widget/gtk/AsyncGtkClipboardRequest.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_AsyncGtkClipboardRequest_h
   8 #define mozilla_AsyncGtkClipboardRequest_h
   9
  10 #include "nsClipboard.h"
  11
  12 namespace mozilla {
  13
  14 // An asynchronous clipboard request that we wait for synchronously by
  15 // spinning the event loop.
  16 class MOZ_STACK_CLASS AsyncGtkClipboardRequest {
  17   // Heap-allocated object that we give GTK as a callback.
  18   struct Request {
  19     explicit Request(ClipboardDataType aDataType) : mDataType(aDataType) {}
  20
  21     void Complete(const void*);
  22
  23     const ClipboardDataType mDataType;
  24     Maybe<ClipboardData> mData;
  25     bool mTimedOut = false;
  26   };
  27
  28   UniquePtr<Request> mRequest;
  29
  30   static void OnDataReceived(GtkClipboard*, GtkSelectionData*, gpointer);
  31   static void OnTextReceived(GtkClipboard*, const gchar*, gpointer);
  32
  33  public:
  34   // Launch a request for a particular GTK clipboard. The current status of the
  35   // request can be observed by calling HasCompleted() and TakeResult().
  36   AsyncGtkClipboardRequest(ClipboardDataType, int32_t aWhichClipboard,
  37                            const char* aMimeType = nullptr);
  38
  39   // Returns whether the request has been answered already.
  40   bool HasCompleted() const { return mRequest->mData.isSome(); }
  41
  42   // Takes the result from the current request if completed, or a
  43   // default-constructed data otherwise. The destructor will take care of
  44   // flagging the request as timed out in that case.
  45   ClipboardData TakeResult() {
  46     if (!HasCompleted()) {
  47       return {};
  48     }
  49     auto request = std::move(mRequest);
  50     return request->mData.extract();
  51   }
  52
  53   // If completed, frees the request if needed. Otherwise, marks it as a timed
  54   // out request so that when it completes the Request object is properly
  55   // freed.
  56   ~AsyncGtkClipboardRequest();
  57 };
  58
  59 };  // namespace mozilla
  60
  61 #endif