FragmentManager extensions. A set of extensions to easily push a fragment to a container with one function.

FragmentManagerExtensions.kt

import androidx.annotation.IdRes
import androidx.fragment.app.*

/**
 * Push [Fragment] into container that gets added to back-stack and later be popped by popping the
 * back-stack.
 *
 * Sample Usage:
 * ```
 *     childFragmentManager.push(myFragment, R.id.childContainer)
 * ```
 *
 * Here's what it does in:
 * 1. Creates a fragment transaction.
 * 1. Sets slide animations.
 *      - Fragment enters from right edge and exits to the right edge.
 * 1. Adds fragment to the container with back-stack.
 * 1. The tag of back-stack gets determined by the [`singleName`](Class.getSimpleName) property
 * of the class.
 * 1. The transaction gets committed based on `now` and `allowStateLoss` parameters. See
 * [FragmentManager.transaction] extension from `androidx` to learn more about how these
 * parameters affect the transaction.
 *
 * @see FragmentManager.transaction
 */
fun <T : Fragment> FragmentManager.push(
    fragment: T, @IdRes containerViewId: Int, now: Boolean = false, allowStateLoss: Boolean = false
) {
    transaction(now, allowStateLoss) {
        setSlideAnimations()
        addWithBackStack(containerViewId, fragment)
    }
}

fun <T : Fragment> FragmentTransaction.addWithBackStack(
    @IdRes containerViewId: Int, fragment: T
) {
    add(containerViewId, fragment, fragment.javaClass.simpleName)
    addToBackStack(fragment.javaClass.simpleName)
}

fun FragmentTransaction.setSlideAnimations() {
    setCustomAnimations(
        R.anim.slide_in_right,
        R.anim.slide_out_left,
        R.anim.slide_in_right,
        R.anim.slide_out_right
    )
}

slide_in_right.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <translate
        android:duration="@android:integer/config_mediumAnimTime"
        android:fromXDelta="100%p"
        android:toXDelta="0" />
</set>

slide_out_left.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <translate
        android:duration="@android:integer/config_mediumAnimTime"
        android:fromXDelta="0"
        android:toXDelta="-100%p" />
</set>