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@matpag
Forked from fbarthelery/DialogNavigator.kt
Last active February 16, 2021 12:29
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<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="DialogFragmentNavigator">
<attr name="android:name"/>
</declare-styleable>
</resources>
package com.geekorum.geekdroid.navigation
import android.content.Context
import android.os.Bundle
import android.util.AttributeSet
import androidx.core.content.res.use
import androidx.core.os.bundleOf
import androidx.fragment.app.DialogFragment
import androidx.fragment.app.Fragment
import androidx.fragment.app.FragmentManager
import androidx.navigation.NavDestination
import androidx.navigation.NavOptions
import androidx.navigation.Navigator
import androidx.navigation.fragment.FragmentNavigator
import androidx.navigation.fragment.NavHostFragment
import androidx.navigation.plusAssign
import com.geekorum.geekdroid.R
import java.util.ArrayDeque
import java.util.Deque
/**
* Allows to navigate to some [DialogFragment].
*
* Usage: add some dialog element in your navigation graph
* ```
* <dialog
* android:id="@+id/my_dialog"
* android:name="com.exemple.MyDialogFragment"
* tools:layout="@layout/fragment_my_dialog" />
*
* ```
* Use [MyNavHostFragment] as your [androidx.navigation.NavHost] in your layout
*/
@Navigator.Name("dialog")
class DialogFragmentNavigator(
private val fragmentManager: FragmentManager
) : Navigator<DialogFragmentNavigator.Destination>() {
private var lastBackStackEntry: FragmentManager.BackStackEntry? = null
private val backstack: Deque<Int> = ArrayDeque()
private var pendingPopBackStack = false
private val onBackstackChangedListener: FragmentManager.OnBackStackChangedListener =
FragmentManager.OnBackStackChangedListener {
if (pendingPopBackStack) {
val entry = fragmentManager.findLastBackStackEntry { it.name == FRAGMENT_BACKSTACK_NAME }
pendingPopBackStack = (entry != null && entry == lastBackStackEntry)
lastBackStackEntry = entry
return@OnBackStackChangedListener
}
if (lastBackStackEntry != null && fragmentManager.noneBackStackEntry { it == lastBackStackEntry }) {
backstack.removeLast()
}
lastBackStackEntry = fragmentManager.findLastBackStackEntry { it.name == FRAGMENT_BACKSTACK_NAME }
}
override fun navigate(
destination: Destination, args: Bundle?, navOptions: NavOptions?, navigatorExtras: Extras?
): NavDestination? {
val lastDialogFragment = instantiateFragment(destination.className!!).apply { arguments = args }
val tr = fragmentManager.beginTransaction().addToBackStack(FRAGMENT_BACKSTACK_NAME)
lastDialogFragment.show(tr, destination.id.toString())
backstack.addLast(destination.id)
// we don't want the destination to be added to the NavController stack,
// because it will update the whole
// navigation chrome (global AppBar, NavigationView, etc)
return null
}
private fun instantiateFragment(className: String): DialogFragment {
val clazz = Class.forName(className)
return fragmentManager.fragmentFactory
.instantiate(clazz.classLoader!!, className) as DialogFragment
}
override fun createDestination(): Destination = Destination(this)
override fun popBackStack(): Boolean {
val lastDialogFragment =
fragmentManager.findFragmentByTag(backstack.lastOrNull()?.toString()) as? DialogFragment ?: return false
lastDialogFragment.dismiss()
backstack.removeLast()
pendingPopBackStack = true
return true
}
/* These 2 lifecycle methods should be handled in the NavHost of this navigator.
* When the NavHost add them it should configure them or call some method so
* that they can configure there listeners. However, this make a strong coupling between a Navigator and
* its host implementation.
*
* The NavigatorProvider of NavController add a Navigator.OnBackStackChangedListener
* who calls these methods */
override fun onBackPressAdded() {
fragmentManager.addOnBackStackChangedListener(onBackstackChangedListener)
}
override fun onBackPressRemoved() {
fragmentManager.removeOnBackStackChangedListener(onBackstackChangedListener)
}
override fun onSaveState(): Bundle? {
return bundleOf(KEY_BACKSTACK_ID to backstack.toIntArray())
}
override fun onRestoreState(savedState: Bundle) {
savedState.getIntArray(KEY_BACKSTACK_ID)?.let {
backstack.clear()
for (id in it) {
backstack.addLast(id)
}
}
lastBackStackEntry = fragmentManager.findLastBackStackEntry { it.name == FRAGMENT_BACKSTACK_NAME }
}
class Destination(navigator: DialogFragmentNavigator) : NavDestination(navigator) {
var className: String? = null
get() = checkNotNull(field) { "Dialog name was not set" }
override fun onInflate(context: Context, attrs: AttributeSet) {
super.onInflate(context, attrs)
context.resources.obtainAttributes(attrs, R.styleable.DialogFragmentNavigator).use {
className = it.getString(R.styleable.DialogFragmentNavigator_android_name)
}
}
}
companion object {
private const val KEY_BACKSTACK_ID = "com.geekorum.geekdroid:navigation:backstack_ids"
private const val FRAGMENT_BACKSTACK_NAME = "com.geekorum.geekdroid:navigation:backstack"
}
private inline fun FragmentManager.findLastBackStackEntry(
predicate: (FragmentManager.BackStackEntry) -> Boolean
): FragmentManager.BackStackEntry? {
for (i in backStackEntryCount - 1 downTo 0) {
val backStackEntry = getBackStackEntryAt(i)
if (predicate(backStackEntry)) {
return backStackEntry
}
}
return null
}
private inline fun FragmentManager.noneBackStackEntry(
predicate: (FragmentManager.BackStackEntry) -> Boolean
): Boolean {
for (i in 0 until backStackEntryCount) {
val backStackEntry = getBackStackEntryAt(i)
if (predicate(backStackEntry)) {
return false
}
}
return true
}
}
/**
* A [NavHostFragment] who supports navigation to [DialogFragment]s.
*/
class MyNavHostFragment : NavHostFragment() {
override fun createFragmentNavigator(): Navigator<out FragmentNavigator.Destination> {
navController.navigatorProvider += DialogFragmentNavigator(childFragmentManager)
return super.createFragmentNavigator()
}
}
@matpag
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matpag commented May 17, 2019

Navigation 2.1.0-alpha03 has been released with support to DialogFragment navigation.
Starting from now this gist is deprecated, move on to the official solution when you can.
Check here and here for more info

@mohodroid
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Navigation 2.1.0-alpha03 has been released with support to DialogFragment navigation.
Starting from now this gist is deprecated, move on to the official solution when you can.
Check here and here for more info

Hii, i updated to latest version(2.1.0-alpha04), but i cant see tag, why?

@matpag
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matpag commented May 22, 2019

What do you mean with tag? If you moved to the latest version of Navigation library, you need to remove all the stuff of this gist from your code and follow the official documentation on how to implement dialog-fragments

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