[Passwords TTF] Add interface and factory to construct coordinator

This CL adds the interface which will be implemented by bridge and
coordinator. The build file currently doesn't add the public_java
target to chrome_java since this would cause a cyclic dependency.


The interface allows to request that the TouchToFill component shows
a set of credentials and ensures that the delegate is notified when
users dismiss the sheet without selecting anything.

Bug: 957532,1004415
Change-Id: Icbba0471febb88dfb4f87d33a1ea4a53992767ff
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1798707
Commit-Queue: Friedrich [CET] <fhorschig@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#697960}

chrome/android/BUILD.gn

@@ -510,6 +510,7 @@ java_group("chrome_all_java") {
     "//chrome/android/features/keyboard_accessory:internal_java",
     "//chrome/android/features/media_router:java",
     "//chrome/android/features/test_dummy/internal:base_module_java",
+    "//chrome/browser/touch_to_fill/android/internal:java",
   ]
 
   if (disable_autofill_assistant_dfm) {
@@ -535,6 +536,7 @@ group("jni_headers") {
     "//chrome/android/features/media_router:jni_headers",
     "//chrome/android/public/profiles:jni_headers",
     "//chrome/browser/image_fetcher:jni_headers",
+    "//chrome/browser/touch_to_fill/android:jni_headers",
     "//chrome/lib/util/public/android:jni_headers",
   ]
 }

chrome/browser/touch_to_fill/DEPS

+include_rules = [
+  "+chrome/android",
+]

chrome/browser/touch_to_fill/android/BUILD.gn

+# Copyright 2019 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/android/rules.gni")
+import("//chrome/android/features/android_library_factory_tmpl.gni")
+
+generate_jni("jni_headers") {
+  sources = [
+    "java/src/org/chromium/chrome/browser/touch_to_fill/data/Credential.java",
+  ]
+}
+
+android_library("public_java") {
+  deps = [
+    # TODO(crbug.com/1004415): Remove dependency on chrome_java and depend on
+    # bottomsheet directly. Add public_java to chrome_java target instead.
+    "//chrome/android:chrome_java",
+    "//chrome/android:chrome_public_java",
+    "//ui/android:ui_java",
+  ]
+  java_files = [
+    "java/src/org/chromium/chrome/browser/touch_to_fill/data/Credential.java",
+    "java/src/org/chromium/chrome/browser/touch_to_fill/TouchToFillComponent.java",
+  ]
+}

chrome/browser/touch_to_fill/android/README.md

@@ -15,18 +15,35 @@ will be shown instead (i.e. by changing the focus).
 
 ## Folder Structure
 
-#### /
+#### java/
 
 The root folder contains the public interface of this component and data that is
 used to fill it with content, e.g. Crendentials. This folder also contains the
-code to instantiate the component.
+factory to instantiate the component. The factory has two implementations:
+
+* an auto-generated one returning null which is used in tests and targets that
+  don't directly depend on this component
+* one that provides the actual implementation
+
+Add `chrome/browser/touch_to_fill/android:public_java` as dependency to use the
+interface and classes defined here.
+
+#### java/internal/
+
+Contains the actual implementation. Don't try to use any class defined here
+outside of this package. If you need access to any method, consider making it
+part of the public interface as defined in `TouchToFillComponent`
+
+This folder contains a separate [README](internal/README.md) that explains in
+detail how the architecture looks like and how to extend the component further.
+
 
 ## Example usage
 
 ``` java
 
-// Use factory to instantiate the component:
-TouchToFillComponent component = TouchToFillComponentFactory.createComponent();
+// Currently, you need access to internal/ to instantiate the component:
+TouchToFillComponent component = new TouchToFillCoordinator(/*...*/);
 
 component.initialize(activity, activity.getBottomSheetController(), () -> {
   // Things to do when the component is dismissed.

chrome/browser/touch_to_fill/android/internal/BUILD.gn

+# Copyright 2019 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/android/rules.gni")
+import("//chrome/common/features.gni")
+
+android_library("java") {
+  deps = [
+    "//base:base_java",
+    "//chrome/android:chrome_java",
+    "//chrome/browser/touch_to_fill/android:public_java",
+    "//ui/android:ui_java",
+  ]
+
+  java_files = [ "java/src/org/chromium/chrome/browser/touch_to_fill/TouchToFillCoordinator.java" ]
+}

chrome/browser/touch_to_fill/android/internal/README.md

+# Touch To Fill Android Feature
+
+This folder contains the internal parts of the Touch To Fill component. Files,
+classes and methods defined in here are not meant to be used outside of this
+package.
+
+This document provides a brief overview of the architecture.
+
+[TOC]
+
+
+## Component structure
+
+This component follows the typical
+[MVC](https://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93controller)
+structure that is widely used in Chrome on Android. The MVC structures separates
+logic from representation:
+
+ * The [controller](#Controller) creates and connects all subcomponents and
+   performs logic that affects the visual appearance of the component.
+ * The [model](#Model) keeps all state that affects the visual appearance of the
+   component. Changes made to it are automatically propagated to the view by a
+   Model-Change-Processor (MCP) as defined in
+    `//src/ui/android/java/src/org/chromium/ui/modelutil/`
+ * The [view](#View) is the representation of the component. It enforces styles
+   and is mostly called by a view binder to set mutable properties.
+
+
+A typical request to the Touch to Fill component API that intends to change the
+visible appearance involves all component parts. For example if the API caller
+requests to show new credentials:
+
+1. The API caller asks the controller to show a set of
+   `credentials`.
+    1. The controller prepares and filters the `credentials` for display.
+    2. The controller writes the prepared credentials into the [model](#Model).
+2. The MCP picks up model changes.
+    1. The MCP identifies that the `CREDENTIAL_LIST` property was changed.
+    2. The MCP uses a ViewBinder to bind each changed credential to the
+       corresponding view (e.g. a TextView inside a RecyclerView).
+3. The view renders the changed credential list.
+    1. The view may apply style, RTL settings and event handlers for click events.
+

chrome/browser/touch_to_fill/android/internal/java/src/org/chromium/chrome/browser/touch_to_fill/TouchToFillCoordinator.java

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.touch_to_fill;
+
+import android.content.Context;
+
+import org.chromium.base.Callback;
+import org.chromium.chrome.browser.touch_to_fill.data.Credential;
+import org.chromium.chrome.browser.widget.bottomsheet.BottomSheetController;
+
+import java.util.List;
+
+/**
+ * Creates the TouchToFill component. TouchToFill uses a bottom sheet to let the
+ * user select a set of credentials and fills it into the focused form.
+ */
+public class TouchToFillCoordinator implements TouchToFillComponent {
+    TouchToFillCoordinator() {}
+
+    @Override
+    public void initialize(Context context, BottomSheetController sheetController,
+            TouchToFillComponent.Delegate delegate) {
+        // TODO(crbug.com/957532): Implement.
+    }
+
+    @Override
+    public void showCredentials(
+            String formattedUrl, List<Credential> credentials, Callback<Credential> callback) {
+        // TODO(crbug.com/957532): Implement.
+    }
+}

chrome/browser/touch_to_fill/android/java/src/org/chromium/chrome/browser/touch_to_fill/TouchToFillComponent.java

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.touch_to_fill;
+
+import android.content.Context;
+
+import org.chromium.base.Callback;
+import org.chromium.chrome.browser.touch_to_fill.data.Credential;
+import org.chromium.chrome.browser.widget.bottomsheet.BottomSheetController;
+
+import java.util.List;
+
+/**
+ * This component allows to fill credentials into a form. It suppresses the keyboard until dismissed
+ * and acts as a safe surface to fill credentials from.
+ */
+public interface TouchToFillComponent {
+    /**
+     * This delegate is called when the TouchToFill component is interacted with (e.g. dismissed or
+     * a suggestion was selected).
+     */
+    interface Delegate {
+        /**
+         * Called when the user dismisses the TouchToFillComponent. Not called if a suggestion was
+         * selected.
+         */
+        void onDismissed();
+    }
+
+    /**
+     * Initializes the component.
+     * @param context A {@link Context} to create views and retrieve resources.
+     * @param sheetController A {@link BottomSheetController} used to show/hide the sheet.
+     * @param delegate A {@link Delegate} that handles dismiss events.
+     */
+    void initialize(Context context, BottomSheetController sheetController, Delegate delegate);
+
+    /**
+     * Displays the given credentials in a new bottom sheet.
+     * @param formattedUrl A {@link String} that contains the URL to display credentials for.
+     * @param credentials A list of {@link Credential}s that will be displayed.
+     * @param callback A {@link Callback} called when the user selects a credential to be filled.
+     */
+    void showCredentials(
+            String formattedUrl, List<Credential> credentials, Callback<Credential> callback);
+}

chrome/browser/touch_to_fill/android/java/src/org/chromium/chrome/browser/touch_to_fill/data/Credential.java

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.touch_to_fill.data;
+
+import org.chromium.base.annotations.CalledByNative;
+
+/**
+ * This class holds the data used to represent a selectable credential in the Touch To Fill sheet.
+ */
+public class Credential {
+    private final String mUsername;
+    private final String mPassword;
+    private final String mOriginUrl;
+    private final boolean mIsPublicSuffixMatch;
+
+    /**
+     * @param username Username shown to the user.
+     * @param password Password shown to the user.
+     * @param originUrl Origin URL shown to the user in case this credential is a PSL match.
+     * @param isPublicSuffixMatch Indicating whether the credential is a PSL match.
+     */
+    public Credential(
+            String username, String password, String originUrl, boolean isPublicSuffixMatch) {
+        mUsername = username;
+        mPassword = password;
+        mOriginUrl = originUrl;
+        mIsPublicSuffixMatch = isPublicSuffixMatch;
+    }
+
+    @CalledByNative
+    public String getUsername() {
+        return mUsername;
+    }
+
+    @CalledByNative
+    public String getPassword() {
+        return mPassword;
+    }
+
+    @CalledByNative
+    public String getOriginUrl() {
+        return mOriginUrl;
+    }
+
+    @CalledByNative
+    public boolean isPublicSuffixMatch() {
+        return mIsPublicSuffixMatch;
+    }
+}