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/scoped_java_ref.h"
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.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.
+using base::android::AttachCurrentThread;
+using base::android::CheckException;
+using base::android::ClearException;
+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* const kPlainTextFormat = "text";

[dcheng, 2012/02/01 19:02:04]

I recall that in the past, there was a slight preference for const char[] over
const char* const, but I don't recall why.

[Peter Beverloo, 2012/02/02 12:16:11]

Done.

+const char* const kHTMLFormat = "html";
+const char* const kBitmapFormat = "bitmap";
+const char* const kWebKitSmartPasteFormat = "webkit_smart";
+const char* const kBookmarkFormat = "bookmark";
+const char* const 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()
+    : clipboard_manager_(NULL),
+      set_text_(NULL),
+      has_text_(NULL),
+      get_text_(NULL),
+      to_string_(NULL) {
+  JNIEnv* env = AttachCurrentThread();
+  DCHECK(env);
+
+  // Get the context
+  jobject context = env->NewLocalRef(base::android::GetApplicationContext());
+
+  if (!context) {
+    // Should be during testing only
+    // Get the ActivityThread class
+    ScopedJavaLocalRef<jclass> activity_thread_class(env,
+        env->FindClass("android/app/ActivityThread"));
+    DCHECK(activity_thread_class.obj());
+
+    // Try to get the current activity thread.
+    jmethodID current_activity_method_id =
+        env->GetStaticMethodID(activity_thread_class.obj(),
+                               "currentActivityThread",
+                               "()Landroid/app/ActivityThread;");
+    DCHECK(current_activity_method_id);
+    jobject current_activity =
+        env->CallStaticObjectMethod(activity_thread_class.obj(),
+                                    current_activity_method_id);
+    if (ClearException(env))
+      current_activity = NULL;
+
+    if (!current_activity) {
+      // There is no current activity, create one
+      ScopedJavaLocalRef<jclass> looper_class(env,
+          env->FindClass("android/os/Looper"));
+      jmethodID prepare_method_id = env->GetStaticMethodID(looper_class.obj(),
+          "prepareMainLooper", "()V");
+      env->CallStaticVoidMethod(looper_class.obj(), prepare_method_id);
+      CheckException(env);
+
+      jmethodID system_main_method_id =
+          env->GetStaticMethodID(activity_thread_class.obj(), "systemMain",
+                                 "()Landroid/app/ActivityThread;");
+      DCHECK(system_main_method_id);
+
+      current_activity = env->CallStaticObjectMethod(
+          activity_thread_class.obj(), system_main_method_id);
+      DCHECK(current_activity);
+      CheckException(env);
+    }
+
+    // Get the context
+    jmethodID get_system_context_id =
+        env->GetMethodID(activity_thread_class.obj(),
+                         "getSystemContext", "()Landroid/app/ContextImpl;");
+
+    DCHECK(get_system_context_id);
+    context = env->CallObjectMethod(current_activity,
+                                    get_system_context_id);
+    DCHECK(context);
+
+    env->DeleteLocalRef(current_activity);
+  }
+
+  // Get the context class
+  jclass context_class = env->FindClass("android/content/Context");
+  DCHECK(context_class);
+  // Get the system service method
+  jmethodID get_system_service =
+      env->GetMethodID(context_class, "getSystemService",
+                       "(Ljava/lang/String;)Ljava/lang/Object;");
+  DCHECK(get_system_service);
+  env->DeleteLocalRef(context_class);
+
+  // Retrieve the system service
+  jstring service_name = env->NewStringUTF("clipboard");
+  jobject cm = env->CallObjectMethod(context, get_system_service, service_name);
+  if (ClearException(env))
+    cm = NULL;
+  DCHECK(cm);
+
+  // Make a global reference for our clipboard manager.
+  clipboard_manager_ = env->NewGlobalRef(cm);
+  DCHECK(clipboard_manager_);
+  env->DeleteLocalRef(cm);
+
+  // Retain a few methods we'll keep using
+  jclass clipboard_class = env->FindClass("android/text/ClipboardManager");
+  DCHECK(clipboard_class);
+  set_text_ = env->GetMethodID(clipboard_class, "setText",
+                               "(Ljava/lang/CharSequence;)V");
+  DCHECK(set_text_);
+  has_text_ = env->GetMethodID(clipboard_class, "hasText", "()Z");
+  DCHECK(has_text_);
+  get_text_ = env->GetMethodID(clipboard_class, "getText",
+                               "()Ljava/lang/CharSequence;");
+  DCHECK(get_text_);
+
+  // Will need to call toString as CharSequence is not always a String
+  jclass charsequence_class = env->FindClass("java/lang/CharSequence");
+  DCHECK(charsequence_class);
+  to_string_ = env->GetMethodID(charsequence_class, "toString",
+                                "()Ljava/lang/String;");
+  DCHECK(to_string_);
+  env->DeleteLocalRef(clipboard_class);
+  env->DeleteLocalRef(charsequence_class);
+
+  // Finally cleanup all our local reference so they don't stay around if this
+  // code was never called from Java. (unit test case)
+  env->DeleteLocalRef(service_name);
+  env->DeleteLocalRef(context);
+
+  // Create the object map if we are the first clipboard
+  g_clipboard_map_lock.Get().Acquire();
+  if (!g_clipboard_map)
+    g_clipboard_map = new ClipboardMap;
+  g_clipboard_map_lock.Get().Release();
+}
+
+Clipboard::~Clipboard() {
+  // Delete the clipboard manager global ref
+  if (clipboard_manager_) {
+    JNIEnv* env = AttachCurrentThread();
+    env->DeleteGlobalRef(clipboard_manager_);
+  }
+}
+
+// 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_, has_text_)) {
+    jstring tmp_string =
+        static_cast<jstring>(env->CallObjectMethod(
+            env->CallObjectMethod(clipboard_manager_, get_text_), to_string_));
+    jboolean is_copy = JNI_FALSE;
+    const char* tmp_string_val = env->GetStringUTFChars(tmp_string, &is_copy);
+    jsize len = env->GetStringUTFLength(tmp_string);
+    UTF8ToUTF16(tmp_string_val, len, result);
+    env->ReleaseStringUTFChars(tmp_string, tmp_string_val);
+    env->DeleteLocalRef(static_cast<jobject>(tmp_string));
+  }
+}
+
+void Clipboard::ReadAsciiText(Clipboard::Buffer buffer,
+                              std::string* result) const {
+  JNIEnv* env = AttachCurrentThread();
+
+  result->clear();
+  if (env->CallBooleanMethod(clipboard_manager_, has_text_)) {
+    jstring tmp_string =
+        static_cast<jstring>(env->CallObjectMethod(
+            env->CallObjectMethod(clipboard_manager_, get_text_), to_string_));
+    jboolean is_copy = JNI_FALSE;
+    const char* tmp_string_val = env->GetStringUTFChars(tmp_string, &is_copy);
+    jsize len = env->GetStringUTFLength(tmp_string);
+    *result = std::string(tmp_string_val, len);
+    env->ReleaseStringUTFChars(tmp_string, tmp_string_val);
+    env->DeleteLocalRef(static_cast<jobject>(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();
+
+  g_clipboard_map_lock.Get().Acquire();
+  ClipboardMap::const_iterator it = g_clipboard_map->find(kHTMLFormat);
+  if (it != g_clipboard_map->end())
+    input = it->second;
+  g_clipboard_map_lock.Get().Release();
+
+  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();
+
+  g_clipboard_map_lock.Get().Acquire();
+  ClipboardMap::const_iterator it = g_clipboard_map->find(format.ToString());
+  if (it != g_clipboard_map->end())
+    result->assign(it->second);
+  g_clipboard_map_lock.Get().Release();
+}
+
+// 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);
+  jstring str = env->NewStringUTF(data.c_str());
+  DCHECK(str);
+
+  env->CallVoidMethod(clipboard_manager_, set_text_, str);
+  env->DeleteLocalRef(str);
+
+  // 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, (unsigned char*)&n, sizeof(int));

[dcheng, 2012/02/01 19:02:04]

Are these casts necessary? It may be (slightly) safer to use sizeof(n) as well
in case the size of n ever changes, though I guess it doesn't really matter.

[Peter Beverloo, 2012/02/02 12:16:11]

Done.

+  p += sizeof(int);
+  n = size->height();
+  memcpy(p, (unsigned char*)&n, sizeof(int));
+  p += sizeof(int);
+  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_, 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();
+  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()) {
+    // Make sure the text in the Android Clipboard matches what we think it
+    // should be.
+    jstring tmp_string =
+        static_cast<jstring>(env->CallObjectMethod(
+            env->CallObjectMethod(clipboard_manager_, get_text_), to_string_));
+    jboolean is_copy = JNI_FALSE;
+    const char* tmp_string_val = env->GetStringUTFChars(tmp_string, &is_copy);
+    jsize len = env->GetStringUTFLength(tmp_string);
+
+    std::string android_text(tmp_string_val, len);
+
+    // 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();
+
+    env->ReleaseStringUTFChars(tmp_string, tmp_string_val);
+    env->DeleteLocalRef(static_cast<jobject>(tmp_string));
+  } 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_, 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