Upstream the clipboard implementation for Android

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.h"
+
+#include <jni.h>
+
+#include "base/android/jni_android.h"
+#include "base/android/jni_string.h"
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/synchronization/lock.h"
+#include "base/utf_string_conversions.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "ui/gfx/size.h"
+
+// Important note:
+// Android's clipboard system only supports text content, so use it only when
+// text is added to or retrieved from the system. For other data types, store
+// the value in a map. This has the consequence that the clipboard's contents
+// will only be available within the current process.
+
+// Global contents map and its lock.

[sky, 2012/02/16 17:06:44]

This comment isn't applicable here.

[Peter Beverloo, 2012/02/16 20:38:40]

Done.

+using base::android::AttachCurrentThread;
+using base::android::CheckException;
+using base::android::ClearException;
+using base::android::ConvertJavaStringToUTF16;
+using base::android::ConvertJavaStringToUTF8;
+using base::android::GetClass;
+using base::android::GetMethodID;
+using base::android::ScopedJavaLocalRef;
+
+namespace ui {
+
+namespace {
+// As Android only supports text in the clipboard, the following map will be
+// used for other kinds of data. Use the lock to make this thread-safe.
+// TODO(beverloo): http://crbug.com/112286 Investigate whether the locks in
+// this file are required.
+typedef std::map<std::string, std::string> ClipboardMap;
+ClipboardMap* g_clipboard_map = NULL;
+base::LazyInstance<base::Lock> g_clipboard_map_lock = LAZY_INSTANCE_INITIALIZER;
+
+// Various format we support.
+const char kPlainTextFormat[] = "text";
+const char kHTMLFormat[] = "html";
+const char kBitmapFormat[] = "bitmap";
+const char kWebKitSmartPasteFormat[] = "webkit_smart";
+const char kBookmarkFormat[] = "bookmark";
+const char kMimeTypeWebCustomData[] = "chromium/x-web-custom-data";
+
+}  // namespace
+
+Clipboard::FormatType::FormatType() {
+}
+
+Clipboard::FormatType::FormatType(const std::string& native_format)
+    : data_(native_format) {
+}
+
+Clipboard::FormatType::~FormatType() {
+}
+
+std::string Clipboard::FormatType::Serialize() const {
+  return data_;
+}
+
+// static
+Clipboard::FormatType Clipboard::FormatType::Deserialize(
+    const std::string& serialization) {
+  return FormatType(serialization);
+}
+
+bool Clipboard::FormatType::Equals(const FormatType& other) const {
+  return data_ == other.data_;
+}
+
+// The clipboard object on the Android platform is simply wrapping the Java
+// object for the text data format. For non-text format, a global map is used.
+Clipboard::Clipboard() : set_text_(NULL), has_text_(NULL), get_text_(NULL) {
+  JNIEnv* env = AttachCurrentThread();

[sky, 2012/02/16 17:06:44]

Do you need to detach at some point?

[Peter Beverloo, 2012/02/16 20:38:40]

Yes, just before the thread exists, which is being done in
platform_thread_posix.cc. Attaching multiple times does not have any
side-effects.

+  DCHECK(env);
+
+  // Get the context.
+  // We have need a ScopedJavaLocalRef to clean-up the local ref if we have to
+  // create the Context.
+  jobject context = base::android::GetApplicationContext();
+  ScopedJavaLocalRef<jobject> scoped_context;
+  if (!context) {
+    // Should be during testing only.
+    // Get the ActivityThread class.
+    ScopedJavaLocalRef<jclass> activity_thread_class =
+        GetClass(env, "android/app/ActivityThread");
+
+    // Try to get the current activity thread.
+    jmethodID current_activity_method_id = GetMethodID(
+        env, activity_thread_class,
+        "currentActivityThread", "()Landroid/app/ActivityThread;");
+
+    ScopedJavaLocalRef<jobject> current_activity(env,
+        env->CallStaticObjectMethod(activity_thread_class.obj(),
+                                    current_activity_method_id));
+    ClearException(env);
+
+    if (!current_activity.obj()) {
+      // There is no current activity, create one.
+      ScopedJavaLocalRef<jclass> looper_class =
+          GetClass(env, "android/os/Looper");
+      jmethodID prepare_method_id =
+          GetStaticMethodID(env, looper_class, "prepareMainLooper", "()V");
+      env->CallStaticVoidMethod(looper_class.obj(), prepare_method_id);
+      CheckException(env);
+
+      jmethodID system_main_method_id =
+          GetStaticMethodID(env, activity_thread_class, "systemMain",
+                            "()Landroid/app/ActivityThread;");
+
+      current_activity.Reset(env, env->CallStaticObjectMethod(
+          activity_thread_class.obj(), system_main_method_id));
+      DCHECK(current_activity.obj());
+      CheckException(env);
+    }
+
+    // Get the context.
+    jmethodID get_system_context_id = GetMethodID(env, activity_thread_class,
+       "getSystemContext", "()Landroid/app/ContextImpl;");
+    scoped_context.Reset(env, env->CallObjectMethod(current_activity.obj(),
+                                                    get_system_context_id));
+    context = scoped_context.obj();
+    DCHECK(context);
+  }
+
+  // Get the context class.
+  ScopedJavaLocalRef<jclass> context_class =
+      GetClass(env, "android/content/Context");
+  // Get the system service method.
+  jmethodID get_system_service = GetMethodID(env, context_class,
+      "getSystemService",  "(Ljava/lang/String;)Ljava/lang/Object;");
+
+  // Retrieve the system service.
+  ScopedJavaLocalRef<jstring> service_name(env, env->NewStringUTF("clipboard"));
+  clipboard_manager_.Reset(env, env->CallObjectMethod(context,
+      get_system_service, service_name.obj()));
+  ClearException(env);
+  DCHECK(clipboard_manager_.obj());
+
+  // Retain a few methods we'll keep using.
+  ScopedJavaLocalRef<jclass> clipboard_class =
+      GetClass(env, "android/text/ClipboardManager");
+  set_text_ = GetMethodID(env, clipboard_class,
+                          "setText", "(Ljava/lang/CharSequence;)V");
+  has_text_ = GetMethodID(env, clipboard_class, "hasText", "()Z");
+  get_text_ = GetMethodID(env, clipboard_class,
+                          "getText", "()Ljava/lang/CharSequence;");
+
+  // Will need to call toString as CharSequence is not always a String.
+  ScopedJavaLocalRef<jclass> charsequence_class =
+      GetClass(env, "java/lang/CharSequence");
+  to_string_ = GetMethodID(env, charsequence_class,
+                           "toString", "()Ljava/lang/String;");
+
+  // Create the object map if we are the first clipboard
+  base::AutoLock lock(g_clipboard_map_lock.Get());
+  if (!g_clipboard_map)
+    g_clipboard_map = new ClipboardMap;
+}
+
+Clipboard::~Clipboard() {
+}
+
+// Main entry point used to write several values in the clipboard.
+void Clipboard::WriteObjects(const ObjectMap& objects) {
+  Clear();
+  for (ObjectMap::const_iterator iter = objects.begin();
+       iter != objects.end(); ++iter) {
+    DispatchObject(static_cast<ObjectType>(iter->first), iter->second);
+  }
+}
+
+uint64 Clipboard::GetSequenceNumber(Clipboard::Buffer /* buffer */) {
+  // TODO: Implement this. For now this interface will advertise
+  // that the clipboard never changes. That's fine as long as we
+  // don't rely on this signal.
+  return 0;
+}
+
+bool Clipboard::IsFormatAvailable(const Clipboard::FormatType& format,
+                                  Clipboard::Buffer buffer) const {
+  DCHECK_EQ(buffer, BUFFER_STANDARD);
+
+  if (!format.compare(kPlainTextFormat))
+    return IsTextAvailableFromAndroid();
+
+  ValidateInternalClipboard();
+
+  base::AutoLock lock(g_clipboard_map_lock.Get());
+  return g_clipboard_map->find(format.ToString()) != g_clipboard_map->end();
+}
+
+void Clipboard::ReadAvailableTypes(Buffer buffer, std::vector<string16>* types,
+                                   bool* contains_filenames) const {
+  if (!types || !contains_filenames) {
+    NOTREACHED();
+    return;
+  }
+
+  // This is unimplemented on the other platforms (e.g. win, linux).
+  NOTIMPLEMENTED();
+
+  types->clear();
+  *contains_filenames = false;
+}
+
+void Clipboard::ReadText(Clipboard::Buffer buffer, string16* result) const {
+  JNIEnv* env = AttachCurrentThread();
+
+  result->clear();
+  if (!env->CallBooleanMethod(clipboard_manager_.obj(), has_text_))
+    return;
+
+  ScopedJavaLocalRef<jobject> char_seq_text(env,
+      env->CallObjectMethod(clipboard_manager_.obj(), get_text_));
+  ScopedJavaLocalRef<jstring> tmp_string(env,
+      static_cast<jstring>(env->CallObjectMethod(char_seq_text.obj(),
+                                                 to_string_)));
+  *result = ConvertJavaStringToUTF16(tmp_string);
+}
+
+void Clipboard::ReadAsciiText(Clipboard::Buffer buffer,
+                              std::string* result) const {
+  JNIEnv* env = AttachCurrentThread();
+
+  result->clear();
+  if (!env->CallBooleanMethod(clipboard_manager_.obj(), has_text_))
+    return;
+
+  ScopedJavaLocalRef<jobject> char_seq_text(env,
+      env->CallObjectMethod(clipboard_manager_.obj(), get_text_));
+  ScopedJavaLocalRef<jstring> tmp_string(env,
+      static_cast<jstring>(env->CallObjectMethod(char_seq_text.obj(),
+                                                 to_string_)));
+  *result = ConvertJavaStringToUTF8(tmp_string);
+}
+
+// Note: |src_url| isn't really used. It is only implemented in Windows.
+void Clipboard::ReadHTML(Clipboard::Buffer buffer,
+                         string16* markup,
+                         std::string* src_url,
+                         uint32* fragment_start,
+                         uint32* fragment_end) const {
+  markup->clear();
+  if (src_url)
+    src_url->clear();
+  *fragment_start = 0;
+  *fragment_end = 0;
+
+  std::string input;
+
+  ValidateInternalClipboard();
+
+  base::AutoLock lock(g_clipboard_map_lock.Get());
+  ClipboardMap::const_iterator it = g_clipboard_map->find(kHTMLFormat);
+  if (it != g_clipboard_map->end())
+    input = it->second;
+
+  if (input.empty())
+    return;
+
+  *fragment_end = static_cast<uint32>(input.length());
+
+  UTF8ToUTF16(input.c_str(), input.length(), markup);
+}
+
+SkBitmap Clipboard::ReadImage(Buffer buffer) const {
+  NOTIMPLEMENTED();
+  return SkBitmap();
+}
+
+void Clipboard::ReadCustomData(Buffer buffer,
+                               const string16& type,
+                               string16* result) const {
+  NOTIMPLEMENTED();
+}
+
+void Clipboard::ReadBookmark(string16* title, std::string* url) const {
+  NOTIMPLEMENTED();
+}
+
+void Clipboard::ReadData(const Clipboard::FormatType& format,
+                         std::string* result) const {
+  result->clear();
+
+  ValidateInternalClipboard();
+
+  base::AutoLock lock(g_clipboard_map_lock.Get());
+  ClipboardMap::const_iterator it = g_clipboard_map->find(format.ToString());
+  if (it != g_clipboard_map->end())
+    result->assign(it->second);
+}
+
+// static
+Clipboard::FormatType Clipboard::GetFormatType(
+    const std::string& format_string) {
+  return FormatType::Deserialize(format_string);
+}
+
+// static
+const Clipboard::FormatType& Clipboard::GetPlainTextFormatType() {
+  CR_DEFINE_STATIC_LOCAL(FormatType, type, (kPlainTextFormat));
+  return type;
+}
+
+// static
+const Clipboard::FormatType& Clipboard::GetPlainTextWFormatType() {
+  CR_DEFINE_STATIC_LOCAL(FormatType, type, (kPlainTextFormat));
+  return type;
+}
+
+// static
+const Clipboard::FormatType& Clipboard::GetWebKitSmartPasteFormatType() {
+  CR_DEFINE_STATIC_LOCAL(FormatType, type, (kWebKitSmartPasteFormat));
+  return type;
+}
+
+// static
+const Clipboard::FormatType& Clipboard::GetHtmlFormatType() {
+  CR_DEFINE_STATIC_LOCAL(FormatType, type, (kHTMLFormat));
+  return type;
+}
+
+// static
+const Clipboard::FormatType& Clipboard::GetBitmapFormatType() {
+  CR_DEFINE_STATIC_LOCAL(FormatType, type, (kBitmapFormat));
+  return type;
+}
+
+// static
+const Clipboard::FormatType& Clipboard::GetWebCustomDataFormatType() {
+  CR_DEFINE_STATIC_LOCAL(FormatType, type, (kMimeTypeWebCustomData));
+  return type;
+}
+
+void Clipboard::WriteText(const char* text_data, size_t text_len) {
+  // Write the text in the Android Clipboard.
+  JNIEnv* env = AttachCurrentThread();
+  DCHECK(env);
+
+  std::string data(text_data, text_len);
+  ScopedJavaLocalRef<jstring> str(env, env->NewStringUTF(data.c_str()));
+  DCHECK(str.obj() && !ClearException(env));
+
+  env->CallVoidMethod(clipboard_manager_.obj(), set_text_, str.obj());
+
+  // Then write it in our internal data structure. We keep it there to check if
+  // another app performed a copy. See ValidateInternalClipboard().
+  Set(kPlainTextFormat, std::string(text_data, text_len));
+}
+
+void Clipboard::WriteHTML(const char* markup_data,
+                          size_t markup_len,
+                          const char* url_data,
+                          size_t url_len) {
+  Set(kHTMLFormat, std::string(markup_data, markup_len));
+}
+
+// Note: according to other platforms implementations, this really writes the
+// URL spec.
+void Clipboard::WriteBookmark(const char* title_data, size_t title_len,
+                              const char* url_data, size_t url_len) {
+  Set(kBookmarkFormat, std::string(url_data, url_len));
+}
+
+// Write an extra flavor that signifies WebKit was the last to modify the
+// pasteboard. This flavor has no data.
+void Clipboard::WriteWebSmartPaste() {
+  Set(kWebKitSmartPasteFormat, std::string());
+}
+
+// All platforms use gfx::Size for size data but it is passed as a const char*
+// Further, pixel_data is expected to be 32 bits per pixel.
+// Note: we implement this to pass all unit tests but it is currently unclear
+// how some code would consume this.
+void Clipboard::WriteBitmap(const char* pixel_data, const char* size_data) {
+  const gfx::Size* size = reinterpret_cast<const gfx::Size*>(size_data);
+  int bm_size = size->width() * size->height() * 4;
+  int total_size = (sizeof(int) * 2) + bm_size;
+  scoped_array<char> buffer(new char[total_size]);
+
+  char* p = buffer.get();
+  int n = size->width();
+  memcpy(p, &n, sizeof(n));

[sky, 2012/02/16 17:06:44]

use sizeof(int) to match total_size above.

[Peter Beverloo, 2012/02/16 20:38:40]

Done.

+  p += sizeof(n);
+  n = size->height();
+  memcpy(p, &n, sizeof(n));
+  p += sizeof(n);
+  memcpy(p, pixel_data, bm_size);
+
+  Set(kBitmapFormat, std::string(buffer.get(), total_size));
+}
+
+void Clipboard::WriteData(const Clipboard::FormatType& format,
+                          const char* data_data, size_t data_len) {
+  Set(format.ToString(), std::string(data_data, data_len));
+}
+
+bool Clipboard::IsTextAvailableFromAndroid() const {
+  JNIEnv* env = AttachCurrentThread();
+  return env->CallBooleanMethod(clipboard_manager_.obj(), has_text_);
+}
+
+void Clipboard::ValidateInternalClipboard() const {
+  JNIEnv* env = AttachCurrentThread();
+
+  // First collect what text we currently have in our internal clipboard.
+  bool has_internal_text;
+  std::string internal_text;
+
+  g_clipboard_map_lock.Get().Acquire();

[sky, 2012/02/16 17:06:44]

This is fragile. Use autolock with braces around 420 to 428.

[Peter Beverloo, 2012/02/16 20:38:40]

Done.

+  ClipboardMap::const_iterator it = g_clipboard_map->find(kPlainTextFormat);
+  if (it != g_clipboard_map->end()) {
+    has_internal_text = true;
+    internal_text = it->second;
+  } else {
+    has_internal_text = false;
+  }
+  g_clipboard_map_lock.Get().Release();
+
+  if (IsTextAvailableFromAndroid()) {

[sky, 2012/02/16 17:06:44]

What happens if g_clipboard_map gets mutated after this?

[Peter Beverloo, 2012/02/16 20:38:40]

You're right, thanks, that could result in the internal_text being freed up.
An issue here is that ClearInternalClipboard() creates a new lock, while we'd
ideally be in a lock already to avoid the race.
I could call g_clipboard_map->clear() on line 442 and 447 instead and placing an
AutoLock on the whole method, but that'd be sensitive to being overseen if CIC()
ever changes (even though g_clipboard_map is already being used directly in
several other places). Alternatively we could add ClearInternalClipboardNoLock.
Do you have a preference here?

[sky, 2012/02/16 20:46:50]

This is why I preferred simplifying the threading. If the other thread only
needs to read, can't it be passed a copy so we don't need to worry about
locking?

+    // Make sure the text in the Android Clipboard matches what we think it
+    // should be.
+    ScopedJavaLocalRef<jstring> tmp_string(env,
+        static_cast<jstring>(env->CallObjectMethod(
+            env->CallObjectMethod(clipboard_manager_.obj(), get_text_),
+            to_string_)));
+    std::string android_text = ConvertJavaStringToUTF8(tmp_string);
+
+    // If the android text doesn't match what we think it should be, our
+    // internal representation is no longer valid.
+    if (android_text.compare(internal_text))
+      ClearInternalClipboard();
+  } else {
+    // If Android has no text but we have some internal text, our internal
+    // representation is no longer valid.
+    if (has_internal_text)
+      ClearInternalClipboard();
+  }
+}
+
+void Clipboard::Clear() {
+  JNIEnv* env = AttachCurrentThread();
+  env->CallVoidMethod(clipboard_manager_.obj(), set_text_, NULL);
+  ClearInternalClipboard();
+}
+
+void Clipboard::ClearInternalClipboard() const {
+  base::AutoLock lock(g_clipboard_map_lock.Get());
+  g_clipboard_map->clear();
+}
+
+void Clipboard::Set(const std::string& key, const std::string& value) {
+  base::AutoLock lock(g_clipboard_map_lock.Get());
+  (*g_clipboard_map)[key] = value;
+}
+
+}  // namespace ui