WebCore/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 "GraphicsContext.h"
  30 #include "IntRect.h"
  31 #include "ScrollTypes.h"
  32
  33 namespace WebCore {
  34
  35 class PlatformMouseEvent;
  36 class Scrollbar;
  37 class ScrollView;
  38
  39 class ScrollbarTheme {
  40 public:
  41     virtual ~ScrollbarTheme() {};
  42
  43     virtual bool paint(Scrollbar*, GraphicsContext*, const IntRect& /*damageRect*/) { return false; }
  44     virtual ScrollbarPart hitTest(Scrollbar*, const PlatformMouseEvent&) { return NoPart; }
  45
  46     virtual int scrollbarThickness(ScrollbarControlSize = RegularScrollbar) { return 0; }
  47
  48     virtual ScrollbarButtonsPlacement buttonsPlacement() const { return ScrollbarButtonsSingle; }
  49
  50     virtual bool supportsControlTints() const { return false; }
  51
  52     virtual void themeChanged() {}
  53
  54     virtual bool invalidateOnMouseEnterExit() { return false; }
  55
  56     void invalidateParts(Scrollbar* scrollbar, ScrollbarControlPartMask mask)
  57     {
  58         if (mask & BackButtonStartPart)
  59             invalidatePart(scrollbar, BackButtonStartPart);
  60         if (mask & ForwardButtonStartPart)
  61             invalidatePart(scrollbar, ForwardButtonStartPart);
  62         if (mask & BackTrackPart)
  63             invalidatePart(scrollbar, BackTrackPart);
  64         if (mask & ThumbPart)
  65             invalidatePart(scrollbar, ThumbPart);
  66         if (mask & ForwardTrackPart)
  67             invalidatePart(scrollbar, ForwardTrackPart);
  68         if (mask & BackButtonEndPart)
  69             invalidatePart(scrollbar, BackButtonEndPart);
  70         if (mask & ForwardButtonEndPart)
  71             invalidatePart(scrollbar, ForwardButtonEndPart);
  72     }
  73
  74     virtual void invalidatePart(Scrollbar*, ScrollbarPart) {}
  75
  76     virtual void paintScrollCorner(ScrollView*, GraphicsContext* context, const IntRect& cornerRect) { context->fillRect(cornerRect, Color::white); }
  77
  78     virtual bool shouldCenterOnThumb(Scrollbar*, const PlatformMouseEvent&) { return false; }
  79     virtual int thumbPosition(Scrollbar*) { return 0; } // The position of the thumb relative to the track.
  80     virtual int thumbLength(Scrollbar*) { return 0; } // The length of the thumb along the axis of the scrollbar.
  81     virtual int trackPosition(Scrollbar*) { return 0; } // The position of the track relative to the scrollbar.
  82     virtual int trackLength(Scrollbar*) { return 0; } // The length of the track along the axis of the scrollbar.
  83
  84     virtual double initialAutoscrollTimerDelay() { return 0.25; }
  85     virtual double autoscrollTimerDelay() { return 0.05; }
  86
  87     virtual void registerScrollbar(Scrollbar*) {}
  88     virtual void unregisterScrollbar(Scrollbar*) {}
  89
  90     static ScrollbarTheme* nativeTheme(); // Must be implemented to return the correct theme subclass.
  91 };
  92
  93 }
  94 #endif