Source/WebCore/page/AutoscrollController.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "config.h"
 #include "AutoscrollController.h"

 #include "EventHandler.h"
 #include "Frame.h"
 #include "FrameView.h"
 #include "HitTestResult.h"
 #include "Page.h"
 #include "RenderBox.h"
 #include "RenderView.h"
 #include "ScrollView.h"
 #include "Settings.h"

 namespace WebCore {

 // Delay time in second for start autoscroll if pointer is in border edge of scrollable element.
 static const Seconds autoscrollDelay { 200_ms };

 // When the autoscroll or the panScroll is triggered when do the scroll every 50ms to make it smooth.
 static const Seconds autoscrollInterval { 50_ms };

 #if ENABLE(PAN_SCROLLING)
 static Frame* getMainFrame(Frame* frame)
 {
     Page* page = frame->page();
     return page ? &page->mainFrame() : 0;
 }
 #endif

 AutoscrollController::AutoscrollController()
     : m_autoscrollTimer(*this, &AutoscrollController::autoscrollTimerFired)
 {
 }

 RenderBox* AutoscrollController::autoscrollRenderer() const
 {
     return m_autoscrollRenderer.get();
 }

 bool AutoscrollController::autoscrollInProgress() const
 {
     return m_autoscrollType == AutoscrollForSelection;
 }

 void AutoscrollController::startAutoscrollForSelection(RenderObject* renderer)
 {
     // We don't want to trigger the autoscroll or the panScroll if it's already active
     if (m_autoscrollTimer.isActive())
         return;
     auto* scrollable = RenderBox::findAutoscrollable(renderer);
     if (!scrollable)
         return;
     m_autoscrollType = AutoscrollForSelection;
     m_autoscrollRenderer = WeakPtr { *scrollable };
     startAutoscrollTimer();
 }

 void AutoscrollController::stopAutoscrollTimer(bool rendererIsBeingDestroyed)
 {
     auto scrollable = m_autoscrollRenderer;

     m_autoscrollTimer.stop();
     m_autoscrollRenderer = nullptr;

     if (!scrollable)
         return;

     auto* frame = scrollable->document().frame();
     if (autoscrollInProgress() && frame && frame->eventHandler().mouseDownWasInSubframe()) {
         if (auto subframe = frame->eventHandler().subframeForTargetNode(frame->eventHandler().mousePressNode()))
             subframe->eventHandler().stopAutoscrollTimer(rendererIsBeingDestroyed);
         return;
     }

     if (!rendererIsBeingDestroyed)
         scrollable->stopAutoscroll();

 #if ENABLE(PAN_SCROLLING)
     if (panScrollInProgress()) {
         FrameView& frameView = scrollable->view().frameView();
         frameView.removePanScrollIcon();
         frameView.setCursor(pointerCursor());
     }
 #endif

     m_autoscrollType = NoAutoscroll;

 #if ENABLE(PAN_SCROLLING)
     // If we're not in the top frame we notify it that we are not doing a panScroll any more.
     if (frame && !frame->isMainFrame())
         frame->mainFrame().eventHandler().didPanScrollStop();
 #endif
 }

 void AutoscrollController::updateAutoscrollRenderer()
 {
     if (!m_autoscrollRenderer)
         return;

     RenderObject* renderer = m_autoscrollRenderer.get();

 #if ENABLE(PAN_SCROLLING)
     constexpr OptionSet<HitTestRequest::Type> hitType { HitTestRequest::Type::ReadOnly, HitTestRequest::Type::Active, HitTestRequest::Type::AllowChildFrameContent };
     HitTestResult hitTest = m_autoscrollRenderer->frame().eventHandler().hitTestResultAtPoint(m_panScrollStartPos, hitType);

     if (auto* nodeAtPoint = hitTest.innerNode())
         renderer = nodeAtPoint->renderer();
 #endif

     while (renderer && !(is<RenderBox>(*renderer) && downcast<RenderBox>(*renderer).canAutoscroll()))
         renderer = renderer->parent();

     if (!is<RenderBox>(renderer)) {
         m_autoscrollRenderer = nullptr;
         return;
     }

     m_autoscrollRenderer = WeakPtr { downcast<RenderBox>(*renderer) };
 }

 void AutoscrollController::updateDragAndDrop(Node* dropTargetNode, const IntPoint& eventPosition, WallTime eventTime)
 {
     IntSize offset;
     auto findDragAndDropScroller = [&]() -> RenderBox* {
         if (!dropTargetNode)
             return nullptr;

         auto* scrollable = RenderBox::findAutoscrollable(dropTargetNode->renderer());
         if (!scrollable)
             return nullptr;

         auto& frame = scrollable->frame();
         auto* page = frame.page();
         if (!page || !page->settings().autoscrollForDragAndDropEnabled())
             return nullptr;

         offset = scrollable->calculateAutoscrollDirection(eventPosition);
         if (offset.isZero())
             return nullptr;

         return scrollable;
     };

     RenderBox* scrollable = findDragAndDropScroller();
     if (!scrollable) {
         stopAutoscrollTimer();
         return;
     }

     m_dragAndDropAutoscrollReferencePosition = eventPosition + offset;

     if (m_autoscrollType == NoAutoscroll) {
         m_autoscrollType = AutoscrollForDragAndDrop;
         m_autoscrollRenderer = WeakPtr { *scrollable };
         m_dragAndDropAutoscrollStartTime = eventTime;
         startAutoscrollTimer();
     } else if (m_autoscrollRenderer != scrollable) {
         m_dragAndDropAutoscrollStartTime = eventTime;
         m_autoscrollRenderer = WeakPtr { *scrollable };
     }
 }

 #if ENABLE(PAN_SCROLLING)
 void AutoscrollController::didPanScrollStart()
 {
     m_autoscrollType = AutoscrollForPan;
 }

 void AutoscrollController::didPanScrollStop()
 {
     m_autoscrollType = NoAutoscroll;
 }

 void AutoscrollController::handleMouseReleaseEvent(const PlatformMouseEvent& mouseEvent)
 {
     switch (m_autoscrollType) {
     case AutoscrollForPan:
         if (mouseEvent.button() == MiddleButton)
             m_autoscrollType = AutoscrollForPanCanStop;
         break;
     case AutoscrollForPanCanStop:
         stopAutoscrollTimer();
         break;
     default:
         break;
     }
 }

 bool AutoscrollController::panScrollInProgress() const
 {
     return m_autoscrollType == AutoscrollForPan || m_autoscrollType == AutoscrollForPanCanStop;
 }

 void AutoscrollController::startPanScrolling(RenderBox& scrollable, const IntPoint& lastKnownMousePosition)
 {
     // We don't want to trigger the autoscroll or the panScroll if it's already active
     if (m_autoscrollTimer.isActive())
         return;

     m_autoscrollType = AutoscrollForPan;
     m_autoscrollRenderer = WeakPtr { scrollable };
     m_panScrollStartPos = lastKnownMousePosition;

     if (auto* view = scrollable.frame().view())
         view->addPanScrollIcon(lastKnownMousePosition);

     scrollable.frame().eventHandler().didPanScrollStart();
     startAutoscrollTimer();
 }
 #else
 bool AutoscrollController::panScrollInProgress() const
 {
     return false;
 }
 #endif

 void AutoscrollController::autoscrollTimerFired()
 {
     if (!m_autoscrollRenderer) {
         stopAutoscrollTimer();
         return;
     }

     Frame& frame = m_autoscrollRenderer->frame();
     switch (m_autoscrollType) {
     case AutoscrollForDragAndDrop:
         if (WallTime::now() - m_dragAndDropAutoscrollStartTime > autoscrollDelay)
             m_autoscrollRenderer->autoscroll(m_dragAndDropAutoscrollReferencePosition);
         break;
     case AutoscrollForSelection: {
         if (!frame.eventHandler().shouldUpdateAutoscroll()) {
             stopAutoscrollTimer();
             return;
         }
 #if ENABLE(DRAG_SUPPORT)
         frame.eventHandler().updateSelectionForMouseDrag();
 #endif
         m_autoscrollRenderer->autoscroll(frame.eventHandler().targetPositionInWindowForSelectionAutoscroll());
         break;
     }
     case NoAutoscroll:
         break;
 #if ENABLE(PAN_SCROLLING)
     case AutoscrollForPanCanStop:
     case AutoscrollForPan:
         // we verify that the main frame hasn't received the order to stop the panScroll
         if (Frame* mainFrame = getMainFrame(&frame)) {
             if (!mainFrame->eventHandler().panScrollInProgress()) {
                 stopAutoscrollTimer();
                 return;
             }
         }
         if (FrameView* view = frame.view())
             updatePanScrollState(view, frame.eventHandler().lastKnownMousePosition());
         m_autoscrollRenderer->panScroll(m_panScrollStartPos);
         break;
 #endif
     }
 }

 void AutoscrollController::startAutoscrollTimer()
 {
     m_autoscrollTimer.startRepeating(autoscrollInterval);
 }

 #if ENABLE(PAN_SCROLLING)
 void AutoscrollController::updatePanScrollState(FrameView* view, const IntPoint& lastKnownMousePosition)
 {
     // At the original click location we draw a 4 arrowed icon. Over this icon there won't be any scroll
     // So we don't want to change the cursor over this area
     bool east = m_panScrollStartPos.x() < (lastKnownMousePosition.x() - ScrollView::noPanScrollRadius);
     bool west = m_panScrollStartPos.x() > (lastKnownMousePosition.x() + ScrollView::noPanScrollRadius);
     bool north = m_panScrollStartPos.y() > (lastKnownMousePosition.y() + ScrollView::noPanScrollRadius);
     bool south = m_panScrollStartPos.y() < (lastKnownMousePosition.y() - ScrollView::noPanScrollRadius);

     if (m_autoscrollType == AutoscrollForPan && (east || west || north || south))
         m_autoscrollType = AutoscrollForPanCanStop;

     if (north) {
         if (east)
             view->setCursor(northEastPanningCursor());
         else if (west)
             view->setCursor(northWestPanningCursor());
         else
             view->setCursor(northPanningCursor());
     } else if (south) {
         if (east)
             view->setCursor(southEastPanningCursor());
         else if (west)
             view->setCursor(southWestPanningCursor());
         else
             view->setCursor(southPanningCursor());
     } else if (east)
         view->setCursor(eastPanningCursor());
     else if (west)
         view->setCursor(westPanningCursor());
     else
         view->setCursor(middlePanningCursor());
 }
 #endif

 } // namespace WebCore
	/*
	* Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
	* Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
	* Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
	* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
	* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
	* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "config.h"
	#include "AutoscrollController.h"

	#include "EventHandler.h"
	#include "Frame.h"
	#include "FrameView.h"
	#include "HitTestResult.h"
	#include "Page.h"
	#include "RenderBox.h"
	#include "RenderView.h"
	#include "ScrollView.h"
	#include "Settings.h"

	namespace WebCore {

	// Delay time in second for start autoscroll if pointer is in border edge of scrollable element.
	static const Seconds autoscrollDelay { 200_ms };

	// When the autoscroll or the panScroll is triggered when do the scroll every 50ms to make it smooth.
	static const Seconds autoscrollInterval { 50_ms };

	#if ENABLE(PAN_SCROLLING)
	static Frame* getMainFrame(Frame* frame)
	{
	Page* page = frame->page();
	return page ? &page->mainFrame() : 0;
	}
	#endif

	AutoscrollController::AutoscrollController()
	: m_autoscrollTimer(*this, &AutoscrollController::autoscrollTimerFired)
	{
	}

	RenderBox* AutoscrollController::autoscrollRenderer() const
	{
	return m_autoscrollRenderer.get();
	}

	bool AutoscrollController::autoscrollInProgress() const
	{
	return m_autoscrollType == AutoscrollForSelection;
	}

	void AutoscrollController::startAutoscrollForSelection(RenderObject* renderer)
	{
	// We don't want to trigger the autoscroll or the panScroll if it's already active
	if (m_autoscrollTimer.isActive())
	return;
	auto* scrollable = RenderBox::findAutoscrollable(renderer);
	if (!scrollable)
	return;
	m_autoscrollType = AutoscrollForSelection;
	m_autoscrollRenderer = WeakPtr { *scrollable };
	startAutoscrollTimer();
	}

	void AutoscrollController::stopAutoscrollTimer(bool rendererIsBeingDestroyed)
	{
	auto scrollable = m_autoscrollRenderer;

	m_autoscrollTimer.stop();
	m_autoscrollRenderer = nullptr;

	if (!scrollable)
	return;

	auto* frame = scrollable->document().frame();
	if (autoscrollInProgress() && frame && frame->eventHandler().mouseDownWasInSubframe()) {
	if (auto subframe = frame->eventHandler().subframeForTargetNode(frame->eventHandler().mousePressNode()))
	subframe->eventHandler().stopAutoscrollTimer(rendererIsBeingDestroyed);
	return;
	}

	if (!rendererIsBeingDestroyed)
	scrollable->stopAutoscroll();

	#if ENABLE(PAN_SCROLLING)
	if (panScrollInProgress()) {
	FrameView& frameView = scrollable->view().frameView();
	frameView.removePanScrollIcon();
	frameView.setCursor(pointerCursor());
	}
	#endif

	m_autoscrollType = NoAutoscroll;

	#if ENABLE(PAN_SCROLLING)
	// If we're not in the top frame we notify it that we are not doing a panScroll any more.
	if (frame && !frame->isMainFrame())
	frame->mainFrame().eventHandler().didPanScrollStop();
	#endif
	}

	void AutoscrollController::updateAutoscrollRenderer()
	{
	if (!m_autoscrollRenderer)
	return;

	RenderObject* renderer = m_autoscrollRenderer.get();

	#if ENABLE(PAN_SCROLLING)
	constexpr OptionSet<HitTestRequest::Type> hitType { HitTestRequest::Type::ReadOnly, HitTestRequest::Type::Active, HitTestRequest::Type::AllowChildFrameContent };
	HitTestResult hitTest = m_autoscrollRenderer->frame().eventHandler().hitTestResultAtPoint(m_panScrollStartPos, hitType);

	if (auto* nodeAtPoint = hitTest.innerNode())
	renderer = nodeAtPoint->renderer();
	#endif

	while (renderer && !(is<RenderBox>(renderer) && downcast<RenderBox>(renderer).canAutoscroll()))
	renderer = renderer->parent();

	if (!is<RenderBox>(renderer)) {
	m_autoscrollRenderer = nullptr;
	return;
	}

	m_autoscrollRenderer = WeakPtr { downcast<RenderBox>(*renderer) };
	}

	void AutoscrollController::updateDragAndDrop(Node* dropTargetNode, const IntPoint& eventPosition, WallTime eventTime)
	{
	IntSize offset;
	auto findDragAndDropScroller = [&]() -> RenderBox* {
	if (!dropTargetNode)
	return nullptr;

	auto* scrollable = RenderBox::findAutoscrollable(dropTargetNode->renderer());
	if (!scrollable)
	return nullptr;

	auto& frame = scrollable->frame();
	auto* page = frame.page();
	if (!page \|\| !page->settings().autoscrollForDragAndDropEnabled())
	return nullptr;

	offset = scrollable->calculateAutoscrollDirection(eventPosition);
	if (offset.isZero())
	return nullptr;

	return scrollable;
	};

	RenderBox* scrollable = findDragAndDropScroller();
	if (!scrollable) {
	stopAutoscrollTimer();
	return;
	}

	m_dragAndDropAutoscrollReferencePosition = eventPosition + offset;

	if (m_autoscrollType == NoAutoscroll) {
	m_autoscrollType = AutoscrollForDragAndDrop;
	m_autoscrollRenderer = WeakPtr { *scrollable };
	m_dragAndDropAutoscrollStartTime = eventTime;
	startAutoscrollTimer();
	} else if (m_autoscrollRenderer != scrollable) {
	m_dragAndDropAutoscrollStartTime = eventTime;
	m_autoscrollRenderer = WeakPtr { *scrollable };
	}
	}

	#if ENABLE(PAN_SCROLLING)
	void AutoscrollController::didPanScrollStart()
	{
	m_autoscrollType = AutoscrollForPan;
	}

	void AutoscrollController::didPanScrollStop()
	{
	m_autoscrollType = NoAutoscroll;
	}

	void AutoscrollController::handleMouseReleaseEvent(const PlatformMouseEvent& mouseEvent)
	{
	switch (m_autoscrollType) {
	case AutoscrollForPan:
	if (mouseEvent.button() == MiddleButton)
	m_autoscrollType = AutoscrollForPanCanStop;
	break;
	case AutoscrollForPanCanStop:
	stopAutoscrollTimer();
	break;
	default:
	break;
	}
	}

	bool AutoscrollController::panScrollInProgress() const
	{
	return m_autoscrollType == AutoscrollForPan \|\| m_autoscrollType == AutoscrollForPanCanStop;
	}

	void AutoscrollController::startPanScrolling(RenderBox& scrollable, const IntPoint& lastKnownMousePosition)
	{
	// We don't want to trigger the autoscroll or the panScroll if it's already active
	if (m_autoscrollTimer.isActive())
	return;

	m_autoscrollType = AutoscrollForPan;
	m_autoscrollRenderer = WeakPtr { scrollable };
	m_panScrollStartPos = lastKnownMousePosition;

	if (auto* view = scrollable.frame().view())
	view->addPanScrollIcon(lastKnownMousePosition);

	scrollable.frame().eventHandler().didPanScrollStart();
	startAutoscrollTimer();
	}
	#else
	bool AutoscrollController::panScrollInProgress() const
	{
	return false;
	}
	#endif

	void AutoscrollController::autoscrollTimerFired()
	{
	if (!m_autoscrollRenderer) {
	stopAutoscrollTimer();
	return;
	}

	Frame& frame = m_autoscrollRenderer->frame();
	switch (m_autoscrollType) {
	case AutoscrollForDragAndDrop:
	if (WallTime::now() - m_dragAndDropAutoscrollStartTime > autoscrollDelay)
	m_autoscrollRenderer->autoscroll(m_dragAndDropAutoscrollReferencePosition);
	break;
	case AutoscrollForSelection: {
	if (!frame.eventHandler().shouldUpdateAutoscroll()) {
	stopAutoscrollTimer();
	return;
	}
	#if ENABLE(DRAG_SUPPORT)
	frame.eventHandler().updateSelectionForMouseDrag();
	#endif
	m_autoscrollRenderer->autoscroll(frame.eventHandler().targetPositionInWindowForSelectionAutoscroll());
	break;
	}
	case NoAutoscroll:
	break;
	#if ENABLE(PAN_SCROLLING)
	case AutoscrollForPanCanStop:
	case AutoscrollForPan:
	// we verify that the main frame hasn't received the order to stop the panScroll
	if (Frame* mainFrame = getMainFrame(&frame)) {
	if (!mainFrame->eventHandler().panScrollInProgress()) {
	stopAutoscrollTimer();
	return;
	}
	}
	if (FrameView* view = frame.view())
	updatePanScrollState(view, frame.eventHandler().lastKnownMousePosition());
	m_autoscrollRenderer->panScroll(m_panScrollStartPos);
	break;
	#endif
	}
	}

	void AutoscrollController::startAutoscrollTimer()
	{
	m_autoscrollTimer.startRepeating(autoscrollInterval);
	}

	#if ENABLE(PAN_SCROLLING)
	void AutoscrollController::updatePanScrollState(FrameView* view, const IntPoint& lastKnownMousePosition)
	{
	// At the original click location we draw a 4 arrowed icon. Over this icon there won't be any scroll
	// So we don't want to change the cursor over this area
	bool east = m_panScrollStartPos.x() < (lastKnownMousePosition.x() - ScrollView::noPanScrollRadius);
	bool west = m_panScrollStartPos.x() > (lastKnownMousePosition.x() + ScrollView::noPanScrollRadius);
	bool north = m_panScrollStartPos.y() > (lastKnownMousePosition.y() + ScrollView::noPanScrollRadius);
	bool south = m_panScrollStartPos.y() < (lastKnownMousePosition.y() - ScrollView::noPanScrollRadius);

	if (m_autoscrollType == AutoscrollForPan && (east \|\| west \|\| north \|\| south))
	m_autoscrollType = AutoscrollForPanCanStop;

	if (north) {
	if (east)
	view->setCursor(northEastPanningCursor());
	else if (west)
	view->setCursor(northWestPanningCursor());
	else
	view->setCursor(northPanningCursor());
	} else if (south) {
	if (east)
	view->setCursor(southEastPanningCursor());
	else if (west)
	view->setCursor(southWestPanningCursor());
	else
	view->setCursor(southPanningCursor());
	} else if (east)
	view->setCursor(eastPanningCursor());
	else if (west)
	view->setCursor(westPanningCursor());
	else
	view->setCursor(middlePanningCursor());
	}
	#endif

	} // namespace WebCore