ui: tweak bottom sheet dialog transitions

Use a native slide animation for entering/editing bottom sheet dialogs,
which looks a good amount nicer overall.

app/src/main/java/org/oxycblt/auxio/ui/ViewBindingBottomSheetDialogFragment.kt

@@ -18,13 +18,16 @@
  
 package org.oxycblt.auxio.ui
 
+import android.content.Context
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
-import androidx.appcompat.app.AlertDialog
+import androidx.annotation.StyleRes
 import androidx.fragment.app.DialogFragment
 import androidx.viewbinding.ViewBinding
+import com.google.android.material.bottomsheet.BottomSheetBehavior
+import com.google.android.material.bottomsheet.BottomSheetDialog
 import com.google.android.material.bottomsheet.BottomSheetDialogFragment
 import org.oxycblt.auxio.util.logD
 import org.oxycblt.auxio.util.unlikelyToBeNull
@@ -39,13 +42,8 @@ abstract class ViewBindingBottomSheetDialogFragment<VB : ViewBinding> :
     BottomSheetDialogFragment() {
     private var _binding: VB? = null
 
-    /**
-     * Configure the [AlertDialog.Builder] during [onCreateDialog].
-     *
-     * @param builder The [AlertDialog.Builder] to configure.
-     * @see onCreateDialog
-     */
-    protected open fun onConfigDialog(builder: AlertDialog.Builder) {}
+    override fun onCreateDialog(savedInstanceState: Bundle?): BottomSheetDialog =
+        RealAnimationBottomSheetDialog(requireContext(), theme)
 
     /**
      * Inflate the [ViewBinding] during [onCreateView].
@@ -108,4 +106,33 @@ abstract class ViewBindingBottomSheetDialogFragment<VB : ViewBinding> :
         _binding = null
         logD("Fragment destroyed")
     }
+
+    private inner class RealAnimationBottomSheetDialog
+    @JvmOverloads
+    constructor(context: Context, @StyleRes theme: Int = 0) : BottomSheetDialog(context, theme) {
+        override fun onCreate(savedInstanceState: Bundle?) {
+            super.onCreate(savedInstanceState)
+            // The dialog already supplies an implementation for dismissing with the normal
+            // bottom sheet sliding, which is odd. It works well save the scrim not actually
+            // activating until the sheet is out of view, but that is tolerated for now.
+            // TODO: Replace with custom impl that runs the scrim animation and bottom sheet
+            //  animation in parallel. Might just switch back to the stock animation if I can
+            //  eliminate the opacity.
+            dismissWithAnimation = true
+        }
+
+        override fun onStart() {
+            super.onStart()
+            // We have to manually trigger a hidden -> expanded transition when the dialog
+            // is initially opened. Hence, we set the state to hidden now and then as soon
+            // as we're drawing updating it to expanded.
+            behavior.state = BottomSheetBehavior.STATE_HIDDEN
+            requireView().post { behavior.state = BottomSheetBehavior.STATE_EXPANDED }
+        }
+
+        override fun dismiss() {
+            super.dismiss()
+            behavior.state = BottomSheetBehavior.STATE_HIDDEN
+        }
+    }
 }

app/src/main/res/anim/bottom_sheet_slide_in.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (C) 2018 The Android Open Source Project
+  ~
+  ~ 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.
+-->
+<set xmlns:android="http://schemas.android.com/apk/res/android"
+    android:duration="@integer/m3_sys_motion_duration_medium4"
+    android:interpolator="@interpolator/m3_sys_motion_easing_emphasized">
+
+  <translate
+      android:fromYDelta="100%p"
+      android:toYDelta="0"/>
+
+</set>

app/src/main/res/anim/bottom_sheet_slide_out.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<set xmlns:android="http://schemas.android.com/apk/res/android">
+
+  <translate
+    android:duration="@integer/m3_sys_motion_duration_medium3"
+    android:interpolator="@interpolator/m3_sys_motion_easing_emphasized"
+    android:fromYDelta="0"
+    android:toYDelta="100%p"/>
+
+</set>

app/src/main/res/values/styles_ui.xml

@@ -50,7 +50,13 @@
     </style>
 
     <style name="Widget.Auxio.BottomSheet.Dialog" parent="ThemeOverlay.Material3.BottomSheetDialog">
-    <item name="bottomSheetStyle">@style/Widget.Auxio.BottomSheet.Modal</item>
+        <item name="bottomSheetStyle">@style/Widget.Auxio.BottomSheet.Modal</item>
+        <item name="android:windowAnimationStyle">@style/Animation.Auxio.BottomSheet.Dialog</item>
+    </style>
+
+    <style name="Animation.Auxio.BottomSheet.Dialog" parent="Animation.Material3.BottomSheetDialog">
+        <item name="android:windowEnterAnimation">@anim/bottom_sheet_slide_in</item>
+        <item name="android:windowExitAnimation">@anim/bottom_sheet_slide_out</item>
     </style>
 
     <style name="Widget.Auxio.Image.Small" parent="">