src/ui/base/x/selection_requestor.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ui/base/x/selection_requestor.h"
   6
   7 #include "base/message_loop/message_pump_x11.h"
   8 #include "base/run_loop.h"
   9 #include "ui/base/x/selection_utils.h"
  10 #include "ui/base/x/x11_util.h"
  11
  12 namespace ui {
  13
  14 namespace {
  15
  16 const char kChromeSelection[] = "CHROME_SELECTION";
  17
  18 const char* kAtomsToCache[] = {
  19   kChromeSelection,
  20   NULL
  21 };
  22
  23 }  // namespace
  24
  25 SelectionRequestor::SelectionRequestor(Display* x_display,
  26                                        Window x_window,
  27                                        Atom selection_name)
  28     : x_display_(x_display),
  29       x_window_(x_window),
  30       selection_name_(selection_name),
  31       atom_cache_(x_display_, kAtomsToCache) {
  32 }
  33
  34 SelectionRequestor::~SelectionRequestor() {}
  35
  36 bool SelectionRequestor::PerformBlockingConvertSelection(
  37     Atom target,
  38     scoped_refptr<base::RefCountedMemory>* out_data,
  39     size_t* out_data_bytes,
  40     size_t* out_data_items,
  41     Atom* out_type) {
  42   // The name of the property we're asking to be set on |x_window_|.
  43   Atom property_to_set = atom_cache_.GetAtom(kChromeSelection);
  44
  45   XConvertSelection(x_display_,
  46                     selection_name_,
  47                     target,
  48                     property_to_set,
  49                     x_window_,
  50                     CurrentTime);
  51
  52   // Now that we've thrown our message off to the X11 server, we block waiting
  53   // for a response.
  54   base::MessageLoopForUI* loop = base::MessageLoopForUI::current();
  55   base::MessageLoop::ScopedNestableTaskAllower allow_nested(loop);
  56   base::RunLoop run_loop;
  57
  58   // Stop waiting for a response after a certain amount of time.
  59   const int kMaxWaitTimeForClipboardResponse = 300;
  60   loop->PostDelayedTask(
  61       FROM_HERE,
  62       run_loop.QuitClosure(),
  63       base::TimeDelta::FromMilliseconds(kMaxWaitTimeForClipboardResponse));
  64
  65   PendingRequest pending_request(target, run_loop.QuitClosure());
  66   pending_requests_.push_back(&pending_request);
  67   run_loop.Run();
  68   DCHECK(!pending_requests_.empty());
  69   DCHECK_EQ(&pending_request, pending_requests_.back());
  70   pending_requests_.pop_back();
  71
  72   if (pending_request.returned_property != property_to_set)
  73     return false;
  74
  75   return ui::GetRawBytesOfProperty(x_window_, pending_request.returned_property,
  76                                    out_data, out_data_bytes, out_data_items,
  77                                    out_type);
  78 }
  79
  80 SelectionData SelectionRequestor::RequestAndWaitForTypes(
  81     const std::vector< ::Atom>& types) {
  82   for (std::vector< ::Atom>::const_iterator it = types.begin();
  83        it != types.end(); ++it) {
  84     scoped_refptr<base::RefCountedMemory> data;
  85     size_t data_bytes = 0;
  86     ::Atom type = None;
  87     if (PerformBlockingConvertSelection(*it,
  88                                         &data,
  89                                         &data_bytes,
  90                                         NULL,
  91                                         &type) &&
  92         type == *it) {
  93       return SelectionData(type, data);
  94     }
  95   }
  96
  97   return SelectionData();
  98 }
  99
 100 void SelectionRequestor::OnSelectionNotify(const XSelectionEvent& event) {
 101   // Find the PendingRequest for the corresponding XConvertSelection call. If
 102   // there are multiple pending requests on the same target, satisfy them in
 103   // FIFO order.
 104   PendingRequest* request_notified = NULL;
 105   if (selection_name_ == event.selection) {
 106     for (std::list<PendingRequest*>::iterator iter = pending_requests_.begin();
 107          iter != pending_requests_.end(); ++iter) {
 108       PendingRequest* request = *iter;
 109       if (request->returned)
 110         continue;
 111       if (request->target != event.target)
 112         continue;
 113       request_notified = request;
 114       break;
 115     }
 116   }
 117
 118   // This event doesn't correspond to any XConvertSelection calls that we
 119   // issued in PerformBlockingConvertSelection. This shouldn't happen, but any
 120   // client can send any message, so it can happen.
 121   if (!request_notified)
 122     return;
 123
 124   request_notified->returned_property = event.property;
 125   request_notified->returned = true;
 126   request_notified->quit_closure.Run();
 127 }
 128
 129 SelectionRequestor::PendingRequest::PendingRequest(Atom target,
 130                                                    base::Closure quit_closure)
 131     : target(target),
 132       quit_closure(quit_closure),
 133       returned_property(None),
 134       returned(false) {
 135 }
 136
 137 SelectionRequestor::PendingRequest::~PendingRequest() {
 138 }
 139
 140 }  // namespace ui