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      1 /*
      2  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
      3  * Copyright (C) 2008, 2009 Google Inc.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
     15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
     18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 
     27 #include "config.h"
     28 #include "ScrollbarThemeChromium.h"
     29 
     30 #include "PlatformBridge.h"
     31 #include "PlatformMouseEvent.h"
     32 #include "ScrollableArea.h"
     33 #include "Scrollbar.h"
     34 #include "ScrollbarThemeComposite.h"
     35 
     36 // -----------------------------------------------------------------------------
     37 // This file contains scrollbar theme code that is cross platform. Additional
     38 // members of ScrollbarThemeChromium can be found in the platform specific files
     39 // -----------------------------------------------------------------------------
     40 
     41 namespace WebCore {
     42 
     43 bool ScrollbarThemeChromium::hasThumb(Scrollbar* scrollbar)
     44 {
     45     // This method is just called as a paint-time optimization to see if
     46     // painting the thumb can be skipped.  We don't have to be exact here.
     47     return thumbLength(scrollbar) > 0;
     48 }
     49 
     50 IntRect ScrollbarThemeChromium::backButtonRect(Scrollbar* scrollbar, ScrollbarPart part, bool)
     51 {
     52     // Windows and Linux just have single arrows.
     53     if (part == BackButtonEndPart)
     54         return IntRect();
     55 
     56     IntSize size = buttonSize(scrollbar);
     57     return IntRect(scrollbar->x(), scrollbar->y(), size.width(), size.height());
     58 }
     59 
     60 IntRect ScrollbarThemeChromium::forwardButtonRect(Scrollbar* scrollbar, ScrollbarPart part, bool)
     61 {
     62     // Windows and Linux just have single arrows.
     63     if (part == ForwardButtonStartPart)
     64         return IntRect();
     65 
     66     IntSize size = buttonSize(scrollbar);
     67     int x, y;
     68     if (scrollbar->orientation() == HorizontalScrollbar) {
     69         x = scrollbar->x() + scrollbar->width() - size.width();
     70         y = scrollbar->y();
     71     } else {
     72         x = scrollbar->x();
     73         y = scrollbar->y() + scrollbar->height() - size.height();
     74     }
     75     return IntRect(x, y, size.width(), size.height());
     76 }
     77 
     78 IntRect ScrollbarThemeChromium::trackRect(Scrollbar* scrollbar, bool)
     79 {
     80     IntSize bs = buttonSize(scrollbar);
     81     // The buttons at the top and bottom of the scrollbar are square, so the
     82     // thickness of the scrollbar is also their height.
     83     int thickness = scrollbarThickness(scrollbar->controlSize());
     84     if (scrollbar->orientation() == HorizontalScrollbar) {
     85         // Once the scrollbar becomes smaller than the natural size of the
     86         // two buttons, the track disappears.
     87         if (scrollbar->width() < 2 * thickness)
     88             return IntRect();
     89         return IntRect(scrollbar->x() + bs.width(), scrollbar->y(), scrollbar->width() - 2 * bs.width(), thickness);
     90     }
     91     if (scrollbar->height() < 2 * thickness)
     92         return IntRect();
     93     return IntRect(scrollbar->x(), scrollbar->y() + bs.height(), thickness, scrollbar->height() - 2 * bs.height());
     94 }
     95 
     96 void ScrollbarThemeChromium::paintTrackBackground(GraphicsContext* context, Scrollbar* scrollbar, const IntRect& rect)
     97 {
     98     // Just assume a forward track part.  We only paint the track as a single piece when there is no thumb.
     99     if (!hasThumb(scrollbar))
    100         paintTrackPiece(context, scrollbar, rect, ForwardTrackPart);
    101 }
    102 
    103 void ScrollbarThemeChromium::paintTickmarks(GraphicsContext* context, Scrollbar* scrollbar, const IntRect& rect)
    104 {
    105     if (scrollbar->orientation() != VerticalScrollbar)
    106         return;
    107 
    108     if (rect.height() <= 0 || rect.width() <= 0)
    109         return;  // nothing to draw on.
    110 
    111     // Get the tickmarks for the frameview.
    112     Vector<IntRect> tickmarks;
    113     scrollbar->scrollableArea()->getTickmarks(tickmarks);
    114     if (!tickmarks.size())
    115         return;
    116 
    117     // Get the image for the tickmarks.
    118     static RefPtr<Image> dash = Image::loadPlatformResource("tickmarkDash");
    119     if (dash->isNull()) {
    120         ASSERT_NOT_REACHED();
    121         return;
    122     }
    123 
    124     context->save();
    125 
    126     for (Vector<IntRect>::const_iterator i = tickmarks.begin(); i != tickmarks.end(); ++i) {
    127         // Calculate how far down (in %) the tick-mark should appear.
    128         const float percent = static_cast<float>(i->y()) / scrollbar->totalSize();
    129 
    130         // Calculate how far down (in pixels) the tick-mark should appear.
    131         const int yPos = rect.y() + (rect.height() * percent);
    132 
    133         IntPoint tick(scrollbar->x(), yPos);
    134         context->drawImage(dash.get(), ColorSpaceDeviceRGB, tick);
    135     }
    136 
    137     context->restore();
    138 }
    139 
    140 } // namespace WebCore
    141