Merge pull request #76 from chrisbanes/cb/column-transition

Column aware Fragment transitions

app/src/main/java/me/banes/chris/tivi/home/discover/DiscoverFragment.kt

@@ -18,11 +18,14 @@ package me.banes.chris.tivi.home.discover
 
 import android.arch.lifecycle.ViewModelProviders
 import android.os.Bundle
+import android.support.transition.Fade
+import android.support.transition.TransitionSet
 import android.support.v7.widget.GridLayoutManager
 import android.view.LayoutInflater
 import android.view.Menu
 import android.view.View
 import android.view.ViewGroup
+import android.view.animation.LinearInterpolator
 import com.xwray.groupie.GroupAdapter
 import com.xwray.groupie.ViewHolder
 import kotlinx.android.synthetic.main.fragment_summary.*
@@ -57,6 +60,24 @@ internal class DiscoverFragment : HomeFragment<DiscoverViewModel>() {
         super.onCreate(savedInstanceState)
         viewModel = ViewModelProviders.of(this, viewModelFactory).get(DiscoverViewModel::class.java)
         homeNavigator = ViewModelProviders.of(activity!!, viewModelFactory).get(HomeNavigatorViewModel::class.java)
+
+        exitTransition = TransitionSet().apply {
+            addTransition(Fade().apply {
+                excludeTarget(R.id.summary_appbarlayout, true)
+                excludeTarget(R.id.summary_status_scrim, true)
+                interpolator = LinearInterpolator()
+                duration = 130
+            })
+            addTransition(Fade().apply {
+                interpolator = LinearInterpolator()
+                duration = 270
+            })
+        }
+
+        reenterTransition = Fade().apply {
+            interpolator = LinearInterpolator()
+            duration = 270
+        }
     }
 
     override fun onActivityCreated(savedInstanceState: Bundle?) {

app/src/main/java/me/banes/chris/tivi/ui/transitions/BabySlide.kt

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2017 Google, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package me.banes.chris.tivi.ui.transitions
+
+import android.animation.Animator
+import android.animation.ObjectAnimator
+import android.animation.PropertyValuesHolder
+import android.support.transition.TransitionValues
+import android.support.transition.Visibility
+import android.view.Gravity
+import android.view.View
+import android.view.ViewGroup
+
+class BabySlide(
+        private val gravity: Int = Gravity.START,
+        private val babyFraction: Float = 2f
+) : Visibility() {
+
+    override fun onAppear(sceneRoot: ViewGroup, view: View,
+            startValues: TransitionValues?,
+            endValues: TransitionValues?): Animator {
+        setupTranslation(view)
+        view.alpha = 0f
+
+        return ObjectAnimator.ofPropertyValuesHolder(view,
+                PropertyValuesHolder.ofFloat(View.TRANSLATION_X, 0f),
+                PropertyValuesHolder.ofFloat(View.ALPHA, 1f))
+    }
+
+    override fun onDisappear(sceneRoot: ViewGroup, view: View,
+            startValues: TransitionValues?, endValues: TransitionValues?): Animator {
+        return ObjectAnimator.ofPropertyValuesHolder(view,
+                translatePropValForGravity(view),
+                PropertyValuesHolder.ofFloat(View.ALPHA, 0f))
+    }
+
+    private fun translatePropValForGravity(view: View): PropertyValuesHolder =
+            when (Gravity.getAbsoluteGravity(gravity, view.layoutDirection)) {
+                Gravity.TOP -> PropertyValuesHolder.ofFloat(View.TRANSLATION_Y, -view.height / babyFraction)
+                Gravity.RIGHT -> PropertyValuesHolder.ofFloat(View.TRANSLATION_X, view.width / babyFraction)
+                Gravity.BOTTOM -> PropertyValuesHolder.ofFloat(View.TRANSLATION_Y, view.height / babyFraction)
+                else -> PropertyValuesHolder.ofFloat(View.TRANSLATION_X, -view.width / babyFraction)
+            }
+
+    private fun setupTranslation(view: View) {
+        when (Gravity.getAbsoluteGravity(gravity, view.layoutDirection)) {
+            Gravity.TOP -> view.translationY = -view.height / babyFraction
+            Gravity.RIGHT -> view.translationX = view.width / babyFraction
+            Gravity.BOTTOM -> view.translationY = view.width / babyFraction
+            else -> view.translationX = -view.width / babyFraction
+        }
+    }
+
+}