WebCore/platform/Scrollbar.h

   1 /*
   2  * Copyright (C) 2004, 2006 Apple Computer, 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 COMPUTER, 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 COMPUTER, 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 Scrollbar_h
  27 #define Scrollbar_h
  28
  29 #include <wtf/RefCounted.h>
  30 #include "ScrollTypes.h"
  31 #include "Timer.h"
  32 #include "Widget.h"
  33 #include <wtf/MathExtras.h>
  34 #include <wtf/PassRefPtr.h>
  35
  36 namespace WebCore {
  37
  38 class GraphicsContext;
  39 class IntRect;
  40 class ScrollbarClient;
  41 class ScrollbarTheme;
  42 class PlatformMouseEvent;
  43
  44 // These match the numbers we use over in WebKit (WebFrameView.m).
  45 const int cScrollbarPixelsPerLineStep =  40;
  46 const float cMouseWheelPixelsPerLineStep = 40.0f / 3.0f;
  47 const int cAmountToKeepWhenPaging = 40;
  48
  49 class Scrollbar : public Widget, public RefCounted<Scrollbar> {
  50 protected:
  51     Scrollbar(ScrollbarClient*, ScrollbarOrientation, ScrollbarControlSize, ScrollbarTheme* = 0);
  52
  53 public:
  54     virtual ~Scrollbar();
  55
  56     // Must be implemented by platforms that can't simply use the Scrollbar base class.  Right now the only platform that is not using the base class is GTK.
  57     static PassRefPtr<Scrollbar> createNativeScrollbar(ScrollbarClient* client, ScrollbarOrientation orientation, ScrollbarControlSize size);
  58
  59     void setClient(ScrollbarClient* client) { m_client = client; }
  60     ScrollbarClient* client() const { return m_client; }
  61
  62     ScrollbarOrientation orientation() const { return m_orientation; }
  63
  64     int value() const { return lroundf(m_currentPos); }
  65     float currentPos() const { return m_currentPos; }
  66     int pressedPos() const { return m_pressedPos; }
  67     int visibleSize() const { return m_visibleSize; }
  68     int totalSize() const { return m_totalSize; }
  69     int maximum() const { return m_totalSize - m_visibleSize; }
  70     ScrollbarControlSize controlSize() const { return m_controlSize; }
  71
  72     int lineStep() const { return m_lineStep; }
  73     int pageStep() const { return m_pageStep; }
  74     float pixelStep() const { return m_pixelStep; }
  75
  76     ScrollbarPart pressedPart() const { return m_pressedPart; }
  77     ScrollbarPart hoveredPart() const { return m_hoveredPart; }
  78     virtual void setHoveredPart(ScrollbarPart);
  79     virtual void setPressedPart(ScrollbarPart);
  80
  81     void setSteps(int lineStep, int pageStep, int pixelsPerStep = 1);
  82     bool setValue(int);
  83     void setProportion(int visibleSize, int totalSize);
  84     void setPressedPos(int p) { m_pressedPos = p; }
  85
  86     bool scroll(ScrollDirection, ScrollGranularity, float multiplier = 1.0f);
  87
  88     virtual void paint(GraphicsContext*, const IntRect& damageRect);
  89
  90     bool enabled() const { return m_enabled; }
  91     virtual void setEnabled(bool e);
  92
  93     bool isWindowActive() const;
  94
  95     // These methods are used for platform scrollbars to give :hover feedback.  They will not get called
  96     // when the mouse went down in a scrollbar, since it is assumed the scrollbar will start
  97     // grabbing all events in that case anyway.
  98     bool mouseMoved(const PlatformMouseEvent&);
  99     bool mouseExited();
 100
 101     // Used by some platform scrollbars to know when they've been released from capture.
 102     bool mouseUp();
 103
 104     bool mouseDown(const PlatformMouseEvent&);
 105
 106 #if PLATFORM(QT)
 107     // For platforms that wish to handle context menu events.
 108     // FIXME: This is misplaced.  Normal hit testing should be used to populate a correct
 109     // context menu.  There's no reason why the scrollbar should have to do it.
 110     bool contextMenu(const PlatformMouseEvent& event);
 111 #endif
 112
 113     // Takes an event and accounts for any transforms that might occur on the scrollbar.  Returns
 114     // a new event that has had all of the transforms applied.
 115     PlatformMouseEvent transformEvent(const PlatformMouseEvent&);
 116
 117     ScrollbarTheme* theme() const { return m_theme; }
 118
 119     virtual void setParent(ScrollView*);
 120     virtual void setFrameRect(const IntRect&);
 121
 122     virtual void invalidateRect(const IntRect&);
 123
 124     bool suppressInvalidation() const { return m_suppressInvalidation; }
 125     void setSuppressInvalidation(bool s) { m_suppressInvalidation = s; }
 126
 127     virtual void styleChanged() { }
 128
 129 protected:
 130     virtual void updateThumbPosition();
 131     virtual void updateThumbProportion();
 132
 133     void autoscrollTimerFired(Timer<Scrollbar>*);
 134     void startTimerIfNeeded(double delay);
 135     void stopTimerIfNeeded();
 136     void autoscrollPressedPart(double delay);
 137     ScrollDirection pressedPartScrollDirection();
 138     ScrollGranularity pressedPartScrollGranularity();
 139
 140     void moveThumb(int pos);
 141
 142     ScrollbarClient* m_client;
 143     ScrollbarOrientation m_orientation;
 144     ScrollbarControlSize m_controlSize;
 145     ScrollbarTheme* m_theme;
 146
 147     int m_visibleSize;
 148     int m_totalSize;
 149     float m_currentPos;
 150     int m_lineStep;
 151     int m_pageStep;
 152     float m_pixelStep;
 153
 154     ScrollbarPart m_hoveredPart;
 155     ScrollbarPart m_pressedPart;
 156     int m_pressedPos;
 157
 158     bool m_enabled;
 159
 160     Timer<Scrollbar> m_scrollTimer;
 161     bool m_overlapsResizer;
 162
 163     bool m_suppressInvalidation;
 164 };
 165
 166 }
 167
 168 #endif