+ shared elements transition

Author: Artem

config.gradle

@@ -8,18 +8,18 @@ ext {
     buildTools = "30.0.2"
 
     //version
-    vCode = 2
-    vName = "1.0.1"
+    vCode = 3
+    vName = "1.0.2"
 
     //gradle
     gradleVersion = '4.1.2'
 
     //kotlin
-    kotlinVersion = '1.4.30'
+    kotlinVersion = '1.4.31'
 
     //android x
     xVersion = '1.2.0'
-    xFragment = '1.3.1'
+    xFragment = '1.3.3'
 
     //cicerone
     ciceroneVersion = '6.6'

mad-navigation/src/main/java/ru/wearemad/mad_navigation/data/SharedTransitionInfo.kt

@@ -0,0 +1,35 @@
+package ru.wearemad.mad_navigation.data
+
+import android.view.View
+
+typealias SharedView = Pair<View, String>
+
+class SharedTransitionInfo {
+
+    private val sharedElements = mutableListOf<SharedView>()
+
+    val names: List<String>
+        get() = sharedElements.map { it.second }
+
+    val elements: List<SharedView>
+        get() = sharedElements
+
+    val hasSharedElements: Boolean
+        get() = sharedElements.isNotEmpty()
+
+    fun add(data: SharedView) {
+        sharedElements.add(data)
+    }
+
+    fun add(name: String, view: View) {
+        sharedElements.add(SharedView(view, name))
+    }
+
+    fun addAll(data: List<SharedView>) {
+        sharedElements.addAll(data)
+    }
+
+    fun clearResources() {
+        sharedElements.clear()
+    }
+}

mad-navigation/src/main/java/ru/wearemad/mad_navigation/navigator/BaseNavigator.kt

@@ -14,13 +14,12 @@ import com.github.terrakok.cicerone.Navigator
 import com.github.terrakok.cicerone.Replace
 import com.github.terrakok.cicerone.androidx.ActivityScreen
 import com.github.terrakok.cicerone.androidx.AppScreen
-import com.github.terrakok.cicerone.androidx.FragmentScreen
 import com.github.terrakok.cicerone.androidx.TransactionInfo
-import ru.wearemad.mad_navigation.route.FragmentRoute
 import ru.wearemad.mad_navigation.commands.AddScreenCommand
 import ru.wearemad.mad_navigation.commands.ExitWithFragmentResult
 import ru.wearemad.mad_navigation.commands.OpenDialogCommand
 import ru.wearemad.mad_navigation.commands.ReplaceTabCommand
+import ru.wearemad.mad_navigation.route.FragmentRoute
 
 abstract class BaseNavigator(
     private val fragmentManager: FragmentManager,
@@ -65,10 +64,8 @@ abstract class BaseNavigator(
 
     protected open fun forward(command: Forward) {
         when (val screen = command.screen as AppScreen) {
-            is ActivityScreen -> {
-                checkAndStartActivity(screen)
-            }
-            is FragmentScreen -> {
+            is ActivityScreen -> checkAndStartActivity(screen)
+            is FragmentRoute -> {
                 val type = if (command.clearContainer) TransactionInfo.Type.REPLACE else TransactionInfo.Type.ADD
                 commitNewFragmentScreen(screen, type, true)
             }
@@ -81,7 +78,7 @@ abstract class BaseNavigator(
                 checkAndStartActivity(screen)
                 activityBack()
             }
-            is FragmentScreen -> {
+            is FragmentRoute -> {
                 if (localStackCopy.isNotEmpty()) {
                     fragmentManager.popBackStack()
                     val removed = localStackCopy.removeAt(localStackCopy.lastIndex)
@@ -165,29 +162,32 @@ abstract class BaseNavigator(
 
 
     protected open fun commitNewFragmentScreen(
-        screen: FragmentScreen,
+        screen: FragmentRoute,
         type: TransactionInfo.Type,
         addToBackStack: Boolean
     ) {
         val fragment = screen.createFragment(fragmentFactory)
+
         val transaction = fragmentManager.beginTransaction()
         transaction.setReorderingAllowed(true)
-        if (screen is FragmentRoute) {
-            screen.animation?.let {
-                transaction
-                    .setCustomAnimations(
-                        it.enter,
-                        it.exit,
-                        it.popEnter,
-                        it.popExit
-                    )
-            }
-        }
+
         setupFragmentTransaction(
             transaction,
             fragmentManager.findFragmentById(containerId),
-            fragment
+            fragment,
+            screen
         )
+
+        screen.animation?.let {
+            transaction
+                .setCustomAnimations(
+                    it.enter,
+                    it.exit,
+                    it.popEnter,
+                    it.popExit
+                )
+        }
+
         when (type) {
             TransactionInfo.Type.ADD -> transaction.add(containerId, fragment, screen.screenKey)
             TransactionInfo.Type.REPLACE -> transaction.replace(containerId, fragment, screen.screenKey)
@@ -232,9 +232,24 @@ abstract class BaseNavigator(
     protected open fun setupFragmentTransaction(
         fragmentTransaction: FragmentTransaction,
         currentFragment: Fragment?,
-        nextFragment: Fragment?
+        nextFragment: Fragment?,
+        screen: FragmentRoute
     ) {
-        // Do nothing by default
+        val transitionInfo = screen.sharedTransitionInfo
+        if (transitionInfo.hasSharedElements.not()) {
+            return
+        }
+        screen.applySharedTransitionInfo(nextFragment)
+        fragmentTransaction.setReorderingAllowed(true)
+        transitionInfo
+            .elements
+            .forEach { pair ->
+                fragmentTransaction.addSharedElement(
+                    pair.first,
+                    pair.second
+                )
+            }
+        transitionInfo.clearResources()
     }
 
     /**
@@ -279,7 +294,17 @@ abstract class BaseNavigator(
     private fun addScreen(command: AddScreenCommand) {
         val screen = command.screen
         val newFragment = screen.createFragment(fragmentFactory)
+
         val fragmentTransaction = fragmentManager.beginTransaction()
+        fragmentTransaction.setReorderingAllowed(true)
+
+        setupFragmentTransaction(
+            fragmentTransaction,
+            fragmentManager.findFragmentById(containerId),
+            newFragment,
+            screen
+        )
+
         command.screen.animation?.let {
             fragmentTransaction
                 .setCustomAnimations(

mad-navigation/src/main/java/ru/wearemad/mad_navigation/navigator/FragmentNavigator.kt

@@ -6,7 +6,7 @@ import androidx.fragment.app.Fragment
 import com.github.terrakok.cicerone.androidx.ActivityScreen
 import ru.wearemad.mad_navigation.commands.ExitWithFragmentResult
 
-class FragmentNavigator(
+open class FragmentNavigator(
     containerId: Int,
     private val fragment: Fragment,
 ) : BaseNavigator(

mad-navigation/src/main/java/ru/wearemad/mad_navigation/route/FragmentRoute.kt

@@ -1,12 +1,24 @@
 package ru.wearemad.mad_navigation.route
 
+import android.os.Bundle
 import androidx.fragment.app.Fragment
 import com.github.terrakok.cicerone.androidx.FragmentScreen
+import ru.wearemad.mad_navigation.data.SharedTransitionInfo
+
+private const val ARG_SHARED_ELEMENTS_NAMES = "ru.wearemad.mad_navigation.route.arg_shared_elements_names"
 
 open class FragmentRoute(
     private val creator: () -> Fragment
 ) : FragmentScreen(fragmentCreator = { creator() }) {
 
+    companion object {
+
+        fun fetchArgSharedElementsNames(args: Bundle?): List<String> =
+            (args?.getStringArray(ARG_SHARED_ELEMENTS_NAMES) ?: emptyArray<String>()).toList()
+    }
+
+    val sharedTransitionInfo = SharedTransitionInfo()
+
     var animation: TransitionAnimation? = null
 
     fun withDefaultAnim(): FragmentRoute = this.apply {
@@ -16,4 +28,21 @@ open class FragmentRoute(
     fun withCustomAnim(transition: TransitionAnimation): FragmentRoute = this.apply {
         animation = transition
     }
+
+    open fun applySharedTransitionInfo(fragment: Fragment?) {
+        fragment ?: return
+        if (sharedTransitionInfo.hasSharedElements.not()) {
+            return
+        }
+        var args = fragment.arguments
+        if (args == null) {
+            args = Bundle()
+            fragment.arguments = args
+        }
+        args.putSharedElementsNamesIfExist()
+    }
+
+    private fun Bundle.putSharedElementsNamesIfExist() {
+        putStringArray(ARG_SHARED_ELEMENTS_NAMES, sharedTransitionInfo.names.toTypedArray())
+    }
 }