CredManUI: support UI cancellation.

The backend can issue an
IntentFactory.createCancelUiIntent(requestToken) call to cancel the UI
matching the corresponding request.

Test: local deployment
Bug: 268708612
Change-Id: I6aef8489cedcbf6cba1901aca1b54ec3e2a3a37d

core/java/android/credentials/ui/CancelUiRequest.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2022 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.
+ */
+
+package android.credentials.ui;
+
+import android.annotation.NonNull;
+import android.os.IBinder;
+import android.os.Parcel;
+import android.os.Parcelable;
+
+import com.android.internal.util.AnnotationValidations;
+
+/**
+ * A request to cancel any ongoing UI matching this request.
+ *
+ * @hide
+ */
+public final class CancelUiRequest implements Parcelable {
+
+    /**
+     * The intent extra key for the {@code CancelUiRequest} object when launching the UX
+     * activities.
+     */
+    @NonNull public static final String EXTRA_CANCEL_UI_REQUEST =
+            "android.credentials.ui.extra.EXTRA_CANCEL_UI_REQUEST";
+
+    @NonNull
+    private final IBinder mToken;
+
+    /** Returns the request token matching the user request that should be cancelled. */
+    @NonNull
+    public IBinder getToken() {
+        return mToken;
+    }
+
+    public CancelUiRequest(@NonNull IBinder token) {
+        mToken = token;
+    }
+
+    private CancelUiRequest(@NonNull Parcel in) {
+        mToken = in.readStrongBinder();
+        AnnotationValidations.validate(NonNull.class, null, mToken);
+    }
+
+    @Override
+    public void writeToParcel(@NonNull Parcel dest, int flags) {
+        dest.writeStrongBinder(mToken);
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @NonNull public static final Creator<CancelUiRequest> CREATOR = new Creator<>() {
+        @Override
+        public CancelUiRequest createFromParcel(@NonNull Parcel in) {
+            return new CancelUiRequest(in);
+        }
+
+        @Override
+        public CancelUiRequest[] newArray(int size) {
+            return new CancelUiRequest[size];
+        }
+    };
+}

core/java/android/credentials/ui/IntentFactory.java

@@ -22,6 +22,7 @@ import android.annotation.TestApi;
 import android.content.ComponentName;
 import android.content.Intent;
 import android.content.res.Resources;
+import android.os.IBinder;
 import android.os.Parcel;
 import android.os.ResultReceiver;
 
@@ -65,6 +66,25 @@ public class IntentFactory {
         return intent;
     }
 
+    /**
+     * Creates an Intent that cancels any UI matching the given request token id.
+     *
+     * @hide
+     */
+    @NonNull
+    public static Intent createCancelUiIntent(@NonNull IBinder requestToken) {
+        Intent intent = new Intent();
+        ComponentName componentName =
+                ComponentName.unflattenFromString(
+                        Resources.getSystem()
+                                .getString(
+                                        com.android.internal.R.string
+                                                .config_credentialManagerDialogComponent));
+        intent.setComponent(componentName);
+        intent.putExtra(CancelUiRequest.EXTRA_CANCEL_UI_REQUEST, new CancelUiRequest(requestToken));
+        return intent;
+    }
+
     /**
      * Notify the UI that providers have been enabled/disabled.
      *

packages/CredentialManager/src/com/android/credentialmanager/CredentialManagerRepo.kt

@@ -23,6 +23,7 @@ import android.credentials.Credential.TYPE_PASSWORD_CREDENTIAL
 import android.credentials.CredentialOption
 import android.credentials.GetCredentialRequest
 import android.credentials.ui.AuthenticationEntry
+import android.credentials.ui.CancelUiRequest
 import android.credentials.ui.Constants
 import android.credentials.ui.Entry
 import android.credentials.ui.CreateCredentialProviderData
@@ -214,6 +215,14 @@ class CredentialManagerRepo(
                 resultReceiver.send(cancelCode, resultData)
             }
         }
+
+        /** Return the request token whose UI should be cancelled, or null otherwise. */
+        fun getCancelUiRequestToken(intent: Intent): IBinder? {
+            return intent.extras?.getParcelable(
+                CancelUiRequest.EXTRA_CANCEL_UI_REQUEST,
+                CancelUiRequest::class.java
+            )?.token
+        }
     }
 
     // TODO: below are prototype functionalities. To be removed for productionization.

packages/CredentialManager/src/com/android/credentialmanager/CredentialSelectorActivity.kt

@@ -47,6 +47,12 @@ class CredentialSelectorActivity : ComponentActivity() {
         super.onCreate(savedInstanceState)
         Log.d(Constants.LOG_TAG, "Creating new CredentialSelectorActivity")
         try {
+            if (CredentialManagerRepo.getCancelUiRequestToken(intent) != null) {
+                Log.d(
+                    Constants.LOG_TAG, "Received UI cancellation intent; cancelling the activity.")
+                this.finish()
+                return
+            }
             val userConfigRepo = UserConfigRepo(this)
             val credManRepo = CredentialManagerRepo(this, intent, userConfigRepo)
             setContent {
@@ -67,10 +73,19 @@ class CredentialSelectorActivity : ComponentActivity() {
         setIntent(intent)
         Log.d(Constants.LOG_TAG, "Existing activity received new intent")
         try {
-            val userConfigRepo = UserConfigRepo(this)
-            val credManRepo = CredentialManagerRepo(this, intent, userConfigRepo)
+            val cancelUiRequestToken = CredentialManagerRepo.getCancelUiRequestToken(intent)
             val viewModel: CredentialSelectorViewModel by viewModels()
-            viewModel.onNewCredentialManagerRepo(credManRepo)
+            if (cancelUiRequestToken != null &&
+                viewModel.shouldCancelCurrentUi(cancelUiRequestToken)) {
+                Log.d(
+                    Constants.LOG_TAG, "Received UI cancellation intent; cancelling the activity.")
+                this.finish()
+                return
+            } else {
+                val userConfigRepo = UserConfigRepo(this)
+                val credManRepo = CredentialManagerRepo(this, intent, userConfigRepo)
+                viewModel.onNewCredentialManagerRepo(credManRepo)
+            }
         } catch (e: Exception) {
             onInitializationError(e, intent)
         }

packages/CredentialManager/src/com/android/credentialmanager/CredentialSelectorViewModel.kt

@@ -17,6 +17,7 @@
 package com.android.credentialmanager
 
 import android.app.Activity
+import android.os.IBinder
 import android.util.Log
 import androidx.activity.compose.ManagedActivityResultLauncher
 import androidx.activity.result.ActivityResult
@@ -135,6 +136,11 @@ class CredentialSelectorViewModel(
         uiState = uiState.copy(dialogState = DialogState.COMPLETE)
     }
 
+    /** Return true if the current UI's request token matches the UI cancellation request token. */
+    fun shouldCancelCurrentUi(cancelRequestToken: IBinder): Boolean {
+        return credManRepo.requestInfo.token.equals(cancelRequestToken)
+    }
+
     /**************************************************************************/
     /*****                      Get Flow Callbacks                        *****/
     /**************************************************************************/