Scrollbar.cpp revision 635860845790a19bf50bbc51ba8fb66a96dde068 
1/*
2 * Copyright (C) 2004, 2006, 2008 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "Scrollbar.h"
28
29#include "EventHandler.h"
30#include "Frame.h"
31#include "FrameView.h"
32#include "GraphicsContext.h"
33#include "PlatformMouseEvent.h"
34#include "ScrollbarClient.h"
35#include "ScrollbarTheme.h"
36
37#include <algorithm>
38
39using std::max;
40using std::min;
41
42namespace WebCore {
43
44#if !PLATFORM(GTK)
45PassRefPtr<Scrollbar> Scrollbar::createNativeScrollbar(ScrollbarClient* client, ScrollbarOrientation orientation, ScrollbarControlSize size)
46{
47    return adoptRef(new Scrollbar(client, orientation, size));
48}
49#endif
50
51Scrollbar::Scrollbar(ScrollbarClient* client, ScrollbarOrientation orientation, ScrollbarControlSize controlSize,
52                     ScrollbarTheme* theme)
53    : m_client(client)
54    , m_orientation(orientation)
55    , m_controlSize(controlSize)
56    , m_theme(theme)
57    , m_visibleSize(0)
58    , m_totalSize(0)
59    , m_currentPos(0)
60    , m_lineStep(0)
61    , m_pageStep(0)
62    , m_pixelStep(1)
63    , m_hoveredPart(NoPart)
64    , m_pressedPart(NoPart)
65    , m_pressedPos(0)
66    , m_enabled(true)
67    , m_scrollTimer(this, &Scrollbar::autoscrollTimerFired)
68    , m_overlapsResizer(false)
69    , m_suppressInvalidation(false)
70{
71    if (!m_theme)
72        m_theme = ScrollbarTheme::nativeTheme();
73
74    m_theme->registerScrollbar(this);
75
76    // FIXME: This is ugly and would not be necessary if we fix cross-platform code to actually query for
77    // scrollbar thickness and use it when sizing scrollbars (rather than leaving one dimension of the scrollbar
78    // alone when sizing).
79    int thickness = m_theme->scrollbarThickness(controlSize);
80    Widget::setFrameRect(IntRect(0, 0, thickness, thickness));
81}
82
83Scrollbar::~Scrollbar()
84{
85    stopTimerIfNeeded();
86
87    m_theme->unregisterScrollbar(this);
88}
89
90bool Scrollbar::setValue(int v)
91{
92    v = max(min(v, m_totalSize - m_visibleSize), 0);
93    if (value() == v)
94        return false; // Our value stayed the same.
95    m_currentPos = v;
96
97    updateThumbPosition();
98
99    if (client())
100        client()->valueChanged(this);
101
102    return true;
103}
104
105void Scrollbar::setProportion(int visibleSize, int totalSize)
106{
107    if (visibleSize == m_visibleSize && totalSize == m_totalSize)
108        return;
109
110    m_visibleSize = visibleSize;
111    m_totalSize = totalSize;
112
113    updateThumbProportion();
114}
115
116void Scrollbar::setSteps(int lineStep, int pageStep, int pixelsPerStep)
117{
118    m_lineStep = lineStep;
119    m_pageStep = pageStep;
120    m_pixelStep = 1.0f / pixelsPerStep;
121}
122
123bool Scrollbar::scroll(ScrollDirection direction, ScrollGranularity granularity, float multiplier)
124{
125    float step = 0;
126    if ((direction == ScrollUp && m_orientation == VerticalScrollbar) || (direction == ScrollLeft && m_orientation == HorizontalScrollbar))
127        step = -1;
128    else if ((direction == ScrollDown && m_orientation == VerticalScrollbar) || (direction == ScrollRight && m_orientation == HorizontalScrollbar))
129        step = 1;
130
131    if (granularity == ScrollByLine)
132        step *= m_lineStep;
133    else if (granularity == ScrollByPage)
134        step *= m_pageStep;
135    else if (granularity == ScrollByDocument)
136        step *= m_totalSize;
137    else if (granularity == ScrollByPixel)
138        step *= m_pixelStep;
139
140    float newPos = m_currentPos + step * multiplier;
141    float maxPos = m_totalSize - m_visibleSize;
142    newPos = max(min(newPos, maxPos), 0.0f);
143
144    if (newPos == m_currentPos)
145        return false;
146
147    int oldValue = value();
148    m_currentPos = newPos;
149    updateThumbPosition();
150
151    if (value() != oldValue && client())
152        client()->valueChanged(this);
153
154    // return true even if the integer value did not change so that scroll event gets eaten
155    return true;
156}
157
158void Scrollbar::updateThumbPosition()
159{
160    theme()->invalidateParts(this, ForwardTrackPart | BackTrackPart | ThumbPart);
161}
162
163void Scrollbar::updateThumbProportion()
164{
165    theme()->invalidateParts(this, ForwardTrackPart | BackTrackPart | ThumbPart);
166}
167
168void Scrollbar::paint(GraphicsContext* context, const IntRect& damageRect)
169{
170    if (context->updatingControlTints() && theme()->supportsControlTints()) {
171        invalidate();
172        return;
173    }
174
175    if (context->paintingDisabled() || !frameRect().intersects(damageRect))
176        return;
177
178    if (!theme()->paint(this, context, damageRect))
179        Widget::paint(context, damageRect);
180}
181
182void Scrollbar::autoscrollTimerFired(Timer<Scrollbar>*)
183{
184    autoscrollPressedPart(theme()->autoscrollTimerDelay());
185}
186
187static bool thumbUnderMouse(Scrollbar* scrollbar)
188{
189    int thumbPos = scrollbar->theme()->trackPosition(scrollbar) + scrollbar->theme()->thumbPosition(scrollbar);
190    int thumbLength = scrollbar->theme()->thumbLength(scrollbar);
191    return scrollbar->pressedPos() >= thumbPos && scrollbar->pressedPos() < thumbPos + thumbLength;
192}
193
194void Scrollbar::autoscrollPressedPart(double delay)
195{
196    // Don't do anything for the thumb or if nothing was pressed.
197    if (m_pressedPart == ThumbPart || m_pressedPart == NoPart)
198        return;
199
200    // Handle the track.
201    if ((m_pressedPart == BackTrackPart || m_pressedPart == ForwardTrackPart) && thumbUnderMouse(this)) {
202        theme()->invalidatePart(this, m_pressedPart);
203        setHoveredPart(ThumbPart);
204        return;
205    }
206
207    // Handle the arrows and track.
208    if (scroll(pressedPartScrollDirection(), pressedPartScrollGranularity()))
209        startTimerIfNeeded(delay);
210}
211
212void Scrollbar::startTimerIfNeeded(double delay)
213{
214    // Don't do anything for the thumb.
215    if (m_pressedPart == ThumbPart)
216        return;
217
218    // Handle the track.  We halt track scrolling once the thumb is level
219    // with us.
220    if ((m_pressedPart == BackTrackPart || m_pressedPart == ForwardTrackPart) && thumbUnderMouse(this)) {
221        theme()->invalidatePart(this, m_pressedPart);
222        setHoveredPart(ThumbPart);
223        return;
224    }
225
226    // We can't scroll if we've hit the beginning or end.
227    ScrollDirection dir = pressedPartScrollDirection();
228    if (dir == ScrollUp || dir == ScrollLeft) {
229        if (m_currentPos == 0)
230            return;
231    } else {
232        if (m_currentPos == maximum())
233            return;
234    }
235
236    m_scrollTimer.startOneShot(delay);
237}
238
239void Scrollbar::stopTimerIfNeeded()
240{
241    if (m_scrollTimer.isActive())
242        m_scrollTimer.stop();
243}
244
245ScrollDirection Scrollbar::pressedPartScrollDirection()
246{
247    if (m_orientation == HorizontalScrollbar) {
248        if (m_pressedPart == BackButtonStartPart || m_pressedPart == BackButtonEndPart || m_pressedPart == BackTrackPart)
249            return ScrollLeft;
250        return ScrollRight;
251    } else {
252        if (m_pressedPart == BackButtonStartPart || m_pressedPart == BackButtonEndPart || m_pressedPart == BackTrackPart)
253            return ScrollUp;
254        return ScrollDown;
255    }
256}
257
258ScrollGranularity Scrollbar::pressedPartScrollGranularity()
259{
260    if (m_pressedPart == BackButtonStartPart || m_pressedPart == BackButtonEndPart ||  m_pressedPart == ForwardButtonStartPart || m_pressedPart == ForwardButtonEndPart)
261        return ScrollByLine;
262    return ScrollByPage;
263}
264
265void Scrollbar::moveThumb(int pos)
266{
267    // Drag the thumb.
268    int thumbPos = theme()->thumbPosition(this);
269    int thumbLen = theme()->thumbLength(this);
270    int trackLen = theme()->trackLength(this);
271    int maxPos = trackLen - thumbLen;
272    int delta = pos - pressedPos();
273    if (delta > 0)
274        delta = min(maxPos - thumbPos, delta);
275    else if (delta < 0)
276        delta = max(-thumbPos, delta);
277    if (delta) {
278        setValue(static_cast<int>(static_cast<float>(thumbPos + delta) * maximum() / (trackLen - thumbLen)));
279        setPressedPos(pressedPos() + theme()->thumbPosition(this) - thumbPos);
280    }
281}
282
283void Scrollbar::setHoveredPart(ScrollbarPart part)
284{
285    if (part == m_hoveredPart)
286        return;
287
288    if ((m_hoveredPart == NoPart || part == NoPart) && theme()->invalidateOnMouseEnterExit())
289        invalidate();  // Just invalidate the whole scrollbar, since the buttons at either end change anyway.
290    else if (m_pressedPart == NoPart) {
291        theme()->invalidatePart(this, part);
292        theme()->invalidatePart(this, m_hoveredPart);
293    }
294    m_hoveredPart = part;
295}
296
297void Scrollbar::setPressedPart(ScrollbarPart part)
298{
299    if (m_pressedPart != NoPart)
300        theme()->invalidatePart(this, m_pressedPart);
301    m_pressedPart = part;
302    if (m_pressedPart != NoPart)
303        theme()->invalidatePart(this, m_pressedPart);
304}
305
306bool Scrollbar::mouseMoved(const PlatformMouseEvent& evt)
307{
308    if (m_pressedPart == ThumbPart) {
309        moveThumb(m_orientation == HorizontalScrollbar ?
310                  convertFromContainingWindow(evt.pos()).x() :
311                  convertFromContainingWindow(evt.pos()).y());
312        return true;
313    }
314
315    if (m_pressedPart != NoPart)
316        m_pressedPos = (orientation() == HorizontalScrollbar ? convertFromContainingWindow(evt.pos()).x() : convertFromContainingWindow(evt.pos()).y());
317
318    ScrollbarPart part = theme()->hitTest(this, evt);
319    if (part != m_hoveredPart) {
320        if (m_pressedPart != NoPart) {
321            if (part == m_pressedPart) {
322                // The mouse is moving back over the pressed part.  We
323                // need to start up the timer action again.
324                startTimerIfNeeded(theme()->autoscrollTimerDelay());
325                theme()->invalidatePart(this, m_pressedPart);
326            } else if (m_hoveredPart == m_pressedPart) {
327                // The mouse is leaving the pressed part.  Kill our timer
328                // if needed.
329                stopTimerIfNeeded();
330                theme()->invalidatePart(this, m_pressedPart);
331            }
332        }
333
334        setHoveredPart(part);
335    }
336
337    return true;
338}
339
340bool Scrollbar::mouseExited()
341{
342    setHoveredPart(NoPart);
343    return true;
344}
345
346bool Scrollbar::mouseUp()
347{
348    setPressedPart(NoPart);
349    m_pressedPos = 0;
350    stopTimerIfNeeded();
351
352    if (parent() && parent()->isFrameView())
353        static_cast<FrameView*>(parent())->frame()->eventHandler()->setMousePressed(false);
354
355    return true;
356}
357
358bool Scrollbar::mouseDown(const PlatformMouseEvent& evt)
359{
360    // Early exit for right click
361    if (evt.button() == RightButton)
362        return true; // FIXME: Handled as context menu by Qt right now.  Should just avoid even calling this method on a right click though.
363
364    setPressedPart(theme()->hitTest(this, evt));
365    int pressedPos = (orientation() == HorizontalScrollbar ? convertFromContainingWindow(evt.pos()).x() : convertFromContainingWindow(evt.pos()).y());
366
367    if ((pressedPart() == BackTrackPart || pressedPart() == ForwardTrackPart) && theme()->shouldCenterOnThumb(this, evt)) {
368        setHoveredPart(ThumbPart);
369        setPressedPart(ThumbPart);
370        int thumbLen = theme()->thumbLength(this);
371        int desiredPos = pressedPos;
372        // Set the pressed position to the middle of the thumb so that when we do the move, the delta
373        // will be from the current pixel position of the thumb to the new desired position for the thumb.
374        m_pressedPos = theme()->trackPosition(this) + theme()->thumbPosition(this) + thumbLen / 2;
375        moveThumb(desiredPos);
376        return true;
377    }
378
379    m_pressedPos = pressedPos;
380
381    autoscrollPressedPart(theme()->initialAutoscrollTimerDelay());
382    return true;
383}
384
385void Scrollbar::setFrameRect(const IntRect& rect)
386{
387    // Get our window resizer rect and see if we overlap.  Adjust to avoid the overlap
388    // if necessary.
389    IntRect adjustedRect(rect);
390    if (parent()) {
391        bool overlapsResizer = false;
392        ScrollView* view = parent();
393        IntRect resizerRect = view->convertFromContainingWindow(view->windowResizerRect());
394        if (rect.intersects(resizerRect)) {
395            if (orientation() == HorizontalScrollbar) {
396                int overlap = rect.right() - resizerRect.x();
397                if (overlap > 0 && resizerRect.right() >= rect.right()) {
398                    adjustedRect.setWidth(rect.width() - overlap);
399                    overlapsResizer = true;
400                }
401            } else {
402                int overlap = rect.bottom() - resizerRect.y();
403                if (overlap > 0 && resizerRect.bottom() >= rect.bottom()) {
404                    adjustedRect.setHeight(rect.height() - overlap);
405                    overlapsResizer = true;
406                }
407            }
408        }
409
410        if (overlapsResizer != m_overlapsResizer) {
411            m_overlapsResizer = overlapsResizer;
412            view->adjustScrollbarsAvoidingResizerCount(m_overlapsResizer ? 1 : -1);
413        }
414    }
415
416    Widget::setFrameRect(adjustedRect);
417}
418
419void Scrollbar::setParent(ScrollView* parentView)
420{
421    if (!parentView && m_overlapsResizer && parent())
422        parent()->adjustScrollbarsAvoidingResizerCount(-1);
423    Widget::setParent(parentView);
424}
425
426void Scrollbar::setEnabled(bool e)
427{
428    if (m_enabled == e)
429        return;
430    m_enabled = e;
431    invalidate();
432}
433
434bool Scrollbar::isWindowActive() const
435{
436    return m_client && m_client->isActive();
437}
438
439void Scrollbar::invalidateRect(const IntRect& rect)
440{
441    if (suppressInvalidation())
442        return;
443    if (m_client)
444        m_client->invalidateScrollbarRect(this, rect);
445}
446
447PlatformMouseEvent Scrollbar::transformEvent(const PlatformMouseEvent& event)
448{
449    return event;
450}
451
452}
453