DragTracker.h (1101B)
1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim: set ts=8 sts=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_layers_DragTracker_h 8 #define mozilla_layers_DragTracker_h 9 10 #include "mozilla/EventForwards.h" 11 #include "mozilla/Maybe.h" 12 13 namespace mozilla { 14 15 class MouseInput; 16 17 namespace layers { 18 19 // DragTracker simply tracks a sequence of mouse inputs and allows us to tell 20 // if we are in a drag or not (i.e. the left mouse button went down and hasn't 21 // gone up yet). 22 class DragTracker { 23 public: 24 DragTracker(); 25 static bool StartsDrag(const MouseInput& aInput); 26 static bool EndsDrag(const MouseInput& aInput); 27 void Update(const MouseInput& aInput); 28 bool InDrag() const; 29 bool IsOnScrollbar(bool aOnScrollbar); 30 31 private: 32 Maybe<bool> mOnScrollbar; 33 bool mInDrag; 34 }; 35 36 } // namespace layers 37 } // namespace mozilla 38 39 #endif /* mozilla_layers_DragTracker_h */