RenderMarquee.cpp revision ab9e7a118cf1ea2e3a93dce683b2ded3e7291ddb 
1/*
2 * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
3 * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
4 *
5 * Portions are Copyright (C) 1998 Netscape Communications Corporation.
6 *
7 * Other contributors:
8 *   Robert O'Callahan <roc+@cs.cmu.edu>
9 *   David Baron <dbaron@fas.harvard.edu>
10 *   Christian Biesinger <cbiesinger@web.de>
11 *   Randall Jesup <rjesup@wgate.com>
12 *   Roland Mainz <roland.mainz@informatik.med.uni-giessen.de>
13 *   Josh Soref <timeless@mac.com>
14 *   Boris Zbarsky <bzbarsky@mit.edu>
15 *
16 * This library is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU Lesser General Public
18 * License as published by the Free Software Foundation; either
19 * version 2.1 of the License, or (at your option) any later version.
20 *
21 * This library is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
24 * Lesser General Public License for more details.
25 *
26 * You should have received a copy of the GNU Lesser General Public
27 * License along with this library; if not, write to the Free Software
28 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
29 *
30 * Alternatively, the contents of this file may be used under the terms
31 * of either the Mozilla Public License Version 1.1, found at
32 * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public
33 * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html
34 * (the "GPL"), in which case the provisions of the MPL or the GPL are
35 * applicable instead of those above.  If you wish to allow use of your
36 * version of this file only under the terms of one of those two
37 * licenses (the MPL or the GPL) and not to allow others to use your
38 * version of this file under the LGPL, indicate your decision by
39 * deletingthe provisions above and replace them with the notice and
40 * other provisions required by the MPL or the GPL, as the case may be.
41 * If you do not delete the provisions above, a recipient may use your
42 * version of this file under any of the LGPL, the MPL or the GPL.
43 */
44
45#include "config.h"
46
47#include "RenderMarquee.h"
48
49#include "FrameView.h"
50#include "HTMLMarqueeElement.h"
51#include "HTMLNames.h"
52#include "RenderLayer.h"
53
54using namespace std;
55
56namespace WebCore {
57
58using namespace HTMLNames;
59
60RenderMarquee::RenderMarquee(RenderLayer* l)
61    : m_layer(l), m_currentLoop(0)
62    , m_totalLoops(0)
63    , m_timer(this, &RenderMarquee::timerFired)
64    , m_start(0), m_end(0), m_speed(0), m_reset(false)
65    , m_suspended(false), m_stopped(false), m_direction(MAUTO)
66{
67}
68
69RenderMarquee::~RenderMarquee()
70{
71}
72
73int RenderMarquee::marqueeSpeed() const
74{
75    int result = m_layer->renderer()->style()->marqueeSpeed();
76    Node* n = m_layer->renderer()->node();
77    if (n && n->hasTagName(marqueeTag)) {
78        HTMLMarqueeElement* marqueeElt = static_cast<HTMLMarqueeElement*>(n);
79        result = max(result, marqueeElt->minimumDelay());
80    }
81    return result;
82}
83
84EMarqueeDirection RenderMarquee::direction() const
85{
86    // FIXME: Support the CSS3 "auto" value for determining the direction of the marquee.
87    // For now just map MAUTO to MBACKWARD
88    EMarqueeDirection result = m_layer->renderer()->style()->marqueeDirection();
89    TextDirection dir = m_layer->renderer()->style()->direction();
90    if (result == MAUTO)
91        result = MBACKWARD;
92    if (result == MFORWARD)
93        result = (dir == LTR) ? MRIGHT : MLEFT;
94    if (result == MBACKWARD)
95        result = (dir == LTR) ? MLEFT : MRIGHT;
96
97    // Now we have the real direction.  Next we check to see if the increment is negative.
98    // If so, then we reverse the direction.
99    Length increment = m_layer->renderer()->style()->marqueeIncrement();
100    if (increment.isNegative())
101        result = static_cast<EMarqueeDirection>(-result);
102
103    return result;
104}
105
106bool RenderMarquee::isHorizontal() const
107{
108    return direction() == MLEFT || direction() == MRIGHT;
109}
110
111int RenderMarquee::computePosition(EMarqueeDirection dir, bool stopAtContentEdge)
112{
113    RenderBox* box = m_layer->renderBox();
114    ASSERT(box);
115    RenderStyle* s = box->style();
116    if (isHorizontal()) {
117        bool ltr = s->isLeftToRightDirection();
118        int clientWidth = box->clientWidth();
119        int contentWidth = ltr ? box->rightLayoutOverflow() : box->leftLayoutOverflow();
120        if (ltr)
121            contentWidth += (box->paddingRight() - box->borderLeft());
122        else {
123            contentWidth = box->width() - contentWidth;
124            contentWidth += (box->paddingLeft() - box->borderRight());
125        }
126        if (dir == MRIGHT) {
127            if (stopAtContentEdge)
128                return max(0, ltr ? (contentWidth - clientWidth) : (clientWidth - contentWidth));
129            else
130                return ltr ? contentWidth : clientWidth;
131        }
132        else {
133            if (stopAtContentEdge)
134                return min(0, ltr ? (contentWidth - clientWidth) : (clientWidth - contentWidth));
135            else
136                return ltr ? -clientWidth : -contentWidth;
137        }
138    }
139    else {
140        int contentHeight = box->bottomLayoutOverflow() - box->borderTop() + box->paddingBottom();
141        int clientHeight = box->clientHeight();
142        if (dir == MUP) {
143            if (stopAtContentEdge)
144                 return min(contentHeight - clientHeight, 0);
145            else
146                return -clientHeight;
147        }
148        else {
149            if (stopAtContentEdge)
150                return max(contentHeight - clientHeight, 0);
151            else
152                return contentHeight;
153        }
154    }
155}
156
157void RenderMarquee::start()
158{
159    if (m_timer.isActive() || m_layer->renderer()->style()->marqueeIncrement().isZero()
160#if ENABLE(WCSS) && ENABLE(XHTMLMP)
161        || (m_layer->renderer()->document()->isXHTMLMPDocument() && !m_layer->renderer()->style()->marqueeLoopCount())
162#endif
163       )
164        return;
165
166    // We may end up propagating a scroll event. It is important that we suspend events until
167    // the end of the function since they could delete the layer, including the marquee.
168    FrameView* frameView = m_layer->renderer()->document()->view();
169    if (frameView)
170        frameView->pauseScheduledEvents();
171
172    if (!m_suspended && !m_stopped) {
173        if (isHorizontal())
174            m_layer->scrollToOffset(m_start, 0);
175        else
176            m_layer->scrollToOffset(0, m_start);
177    }
178    else {
179        m_suspended = false;
180        m_stopped = false;
181    }
182
183    m_timer.startRepeating(speed() * 0.001);
184
185    if (frameView)
186        frameView->resumeScheduledEvents();
187}
188
189void RenderMarquee::suspend()
190{
191    m_timer.stop();
192    m_suspended = true;
193}
194
195void RenderMarquee::stop()
196{
197    m_timer.stop();
198    m_stopped = true;
199}
200
201void RenderMarquee::updateMarqueePosition()
202{
203    bool activate = (m_totalLoops <= 0 || m_currentLoop < m_totalLoops);
204    if (activate) {
205        EMarqueeBehavior behavior = m_layer->renderer()->style()->marqueeBehavior();
206        m_start = computePosition(direction(), behavior == MALTERNATE);
207        m_end = computePosition(reverseDirection(), behavior == MALTERNATE || behavior == MSLIDE);
208        if (!m_stopped)
209            start();
210    }
211}
212
213void RenderMarquee::updateMarqueeStyle()
214{
215    RenderStyle* s = m_layer->renderer()->style();
216
217    if (m_direction != s->marqueeDirection() || (m_totalLoops != s->marqueeLoopCount() && m_currentLoop >= m_totalLoops))
218        m_currentLoop = 0; // When direction changes or our loopCount is a smaller number than our current loop, reset our loop.
219
220    m_totalLoops = s->marqueeLoopCount();
221    m_direction = s->marqueeDirection();
222
223    if (m_layer->renderer()->isHTMLMarquee()) {
224        // Hack for WinIE.  In WinIE, a value of 0 or lower for the loop count for SLIDE means to only do
225        // one loop.
226        if (m_totalLoops <= 0 && s->marqueeBehavior() == MSLIDE)
227            m_totalLoops = 1;
228
229        // Hack alert: Set the white-space value to nowrap for horizontal marquees with inline children, thus ensuring
230        // all the text ends up on one line by default.  Limit this hack to the <marquee> element to emulate
231        // WinIE's behavior.  Someone using CSS3 can use white-space: nowrap on their own to get this effect.
232        // Second hack alert: Set the text-align back to auto.  WinIE completely ignores text-align on the
233        // marquee element.
234        // FIXME: Bring these up with the CSS WG.
235        if (isHorizontal() && m_layer->renderer()->childrenInline()) {
236            s->setWhiteSpace(NOWRAP);
237            s->setTextAlign(TAAUTO);
238        }
239    }
240
241    // Marquee height hack!! Make sure that, if it is a horizontal marquee, the height attribute is overridden
242    // if it is smaller than the font size. If it is a vertical marquee and height is not specified, we default
243    // to a marquee of 200px.
244    if (isHorizontal()) {
245        if (s->height().isFixed() && s->height().value() < s->fontSize())
246            s->setHeight(Length(s->fontSize(), Fixed));
247    } else if (s->height().isAuto())  //vertical marquee with no specified height
248        s->setHeight(Length(200, Fixed));
249
250    if (speed() != marqueeSpeed()) {
251        m_speed = marqueeSpeed();
252        if (m_timer.isActive())
253            m_timer.startRepeating(speed() * 0.001);
254    }
255
256    // Check the loop count to see if we should now stop.
257    bool activate = (m_totalLoops <= 0 || m_currentLoop < m_totalLoops);
258    if (activate && !m_timer.isActive())
259        m_layer->renderer()->setNeedsLayout(true);
260    else if (!activate && m_timer.isActive())
261        m_timer.stop();
262}
263
264void RenderMarquee::timerFired(Timer<RenderMarquee>*)
265{
266    if (m_layer->renderer()->needsLayout())
267        return;
268
269    if (m_reset) {
270        m_reset = false;
271        if (isHorizontal())
272            m_layer->scrollToXOffset(m_start);
273        else
274            m_layer->scrollToYOffset(m_start);
275        return;
276    }
277
278    RenderStyle* s = m_layer->renderer()->style();
279
280    int endPoint = m_end;
281    int range = m_end - m_start;
282    int newPos;
283    if (range == 0)
284        newPos = m_end;
285    else {
286        bool addIncrement = direction() == MUP || direction() == MLEFT;
287        bool isReversed = s->marqueeBehavior() == MALTERNATE && m_currentLoop % 2;
288        if (isReversed) {
289            // We're going in the reverse direction.
290            endPoint = m_start;
291            range = -range;
292            addIncrement = !addIncrement;
293        }
294        bool positive = range > 0;
295        int clientSize = (isHorizontal() ? m_layer->renderBox()->clientWidth() : m_layer->renderBox()->clientHeight());
296        int increment = abs(m_layer->renderer()->style()->marqueeIncrement().calcValue(clientSize));
297        int currentPos = (isHorizontal() ? m_layer->scrollXOffset() : m_layer->scrollYOffset());
298        newPos =  currentPos + (addIncrement ? increment : -increment);
299        if (positive)
300            newPos = min(newPos, endPoint);
301        else
302            newPos = max(newPos, endPoint);
303    }
304
305    if (newPos == endPoint) {
306        m_currentLoop++;
307        if (m_totalLoops > 0 && m_currentLoop >= m_totalLoops)
308            m_timer.stop();
309        else if (s->marqueeBehavior() != MALTERNATE)
310            m_reset = true;
311    }
312
313    if (isHorizontal())
314        m_layer->scrollToXOffset(newPos);
315    else
316        m_layer->scrollToYOffset(newPos);
317}
318
319} // namespace WebCore
320