[ButtonGroups] Added expressive styles.

PiperOrigin-RevId: 748866556

Author: pekingme

lib/java/com/google/android/material/button/res/values/button_group_tokens.xml

@@ -27,5 +27,7 @@
        audience=3p). -->
   <dimen name="m3_comp_button_group_connected_small_between_space">2dp</dimen>
   <style name="ShapeAppearance.M3.Comp.ButtonGroup.Connected.Small.Container.Shape" parent="ShapeAppearance.M3.Sys.Shape.Corner.Full"/>
+  <macro name="m3_comp_button_group_connected_small_inner_corner_corner_size">?attr/shapeCornerSizeSmall</macro>
+  <macro name="m3_comp_button_group_connected_small_pressed_inner_corner_corner_size">?attr/shapeCornerSizeExtraSmall</macro>
 
 </resources>

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

@@ -17,6 +17,23 @@
 
 <resources xmlns:tools="http://schemas.android.com/tools">
 
+  <!-- Styles for M3 Expressive Button Groups. -->
+
+  <!-- M3 Expressive Button Group. -->
+  <style name="Widget.Material3Expressive.MaterialButtonGroup" parent="Widget.Material3.MaterialButtonGroup"/>
+
+  <!-- M3 Expressive Connected Button Group. -->
+  <style name="Widget.Material3Expressive.MaterialButtonGroup.Connected" parent="Widget.Material3.MaterialButtonGroup.Connected">
+    <item name="innerCornerSize">@xml/m3expressive_connected_buttons_inner_corner_size_state_list</item>
+  </style>
+
+  <!-- M3 Expressive Connected Button Toggle Group (Segmented Button). -->
+  <style name="Widget.Material3Expressive.MaterialButtonToggleGroup" parent="Widget.Material3.MaterialButtonToggleGroup">
+    <item name="innerCornerSize">@xml/m3expressive_connected_buttons_inner_corner_size_state_list</item>
+    <item name="shapeAppearance">@style/ShapeAppearance.M3.Comp.ButtonGroup.Connected.Small.Container.Shape</item>
+    <item name="android:spacing">@dimen/m3_comp_button_group_connected_small_between_space</item>
+  </style>
+
   <!-- Styles for M3 Expressive Buttons. -->
 
   <!-- M3 Expressive filled button style. -->

lib/java/com/google/android/material/button/res/xml/m3expressive_connected_buttons_inner_corner_size_state_list.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    Copyright 2025 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.
+-->
+<selector xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+  <item android:state_checkable="true" android:state_pressed="true"
+        app:cornerSize="@macro/m3_comp_button_group_connected_small_pressed_inner_corner_corner_size"/>
+  <item android:state_checked="true" app:cornerSize="50%"/>
+  <item app:cornerSize="@macro/m3_comp_button_group_connected_small_inner_corner_corner_size"/>
+</selector>

lib/java/com/google/android/material/dialog/res/values/themes_base.xml

@@ -61,6 +61,9 @@
     <item name="materialIconButtonFilledStyle">@style/Widget.Material3Expressive.Button.IconButton.Filled</item>
     <item name="materialIconButtonFilledTonalStyle">@style/Widget.Material3Expressive.Button.IconButton.Tonal</item>
 
+    <item name="materialButtonGroupStyle">@style/Widget.Material3Expressive.MaterialButtonGroup</item>
+    <item name="materialButtonToggleGroupStyle">@style/Widget.Material3Expressive.MaterialButtonToggleGroup</item>
+
     <item name="toolbarStyle">@style/Widget.Material3Expressive.Toolbar</item>
     <item name="toolbarSurfaceStyle">@style/Widget.Material3Expressive.Toolbar.Surface</item>
 
@@ -106,6 +109,9 @@
     <item name="materialIconButtonFilledStyle">@style/Widget.Material3Expressive.Button.IconButton.Filled</item>
     <item name="materialIconButtonFilledTonalStyle">@style/Widget.Material3Expressive.Button.IconButton.Tonal</item>
 
+    <item name="materialButtonGroupStyle">@style/Widget.Material3Expressive.MaterialButtonGroup</item>
+    <item name="materialButtonToggleGroupStyle">@style/Widget.Material3Expressive.MaterialButtonToggleGroup</item>
+
     <item name="toolbarStyle">@style/Widget.Material3Expressive.Toolbar</item>
     <item name="toolbarSurfaceStyle">@style/Widget.Material3Expressive.Toolbar.Surface</item>
 

lib/java/com/google/android/material/theme/res/values/themes_base.xml

@@ -68,6 +68,9 @@
     <item name="toolbarStyle">@style/Widget.Material3Expressive.Toolbar</item>
     <item name="toolbarSurfaceStyle">@style/Widget.Material3Expressive.Toolbar.Surface</item>
 
+    <item name="materialButtonGroupStyle">@style/Widget.Material3Expressive.MaterialButtonGroup</item>
+    <item name="materialButtonToggleGroupStyle">@style/Widget.Material3Expressive.MaterialButtonToggleGroup</item>
+
     <!-- Top App Bars. -->
     <item name="collapsingToolbarLayoutMediumSize">@dimen/m3_comp_app_bar_medium_flexible_container_height</item>
     <item name="collapsingToolbarLayoutLargeSize">@dimen/m3_comp_app_bar_large_flexible_container_height</item>
@@ -117,6 +120,9 @@
     <item name="materialIconButtonFilledStyle">@style/Widget.Material3Expressive.Button.IconButton.Filled</item>
     <item name="materialIconButtonFilledTonalStyle">@style/Widget.Material3Expressive.Button.IconButton.Tonal</item>
 
+    <item name="materialButtonGroupStyle">@style/Widget.Material3Expressive.MaterialButtonGroup</item>
+    <item name="materialButtonToggleGroupStyle">@style/Widget.Material3Expressive.MaterialButtonToggleGroup</item>
+
     <item name="toolbarStyle">@style/Widget.Material3Expressive.Toolbar</item>
     <item name="toolbarSurfaceStyle">@style/Widget.Material3Expressive.Toolbar.Surface</item>