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      1 /*
      2  * Copyright (C) 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 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 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 "core/rendering/RenderScrollbarPart.h"
     28 
     29 #include "core/rendering/PaintInfo.h"
     30 #include "core/rendering/RenderScrollbar.h"
     31 #include "core/rendering/RenderScrollbarTheme.h"
     32 #include "core/rendering/RenderView.h"
     33 
     34 using namespace std;
     35 
     36 namespace WebCore {
     37 
     38 RenderScrollbarPart::RenderScrollbarPart(RenderScrollbar* scrollbar, ScrollbarPart part)
     39     : RenderBlock(0)
     40     , m_scrollbar(scrollbar)
     41     , m_part(part)
     42 {
     43 }
     44 
     45 RenderScrollbarPart::~RenderScrollbarPart()
     46 {
     47 }
     48 
     49 RenderScrollbarPart* RenderScrollbarPart::createAnonymous(Document* document, RenderScrollbar* scrollbar, ScrollbarPart part)
     50 {
     51     RenderScrollbarPart* renderer = new RenderScrollbarPart(scrollbar, part);
     52     renderer->setDocumentForAnonymous(document);
     53     return renderer;
     54 }
     55 
     56 void RenderScrollbarPart::layout()
     57 {
     58     StackStats::LayoutCheckPoint layoutCheckPoint;
     59     setLocation(LayoutPoint()); // We don't worry about positioning ourselves. We're just determining our minimum width/height.
     60     if (m_scrollbar->orientation() == HorizontalScrollbar)
     61         layoutHorizontalPart();
     62     else
     63         layoutVerticalPart();
     64 
     65     clearNeedsLayout();
     66 }
     67 
     68 void RenderScrollbarPart::layoutHorizontalPart()
     69 {
     70     if (m_part == ScrollbarBGPart) {
     71         setWidth(m_scrollbar->width());
     72         computeScrollbarHeight();
     73     } else {
     74         computeScrollbarWidth();
     75         setHeight(m_scrollbar->height());
     76     }
     77 }
     78 
     79 void RenderScrollbarPart::layoutVerticalPart()
     80 {
     81     if (m_part == ScrollbarBGPart) {
     82         computeScrollbarWidth();
     83         setHeight(m_scrollbar->height());
     84     } else {
     85         setWidth(m_scrollbar->width());
     86         computeScrollbarHeight();
     87     }
     88 }
     89 
     90 static int calcScrollbarThicknessUsing(SizeType sizeType, const Length& length, int containingLength, RenderView* renderView)
     91 {
     92     if (!length.isIntrinsicOrAuto() || (sizeType == MinSize && length.isAuto()))
     93         return minimumValueForLength(length, containingLength, renderView);
     94     return ScrollbarTheme::theme()->scrollbarThickness();
     95 }
     96 
     97 void RenderScrollbarPart::computeScrollbarWidth()
     98 {
     99     if (!m_scrollbar->owningRenderer())
    100         return;
    101     RenderView* renderView = view();
    102     // FIXME: We are querying layout information but nothing guarantees that it's up-to-date, especially since we are called at style change.
    103     // FIXME: Querying the style's border information doesn't work on table cells with collapsing borders.
    104     int visibleSize = m_scrollbar->owningRenderer()->width() - m_scrollbar->owningRenderer()->style()->borderLeftWidth() - m_scrollbar->owningRenderer()->style()->borderRightWidth();
    105     int w = calcScrollbarThicknessUsing(MainOrPreferredSize, style()->width(), visibleSize, renderView);
    106     int minWidth = calcScrollbarThicknessUsing(MinSize, style()->minWidth(), visibleSize, renderView);
    107     int maxWidth = style()->maxWidth().isUndefined() ? w : calcScrollbarThicknessUsing(MaxSize, style()->maxWidth(), visibleSize, renderView);
    108     setWidth(max(minWidth, min(maxWidth, w)));
    109 
    110     // Buttons and track pieces can all have margins along the axis of the scrollbar.
    111     m_marginBox.setLeft(minimumValueForLength(style()->marginLeft(), visibleSize, renderView));
    112     m_marginBox.setRight(minimumValueForLength(style()->marginRight(), visibleSize, renderView));
    113 }
    114 
    115 void RenderScrollbarPart::computeScrollbarHeight()
    116 {
    117     if (!m_scrollbar->owningRenderer())
    118         return;
    119     RenderView* renderView = view();
    120     // FIXME: We are querying layout information but nothing guarantees that it's up-to-date, especially since we are called at style change.
    121     // FIXME: Querying the style's border information doesn't work on table cells with collapsing borders.
    122     int visibleSize = m_scrollbar->owningRenderer()->height() -  m_scrollbar->owningRenderer()->style()->borderTopWidth() - m_scrollbar->owningRenderer()->style()->borderBottomWidth();
    123     int h = calcScrollbarThicknessUsing(MainOrPreferredSize, style()->height(), visibleSize, renderView);
    124     int minHeight = calcScrollbarThicknessUsing(MinSize, style()->minHeight(), visibleSize, renderView);
    125     int maxHeight = style()->maxHeight().isUndefined() ? h : calcScrollbarThicknessUsing(MaxSize, style()->maxHeight(), visibleSize, renderView);
    126     setHeight(max(minHeight, min(maxHeight, h)));
    127 
    128     // Buttons and track pieces can all have margins along the axis of the scrollbar.
    129     m_marginBox.setTop(minimumValueForLength(style()->marginTop(), visibleSize, renderView));
    130     m_marginBox.setBottom(minimumValueForLength(style()->marginBottom(), visibleSize, renderView));
    131 }
    132 
    133 void RenderScrollbarPart::computePreferredLogicalWidths()
    134 {
    135     if (!preferredLogicalWidthsDirty())
    136         return;
    137 
    138     m_minPreferredLogicalWidth = m_maxPreferredLogicalWidth = 0;
    139 
    140     setPreferredLogicalWidthsDirty(false);
    141 }
    142 
    143 void RenderScrollbarPart::styleWillChange(StyleDifference diff, const RenderStyle* newStyle)
    144 {
    145     RenderBlock::styleWillChange(diff, newStyle);
    146     setInline(false);
    147 }
    148 
    149 void RenderScrollbarPart::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
    150 {
    151     RenderBlock::styleDidChange(diff, oldStyle);
    152     setInline(false);
    153     clearPositionedState();
    154     setFloating(false);
    155     setHasOverflowClip(false);
    156     if (oldStyle && m_scrollbar && m_part != NoPart && diff >= StyleDifferenceRepaint)
    157         m_scrollbar->theme()->invalidatePart(m_scrollbar, m_part);
    158 }
    159 
    160 void RenderScrollbarPart::imageChanged(WrappedImagePtr image, const IntRect* rect)
    161 {
    162     if (m_scrollbar && m_part != NoPart)
    163         m_scrollbar->theme()->invalidatePart(m_scrollbar, m_part);
    164     else {
    165         if (FrameView* frameView = view()->frameView()) {
    166             if (frameView->isFrameViewScrollCorner(this)) {
    167                 frameView->invalidateScrollCorner(frameView->scrollCornerRect());
    168                 return;
    169             }
    170         }
    171 
    172         RenderBlock::imageChanged(image, rect);
    173     }
    174 }
    175 
    176 void RenderScrollbarPart::paintIntoRect(GraphicsContext* graphicsContext, const LayoutPoint& paintOffset, const LayoutRect& rect)
    177 {
    178     // Make sure our dimensions match the rect.
    179     setLocation(rect.location() - toSize(paintOffset));
    180     setWidth(rect.width());
    181     setHeight(rect.height());
    182 
    183     if (graphicsContext->paintingDisabled())
    184         return;
    185 
    186     // Now do the paint.
    187     PaintInfo paintInfo(graphicsContext, pixelSnappedIntRect(rect), PaintPhaseBlockBackground, PaintBehaviorNormal);
    188     paint(paintInfo, paintOffset);
    189     paintInfo.phase = PaintPhaseChildBlockBackgrounds;
    190     paint(paintInfo, paintOffset);
    191     paintInfo.phase = PaintPhaseFloat;
    192     paint(paintInfo, paintOffset);
    193     paintInfo.phase = PaintPhaseForeground;
    194     paint(paintInfo, paintOffset);
    195     paintInfo.phase = PaintPhaseOutline;
    196     paint(paintInfo, paintOffset);
    197 }
    198 
    199 RenderObject* RenderScrollbarPart::rendererOwningScrollbar() const
    200 {
    201     if (!m_scrollbar)
    202         return 0;
    203     return m_scrollbar->owningRenderer();
    204 }
    205 
    206 }
    207