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Add FoldingTab Bar and Menu in Android

In current market, Mobile app is on hike and the major success of app is their UI design, no matter it is Android or iOS application. In my previous article i share some cool UI design with their code implementation and today also i share a cool code of UI for Tab bar and menu is called FoldingTab bar and Folding menu in Android. But before going ahead you should know about Common 10 Mistakes by Android Developer which we cover in previous article.
You should also friendly with Bad features of Java. Now we dive with this cool library but firstly know about what is it ?
A sort of UI revolution in android development is going on recently. ready for it?
Google finally added a bottom tab bar as a suggested style pattern for android development!

Add FoldingTab Bar and Menu in Android

Obviously, there aren't any tab bar components by Google within the support libraries yet. Therefore we decided that it’s time to bring our legendary FoldingTabBar to android – before 2017 arrives.

FoldingTabBar to android

How to use this FoldingTabBar library

Requirements

Android SDK 19+

Usage

Add to your root build.gradle:
allprojects {
    repositories {
    ...
    maven { url "https://jitpack.io" }
    }
}

Add the dependency:

dependencies {
    compile 'com.github.Yalantis:OfficialFoldingTabBar.Android:v0.9'
}
It’s very simple. On Android we have the @menu resource type. We can think of FoldingTabBar as a menu. Let’s create our menu file:
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:id="@+id/ftb_menu_nearby"
        android:icon="@drawable/ic_nearby_icon"
        android:title="Nearby"/>
 
    <item
        android:id="@+id/ftb_menu_new_chat"
        android:icon="@drawable/ic_new_chat_icon"
        android:title="Chat"/>
 
    <item
        android:id="@+id/ftb_menu_profile"
        android:icon="@drawable/ic_profile_icon"
        android:title="Profile"/>
 
    <item
        android:id="@+id/ftb_menu_settings"
        android:icon="@drawable/ic_settings_icon"
        android:title="Settings"/>
 
</menu>
Looks good. This is the menu that you’re using for dialogs, toolbar menus, or the navigation drawer.

You can add this also : PanoramaImageView in Android

The coolest thing is that you can easily switch from the navigation drawer to our FoldingTabBar. Or you can use both menus simultaneously on the same screen.

 Here’s an example of how you can implement this FoldingTabBar into your layout file:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    android:id="@+id/activity_main"
    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:background="@color/colorAccent"
    tools:context="client.yalantis.com.foldingtabbarandroid.MainActivity">
 
    <android.support.v4.view.ViewPager
        android:id="@+id/viewPager"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    </android.support.v4.view.ViewPager>
 
    <client.yalantis.com.foldingtabbar.FoldingTabBar
        android:id="@+id/folding_tab_bar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="@dimen/activity_horizontal_margin"
        android:layout_centerInParent="true"
        android:layout_alignParentBottom="true"
        app:menu="@menu/menu_tab_bar"/>
</RelativeLayout>
As you can see, we have some custom attributes. The main and required attribute is app:menu – here you can link your menu file to our component.
There are also some additional attributes:

  • app:itemPadding - sets padding for your menu items. Default item padding is 17dp.
  • app:mainImage - here you can link your image resource for the main image.
  • app:selectionColor - our menu supports color selection. You can change the menu’s color here.

This menu is flexible, so you can use wrap_content or hard-coded sizes. When you’re using wrap_content, the size will equal 70dp.

How to use our FoldingTabBar in Java code

Here we have two interfaces. The first works when your menu item is pressed:
tabBar.setOnFoldingItemClickListener(new FoldingTabBar.OnFoldingItemSelectedListener() {
            @Override
            public boolean onFoldingItemSelected(@NotNull MenuItem item) {
                switch (item.getItemId()) {
                    case R.id.ftb_menu_nearby:
                        mViewPager.setCurrentItem(0);
                        break;
                    case R.id.ftb_menu_new_chat:
                        mViewPager.setCurrentItem(1);
                        break;
                    case R.id.ftb_menu_profile:
                        mViewPager.setCurrentItem(2);
                        break;
                    case R.id.ftb_menu_settings:
                        mViewPager.setCurrentItem(3);
                        break;
                }
                return false;
            }
        });
The second works when a user presses the home button:
tabBar.setOnMainButtonClickListener(new FoldingTabBar.OnMainButtonClickedListener() {
            @Override
            public void onMainButtonClicked() {
               
            }
        });
We created two interfaces instead of one because this corresponds with the Interface Segregation principle (from SOLID).

Technology stack

We chose Kotlin as the language for our library. We already have a few components in Kotlin; we love Kotlin because it’s a powerful language that makes it much more fun to develop apps than Java does.

Collections

Here we’re using some functional “magic” of Kotlin collections:
mData = mMenu.visibleItems.map {
            initAndAddMenuItem(it)
        }
Also, note that we’ve used forEach instead of for loops.

Null Safety

This fantastic feature of Kotlin is used everywhere across our library (where needed, of course). Now our code is much cleaner and more understandable.
Lambda functions
We’ve only had this feature in Java since version 8. But Java 8 is not yet ready for Android. In Kotlin we have this feature by default.
rotationAnimator.addUpdateListener {
            valueAnimator ->
            val value = valueAnimator.animatedValue as Float
            mainImageView.rotation = value
        }
Really beautiful, isn’t it?

Apply function

The apply function defines an extension function for all types. When you invoke the apply function, it calls the closure passed as a parameter and then returns the receiver object that the closure ran on. This is an amazing feature!
val scalingAnimator = ValueAnimator.ofInt(mSize, destWidth).apply {
            addUpdateListener(scaleAnimator)
            addListener(rollUpListener)
        }

Animations

We’re using different ValueAnimators and, of course, AnimationSets for playing our animators together. Obviously, we made our own interpolator:
internal class CustomBounceInterpolator(val amplitude: Double = 0.1,
                                        val frequency: Double = 0.8) : Interpolator {
 
    override fun getInterpolation(time: Float): Float {
        return (-1.0 * Math.exp(-time / amplitude) *
                Math.cos(frequency * time) + 1).toFloat()
    }
}
That’s all about the technologies. If you've have any problem then you can download this library with demo.

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