Expose Physical Web metadata to native clients over JNI

chrome/browser/android/physical_web/physical_web_data_source_android.cc

 // Copyright 2016 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.
 
 #include "chrome/browser/android/physical_web/physical_web_data_source_android.h"
 
 #include <jni.h>
 
+#include "base/android/jni_android.h"
+#include "base/android/jni_string.h"
 #include "base/memory/ptr_util.h"
 #include "base/values.h"
 #include "chrome/browser/browser_process.h"
 #include "jni/UrlManager_jni.h"
 
 using base::android::AttachCurrentThread;
+using base::android::ConvertJavaStringToUTF8;
 using base::android::JavaParamRef;
 using base::android::ScopedJavaLocalRef;
 
+PhysicalWebCollection::PhysicalWebCollection()
+    : metadata_list_(base::MakeUnique<base::ListValue>()) {}
+
+PhysicalWebCollection::~PhysicalWebCollection() {}
+
+void PhysicalWebCollection::AppendMetadataItem(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj,
+    const JavaParamRef<jstring>& j_request_url,
+    jdouble distance_estimate,
+    jint scan_timestamp,
+    const JavaParamRef<jstring>& j_site_url,
+    const JavaParamRef<jstring>& j_icon_url,
+    const JavaParamRef<jstring>& j_title,
+    const JavaParamRef<jstring>& j_description,
+    const JavaParamRef<jstring>& j_group_id) {
+  auto metadata_item = new base::DictionaryValue();
+  metadata_item->SetString("scannedUrl",

[gone, 2016/10/24 16:35:35]

Are these key constants referenced anywhere else?  Worth pulling out?

[mattreynolds, 2016/10/24 22:39:52]

Done. They are also hard-coded in the WebUI HTML but I couldn't find an easy way
to pull them out.

+                           ConvertJavaStringToUTF8(j_request_url));
+  metadata_item->SetDouble("distanceEstimate", distance_estimate);
+  metadata_item->SetInteger("scanTimestamp", scan_timestamp);
+  metadata_item->SetString("resolvedUrl", ConvertJavaStringToUTF8(j_site_url));
+  metadata_item->SetString("icon", ConvertJavaStringToUTF8(j_icon_url));
+  metadata_item->SetString("title", ConvertJavaStringToUTF8(j_title));
+  metadata_item->SetString("description",
+                           ConvertJavaStringToUTF8(j_description));
+  metadata_item->SetString("groupId", ConvertJavaStringToUTF8(j_group_id));
+  metadata_list_->Append(std::move(metadata_item));
+}
+
+std::unique_ptr<base::ListValue> PhysicalWebCollection::GetMetadataList() {
+  return std::move(metadata_list_);
+}
+
 PhysicalWebDataSourceAndroid::PhysicalWebDataSourceAndroid() {
   Initialize();
 }
 
 PhysicalWebDataSourceAndroid::~PhysicalWebDataSourceAndroid() {}
 
 void PhysicalWebDataSourceAndroid::Initialize() {
   JNIEnv* env = AttachCurrentThread();
 
   // Cache a reference to the singleton instance of UrlManager.
   url_manager_.Reset(Java_UrlManager_getInstance(env));
   DCHECK(url_manager_.obj());
 }
 
 void PhysicalWebDataSourceAndroid::StartDiscovery(
     bool network_request_enabled) {
   // On Android, scanning is started and stopped through the Java layer.
   NOTREACHED();
 }
 
 void PhysicalWebDataSourceAndroid::StopDiscovery() {
   // On Android, scanning is started and stopped through the Java layer.
   NOTREACHED();
 }
 
 std::unique_ptr<base::ListValue> PhysicalWebDataSourceAndroid::GetMetadata() {
-  // TODO(mattreynolds): get the metadata from the Java layer
-  return base::MakeUnique<base::ListValue>();
+  JNIEnv* env = AttachCurrentThread();
+
+  auto pw_collection = base::MakeUnique<PhysicalWebCollection>();
+  Java_UrlManager_getPwCollection(env, url_manager_.obj(),
+                                  (long)pw_collection.get());
+
+  return pw_collection->GetMetadataList();
 }
 
 bool PhysicalWebDataSourceAndroid::HasUnresolvedDiscoveries() {
   NOTIMPLEMENTED();
   return false;
 }
 
 // static
 bool PhysicalWebDataSourceAndroid::RegisterPhysicalWebDataSource(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 static jlong Init(JNIEnv* env, const JavaParamRef<jobject>& obj) {
   PhysicalWebDataSource* data_source =
       g_browser_process->GetPhysicalWebDataSource();
   return reinterpret_cast<intptr_t>(data_source);
 }