PasswordFragment: animate FAB in action mode

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

app/src/main/java/com/zeapo/pwdstore/PasswordFragment.kt

@@ -13,6 +13,8 @@ import android.view.Menu
 import android.view.MenuItem
 import android.view.View
 import android.view.ViewGroup
+import android.view.animation.Animation
+import android.view.animation.AnimationUtils
 import androidx.appcompat.view.ActionMode
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.activityViewModels
@@ -156,7 +158,7 @@ class PasswordFragment : Fragment() {
             // Inflate a menu resource providing context menu items
             mode.menuInflater.inflate(R.menu.context_pass, menu)
             // hide the fab
-            binding.fab.visibility = View.GONE
+            animateFab(false)
             return true
         }
 
@@ -202,7 +204,30 @@ class PasswordFragment : Fragment() {
             recyclerAdapter.requireSelectionTracker().clearSelection()
             actionMode = null
             // show the fab
-            binding.fab.visibility = View.VISIBLE
+            animateFab(true)
+        }
+
+        private fun animateFab(show: Boolean) = with(binding.fab) {
+            val animation = AnimationUtils.loadAnimation(
+                    context, if (show) R.anim.scale_up else R.anim.scale_down
+            )
+            animation.setAnimationListener(object : Animation.AnimationListener {
+                override fun onAnimationRepeat(animation: Animation?) {
+                }
+
+                override fun onAnimationEnd(animation: Animation?) {
+                    if (!show) visibility = View.GONE
+                }
+
+                override fun onAnimationStart(animation: Animation?) {
+                    if (show) visibility = View.VISIBLE
+                }
+            })
+            animate().rotationBy(if (show) -90f else 90f)
+                    .setStartDelay(if (show) 100 else 0)
+                    .setDuration(100)
+                    .start()
+            startAnimation(animation)
         }
     }
 

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

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<set xmlns:android="http://schemas.android.com/apk/res/android" >
+    <scale
+        android:duration="300"
+        android:fromXScale="1.0"
+        android:fromYScale="1.0"
+        android:interpolator="@android:anim/linear_interpolator"
+        android:pivotX="50%"
+        android:pivotY="50%"
+        android:toXScale="0"
+        android:toYScale="0" />
+</set>

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

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<set xmlns:android="http://schemas.android.com/apk/res/android" >
+    <scale
+        android:duration="300"
+        android:fromXScale="0"
+        android:fromYScale="0"
+        android:interpolator="@android:anim/linear_interpolator"
+        android:pivotX="50%"
+        android:pivotY="50%"
+        android:toXScale="1.0"
+        android:toYScale="1.0" />
+</set>