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      1 /*
      2  * Copyright (C) 2011 Google 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  *
      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 AND ITS CONTRIBUTORS "AS IS" AND ANY
     15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     17  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
     18  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     19  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     20  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     21  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #include "config.h"
     27 #include "platform/scroll/ScrollbarThemeOverlay.h"
     28 
     29 #include "platform/PlatformMouseEvent.h"
     30 #include "platform/graphics/GraphicsContext.h"
     31 #include "platform/scroll/ScrollbarThemeClient.h"
     32 #include "platform/transforms/TransformationMatrix.h"
     33 #include "public/platform/Platform.h"
     34 #include "public/platform/WebRect.h"
     35 #include "public/platform/WebThemeEngine.h"
     36 
     37 #include <algorithm>
     38 
     39 namespace blink {
     40 
     41 ScrollbarThemeOverlay::ScrollbarThemeOverlay(int thumbThickness, int scrollbarMargin, HitTestBehavior allowHitTest, Color color)
     42     : ScrollbarTheme()
     43     , m_thumbThickness(thumbThickness)
     44     , m_scrollbarMargin(scrollbarMargin)
     45     , m_allowHitTest(allowHitTest)
     46     , m_color(color)
     47     , m_useSolidColor(true)
     48 {
     49 }
     50 
     51 ScrollbarThemeOverlay::ScrollbarThemeOverlay(int thumbThickness, int scrollbarMargin, HitTestBehavior allowHitTest)
     52     : ScrollbarTheme()
     53     , m_thumbThickness(thumbThickness)
     54     , m_scrollbarMargin(scrollbarMargin)
     55     , m_allowHitTest(allowHitTest)
     56     , m_useSolidColor(false)
     57 {
     58 }
     59 
     60 int ScrollbarThemeOverlay::scrollbarThickness(ScrollbarControlSize controlSize)
     61 {
     62     return m_thumbThickness + m_scrollbarMargin;
     63 }
     64 
     65 bool ScrollbarThemeOverlay::usesOverlayScrollbars() const
     66 {
     67     return true;
     68 }
     69 
     70 int ScrollbarThemeOverlay::thumbPosition(ScrollbarThemeClient* scrollbar)
     71 {
     72     if (!scrollbar->totalSize())
     73         return 0;
     74 
     75     int trackLen = trackLength(scrollbar);
     76     float proportion = static_cast<float>(scrollbar->currentPos()) / scrollbar->totalSize();
     77     return round(proportion * trackLen);
     78 }
     79 
     80 int ScrollbarThemeOverlay::thumbLength(ScrollbarThemeClient* scrollbar)
     81 {
     82     int trackLen = trackLength(scrollbar);
     83 
     84     if (!scrollbar->totalSize())
     85         return trackLen;
     86 
     87     float proportion = static_cast<float>(scrollbar->visibleSize()) / scrollbar->totalSize();
     88     int length = round(proportion * trackLen);
     89     length = std::min(std::max(length, minimumThumbLength(scrollbar)), trackLen);
     90     return length;
     91 }
     92 
     93 bool ScrollbarThemeOverlay::hasThumb(ScrollbarThemeClient* scrollbar)
     94 {
     95     return true;
     96 }
     97 
     98 IntRect ScrollbarThemeOverlay::backButtonRect(ScrollbarThemeClient*, ScrollbarPart, bool)
     99 {
    100     return IntRect();
    101 }
    102 
    103 IntRect ScrollbarThemeOverlay::forwardButtonRect(ScrollbarThemeClient*, ScrollbarPart, bool)
    104 {
    105     return IntRect();
    106 }
    107 
    108 IntRect ScrollbarThemeOverlay::trackRect(ScrollbarThemeClient* scrollbar, bool)
    109 {
    110     IntRect rect = scrollbar->frameRect();
    111     if (scrollbar->orientation() == HorizontalScrollbar)
    112         rect.inflateX(-m_scrollbarMargin);
    113     else
    114         rect.inflateY(-m_scrollbarMargin);
    115     return rect;
    116 }
    117 
    118 int ScrollbarThemeOverlay::thumbThickness(ScrollbarThemeClient*)
    119 {
    120     return m_thumbThickness;
    121 }
    122 
    123 void ScrollbarThemeOverlay::paintThumb(GraphicsContext* context, ScrollbarThemeClient* scrollbar, const IntRect& rect)
    124 {
    125     IntRect thumbRect = rect;
    126     if (scrollbar->orientation() == HorizontalScrollbar) {
    127         thumbRect.setHeight(thumbRect.height() - m_scrollbarMargin);
    128     } else {
    129         thumbRect.setWidth(thumbRect.width() - m_scrollbarMargin);
    130         if (scrollbar->isLeftSideVerticalScrollbar())
    131             thumbRect.setX(thumbRect.x() + m_scrollbarMargin);
    132     }
    133 
    134     if (m_useSolidColor) {
    135         context->fillRect(thumbRect, m_color);
    136         return;
    137     }
    138 
    139     blink::WebThemeEngine::State state = blink::WebThemeEngine::StateNormal;
    140     if (scrollbar->pressedPart() == ThumbPart)
    141         state = blink::WebThemeEngine::StatePressed;
    142     else if (scrollbar->hoveredPart() == ThumbPart)
    143         state = blink::WebThemeEngine::StateHover;
    144 
    145     blink::WebCanvas* canvas = context->canvas();
    146 
    147     blink::WebThemeEngine::Part part = blink::WebThemeEngine::PartScrollbarHorizontalThumb;
    148     if (scrollbar->orientation() == VerticalScrollbar)
    149         part = blink::WebThemeEngine::PartScrollbarVerticalThumb;
    150 
    151     blink::Platform::current()->themeEngine()->paint(canvas, part, state, blink::WebRect(rect), 0);
    152 }
    153 
    154 ScrollbarPart ScrollbarThemeOverlay::hitTest(ScrollbarThemeClient* scrollbar, const IntPoint& position)
    155 {
    156     if (m_allowHitTest == DisallowHitTest)
    157         return NoPart;
    158 
    159     return ScrollbarTheme::hitTest(scrollbar, position);
    160 }
    161 
    162 } // namespace blink
    163