1/*
2 * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
3 * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
4 * Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
16 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
22 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
23 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include "config.h"
29#include "AutoscrollController.h"
30
31#include "EventHandler.h"
32#include "FrameView.h"
33#include "HitTestResult.h"
34#include "MainFrame.h"
35#include "Page.h"
36#include "RenderBox.h"
37#include "RenderView.h"
38#include "ScrollView.h"
39#include "Settings.h"
40#include <wtf/CurrentTime.h>
41
42namespace WebCore {
43
44// Delay time in second for start autoscroll if pointer is in border edge of scrollable element.
45static double autoscrollDelay = 0.2;
46
47// When the autoscroll or the panScroll is triggered when do the scroll every 0.05s to make it smooth
48static const double autoscrollInterval = 0.05;
49
50#if ENABLE(PAN_SCROLLING)
51static Frame* getMainFrame(Frame* frame)
52{
53    Page* page = frame->page();
54    return page ? &page->mainFrame() : 0;
55}
56#endif
57
58AutoscrollController::AutoscrollController()
59    : m_autoscrollTimer(this, &AutoscrollController::autoscrollTimerFired)
60    , m_autoscrollRenderer(0)
61    , m_autoscrollType(NoAutoscroll)
62    , m_dragAndDropAutoscrollStartTime(0)
63{
64}
65
66RenderBox* AutoscrollController::autoscrollRenderer() const
67{
68    return m_autoscrollRenderer;
69}
70
71bool AutoscrollController::autoscrollInProgress() const
72{
73    return m_autoscrollType == AutoscrollForSelection;
74}
75
76void AutoscrollController::startAutoscrollForSelection(RenderObject* renderer)
77{
78    // We don't want to trigger the autoscroll or the panScroll if it's already active
79    if (m_autoscrollTimer.isActive())
80        return;
81    RenderBox* scrollable = RenderBox::findAutoscrollable(renderer);
82    if (!scrollable)
83        return;
84    m_autoscrollType = AutoscrollForSelection;
85    m_autoscrollRenderer = scrollable;
86    startAutoscrollTimer();
87}
88
89void AutoscrollController::stopAutoscrollTimer(bool rendererIsBeingDestroyed)
90{
91    RenderBox* scrollable = m_autoscrollRenderer;
92    m_autoscrollTimer.stop();
93    m_autoscrollRenderer = 0;
94
95    if (!scrollable)
96        return;
97
98    Frame& frame = scrollable->frame();
99    if (autoscrollInProgress() && frame.eventHandler().mouseDownWasInSubframe()) {
100        if (Frame* subframe = frame.eventHandler().subframeForTargetNode(frame.eventHandler().mousePressNode()))
101            subframe->eventHandler().stopAutoscrollTimer(rendererIsBeingDestroyed);
102        return;
103    }
104
105    if (!rendererIsBeingDestroyed)
106        scrollable->stopAutoscroll();
107#if ENABLE(PAN_SCROLLING)
108    if (panScrollInProgress()) {
109        FrameView& frameView = scrollable->view().frameView();
110        frameView.removePanScrollIcon();
111        frameView.setCursor(pointerCursor());
112    }
113#endif
114
115    m_autoscrollType = NoAutoscroll;
116
117#if ENABLE(PAN_SCROLLING)
118    // If we're not in the top frame we notify it that we are not doing a panScroll any more.
119    if (!frame.isMainFrame())
120        frame.mainFrame().eventHandler().didPanScrollStop();
121#endif
122}
123
124void AutoscrollController::updateAutoscrollRenderer()
125{
126    if (!m_autoscrollRenderer)
127        return;
128
129    RenderObject* renderer = m_autoscrollRenderer;
130
131#if ENABLE(PAN_SCROLLING)
132    HitTestResult hitTest = m_autoscrollRenderer->frame().eventHandler().hitTestResultAtPoint(m_panScrollStartPos, HitTestRequest::ReadOnly | HitTestRequest::Active);
133
134    if (Node* nodeAtPoint = hitTest.innerNode())
135        renderer = nodeAtPoint->renderer();
136#endif
137
138    while (renderer && !(renderer->isBox() && toRenderBox(renderer)->canAutoscroll()))
139        renderer = renderer->parent();
140    m_autoscrollRenderer = renderer && renderer->isBox() ? toRenderBox(renderer) : 0;
141}
142
143void AutoscrollController::updateDragAndDrop(Node* dropTargetNode, const IntPoint& eventPosition, double eventTime)
144{
145    if (!dropTargetNode) {
146        stopAutoscrollTimer();
147        return;
148    }
149
150    RenderBox* scrollable = RenderBox::findAutoscrollable(dropTargetNode->renderer());
151    if (!scrollable) {
152        stopAutoscrollTimer();
153        return;
154    }
155
156    Frame& frame = scrollable->frame();
157
158    Page* page = frame.page();
159    if (!page || !page->settings().autoscrollForDragAndDropEnabled()) {
160        stopAutoscrollTimer();
161        return;
162    }
163
164    IntSize offset = scrollable->calculateAutoscrollDirection(eventPosition);
165    if (offset.isZero()) {
166        stopAutoscrollTimer();
167        return;
168    }
169
170    m_dragAndDropAutoscrollReferencePosition = eventPosition + offset;
171
172    if (m_autoscrollType == NoAutoscroll) {
173        m_autoscrollType = AutoscrollForDragAndDrop;
174        m_autoscrollRenderer = scrollable;
175        m_dragAndDropAutoscrollStartTime = eventTime;
176        startAutoscrollTimer();
177    } else if (m_autoscrollRenderer != scrollable) {
178        m_dragAndDropAutoscrollStartTime = eventTime;
179        m_autoscrollRenderer = scrollable;
180    }
181}
182
183#if ENABLE(PAN_SCROLLING)
184void AutoscrollController::didPanScrollStart()
185{
186    m_autoscrollType = AutoscrollForPan;
187}
188
189void AutoscrollController::didPanScrollStop()
190{
191    m_autoscrollType = NoAutoscroll;
192}
193
194void AutoscrollController::handleMouseReleaseEvent(const PlatformMouseEvent& mouseEvent)
195{
196    switch (m_autoscrollType) {
197    case AutoscrollForPan:
198        if (mouseEvent.button() == MiddleButton)
199            m_autoscrollType = AutoscrollForPanCanStop;
200        break;
201    case AutoscrollForPanCanStop:
202        stopAutoscrollTimer();
203        break;
204    }
205}
206
207bool AutoscrollController::panScrollInProgress() const
208{
209    return m_autoscrollType == AutoscrollForPan || m_autoscrollType == AutoscrollForPanCanStop;
210}
211
212void AutoscrollController::startPanScrolling(RenderBox* scrollable, const IntPoint& lastKnownMousePosition)
213{
214    // We don't want to trigger the autoscroll or the panScroll if it's already active
215    if (m_autoscrollTimer.isActive())
216        return;
217
218    m_autoscrollType = AutoscrollForPan;
219    m_autoscrollRenderer = scrollable;
220    m_panScrollStartPos = lastKnownMousePosition;
221
222    if (FrameView* view = scrollable->frame().view())
223        view->addPanScrollIcon(lastKnownMousePosition);
224    scrollable->frame().eventHandler().didPanScrollStart();
225    startAutoscrollTimer();
226}
227#else
228bool AutoscrollController::panScrollInProgress() const
229{
230    return false;
231}
232#endif
233
234void AutoscrollController::autoscrollTimerFired(Timer<AutoscrollController>&)
235{
236    if (!m_autoscrollRenderer) {
237        stopAutoscrollTimer();
238        return;
239    }
240
241    Frame& frame = m_autoscrollRenderer->frame();
242    switch (m_autoscrollType) {
243    case AutoscrollForDragAndDrop:
244        if (WTF::currentTime() - m_dragAndDropAutoscrollStartTime > autoscrollDelay)
245            m_autoscrollRenderer->autoscroll(m_dragAndDropAutoscrollReferencePosition);
246        break;
247    case AutoscrollForSelection: {
248        if (!frame.eventHandler().mousePressed()) {
249            stopAutoscrollTimer();
250            return;
251        }
252#if ENABLE(DRAG_SUPPORT)
253        frame.eventHandler().updateSelectionForMouseDrag();
254#endif
255        m_autoscrollRenderer->autoscroll(frame.eventHandler().lastKnownMousePosition());
256        break;
257    }
258    case NoAutoscroll:
259        break;
260#if ENABLE(PAN_SCROLLING)
261    case AutoscrollForPanCanStop:
262    case AutoscrollForPan:
263        // we verify that the main frame hasn't received the order to stop the panScroll
264        if (Frame* mainFrame = getMainFrame(&frame)) {
265            if (!mainFrame->eventHandler().panScrollInProgress()) {
266                stopAutoscrollTimer();
267                return;
268            }
269        }
270        if (FrameView* view = frame.view())
271            updatePanScrollState(view, frame.eventHandler().lastKnownMousePosition());
272        m_autoscrollRenderer->panScroll(m_panScrollStartPos);
273        break;
274#endif
275    }
276}
277
278void AutoscrollController::startAutoscrollTimer()
279{
280    m_autoscrollTimer.startRepeating(autoscrollInterval);
281}
282
283#if ENABLE(PAN_SCROLLING)
284void AutoscrollController::updatePanScrollState(FrameView* view, const IntPoint& lastKnownMousePosition)
285{
286    // At the original click location we draw a 4 arrowed icon. Over this icon there won't be any scroll
287    // So we don't want to change the cursor over this area
288    bool east = m_panScrollStartPos.x() < (lastKnownMousePosition.x() - ScrollView::noPanScrollRadius);
289    bool west = m_panScrollStartPos.x() > (lastKnownMousePosition.x() + ScrollView::noPanScrollRadius);
290    bool north = m_panScrollStartPos.y() > (lastKnownMousePosition.y() + ScrollView::noPanScrollRadius);
291    bool south = m_panScrollStartPos.y() < (lastKnownMousePosition.y() - ScrollView::noPanScrollRadius);
292
293    if (m_autoscrollType == AutoscrollForPan && (east || west || north || south))
294        m_autoscrollType = AutoscrollForPanCanStop;
295
296    if (north) {
297        if (east)
298            view->setCursor(northEastPanningCursor());
299        else if (west)
300            view->setCursor(northWestPanningCursor());
301        else
302            view->setCursor(northPanningCursor());
303    } else if (south) {
304        if (east)
305            view->setCursor(southEastPanningCursor());
306        else if (west)
307            view->setCursor(southWestPanningCursor());
308        else
309            view->setCursor(southPanningCursor());
310    } else if (east)
311        view->setCursor(eastPanningCursor());
312    else if (west)
313        view->setCursor(westPanningCursor());
314    else
315        view->setCursor(middlePanningCursor());
316}
317#endif
318
319} // namespace WebCore
320