Clipboard Android - Store and Read Last Modified Time from Prefs

ui/base/clipboard/clipboard_android.cc

 // Copyright (c) 2012 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 "ui/base/clipboard/clipboard_android.h"
 
 #include <algorithm>
 
 #include "base/android/context_utils.h"
 #include "base/android/jni_string.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/lazy_instance.h"
 #include "base/stl_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/synchronization/lock.h"
 #include "base/time/time.h"
+#include "components/prefs/pref_registry_simple.h"
+#include "components/prefs/pref_service.h"
 #include "jni/Clipboard_jni.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/gfx/geometry/size.h"
 
 // TODO:(andrewhayden) Support additional formats in Android: Bitmap, URI, HTML,
 // HTML+text now that Android's clipboard system supports them, then nuke the
 // legacy implementation note below.
 
 // Legacy implementation note:
 // The Android clipboard system used to only support text format. So we used the
 // Android system when some text was added or retrieved from the system. For
 // anything else, we STILL store the value in some process wide static
 // variable protected by a lock. So the (non-text) clipboard will only work
 // within the same process.
 
 using base::android::AttachCurrentThread;
 using base::android::ClearException;
 using base::android::ConvertJavaStringToUTF8;
 using base::android::ConvertUTF8ToJavaString;
 using base::android::ScopedJavaGlobalRef;
 using base::android::ScopedJavaLocalRef;
 
 namespace ui {
 
 namespace {
 
+// Stores the last modified time in Time::Time's internal format (int64) as

[Bernhard Bauer, 2017/04/25 13:30:06]

base::Time?

[Mark P, 2017/04/25 18:51:21]

Correct.  Done.

+// a pref in local store.  (I.e., this is not a per-profile pref.)

[Bernhard Bauer, 2017/04/25 13:30:06]

Again, also kind of a layering violation, but I guess if it serves to clarify
mistaken assumptions a reader might have, I'm okay with it.

[Mark P, 2017/04/25 18:51:21]

Acknowledged.

+const char kClipboardLastModifiedTimePref[] = "ui.clipboard.last_modified_time";
+
 // Various formats we support.
 const char kURLFormat[] = "url";
 const char kPlainTextFormat[] = "text";
 const char kHTMLFormat[] = "html";
 const char kRTFFormat[] = "rtf";
 const char kBitmapFormat[] = "bitmap";
 const char kWebKitSmartPasteFormat[] = "webkit_smart";
 const char kBookmarkFormat[] = "bookmark";
 
 class ClipboardMap {
  public:
   ClipboardMap();
+  void SetLocalState(PrefService* local_state);
   std::string Get(const std::string& format);
   uint64_t GetSequenceNumber() const;
   base::Time GetLastModifiedTime() const;
   void ClearLastModifiedTime();
   bool HasFormat(const std::string& format);
   void OnPrimaryClipboardChanged();
   void Set(const std::string& format, const std::string& data);
   void CommitToAndroidClipboard();
   void Clear();
 
  private:
   enum class MapState {
     kOutOfDate,
     kUpToDate,
     kPreparingCommit,
   };
 
+  // Updates |last_modified_time_| to |time| and writes it to |local_state_|.
+  void UpdateLastModifiedTime(const base::Time& time);
+
+  // Updates |map_| and |map_state_| if necessary by fetching data from Java.
   void UpdateFromAndroidClipboard();
+
   std::map<std::string, std::string> map_;
   MapState map_state_;
   base::Lock lock_;
 
   uint64_t sequence_number_;
   base::Time last_modified_time_;
 
+  PrefService* local_state_;
+
   // Java class and methods for the Android ClipboardManager.
   ScopedJavaGlobalRef<jobject> clipboard_manager_;
 };
 base::LazyInstance<ClipboardMap>::Leaky g_map = LAZY_INSTANCE_INITIALIZER;
 
 ClipboardMap::ClipboardMap() : map_state_(MapState::kOutOfDate) {
   clipboard_manager_.Reset(Java_Clipboard_getInstance(AttachCurrentThread()));
   DCHECK(clipboard_manager_.obj());
 }
 
+void ClipboardMap::SetLocalState(PrefService* local_state) {
+  local_state_ = local_state;
+  last_modified_time_ = base::Time::FromInternalValue(
+      local_state_->GetInt64(kClipboardLastModifiedTimePref));
+}
+
 std::string ClipboardMap::Get(const std::string& format) {
   base::AutoLock lock(lock_);
   UpdateFromAndroidClipboard();
   std::map<std::string, std::string>::const_iterator it = map_.find(format);
   return it == map_.end() ? std::string() : it->second;
 }
 
 uint64_t ClipboardMap::GetSequenceNumber() const {
   return sequence_number_;
 }
 
 base::Time ClipboardMap::GetLastModifiedTime() const {
   return last_modified_time_;
 }
 
 void ClipboardMap::ClearLastModifiedTime() {
-  last_modified_time_ = base::Time();
+  UpdateLastModifiedTime(base::Time());
 }
 
 bool ClipboardMap::HasFormat(const std::string& format) {
   base::AutoLock lock(lock_);
   UpdateFromAndroidClipboard();
   return base::ContainsKey(map_, format);
 }
 
 void ClipboardMap::OnPrimaryClipboardChanged() {
   sequence_number_++;
-  last_modified_time_ = base::Time::Now();
+  UpdateLastModifiedTime(base::Time::Now());
   map_state_ = MapState::kOutOfDate;
 }
 
 void ClipboardMap::Set(const std::string& format, const std::string& data) {
   base::AutoLock lock(lock_);
   map_[format] = data;
   map_state_ = MapState::kPreparingCommit;
 }
 
 void ClipboardMap::CommitToAndroidClipboard() {
@@ skipping 16 matching lines @@
     ScopedJavaLocalRef<jstring> str =
         ConvertUTF8ToJavaString(env, map_[kPlainTextFormat]);
     DCHECK(str.obj());
     Java_Clipboard_setText(env, clipboard_manager_, str);
   } else {
     Java_Clipboard_clear(env, clipboard_manager_);
     NOTIMPLEMENTED();
   }
   map_state_ = MapState::kUpToDate;
   sequence_number_++;
-  last_modified_time_ = base::Time::Now();
+  UpdateLastModifiedTime(base::Time::Now());
 }
 
 void ClipboardMap::Clear() {
   JNIEnv* env = AttachCurrentThread();
   base::AutoLock lock(lock_);
   map_.clear();
   Java_Clipboard_clear(env, clipboard_manager_);
   map_state_ = MapState::kUpToDate;
   sequence_number_++;
-  last_modified_time_ = base::Time::Now();
+  UpdateLastModifiedTime(base::Time::Now());
 }
 
 // Add a key:jstr pair to map, but only if jstr is not null, and also
 // not empty.
 void AddMapEntry(JNIEnv* env,
                  std::map<std::string, std::string>* map,
                  const char* key,
                  const ScopedJavaLocalRef<jstring>& jstr) {
   if (!jstr.is_null()) {
     std::string str = ConvertJavaStringToUTF8(env, jstr.obj());
     if (!str.empty())
       (*map)[key] = str;
   }
 }
 
+void ClipboardMap::UpdateLastModifiedTime(const base::Time& time) {

[dcheng, 2017/04/25 13:17:12]

base::Time is designed to be efficiently passed by value, so we should prefer
that here.

[Mark P, 2017/04/25 18:51:21]

Done.

+  last_modified_time_ = time;
+  // |local_state_| may be null in tests.
+  if (local_state_) {
+    local_state_->SetInt64(kClipboardLastModifiedTimePref,
+                           last_modified_time_.ToInternalValue());
+  }
+}
+
 void ClipboardMap::UpdateFromAndroidClipboard() {
   DCHECK_NE(MapState::kPreparingCommit, map_state_);
   if (map_state_ == MapState::kUpToDate)
     return;
 
   // Fetch the current Android clipboard state.
   lock_.AssertAcquired();
   JNIEnv* env = AttachCurrentThread();
 
   ScopedJavaLocalRef<jstring> jtext =
@@ skipping 100 matching lines @@
 }
 
 // Clipboard factory method.
 // static
 Clipboard* Clipboard::Create() {
   return new ClipboardAndroid;
 }
 
 // ClipboardAndroid implementation.
 
+// static
+void ClipboardAndroid::RegisterPrefs(PrefRegistrySimple* registry) {
+  registry->RegisterInt64Pref(kClipboardLastModifiedTimePref, 0u);
+}
+
+void ClipboardAndroid::SetLocalState(PrefService* local_state) {
+  g_map.Get().SetLocalState(local_state);
+}
+
 void ClipboardAndroid::OnPrimaryClipChanged(
     JNIEnv* env,
     const base::android::JavaParamRef<jobject>& obj) {
   g_map.Get().OnPrimaryClipboardChanged();
 }
 
 ClipboardAndroid::ClipboardAndroid() {
   DCHECK(CalledOnValidThread());
 }
 
@@ skipping 203 matching lines @@
   return RegisterNativesImpl(env);
 }
 
 // Returns a pointer to the current ClipboardAndroid object.
 static jlong Init(JNIEnv* env,
                   const base::android::JavaParamRef<jobject>& obj) {
   return reinterpret_cast<intptr_t>(Clipboard::GetForCurrentThread());
 }
 
 } // namespace ui