Update choice chip to align with spec and use primary color to denote selection.

PiperOrigin-RevId: 246504982

Author: wcshi

lib/java/com/google/android/material/chip/res/color/mtrl_choice_chip_background_color.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Copyright 2019 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
+
+      https://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.
+  -->
+
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+  <!-- 24% opacity -->
+  <item android:alpha="0.24" android:color="?attr/colorPrimary" android:state_enabled="true" android:state_selected="true"/>
+  <item android:alpha="0.24" android:color="?attr/colorPrimary" android:state_enabled="true" android:state_checked="true"/>
+  <!-- 12% of 87% opacity -->
+  <item android:alpha="0.10" android:color="?attr/colorOnSurface" android:state_enabled="true"/>
+  <item android:alpha="0.12" android:color="?attr/colorOnSurface"/>
+
+</selector>

lib/java/com/google/android/material/chip/res/color/mtrl_choice_chip_ripple_color.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Copyright 2019 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
+
+      https://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.
+  -->
+
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+
+  <item android:alpha="0.16" android:color="?attr/colorPrimary" android:state_pressed="true"/>
+  <item android:alpha="0.16" android:color="?attr/colorOnSurface" android:state_focused="true" android:state_hovered="true"/>
+  <item android:alpha="0.12" android:color="?attr/colorOnSurface" android:state_focused="true"/>
+  <item android:alpha="0.04" android:color="?attr/colorOnSurface" android:state_hovered="true"/>
+  <item android:alpha="0.00" android:color="?attr/colorOnSurface"/>
+
+</selector>

lib/java/com/google/android/material/chip/res/color/mtrl_choice_chip_text_color.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Copyright 2019 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
+
+      https://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.
+  -->
+
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+
+  <item android:color="?attr/colorPrimary" android:state_enabled="true" android:state_selected="true"/>
+  <item android:color="?attr/colorPrimary" android:state_enabled="true" android:state_checked="true"/>
+  <!-- 87% opacity. -->
+  <item android:alpha="0.87" android:color="?attr/colorOnSurface" android:state_enabled="true"/>
+  <!-- 38% of 87% opacity. -->
+  <item android:alpha="0.33" android:color="?attr/colorOnSurface"/>
+
+</selector>

lib/java/com/google/android/material/chip/res/values/styles.xml

@@ -120,6 +120,12 @@
     <item name="closeIconVisible">false</item>
 
     <item name="checkedIcon">@drawable/ic_mtrl_chip_checked_black</item>
+
+    <item name="android:textColor">@color/mtrl_choice_chip_text_color</item>
+
+    <item name="chipBackgroundColor">@color/mtrl_choice_chip_background_color</item>
+    <item name="rippleColor">@color/mtrl_choice_chip_ripple_color</item>
+
   </style>
 
   <!-- Style for Chips that act as a button.