third_party/WebKit/Source/platform/scroll/ScrollbarTheme.h

   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 #ifndef ScrollbarTheme_h
  27 #define ScrollbarTheme_h
  28
  29 #include "platform/PlatformExport.h"
  30 #include "platform/geometry/IntRect.h"
  31 #include "platform/graphics/paint/DisplayItem.h"
  32 #include "platform/scroll/ScrollTypes.h"
  33 #include "public/platform/mac/MacScrollTypes.h"
  34
  35 namespace blink {
  36
  37 class GraphicsContext;
  38 class PlatformMouseEvent;
  39 class ScrollbarThemeClient;
  40
  41 class PLATFORM_EXPORT ScrollbarTheme {
  42     WTF_MAKE_NONCOPYABLE(ScrollbarTheme); WTF_MAKE_FAST_ALLOCATED(ScrollbarTheme);
  43 public:
  44     ScrollbarTheme() { }
  45     virtual ~ScrollbarTheme() { }
  46
  47     virtual void updateEnabledState(ScrollbarThemeClient*) { }
  48
  49     virtual bool paint(ScrollbarThemeClient*, GraphicsContext*, const IntRect& damageRect);
  50
  51     virtual ScrollbarPart hitTest(ScrollbarThemeClient*, const IntPoint&);
  52
  53     virtual int scrollbarThickness(ScrollbarControlSize = RegularScrollbar) { return 0; }
  54     virtual int scrollbarMargin() const { return 0; }
  55
  56     virtual ScrollbarButtonsPlacement buttonsPlacement() const { return ScrollbarButtonsPlacementSingle; }
  57
  58     virtual bool supportsControlTints() const { return false; }
  59     virtual bool usesOverlayScrollbars() const { return false; }
  60     virtual void updateScrollbarOverlayStyle(ScrollbarThemeClient*) { }
  61
  62     virtual bool invalidateOnMouseEnterExit() { return false; }
  63
  64     void invalidateParts(ScrollbarThemeClient* scrollbar, ScrollbarControlPartMask mask)
  65     {
  66         if (mask & BackButtonStartPart)
  67             invalidatePart(scrollbar, BackButtonStartPart);
  68         if (mask & ForwardButtonStartPart)
  69             invalidatePart(scrollbar, ForwardButtonStartPart);
  70         if (mask & BackTrackPart)
  71             invalidatePart(scrollbar, BackTrackPart);
  72         if (mask & ThumbPart)
  73             invalidatePart(scrollbar, ThumbPart);
  74         if (mask & ForwardTrackPart)
  75             invalidatePart(scrollbar, ForwardTrackPart);
  76         if (mask & BackButtonEndPart)
  77             invalidatePart(scrollbar, BackButtonEndPart);
  78         if (mask & ForwardButtonEndPart)
  79             invalidatePart(scrollbar, ForwardButtonEndPart);
  80     }
  81
  82     virtual void invalidatePart(ScrollbarThemeClient*, ScrollbarPart);
  83
  84     virtual void paintScrollCorner(GraphicsContext*, const DisplayItemClientWrapper&, const IntRect& cornerRect);
  85     virtual void paintTickmarks(GraphicsContext*, ScrollbarThemeClient*, const IntRect&) { }
  86
  87     virtual bool shouldCenterOnThumb(ScrollbarThemeClient*, const PlatformMouseEvent&);
  88     virtual bool shouldSnapBackToDragOrigin(ScrollbarThemeClient*, const PlatformMouseEvent&);
  89     virtual bool shouldDragDocumentInsteadOfThumb(ScrollbarThemeClient*, const PlatformMouseEvent&) { return false; }
  90
  91     // The position of the thumb relative to the track.
  92     virtual int thumbPosition(ScrollbarThemeClient*);
  93     // The length of the thumb along the axis of the scrollbar.
  94     virtual int thumbLength(ScrollbarThemeClient*);
  95     // The position of the track relative to the scrollbar.
  96     virtual int trackPosition(ScrollbarThemeClient*);
  97     // The length of the track along the axis of the scrollbar.
  98     virtual int trackLength(ScrollbarThemeClient*);
  99
 100     virtual bool hasButtons(ScrollbarThemeClient*) = 0;
 101     virtual bool hasThumb(ScrollbarThemeClient*) = 0;
 102
 103     virtual IntRect backButtonRect(ScrollbarThemeClient*, ScrollbarPart, bool painting = false) = 0;
 104     virtual IntRect forwardButtonRect(ScrollbarThemeClient*, ScrollbarPart, bool painting = false) = 0;
 105     virtual IntRect trackRect(ScrollbarThemeClient*, bool painting = false) = 0;
 106     virtual IntRect thumbRect(ScrollbarThemeClient*);
 107     virtual int thumbThickness(ScrollbarThemeClient*);
 108
 109     virtual int minimumThumbLength(ScrollbarThemeClient*);
 110
 111     virtual void splitTrack(ScrollbarThemeClient*, const IntRect& track, IntRect& startTrack, IntRect& thumb, IntRect& endTrack);
 112
 113     virtual void paintScrollbarBackground(GraphicsContext*, ScrollbarThemeClient*) { }
 114     virtual void paintTrackBackground(GraphicsContext*, ScrollbarThemeClient*, const IntRect&) { }
 115     virtual void paintTrackPiece(GraphicsContext*, ScrollbarThemeClient*, const IntRect&, ScrollbarPart) { }
 116     virtual void paintButton(GraphicsContext*, ScrollbarThemeClient*, const IntRect&, ScrollbarPart) { }
 117     virtual void paintThumb(GraphicsContext*, ScrollbarThemeClient*, const IntRect&) { }
 118
 119     virtual int maxOverlapBetweenPages() { return std::numeric_limits<int>::max(); }
 120
 121     virtual double initialAutoscrollTimerDelay() { return 0.25; }
 122     virtual double autoscrollTimerDelay() { return 0.05; }
 123
 124     virtual IntRect constrainTrackRectToTrackPieces(ScrollbarThemeClient*, const IntRect& rect) { return rect; }
 125
 126     virtual void registerScrollbar(ScrollbarThemeClient*) { }
 127     virtual void unregisterScrollbar(ScrollbarThemeClient*) { }
 128
 129     virtual bool isMockTheme() const { return false; }
 130
 131     static ScrollbarTheme* theme();
 132
 133     static void setMockScrollbarsEnabled(bool flag);
 134     static bool mockScrollbarsEnabled();
 135
 136 protected:
 137     static DisplayItem::Type buttonPartToDisplayItemType(ScrollbarPart);
 138     static DisplayItem::Type trackPiecePartToDisplayItemType(ScrollbarPart);
 139
 140 private:
 141     static ScrollbarTheme* nativeTheme(); // Must be implemented to return the correct theme subclass.
 142     static bool gMockScrollbarsEnabled;
 143 };
 144
 145 }
 146 #endif