Animate keyboard fadein/fadeout.

Closes #27

app/src/main/java/me/zobrist/tichucounter/ui/counter/CounterView.kt

@@ -1,6 +1,12 @@
 package me.zobrist.tichucounter.ui.counter
 
 import android.content.res.Configuration
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.animation.core.tween
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.animation.scaleIn
+import androidx.compose.animation.scaleOut
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.material.icons.Icons
@@ -17,6 +23,7 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.focus.FocusRequester
+import androidx.compose.ui.graphics.TransformOrigin
 import androidx.compose.ui.platform.LocalConfiguration
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.tooling.preview.Preview
@@ -75,10 +82,21 @@ fun Landscape(viewModel: ICounterViewModel) {
                 Modifier.weight(1f)
             )
         }
-        if (!viewModel.keyboardHidden) {
+        AnimatedVisibility(
-            Column(Modifier.weight(1f)) {
+            visible = !viewModel.keyboardHidden,
-                KeyBoardView(viewModel = viewModel)
+            enter = fadeIn(animationSpec = tween(100)) + scaleIn(
-            }
+                animationSpec = tween(100),
+                initialScale = 0.8f,
+                transformOrigin = TransformOrigin(1f, 1f)
+            ),
+            exit = fadeOut(animationSpec = tween(100)) + scaleOut(
+                animationSpec = tween(100),
+                targetScale = 0.8f,
+                transformOrigin = TransformOrigin(1f, 1f)
+            ),
+            modifier = Modifier.weight(1f)
+        ) {
+            KeyBoardView(viewModel = viewModel)
         }
     }
 }
@@ -106,7 +124,19 @@ fun Portrait(viewModel: ICounterViewModel) {
             Modifier.weight(1f)
         )
 
-        if (!viewModel.keyboardHidden) {
+        AnimatedVisibility(
+            visible = !viewModel.keyboardHidden,
+            enter = fadeIn(animationSpec = tween(100)) + scaleIn(
+                animationSpec = tween(100),
+                initialScale = 0.8f,
+                transformOrigin = TransformOrigin(1f, 1f)
+            ),
+            exit = fadeOut(animationSpec = tween(100)) + scaleOut(
+                animationSpec = tween(100),
+                targetScale = 0.8f,
+                transformOrigin = TransformOrigin(1f, 1f)
+            )
+        ) {
             KeyBoardView(viewModel = viewModel)
         }
     }