From 5f8de423f190bbb79a62f804151bc24824fa32d8 Mon Sep 17 00:00:00 2001 From: "Matt A. Tobin" Date: Fri, 2 Feb 2018 04:16:08 -0500 Subject: Add m-esr52 at 52.6.0 --- dom/events/WheelHandlingHelper.h | 182 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 182 insertions(+) create mode 100644 dom/events/WheelHandlingHelper.h (limited to 'dom/events/WheelHandlingHelper.h') diff --git a/dom/events/WheelHandlingHelper.h b/dom/events/WheelHandlingHelper.h new file mode 100644 index 000000000..b88aa23b2 --- /dev/null +++ b/dom/events/WheelHandlingHelper.h @@ -0,0 +1,182 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef mozilla_WheelHandlingHelper_h_ +#define mozilla_WheelHandlingHelper_h_ + +#include "mozilla/Attributes.h" +#include "mozilla/EventForwards.h" +#include "nsCoord.h" +#include "nsIFrame.h" +#include "nsPoint.h" + +class nsIScrollableFrame; +class nsITimer; + +namespace mozilla { + +class EventStateManager; + +/** + * DeltaValues stores two delta values which are along X and Y axis. This is + * useful for arguments and results of some methods. + */ + +struct DeltaValues +{ + DeltaValues() + : deltaX(0.0) + , deltaY(0.0) + { + } + + DeltaValues(double aDeltaX, double aDeltaY) + : deltaX(aDeltaX) + , deltaY(aDeltaY) + { + } + + explicit DeltaValues(WidgetWheelEvent* aEvent); + + double deltaX; + double deltaY; +}; + +/** + * WheelHandlingUtils provides some static methods which are useful at handling + * wheel events. + */ + +class WheelHandlingUtils +{ +public: + /** + * Returns true if aFrame is a scrollable frame and it can be scrolled to + * either aDirectionX or aDirectionY along each axis. Or if aFrame is a + * plugin frame (in this case, aDirectionX and aDirectionY are ignored). + * Otherwise, false. + */ + static bool CanScrollOn(nsIFrame* aFrame, + double aDirectionX, double aDirectionY); + /** + * Returns true if the scrollable frame can be scrolled to either aDirectionX + * or aDirectionY along each axis. Otherwise, false. + */ + static bool CanScrollOn(nsIScrollableFrame* aScrollFrame, + double aDirectionX, double aDirectionY); + +private: + static bool CanScrollInRange(nscoord aMin, nscoord aValue, nscoord aMax, + double aDirection); +}; + +/** + * ScrollbarsForWheel manages scrollbars state during wheel operation. + * E.g., on some platforms, scrollbars should show only while user attempts to + * scroll. At that time, scrollbars which may be possible to scroll by + * operation of wheel at the point should show temporarily. + */ + +class ScrollbarsForWheel +{ +public: + static void PrepareToScrollText(EventStateManager* aESM, + nsIFrame* aTargetFrame, + WidgetWheelEvent* aEvent); + static void SetActiveScrollTarget(nsIScrollableFrame* aScrollTarget); + // Hide all scrollbars (both mActiveOwner's and mActivatedScrollTargets') + static void MayInactivate(); + static void Inactivate(); + static bool IsActive(); + static void OwnWheelTransaction(bool aOwn); + +protected: + static const size_t kNumberOfTargets = 4; + static const DeltaValues directions[kNumberOfTargets]; + static nsWeakFrame sActiveOwner; + static nsWeakFrame sActivatedScrollTargets[kNumberOfTargets]; + static bool sHadWheelStart; + static bool sOwnWheelTransaction; + + + /** + * These two methods are called upon eWheelOperationStart/eWheelOperationEnd + * events to show/hide the right scrollbars. + */ + static void TemporarilyActivateAllPossibleScrollTargets( + EventStateManager* aESM, + nsIFrame* aTargetFrame, + WidgetWheelEvent* aEvent); + static void DeactivateAllTemporarilyActivatedScrollTargets(); +}; + +/** + * WheelTransaction manages a series of wheel events as a transaction. + * While in a transaction, every wheel event should scroll the same scrollable + * element even if a different scrollable element is under the mouse cursor. + * + * Additionally, this class also manages wheel scroll speed acceleration. + */ + +class WheelTransaction +{ +public: + static nsIFrame* GetTargetFrame() { return sTargetFrame; } + static void EndTransaction(); + /** + * WillHandleDefaultAction() is called before handling aWheelEvent on + * aTargetFrame. + * + * @return false if the caller cannot continue to handle the default + * action. Otherwise, true. + */ + static bool WillHandleDefaultAction(WidgetWheelEvent* aWheelEvent, + nsWeakFrame& aTargetWeakFrame); + static bool WillHandleDefaultAction(WidgetWheelEvent* aWheelEvent, + nsIFrame* aTargetFrame) + { + nsWeakFrame targetWeakFrame(aTargetFrame); + return WillHandleDefaultAction(aWheelEvent, targetWeakFrame); + } + static void OnEvent(WidgetEvent* aEvent); + static void Shutdown(); + static uint32_t GetTimeoutTime(); + + static void OwnScrollbars(bool aOwn); + + static DeltaValues AccelerateWheelDelta(WidgetWheelEvent* aEvent, + bool aAllowScrollSpeedOverride); + +protected: + static void BeginTransaction(nsIFrame* aTargetFrame, + WidgetWheelEvent* aEvent); + // Be careful, UpdateTransaction may fire a DOM event, therefore, the target + // frame might be destroyed in the event handler. + static bool UpdateTransaction(WidgetWheelEvent* aEvent); + static void MayEndTransaction(); + + static nsIntPoint GetScreenPoint(WidgetGUIEvent* aEvent); + static void OnFailToScrollTarget(); + static void OnTimeout(nsITimer* aTimer, void* aClosure); + static void SetTimeout(); + static uint32_t GetIgnoreMoveDelayTime(); + static int32_t GetAccelerationStart(); + static int32_t GetAccelerationFactor(); + static DeltaValues OverrideSystemScrollSpeed(WidgetWheelEvent* aEvent); + static double ComputeAcceleratedWheelDelta(double aDelta, int32_t aFactor); + static bool OutOfTime(uint32_t aBaseTime, uint32_t aThreshold); + + static nsWeakFrame sTargetFrame; + static uint32_t sTime; // in milliseconds + static uint32_t sMouseMoved; // in milliseconds + static nsITimer* sTimer; + static int32_t sScrollSeriesCounter; + static bool sOwnScrollbars; +}; + +} // namespace mozilla + +#endif // mozilla_WheelHandlingHelper_h_ -- cgit v1.2.3