        // The user reselected a tab at the specified position!
    }
});

For a working example, refer to the sample app.

Common problems and solutions

Can I use it by XML?

No, but you can still put it anywhere in the View hierarchy. Just attach it to any View you want like this:

mBottomBar.attach(findViewById(R.id.myContent), savedInstanceState);

Why does the top of my content have sooooo much empty space?!

Probably because you're doing some next-level advanced Android stuff (such as using CoordinatorLayout and fitsSystemWindows="true") and the normal paddings for the content are too much. Add this right after calling attach():

mBottomBar.noTopOffset();

I don't like the awesome transparent Navigation Bar!

You can disable it.

mBottomBar.noNavBarGoodness();

Why is it overlapping my Navigation Drawer?

All you need to do is instead of attaching the BottomBar to your Activity, attach it to the view that has your content. For example, if your fragments are in a ViewGroup that has the id fragmentContainer, you would do something like this:

mBottomBar.attach(findViewById(R.id.fragmentContainer), savedInstanceState);

What about Tablets?

It works nicely with tablets straight out of the box. When the library detects that the user has a tablet, the BottomBar will become a "LeftBar", just like in the Material Design Guidelines.

The fancy colour changing background animation isn't working!

By default, BottomBar only starts to use the specified mapColorForTab value for the BottomBar background if you have more than three tabs. If you want to enable this functionality for tab bars with three items or less, do the following before you add any items to the BottomBar:

mBottomBar.setMaxFixedTabs(n-1);

(where n is the number of tabs: so, if you have a BottomBar with 3 items, you would call setMaxFixedTabs(2);)

Apps using BottomBar

FragNav : An Android Library for managing multiple stacks of Fragments. BottomBar is used in the sample app.
BottomNavigationBar : BottomBar ported to C# for Xamarin developers
KyudoScoreBookTeam : BottomBar is used in the KyudoScoreBookTeam app.

Send me a pull request with modified README.md to get a shoutout!

Contributions

Feel free to create issues and pull requests.

When creating pull requests, more is more: I'd like to see ten small pull requests separated by feature rather than all those combined into a huge one.

License

BottomBar library for Android
Copyright (c) 2016 Iiro Krankka (http://github.com/roughike).

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

zetbaitsu / BottomBar