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1 /*
2  * Copyright (C) 2013 Google Inc. All rights reserved.
3  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
4  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
5  * Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
20  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
21  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
23  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
24  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "config.h"
30 #include "core/page/AutoscrollController.h"
31 
32 #include "core/page/EventHandler.h"
33 #include "core/frame/Frame.h"
34 #include "core/frame/FrameView.h"
35 #include "core/page/Chrome.h"
36 #include "core/page/Page.h"
37 #include "core/rendering/HitTestResult.h"
38 #include "core/rendering/RenderBox.h"
39 #include "wtf/CurrentTime.h"
40 
41 namespace WebCore {
42 
43 // Delay time in second for start autoscroll if pointer is in border edge of scrollable element.
44 static double autoscrollDelay = 0.2;
45 
create(Page & page)46 PassOwnPtr<AutoscrollController> AutoscrollController::create(Page& page)
47 {
48     return adoptPtr(new AutoscrollController(page));
49 }
50 
AutoscrollController(Page & page)51 AutoscrollController::AutoscrollController(Page& page)
52     : m_page(page)
53     , m_autoscrollRenderer(0)
54     , m_autoscrollType(NoAutoscroll)
55     , m_dragAndDropAutoscrollStartTime(0)
56 {
57 }
58 
autoscrollInProgress() const59 bool AutoscrollController::autoscrollInProgress() const
60 {
61     return m_autoscrollType == AutoscrollForSelection;
62 }
63 
autoscrollInProgress(const RenderBox * renderer) const64 bool AutoscrollController::autoscrollInProgress(const RenderBox* renderer) const
65 {
66     return m_autoscrollRenderer == renderer;
67 }
68 
startAutoscrollForSelection(RenderObject * renderer)69 void AutoscrollController::startAutoscrollForSelection(RenderObject* renderer)
70 {
71     // We don't want to trigger the autoscroll or the panScroll if it's already active
72     if (m_autoscrollType != NoAutoscroll)
73         return;
74     RenderBox* scrollable = RenderBox::findAutoscrollable(renderer);
75     if (!scrollable)
76         return;
77     m_autoscrollType = AutoscrollForSelection;
78     m_autoscrollRenderer = scrollable;
79     startAutoscroll();
80 }
81 
stopAutoscroll()82 void AutoscrollController::stopAutoscroll()
83 {
84     RenderBox* scrollable = m_autoscrollRenderer;
85     m_autoscrollRenderer = 0;
86 
87     if (!scrollable)
88         return;
89 
90     scrollable->stopAutoscroll();
91 #if OS(WIN)
92     if (panScrollInProgress()) {
93         if (FrameView* view = scrollable->frame()->view()) {
94             view->removePanScrollIcon();
95             view->setCursor(pointerCursor());
96         }
97     }
98 #endif
99 
100     m_autoscrollType = NoAutoscroll;
101 }
102 
stopAutoscrollIfNeeded(RenderObject * renderer)103 void AutoscrollController::stopAutoscrollIfNeeded(RenderObject* renderer)
104 {
105     if (m_autoscrollRenderer != renderer)
106         return;
107     m_autoscrollRenderer = 0;
108     m_autoscrollType = NoAutoscroll;
109 }
110 
updateAutoscrollRenderer()111 void AutoscrollController::updateAutoscrollRenderer()
112 {
113     if (!m_autoscrollRenderer)
114         return;
115 
116     RenderObject* renderer = m_autoscrollRenderer;
117 
118 #if OS(WIN)
119     HitTestResult hitTest = renderer->frame()->eventHandler().hitTestResultAtPoint(m_panScrollStartPos, HitTestRequest::ReadOnly | HitTestRequest::Active | HitTestRequest::ConfusingAndOftenMisusedDisallowShadowContent);
120 
121     if (Node* nodeAtPoint = hitTest.innerNode())
122         renderer = nodeAtPoint->renderer();
123 #endif
124 
125     while (renderer && !(renderer->isBox() && toRenderBox(renderer)->canAutoscroll()))
126         renderer = renderer->parent();
127     m_autoscrollRenderer = renderer && renderer->isBox() ? toRenderBox(renderer) : 0;
128 }
129 
updateDragAndDrop(Node * dropTargetNode,const IntPoint & eventPosition,double eventTime)130 void AutoscrollController::updateDragAndDrop(Node* dropTargetNode, const IntPoint& eventPosition, double eventTime)
131 {
132     if (!dropTargetNode || !dropTargetNode->renderer()) {
133         stopAutoscroll();
134         return;
135     }
136 
137     if (m_autoscrollRenderer && m_autoscrollRenderer->frame() != dropTargetNode->renderer()->frame())
138         return;
139 
140     RenderBox* scrollable = RenderBox::findAutoscrollable(dropTargetNode->renderer());
141     if (!scrollable) {
142         stopAutoscroll();
143         return;
144     }
145 
146     Page* page = scrollable->frame() ? scrollable->frame()->page() : 0;
147     if (!page) {
148         stopAutoscroll();
149         return;
150     }
151 
152     IntSize offset = scrollable->calculateAutoscrollDirection(eventPosition);
153     if (offset.isZero()) {
154         stopAutoscroll();
155         return;
156     }
157 
158     m_dragAndDropAutoscrollReferencePosition = eventPosition + offset;
159 
160     if (m_autoscrollType == NoAutoscroll) {
161         m_autoscrollType = AutoscrollForDragAndDrop;
162         m_autoscrollRenderer = scrollable;
163         m_dragAndDropAutoscrollStartTime = eventTime;
164         startAutoscroll();
165     } else if (m_autoscrollRenderer != scrollable) {
166         m_dragAndDropAutoscrollStartTime = eventTime;
167         m_autoscrollRenderer = scrollable;
168     }
169 }
170 
171 #if OS(WIN)
handleMouseReleaseForPanScrolling(Frame * frame,const PlatformMouseEvent & mouseEvent)172 void AutoscrollController::handleMouseReleaseForPanScrolling(Frame* frame, const PlatformMouseEvent& mouseEvent)
173 {
174     if (!frame->isMainFrame())
175         return;
176     switch (m_autoscrollType) {
177     case AutoscrollForPan:
178         if (mouseEvent.button() == MiddleButton)
179             m_autoscrollType = AutoscrollForPanCanStop;
180         break;
181     case AutoscrollForPanCanStop:
182         stopAutoscroll();
183         break;
184     }
185 }
186 
panScrollInProgress() const187 bool AutoscrollController::panScrollInProgress() const
188 {
189     return m_autoscrollType == AutoscrollForPanCanStop || m_autoscrollType == AutoscrollForPan;
190 }
191 
startPanScrolling(RenderBox * scrollable,const IntPoint & lastKnownMousePosition)192 void AutoscrollController::startPanScrolling(RenderBox* scrollable, const IntPoint& lastKnownMousePosition)
193 {
194     // We don't want to trigger the autoscroll or the panScroll if it's already active
195     if (m_autoscrollType != NoAutoscroll)
196         return;
197 
198     m_autoscrollType = AutoscrollForPan;
199     m_autoscrollRenderer = scrollable;
200     m_panScrollStartPos = lastKnownMousePosition;
201 
202     if (FrameView* view = scrollable->frame()->view())
203         view->addPanScrollIcon(lastKnownMousePosition);
204     startAutoscroll();
205 }
206 #else
panScrollInProgress() const207 bool AutoscrollController::panScrollInProgress() const
208 {
209     return false;
210 }
211 #endif
212 
213 // FIXME: This would get get better animation fidelity if it used the monotonicFrameBeginTime instead
214 // of WTF::currentTime().
animate(double)215 void AutoscrollController::animate(double)
216 {
217     if (!m_autoscrollRenderer) {
218         stopAutoscroll();
219         return;
220     }
221 
222     EventHandler& eventHandler = m_autoscrollRenderer->frame()->eventHandler();
223     switch (m_autoscrollType) {
224     case AutoscrollForDragAndDrop:
225         if (WTF::currentTime() - m_dragAndDropAutoscrollStartTime > autoscrollDelay)
226             m_autoscrollRenderer->autoscroll(m_dragAndDropAutoscrollReferencePosition);
227         break;
228     case AutoscrollForSelection:
229         if (!eventHandler.mousePressed()) {
230             stopAutoscroll();
231             return;
232         }
233         eventHandler.updateSelectionForMouseDrag();
234         m_autoscrollRenderer->autoscroll(eventHandler.lastKnownMousePosition());
235         break;
236     case NoAutoscroll:
237         break;
238 #if OS(WIN)
239     case AutoscrollForPanCanStop:
240     case AutoscrollForPan:
241         if (!panScrollInProgress()) {
242             stopAutoscroll();
243             return;
244         }
245         if (FrameView* view = m_autoscrollRenderer->frame()->view())
246             updatePanScrollState(view, eventHandler.lastKnownMousePosition());
247         m_autoscrollRenderer->panScroll(m_panScrollStartPos);
248         break;
249 #endif
250     }
251     if (m_autoscrollType != NoAutoscroll)
252         m_page.chrome().scheduleAnimation();
253 }
254 
startAutoscroll()255 void AutoscrollController::startAutoscroll()
256 {
257     m_page.chrome().scheduleAnimation();
258 }
259 
260 #if OS(WIN)
updatePanScrollState(FrameView * view,const IntPoint & lastKnownMousePosition)261 void AutoscrollController::updatePanScrollState(FrameView* view, const IntPoint& lastKnownMousePosition)
262 {
263     // At the original click location we draw a 4 arrowed icon. Over this icon there won't be any scroll
264     // So we don't want to change the cursor over this area
265     bool east = m_panScrollStartPos.x() < (lastKnownMousePosition.x() - ScrollView::noPanScrollRadius);
266     bool west = m_panScrollStartPos.x() > (lastKnownMousePosition.x() + ScrollView::noPanScrollRadius);
267     bool north = m_panScrollStartPos.y() > (lastKnownMousePosition.y() + ScrollView::noPanScrollRadius);
268     bool south = m_panScrollStartPos.y() < (lastKnownMousePosition.y() - ScrollView::noPanScrollRadius);
269 
270     if (m_autoscrollType == AutoscrollForPan && (east || west || north || south))
271         m_autoscrollType = AutoscrollForPanCanStop;
272 
273     if (north) {
274         if (east)
275             view->setCursor(northEastPanningCursor());
276         else if (west)
277             view->setCursor(northWestPanningCursor());
278         else
279             view->setCursor(northPanningCursor());
280     } else if (south) {
281         if (east)
282             view->setCursor(southEastPanningCursor());
283         else if (west)
284             view->setCursor(southWestPanningCursor());
285         else
286             view->setCursor(southPanningCursor());
287     } else if (east)
288         view->setCursor(eastPanningCursor());
289     else if (west)
290         view->setCursor(westPanningCursor());
291     else
292         view->setCursor(middlePanningCursor());
293 }
294 #endif
295 
296 } // namespace WebCore
297