Lift the folding logic out of the FoldingText module

app/src/main/java/eu/pkgsoftware/babybuddywidgets/widgets/FoldingLogic.kt

@@ -0,0 +1,71 @@
+package eu.pkgsoftware.babybuddywidgets.widgets
+
+import android.animation.Animator
+import android.animation.AnimatorSet
+import android.animation.ObjectAnimator
+import android.view.View
+import android.view.ViewGroup
+import androidx.core.view.children
+import androidx.transition.Scene
+import androidx.transition.TransitionManager
+import androidx.transition.ChangeBounds
+
+class FoldingLogic(val container: ViewGroup, val foldingArrow: View?) {
+    var animationDuration = 200L
+    var folded: Boolean = true
+        set(value) {
+            field = value
+            updateFolding()
+        }
+
+    private val unfoldedScene: Scene
+    private val foldedScene: Scene
+    private var arrowAnimation: Animator? = null
+
+    init {
+        unfoldedScene = Scene(container)
+        unfoldedScene.setEnterAction {
+            var first = true
+            for (child in container.children) {
+                child.visibility = if (first) View.GONE else View.VISIBLE
+                first = false
+            }
+        }
+        foldedScene = Scene(container)
+        foldedScene.setEnterAction {
+            var first = true
+            for (child in container.children) {
+                child.visibility = if (first) View.VISIBLE else View.GONE
+                first = false
+            }
+        }
+
+        updateFolding()
+    }
+
+    fun updateFolding() {
+        val transition = ChangeBounds()
+        transition.duration = animationDuration
+
+        TransitionManager.endTransitions(container)
+        if (folded) {
+            TransitionManager.go(foldedScene, transition)
+        } else {
+            TransitionManager.go(unfoldedScene, transition)
+        }
+
+        foldingArrow?.let { arrow ->
+            arrowAnimation?.cancel()
+
+            arrowAnimation = AnimatorSet().apply {
+                if (folded) {
+                    play(ObjectAnimator.ofFloat(arrow, View.ROTATION, 90f, 0f))
+                } else {
+                    play(ObjectAnimator.ofFloat(arrow, View.ROTATION, 0f, 90f))
+                }
+                duration = animationDuration
+                start()
+            }
+        }
+    }
+}

app/src/main/java/eu/pkgsoftware/babybuddywidgets/widgets/FoldingText.kt

@@ -1,78 +1,26 @@
 package eu.pkgsoftware.babybuddywidgets.widgets
 
-import android.animation.Animator
-import android.animation.AnimatorSet
-import android.animation.LayoutTransition
-import android.animation.ObjectAnimator
-import android.animation.TimeInterpolator
-import android.animation.ValueAnimator
 import android.app.Activity
-import androidx.transition.ChangeBounds
-import android.transition.Transition
 import android.view.View
-import androidx.transition.Scene
-import androidx.transition.TransitionManager
 import eu.pkgsoftware.babybuddywidgets.databinding.FoldingTextBinding
 
 class FoldingText(activity: Activity, shortText: String, longText: String) {
     val binding: FoldingTextBinding
 
     val view: View get() = binding.root
-    var folded = true
-    val foldedScene: Scene
-    val unfoldedScene: Scene
 
-    var arrowAnimation: Animator? = null
+    private val foldingLogic: FoldingLogic
 
     init {
         binding = FoldingTextBinding.inflate(activity.layoutInflater)
         binding.shortText.text = shortText
         binding.longText.text = longText
 
-        unfoldedScene = Scene(binding.textContainer)
-        unfoldedScene.setEnterAction {
-            binding.shortText.visibility = View.GONE
-            binding.longText.visibility = View.VISIBLE
-        }
-        foldedScene = Scene(binding.textContainer)
-        foldedScene.setEnterAction {
-            binding.shortText.visibility = View.VISIBLE
-            binding.longText.visibility = View.GONE
-        }
-
-        updateFolding()
-
+        foldingLogic = FoldingLogic(binding.textContainer, binding.foldingArrow)
         binding.root.setOnClickListener { onClick() }
     }
 
-    private fun updateFolding() {
-        binding.shortText.visibility = if (!folded) View.GONE else View.VISIBLE
-        binding.longText.visibility = if (folded) View.GONE else View.VISIBLE
-
-        arrowAnimation?.cancel()
-        arrowAnimation = AnimatorSet().apply {
-            if (folded) {
-                play(ObjectAnimator.ofFloat(binding.foldingArrow, View.ROTATION, 90f, 0f))
-            } else {
-                play(ObjectAnimator.ofFloat(binding.foldingArrow, View.ROTATION, 0f, 90f))
-            }
-            duration = 200
-            start()
-        }
-
-        val transition = ChangeBounds()
-        transition.duration = 200
-
-        TransitionManager.endTransitions(binding.textContainer)
-        if (folded) {
-            TransitionManager.go(foldedScene, transition)
-        } else {
-            TransitionManager.go(unfoldedScene, transition)
-        }
-    }
-
     private fun onClick() {
-        folded = !folded
-        updateFolding()
+        foldingLogic.folded = !foldingLogic.folded
     }
 }