Fix disabled state of CallStyle buttons to make them look/act disabled

TLDR; Call Style Buttons does not seem disabled when they dont have intent.

In Android Notifications, Button's enabled state is coupled with the action intent. It means when there is an intent, the button is enabled. Otherwise, it is disabled.
We are handling this for normal action button by creating specific layout for disabled view but not for emphasized buttons. We follow the similar approach here to mitigate
this visual issue.

Bug: 265021861
Test: We can verify the change by observing visual effect on the Call Style Notification.

Change-Id: I2427f613e6051bf887dfe99c6caead1521b1e661

core/java/android/app/Notification.java

@@ -6185,10 +6185,8 @@ public class Notification implements Parcelable
         private RemoteViews generateActionButton(Action action, boolean emphasizedMode,
                 StandardTemplateParams p) {
             final boolean tombstone = (action.actionIntent == null);
-            RemoteViews button = new BuilderRemoteViews(mContext.getApplicationInfo(),
-                    emphasizedMode ? getEmphasizedActionLayoutResource()
-                            : tombstone ? getActionTombstoneLayoutResource()
-                                    : getActionLayoutResource());
+            final RemoteViews button = new BuilderRemoteViews(mContext.getApplicationInfo(),
+                    getActionButtonLayoutResource(emphasizedMode, tombstone));
             if (!tombstone) {
                 button.setOnClickPendingIntent(R.id.action0, action.actionIntent);
             }
@@ -6200,6 +6198,12 @@ public class Notification implements Parcelable
                 // change the background bgColor
                 CharSequence title = action.title;
                 int buttonFillColor = getColors(p).getSecondaryAccentColor();
+                if (tombstone) {
+                    buttonFillColor = setAlphaComponentByFloatDimen(mContext,
+                            ContrastColorUtil.resolveSecondaryColor(
+                                    mContext, getColors(p).getBackgroundColor(), mInNightMode),
+                            R.dimen.notification_action_disabled_container_alpha);
+                }
                 if (isLegacy()) {
                     title = ContrastColorUtil.clearColorSpans(title);
                 } else {
@@ -6215,8 +6219,14 @@ public class Notification implements Parcelable
                     title = ensureColorSpanContrast(title, buttonFillColor);
                 }
                 button.setTextViewText(R.id.action0, processTextSpans(title));
-                final int textColor = ContrastColorUtil.resolvePrimaryColor(mContext,
+                int textColor = ContrastColorUtil.resolvePrimaryColor(mContext,
                         buttonFillColor, mInNightMode);
+                if (tombstone) {
+                    textColor = setAlphaComponentByFloatDimen(mContext,
+                            ContrastColorUtil.resolveSecondaryColor(
+                                    mContext, getColors(p).getBackgroundColor(), mInNightMode),
+                            R.dimen.notification_action_disabled_content_alpha);
+                }
                 button.setTextColor(R.id.action0, textColor);
                 // We only want about 20% alpha for the ripple
                 final int rippleColor = (textColor & 0x00ffffff) | 0x33000000;
@@ -6246,6 +6256,26 @@ public class Notification implements Parcelable
             return button;
         }
 
+        private int getActionButtonLayoutResource(boolean emphasizedMode, boolean tombstone) {
+            if (emphasizedMode) {
+                return tombstone ? getEmphasizedTombstoneActionLayoutResource()
+                        : getEmphasizedActionLayoutResource();
+            } else {
+                return tombstone ? getActionTombstoneLayoutResource()
+                        : getActionLayoutResource();
+            }
+        }
+
+        /**
+         * Set the alpha component of {@code color} to be {@code alphaDimenResId}.
+         */
+        private static int setAlphaComponentByFloatDimen(Context context, @ColorInt int color,
+                @DimenRes int alphaDimenResId) {
+            final TypedValue alphaValue = new TypedValue();
+            context.getResources().getValue(alphaDimenResId, alphaValue, true);
+            return ColorUtils.setAlphaComponent(color, Math.round(alphaValue.getFloat() * 255));
+        }
+
         /**
          * Extract the color from a full-length span from the text.
          *
@@ -6725,6 +6755,10 @@ public class Notification implements Parcelable
             return R.layout.notification_material_action_emphasized;
         }
 
+        private int getEmphasizedTombstoneActionLayoutResource() {
+            return R.layout.notification_material_action_emphasized_tombstone;
+        }
+
         private int getActionTombstoneLayoutResource() {
             return R.layout.notification_material_action_tombstone;
         }

core/res/res/layout/notification_material_action_emphasized_tombstone.xml

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (C) 2023 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.
+  -->
+
+<com.android.internal.widget.EmphasizedNotificationButton
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    style="@style/NotificationEmphasizedAction"
+    android:id="@+id/action0"
+    android:layout_width="wrap_content"
+    android:layout_height="match_parent"
+    android:layout_marginStart="12dp"
+    android:drawablePadding="6dp"
+    android:enabled="false"
+    android:gravity="center"
+    android:singleLine="true"
+    android:ellipsize="end"
+/>

core/res/res/values/colors.xml

@@ -150,6 +150,8 @@
     <color name="notification_default_color">#757575</color> <!-- Gray 600 -->
 
     <color name="notification_action_button_text_color">@color/notification_default_color</color>
+    <item  name="notification_action_disabled_content_alpha" format="float" type="dimen">0.38</item>
+    <item  name="notification_action_disabled_container_alpha" format="float" type="dimen">0.12</item>
 
     <color name="notification_progress_background_color">@color/notification_secondary_text_color_current</color>
 

core/res/res/values/symbols.xml

@@ -3304,7 +3304,10 @@
   <java-symbol type="id" name="notification_action_list_margin_target" />
   <java-symbol type="dimen" name="notification_actions_padding_start"/>
   <java-symbol type="dimen" name="notification_actions_collapsed_priority_width"/>
+  <!--prefer to use disabled content and surface alpha values for disabled actions-->
   <java-symbol type="dimen" name="notification_action_disabled_alpha" />
+  <java-symbol type="dimen" name="notification_action_disabled_content_alpha" />
+  <java-symbol type="dimen" name="notification_action_disabled_container_alpha" />
   <java-symbol type="id" name="tag_margin_end_when_icon_visible" />
   <java-symbol type="id" name="tag_margin_end_when_icon_gone" />
   <java-symbol type="id" name="tag_uses_right_icon_drawable" />
@@ -3356,6 +3359,7 @@
   <java-symbol type="string" name="unsupported_display_size_message" />
 
   <java-symbol type="layout" name="notification_material_action_emphasized" />
+  <java-symbol type="layout" name="notification_material_action_emphasized_tombstone" />
 
   <!-- Package name for the device provisioning package -->
   <java-symbol type="string" name="config_deviceProvisioningPackage" />