Enable copying long text to Chrome and pasting long text from Chrome

ui/base/x/selection_requestor.cc

 // Copyright (c) 2013 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/x/selection_requestor.h"
 
 #include <algorithm>
 #include <X11/Xlib.h>
 
 #include "base/run_loop.h"
 #include "ui/base/x/selection_utils.h"
 #include "ui/base/x/x11_util.h"
 #include "ui/events/platform/platform_event_dispatcher.h"
 #include "ui/events/platform/platform_event_source.h"
 #include "ui/gfx/x/x11_types.h"
 
 namespace ui {
 
 namespace {
 
 const char kChromeSelection[] = "CHROME_SELECTION";
+const char kIncr[] = "INCR";
 
 const char* kAtomsToCache[] = {
   kChromeSelection,
+  kIncr,
   NULL
 };
 
-// The amount of time to wait for a request to complete.
-const int kRequestTimeoutMs = 300;
+// The period of |abort_timer_|. Arbitrary but must be <= than
+// kRequestTimeoutMs.
+const int kTimerPeriodMs = 100;
+
+// The amount of time to wait for a request to complete before aborting it.
+const int kRequestTimeoutMs = 10000;
+
+COMPILE_ASSERT(kTimerPeriodMs <= kRequestTimeoutMs,
+               timer_period_must_be_less_or_equal_to_request_timeout);
+
+// Combines |data| into a single RefCountedMemory object.
+scoped_refptr<base::RefCountedMemory> CombineRefCountedMemory(
+    const std::vector<scoped_refptr<base::RefCountedMemory> >& data) {
+  if (data.size() == 1u)
+    return data[0];
+
+  size_t length = 0;
+  for (size_t i = 0; i < data.size(); ++i)
+    length += data[i]->size();
+  std::vector<unsigned char> combined_data;
+  combined_data.reserve(length);
+
+  for (size_t i = 0; i < data.size(); ++i) {
+    combined_data.insert(combined_data.end(),
+                         data[i]->front(),
+                         data[i]->front() + data[i]->size());
+  }
+  return scoped_refptr<base::RefCountedMemory>(
+      base::RefCountedBytes::TakeVector(&combined_data));
+}
 
 }  // namespace
 
 SelectionRequestor::SelectionRequestor(XDisplay* x_display,
                                        XID x_window,
                                        PlatformEventDispatcher* dispatcher)
     : x_display_(x_display),
       x_window_(x_window),
       x_property_(None),
       dispatcher_(dispatcher),
@@ skipping 26 matching lines @@
       request_it - requests_.begin()) {
     --current_request_index_;
   }
   requests_.erase(request_it);
 
   if (requests_.empty())
     abort_timer_.Stop();
 
   if (request.success) {
     if (out_data)
-      *out_data = request.out_data;
+      *out_data = CombineRefCountedMemory(request.out_data);
     if (out_data_items)
       *out_data_items = request.out_data_items;
     if (out_type)
       *out_type = request.out_type;
   }
   return request.success;
 }
 
 void SelectionRequestor::PerformBlockingConvertSelectionWithParameter(
     XAtom selection,
@@ skipping 29 matching lines @@
   if (!request ||
       request->completed ||
       request->selection != event.xselection.selection ||
       request->target != event.xselection.target) {
     // ICCCM requires us to delete the property passed into SelectionNotify.
     if (event_property != None)
       XDeleteProperty(x_display_, x_window_, event_property);
     return;
   }
 
-  request->success = false;
+  bool success = false;
   if (event_property == x_property_) {
-    request->success = ui::GetRawBytesOfProperty(x_window_,
-                                                 x_property_,
-                                                 &request->out_data,
-                                                 &request->out_data_items,
-                                                 &request->out_type);
+    scoped_refptr<base::RefCountedMemory> out_data;
+    success = ui::GetRawBytesOfProperty(x_window_,
+                                        x_property_,
+                                        &out_data,
+                                        &request->out_data_items,
+                                        &request->out_type);
+    if (success)
+      request->out_data.push_back(out_data);
   }
   if (event_property != None)
     XDeleteProperty(x_display_, x_window_, event_property);
 
-  CompleteRequest(current_request_index_);
+  if (request->out_type == atom_cache_.GetAtom(kIncr)) {

[pkotwicz, 2014/07/26 20:09:53]

I now clear request->out_data and request->out_data_items here

+    request->data_sent_incrementally = true;
+    request->out_data.clear();
+    request->out_data_items = 0u;
+    request->out_type = None;
+    request->timeout = base::TimeTicks::Now() +
+        base::TimeDelta::FromMilliseconds(kRequestTimeoutMs);
+  } else {
+    CompleteRequest(current_request_index_, success);
+  }
+}
+
+bool SelectionRequestor::CanDispatchPropertyEvent(const XEvent& event) {
+  return event.xproperty.window == x_window_ &&
+      event.xproperty.atom == x_property_ &&
+      event.xproperty.state == PropertyNewValue;
+}
+
+void SelectionRequestor::OnPropertyEvent(const XEvent& event) {
+  Request* request = GetCurrentRequest();
+  if (!request || !request->data_sent_incrementally)

[pkotwicz, 2014/07/26 20:09:53]

I now check request->data_sent_incrementally
This causes us to early return if we have not yet received the SelectionNotify
event.

+    return;
+
+  scoped_refptr<base::RefCountedMemory> out_data;
+  size_t out_data_items = 0u;
+  Atom out_type = None;
+  bool success = ui::GetRawBytesOfProperty(x_window_,
+                                           x_property_,
+                                           &out_data,
+                                           &out_data_items,
+                                           &out_type);
+  if (!success) {
+    CompleteRequest(current_request_index_, false);
+    return;
+  }
+
+  if (request->out_type != None && request->out_type != out_type) {
+    CompleteRequest(current_request_index_, false);
+    return;
+  }
+
+  request->out_data.push_back(out_data);
+  request->out_data_items += out_data_items;
+  request->out_type = out_type;
+
+  // Delete the property to tell the selection owner to send the next chunk.
+  XDeleteProperty(x_display_, x_window_, x_property_);
+
+  request->timeout = base::TimeTicks::Now() +
+      base::TimeDelta::FromMilliseconds(kRequestTimeoutMs);
+
+  if (out_data->size() == 0u)
+    CompleteRequest(current_request_index_, true);
 }
 
 void SelectionRequestor::AbortStaleRequests() {
   base::TimeTicks now = base::TimeTicks::Now();
-  for (size_t i = current_request_index_;
-       i < requests_.size() && requests_[i]->timeout <= now;
-       ++i) {
-    CompleteRequest(i);
+  for (size_t i = current_request_index_; i < requests_.size(); ++i) {
+    if (requests_[i]->timeout <= now)
+      CompleteRequest(i, false);
   }
 }
 
-void SelectionRequestor::CompleteRequest(size_t index) {
+void SelectionRequestor::CompleteRequest(size_t index, bool success) {
    if (index >= requests_.size())
      return;
 
   Request* request = requests_[index];
   if (request->completed)
     return;
+  request->success = success;
   request->completed = true;
 
   if (index == current_request_index_) {
-    ++current_request_index_;
+    while (GetCurrentRequest() && GetCurrentRequest()->completed)

[pkotwicz, 2014/07/26 20:09:53]

It is now possible for the timeouts not to be in increasing order from the
beginning to the end of the array because we update the timeout in
SelectionRequestor::OnPropertyEvent()

I now correctly handle aborting a request which is not the current request.

Being able to abort a request which is not the current request is confusing.
However, setting the timeout upon calling
SelectionRequestor::PerformBlockingConvertSelection() puts an upper bound on the
amount of time that the UI thread can be blocked due to queued clipboard
requests.

+      ++current_request_index_;
     ConvertSelectionForCurrentRequest();
   }
 
   if (!request->quit_closure.is_null())
     request->quit_closure.Run();
 }
 
 void SelectionRequestor::ConvertSelectionForCurrentRequest() {
   Request* request = GetCurrentRequest();
   if (request) {
     XConvertSelection(x_display_,
                       request->selection,
                       request->target,
                       x_property_,
                       x_window_,
                       CurrentTime);
   }
 }
 
 void SelectionRequestor::BlockTillSelectionNotifyForRequest(Request* request) {
   if (PlatformEventSource::GetInstance()) {
     if (!abort_timer_.IsRunning()) {
       abort_timer_.Start(FROM_HERE,
-                         base::TimeDelta::FromMilliseconds(kRequestTimeoutMs),
+                         base::TimeDelta::FromMilliseconds(kTimerPeriodMs),
                          this,
                          &SelectionRequestor::AbortStaleRequests);
     }
 
     base::MessageLoop::ScopedNestableTaskAllower allow_nested(
         base::MessageLoopForUI::current());
     base::RunLoop run_loop;
     request->quit_closure = run_loop.QuitClosure();
     run_loop.Run();
 
@@ skipping 18 matching lines @@
 SelectionRequestor::Request* SelectionRequestor::GetCurrentRequest() {
   return current_request_index_ == requests_.size() ?
       NULL : requests_[current_request_index_];
 }
 
 SelectionRequestor::Request::Request(XAtom selection,
                                      XAtom target,
                                      base::TimeTicks timeout)
     : selection(selection),
       target(target),
+      data_sent_incrementally(false),
       out_data_items(0u),
       out_type(None),
       success(false),
       timeout(timeout),
       completed(false) {
 }
 
 SelectionRequestor::Request::~Request() {
 }
 
 }  // namespace ui