Implement X11 clipboard for ozone x11

Supports only CLIPBOARD selection and not PRIMARY (for now) since
ozone only supports a single clipboard.

Regisers to receive XFixesSetSelectionOwnerNotify events and
prefetches and caches supported mime types whenever ownership
changes.  Also prefetches clipboard contents as 'text/plain'
since that is the most likely type to be requested.  If clients
request a different type, it will be fetched at the time of
requesting.

Converts text/plain[;charset=utf-8] <=> [UTF8_]STRING to
allow interoperability with other applications which do not
use the same mime types as chrome.

This code can be patched into linux-chromeos (chrome os running
on a linux desktop) by modifying the build file:
 sed -i s/is_desktop_linux/is_linux/ ui/base/clipboard/BUILD.gn

Bug: 985187
Change-Id: I4277f903ab8f11e0f5ad14d095eb099cf775f771
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1736619Reviewed-by: kylechar <kylechar@chromium.org>
Commit-Queue: Joel Hockey <joelhockey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#691892}

ui/ozone/platform/x11/BUILD.gn

@@ -20,8 +20,8 @@ source_set("x11") {
     "gl_surface_glx_ozone.h",
     "ozone_platform_x11.cc",
     "ozone_platform_x11.h",
-    "x11_clipboard.cc",
-    "x11_clipboard.h",
+    "x11_clipboard_ozone.cc",
+    "x11_clipboard_ozone.h",
     "x11_cursor_factory_ozone.cc",
     "x11_cursor_factory_ozone.h",
     "x11_cursor_ozone.cc",
@@ -41,6 +41,7 @@ source_set("x11") {
     "//gpu/vulkan:buildflags",
     "//skia",
     "//ui/base",
+    "//ui/base/clipboard:clipboard_types",
     "//ui/base/ime",
     "//ui/base/x",
     "//ui/display/fake",

ui/ozone/platform/x11/ozone_platform_x11.cc

@@ -15,7 +15,7 @@
 #include "ui/events/platform/x11/x11_event_source_default.h"
 #include "ui/gfx/x/x11.h"
 #include "ui/ozone/common/stub_overlay_manager.h"
-#include "ui/ozone/platform/x11/x11_clipboard.h"
+#include "ui/ozone/platform/x11/x11_clipboard_ozone.h"
 #include "ui/ozone/platform/x11/x11_cursor_factory_ozone.h"
 #include "ui/ozone/platform/x11/x11_screen_ozone.h"
 #include "ui/ozone/platform/x11/x11_surface_factory.h"
@@ -126,7 +126,7 @@ class OzonePlatformX11 : public OzonePlatform {
     window_manager_ = std::make_unique<X11WindowManagerOzone>();
     overlay_manager_ = std::make_unique<StubOverlayManager>();
     input_controller_ = CreateStubInputController();
-    clipboard_ = std::make_unique<X11Clipboard>();
+    clipboard_ = std::make_unique<X11ClipboardOzone>();
     cursor_factory_ozone_ = std::make_unique<X11CursorFactoryOzone>();
     gpu_platform_support_host_.reset(CreateStubGpuPlatformSupportHost());
 
@@ -179,7 +179,7 @@ class OzonePlatformX11 : public OzonePlatform {
   std::unique_ptr<X11WindowManagerOzone> window_manager_;
   std::unique_ptr<OverlayManagerOzone> overlay_manager_;
   std::unique_ptr<InputController> input_controller_;
-  std::unique_ptr<X11Clipboard> clipboard_;
+  std::unique_ptr<X11ClipboardOzone> clipboard_;
   std::unique_ptr<X11CursorFactoryOzone> cursor_factory_ozone_;
   std::unique_ptr<GpuPlatformSupportHost> gpu_platform_support_host_;
 

ui/ozone/platform/x11/x11_clipboard.cc

-// 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.
-
-#include <utility>
-
-#include "ui/ozone/platform/x11/x11_clipboard.h"
-
-namespace ui {
-
-X11Clipboard::X11Clipboard() = default;
-X11Clipboard::~X11Clipboard() = default;
-
-void X11Clipboard::OfferClipboardData(
-    const PlatformClipboard::DataMap& data_map,
-    PlatformClipboard::OfferDataClosure callback) {
-  // TODO(crbug.com/973295): Implement X11Clipboard
-  NOTIMPLEMENTED_LOG_ONCE();
-  std::move(callback).Run();
-}
-
-void X11Clipboard::RequestClipboardData(
-    const std::string& mime_type,
-    PlatformClipboard::DataMap* data_map,
-    PlatformClipboard::RequestDataClosure callback) {
-  // TODO(crbug.com/973295): Implement X11Clipboard
-  NOTIMPLEMENTED_LOG_ONCE();
-  std::move(callback).Run({});
-}
-
-void X11Clipboard::GetAvailableMimeTypes(
-    PlatformClipboard::GetMimeTypesClosure callback) {
-  // TODO(crbug.com/973295): Implement X11Clipboard
-  NOTIMPLEMENTED_LOG_ONCE();
-  std::move(callback).Run({});
-}
-
-bool X11Clipboard::IsSelectionOwner() {
-  // TODO(crbug.com/973295): Implement X11Clipboard
-  NOTIMPLEMENTED_LOG_ONCE();
-  return false;
-}
-
-void X11Clipboard::SetSequenceNumberUpdateCb(
-    PlatformClipboard::SequenceNumberUpdateCb cb) {
-  DCHECK(update_sequence_cb_.is_null())
-      << " The callback can be installed only once.";
-  update_sequence_cb_ = std::move(cb);
-}
-
-void X11Clipboard::UpdateSequenceNumber() {
-  if (!update_sequence_cb_.is_null())
-    update_sequence_cb_.Run();
-}
-
-}  // namespace ui

ui/ozone/platform/x11/x11_clipboard.h

-// 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.
-
-#ifndef UI_OZONE_PLATFORM_X11_X11_CLIPBOARD_H_
-#define UI_OZONE_PLATFORM_X11_X11_CLIPBOARD_H_
-
-#include <string>
-
-#include "base/callback.h"
-#include "ui/ozone/public/platform_clipboard.h"
-
-namespace ui {
-
-// Handles clipboard operations for X11 Platform
-class X11Clipboard : public PlatformClipboard {
- public:
-  X11Clipboard();
-  ~X11Clipboard() override;
-
-  // PlatformClipboard.
-  void OfferClipboardData(
-      const PlatformClipboard::DataMap& data_map,
-      PlatformClipboard::OfferDataClosure callback) override;
-  void RequestClipboardData(
-      const std::string& mime_type,
-      PlatformClipboard::DataMap* data_map,
-      PlatformClipboard::RequestDataClosure callback) override;
-  void GetAvailableMimeTypes(
-      PlatformClipboard::GetMimeTypesClosure callback) override;
-  bool IsSelectionOwner() override;
-  void SetSequenceNumberUpdateCb(
-      PlatformClipboard::SequenceNumberUpdateCb cb) override;
-
- private:
-  void UpdateSequenceNumber();
-
-  // Notifies whenever clipboard sequence number is changed.
-  PlatformClipboard::SequenceNumberUpdateCb update_sequence_cb_;
-
-  DISALLOW_COPY_AND_ASSIGN(X11Clipboard);
-};
-
-}  // namespace ui
-
-#endif  // UI_OZONE_PLATFORM_X11_X11_CLIPBOARD_H_

ui/ozone/platform/x11/x11_clipboard_ozone.h

+// 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.
+
+#ifndef UI_OZONE_PLATFORM_X11_X11_CLIPBOARD_OZONE_H_
+#define UI_OZONE_PLATFORM_X11_X11_CLIPBOARD_OZONE_H_
+
+#include <string>
+#include <vector>
+
+#include "base/callback.h"
+#include "ui/events/platform/x11/x11_event_source.h"
+#include "ui/gfx/x/x11.h"
+#include "ui/gfx/x/x11_types.h"
+#include "ui/ozone/public/platform_clipboard.h"
+
+namespace ui {
+
+// Handles clipboard operations for X11.
+// Registers to receive standard X11 events, as well as
+// XFixesSetSelectionOwnerNotify.  When the remote owner changes, TARGETS and
+// text/plain are preemptively fetched.  They can then be provided immediately
+// to GetAvailableMimeTypes, and RequestClipboardData when mime_type is
+// text/plain.  Otherwise GetAvailableMimeTypes and RequestClipboardData call
+// the appropriate X11 functions and invoke callbacks when the associated events
+// are received.
+class X11ClipboardOzone : public PlatformClipboard, public XEventDispatcher {
+ public:
+  X11ClipboardOzone();
+  ~X11ClipboardOzone() override;
+
+  // PlatformClipboard:
+  void OfferClipboardData(
+      const PlatformClipboard::DataMap& data_map,
+      PlatformClipboard::OfferDataClosure callback) override;
+  void RequestClipboardData(
+      const std::string& mime_type,
+      PlatformClipboard::DataMap* data_map,
+      PlatformClipboard::RequestDataClosure callback) override;
+  void GetAvailableMimeTypes(
+      PlatformClipboard::GetMimeTypesClosure callback) override;
+  bool IsSelectionOwner() override;
+  void SetSequenceNumberUpdateCb(
+      PlatformClipboard::SequenceNumberUpdateCb cb) override;
+
+ private:
+  // XEventDispatcher:
+  bool DispatchXEvent(XEvent* xev) override;
+
+  bool OnSelectionRequest(XEvent* xev);
+  bool OnSelectionNotify(XEvent* xev);
+  bool OnSetSelectionOwnerNotify(XEvent* xev);
+
+  // Queries the current clipboard owner for what mime types are available by
+  // sending XConvertSelection with target=TARGETS.  After sending this, we
+  // will receive a SelectionNotify event with xselection.target=TARGETS which
+  // is processed in |OnSelectionNotify|.
+  void QueryTargets();
+
+  // Reads the contents of the remote clipboard by sending XConvertSelection
+  // with target=<mime-type>.  After sending this, we will receive a
+  // SelectionNotify event with xselection.target=<mime-type> which is processed
+  // in |OnSelectionNotify|.
+  void ReadRemoteClipboard();
+
+  // Notifies whenever clipboard sequence number is changed.
+  PlatformClipboard::SequenceNumberUpdateCb update_sequence_cb_;
+
+  // DataMap we keep from |OfferClipboardData| to service remote requests for
+  // the clipboard.
+  PlatformClipboard::DataMap offer_data_map_;
+
+  // DataMap from |RequestClipboardData| that we write remote clipboard contents
+  // to before calling the completion callback.
+  PlatformClipboard::DataMap* request_data_map_ = nullptr;
+
+  // Mime types supported by remote clipboard.
+  std::vector<std::string> mime_types_;
+
+  // Data most recently read from remote clipboard.
+  std::vector<unsigned char> data_;
+
+  // Mime type of most recently read data from remote clipboard.
+  std::string data_mime_type_;
+
+  // If XFixes is unavailable, this clipboard window will not register to
+  // receive events and no processing will take place.
+  // TODO(joelhockey): Make clipboard work without xfixes.
+  bool using_xfixes_ = false;
+
+  // The event base returned by XFixesQueryExtension().
+  int xfixes_event_base_;
+
+  // Callbacks are stored when we haven't already prefetched the remote
+  // clipboard.
+  PlatformClipboard::GetMimeTypesClosure get_available_mime_types_callback_;
+  PlatformClipboard::RequestDataClosure request_clipboard_data_callback_;
+
+  // Local cache of atoms.
+  const XAtom atom_clipboard_;
+  const XAtom atom_targets_;
+  const XAtom atom_timestamp_;
+
+  // The property on |x_window_| which will receive remote clipboard contents.
+  const XAtom x_property_;
+
+  // Our X11 state.
+  Display* const x_display_;
+
+  // Input-only window used as a selection owner.
+  const XID x_window_;
+
+  // The time that this instance took ownership of the clipboard.
+  Time acquired_selection_timestamp_;
+
+  DISALLOW_COPY_AND_ASSIGN(X11ClipboardOzone);
+};
+
+}  // namespace ui
+
+#endif  // UI_OZONE_PLATFORM_X11_X11_CLIPBOARD_OZONE_H_