WebCore/platform/ScrollView.h

   1 /*
   2  * Copyright (C) 2004, 2006, 2007, 2008 Apple Inc. All rights reserved.
   3  * Copyright (C) 2009 Holger Hans Peter Freyther
   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 COMPUTER, 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 COMPUTER, 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 #ifndef ScrollView_h
  28 #define ScrollView_h
  29
  30 #include "IntRect.h"
  31 #include "Scrollbar.h"
  32 #include "ScrollbarClient.h"
  33 #include "ScrollTypes.h"
  34 #include "Widget.h"
  35
  36 #include <wtf/HashSet.h>
  37
  38 #if PLATFORM(MAC) && defined __OBJC__
  39 @protocol WebCoreFrameScrollView;
  40 #endif
  41
  42 #if PLATFORM(GTK)
  43 typedef struct _GtkAdjustment GtkAdjustment;
  44 #endif
  45
  46 #if PLATFORM(WX)
  47 class wxScrollWinEvent;
  48 #endif
  49
  50 namespace WebCore {
  51
  52 class HostWindow;
  53 class PlatformWheelEvent;
  54 class Scrollbar;
  55
  56 class ScrollView : public Widget, public ScrollbarClient {
  57 public:
  58     ~ScrollView();
  59
  60     // ScrollbarClient method.  FrameView overrides the other two.
  61     virtual void valueChanged(Scrollbar*);
  62
  63     // The window thats hosts the ScrollView.  The ScrollView will communicate scrolls and repaints to the
  64     // host window in the window's coordinate space.
  65     virtual HostWindow* hostWindow() const = 0;
  66
  67     // Returns a clip rect in host window coordinates.  Used to clip the blit on a scroll.
  68     virtual IntRect windowClipRect(bool clipToContents = true) const = 0;
  69
  70     // Methods for child manipulation and inspection.
  71     const HashSet<RefPtr<Widget> >* children() const { return &m_children; }
  72     void addChild(PassRefPtr<Widget>);
  73     void removeChild(Widget*);
  74
  75     // If the scroll view does not use a native widget, then it will have cross-platform Scrollbars.  These methods
  76     // can be used to obtain those scrollbars.
  77     Scrollbar* horizontalScrollbar() const { return m_horizontalScrollbar.get(); }
  78     Scrollbar* verticalScrollbar() const { return m_verticalScrollbar.get(); }
  79     bool isScrollViewScrollbar(const Widget* child) const { return horizontalScrollbar() == child || verticalScrollbar() == child; }
  80
  81     // Methods for setting and retrieving the scrolling mode in each axis (horizontal/vertical).  The mode has values of
  82     // AlwaysOff, AlwaysOn, and Auto.  AlwaysOff means never show a scrollbar, AlwaysOn means always show a scrollbar.
  83     // Auto means show a scrollbar only when one is needed.
  84     // Note that for platforms with native widgets, these modes are considered advisory.  In other words the underlying native
  85     // widget may choose not to honor the requested modes.
  86     void setScrollbarModes(ScrollbarMode horizontalMode, ScrollbarMode verticalMode);
  87     void setHorizontalScrollbarMode(ScrollbarMode mode) { setScrollbarModes(mode, verticalScrollbarMode()); }
  88     void setVerticalScrollbarMode(ScrollbarMode mode) { setScrollbarModes(horizontalScrollbarMode(), mode); }
  89     void scrollbarModes(ScrollbarMode& horizontalMode, ScrollbarMode& verticalMode) const;
  90     ScrollbarMode horizontalScrollbarMode() const { ScrollbarMode horizontal, vertical; scrollbarModes(horizontal, vertical); return horizontal; }
  91     ScrollbarMode verticalScrollbarMode() const { ScrollbarMode horizontal, vertical; scrollbarModes(horizontal, vertical); return vertical; }
  92     virtual void setCanHaveScrollbars(bool);
  93     bool canHaveScrollbars() const { return horizontalScrollbarMode() != ScrollbarAlwaysOff || verticalScrollbarMode() != ScrollbarAlwaysOff; }
  94
  95     // By default you only receive paint events for the area that is visible. In the case of using a
  96     // tiled backing store, this method can be set, so that the view paints the entire contents.
  97     bool paintsEntireContents() const { return m_paintsEntireContents; }
  98     void setPaintsEntireContents(bool);
  99
 100     // Overridden by FrameView to create custom CSS scrollbars if applicable.
 101     virtual PassRefPtr<Scrollbar> createScrollbar(ScrollbarOrientation);
 102
 103     // If the prohibits scrolling flag is set, then all scrolling in the view (even programmatic scrolling) is turned off.
 104     void setProhibitsScrolling(bool b) { m_prohibitsScrolling = b; }
 105     bool prohibitsScrolling() const { return m_prohibitsScrolling; }
 106
 107     // Whether or not a scroll view will blit visible contents when it is scrolled.  Blitting is disabled in situations
 108     // where it would cause rendering glitches (such as with fixed backgrounds or when the view is partially transparent).
 109     void setCanBlitOnScroll(bool);
 110     bool canBlitOnScroll() const;
 111
 112     // The visible content rect has a location that is the scrolled offset of the document. The width and height are the viewport width
 113     // and height.  By default the scrollbars themselves are excluded from this rectangle, but an optional boolean argument allows them to be
 114     // included.
 115     IntRect visibleContentRect(bool includeScrollbars = false) const;
 116     int visibleWidth() const { return visibleContentRect().width(); }
 117     int visibleHeight() const { return visibleContentRect().height(); }
 118
 119     // Methods for getting/setting the size webkit should use to layout the contents.  By default this is the same as the visible
 120     // content size.  Explicitly setting a layout size value will cause webkit to layout the contents using this size instead.
 121     int layoutWidth() const;
 122     int layoutHeight() const;
 123     IntSize fixedLayoutSize() const;
 124     void setFixedLayoutSize(const IntSize&);
 125     bool useFixedLayout() const;
 126     void setUseFixedLayout(bool enable);
 127
 128     // Methods for getting/setting the size of the document contained inside the ScrollView (as an IntSize or as individual width and height
 129     // values).
 130     IntSize contentsSize() const; // Always at least as big as the visibleWidth()/visibleHeight().
 131     int contentsWidth() const { return contentsSize().width(); }
 132     int contentsHeight() const { return contentsSize().height(); }
 133     virtual void setContentsSize(const IntSize&);
 134
 135     // Methods for querying the current scrolled position (both as a point, a size, or as individual X and Y values).
 136     IntPoint scrollPosition() const { return visibleContentRect().location(); }
 137     IntSize scrollOffset() const { return visibleContentRect().location() - IntPoint(); } // Gets the scrolled position as an IntSize. Convenient for adding to other sizes.
 138     IntPoint maximumScrollPosition() const; // The maximum position we can be scrolled to.
 139     int scrollX() const { return scrollPosition().x(); }
 140     int scrollY() const { return scrollPosition().y(); }
 141
 142     // Methods for scrolling the view.  setScrollPosition is the only method that really scrolls the view.  The other two methods are helper functions
 143     // that ultimately end up calling setScrollPosition.
 144     void setScrollPosition(const IntPoint&);
 145     void scrollBy(const IntSize& s) { return setScrollPosition(scrollPosition() + s); }
 146     void scrollRectIntoViewRecursively(const IntRect&);
 147
 148     // This method scrolls by lines, pages or pixels.
 149     bool scroll(ScrollDirection, ScrollGranularity);
 150
 151     // Scroll the actual contents of the view (either blitting or invalidating as needed).
 152     void scrollContents(const IntSize& scrollDelta);
 153
 154     // This gives us a means of blocking painting on our scrollbars until the first layout has occurred.
 155     void setScrollbarsSuppressed(bool suppressed, bool repaintOnUnsuppress = false);
 156     bool scrollbarsSuppressed() const { return m_scrollbarsSuppressed; }
 157
 158     // Event coordinates are assumed to be in the coordinate space of a window that contains
 159     // the entire widget hierarchy. It is up to the platform to decide what the precise definition
 160     // of containing window is. (For example on Mac it is the containing NSWindow.)
 161     IntPoint windowToContents(const IntPoint&) const;
 162     IntPoint contentsToWindow(const IntPoint&) const;
 163     IntRect windowToContents(const IntRect&) const;
 164     IntRect contentsToWindow(const IntRect&) const;
 165
 166     // Methods for converting to and from screen coordinates.
 167     IntRect contentsToScreen(const IntRect&) const;
 168     IntPoint screenToContents(const IntPoint&) const;
 169
 170     // The purpose of this method is to answer whether or not the scroll view is currently visible.  Animations and painting updates can be suspended if
 171     // we know that we are either not in a window right now or if that window is not visible.
 172     bool isOffscreen() const;
 173
 174     // These methods are used to enable scrollbars to avoid window resizer controls that overlap the scroll view.  This happens on Mac
 175     // for example.
 176     virtual IntRect windowResizerRect() const { return IntRect(); }
 177     bool containsScrollbarsAvoidingResizer() const;
 178     void adjustScrollbarsAvoidingResizerCount(int overlapDelta);
 179     virtual void setParent(ScrollView*); // Overridden to update the overlapping scrollbar count.
 180
 181     // Called when our frame rect changes (or the rect/scroll position of an ancestor changes).
 182     virtual void frameRectsChanged();
 183
 184     // Widget override to update our scrollbars and notify our contents of the resize.
 185     virtual void setFrameRect(const IntRect&);
 186
 187     // For platforms that need to hit test scrollbars from within the engine's event handlers (like Win32).
 188     Scrollbar* scrollbarAtPoint(const IntPoint& windowPoint);
 189
 190     // This method exists for scrollviews that need to handle wheel events manually.
 191     // On Mac the underlying NSScrollView just does the scrolling, but on other platforms
 192     // (like Windows), we need this method in order to do the scroll ourselves.
 193     void wheelEvent(PlatformWheelEvent&);
 194
 195     IntPoint convertChildToSelf(const Widget* child, const IntPoint& point) const
 196     {
 197         IntPoint newPoint = point;
 198         if (!isScrollViewScrollbar(child))
 199             newPoint = point - scrollOffset();
 200         newPoint.move(child->x(), child->y());
 201         return newPoint;
 202     }
 203
 204     IntPoint convertSelfToChild(const Widget* child, const IntPoint& point) const
 205     {
 206         IntPoint newPoint = point;
 207         if (!isScrollViewScrollbar(child))
 208             newPoint = point + scrollOffset();
 209         newPoint.move(-child->x(), -child->y());
 210         return newPoint;
 211     }
 212
 213     // Widget override.  Handles painting of the contents of the view as well as the scrollbars.
 214     virtual void paint(GraphicsContext*, const IntRect&);
 215     void paintScrollbars(GraphicsContext*, const IntRect&);
 216
 217     // Widget overrides to ensure that our children's visibility status is kept up to date when we get shown and hidden.
 218     virtual void show();
 219     virtual void hide();
 220     virtual void setParentVisible(bool);
 221
 222     // Pan scrolling.
 223     static const int noPanScrollRadius = 15;
 224     void addPanScrollIcon(const IntPoint&);
 225     void removePanScrollIcon();
 226     void paintPanScrollIcon(GraphicsContext*);
 227
 228     virtual bool isPointInScrollbarCorner(const IntPoint&);
 229     virtual bool scrollbarCornerPresent() const;
 230
 231     virtual IntRect convertFromScrollbarToContainingView(const Scrollbar*, const IntRect&) const;
 232     virtual IntRect convertFromContainingViewToScrollbar(const Scrollbar*, const IntRect&) const;
 233     virtual IntPoint convertFromScrollbarToContainingView(const Scrollbar*, const IntPoint&) const;
 234     virtual IntPoint convertFromContainingViewToScrollbar(const Scrollbar*, const IntPoint&) const;
 235
 236 protected:
 237     ScrollView();
 238
 239     virtual void repaintContentRectangle(const IntRect&, bool now = false);
 240     virtual void paintContents(GraphicsContext*, const IntRect& damageRect) = 0;
 241
 242     virtual void contentsResized() = 0;
 243     virtual void visibleContentsResized() = 0;
 244
 245     // These methods are used to create/destroy scrollbars.
 246     void setHasHorizontalScrollbar(bool);
 247     void setHasVerticalScrollbar(bool);
 248
 249     IntRect scrollCornerRect() const;
 250     virtual void updateScrollCorner();
 251     virtual void paintScrollCorner(GraphicsContext*, const IntRect& cornerRect);
 252
 253 private:
 254     RefPtr<Scrollbar> m_horizontalScrollbar;
 255     RefPtr<Scrollbar> m_verticalScrollbar;
 256     ScrollbarMode m_horizontalScrollbarMode;
 257     ScrollbarMode m_verticalScrollbarMode;
 258     bool m_prohibitsScrolling;
 259
 260     HashSet<RefPtr<Widget> > m_children;
 261
 262     // This bool is unused on Mac OS because we directly ask the platform widget
 263     // whether it is safe to blit on scroll.
 264     bool m_canBlitOnScroll;
 265
 266     IntSize m_scrollOffset; // FIXME: Would rather store this as a position, but we will wait to make this change until more code is shared.
 267     IntSize m_fixedLayoutSize;
 268     IntSize m_contentsSize;
 269
 270     int m_scrollbarsAvoidingResizer;
 271     bool m_scrollbarsSuppressed;
 272
 273     bool m_inUpdateScrollbars;
 274     unsigned m_updateScrollbarsPass;
 275
 276     IntPoint m_panScrollIconPoint;
 277     bool m_drawPanScrollIcon;
 278     bool m_useFixedLayout;
 279
 280     bool m_paintsEntireContents;
 281
 282     void init();
 283     void destroy();
 284
 285     // Called to update the scrollbars to accurately reflect the state of the view.
 286     void updateScrollbars(const IntSize& desiredOffset);
 287
 288     void platformInit();
 289     void platformDestroy();
 290     void platformAddChild(Widget*);
 291     void platformRemoveChild(Widget*);
 292     void platformSetScrollbarModes();
 293     void platformScrollbarModes(ScrollbarMode& horizontal, ScrollbarMode& vertical) const;
 294     void platformSetCanBlitOnScroll(bool);
 295     bool platformCanBlitOnScroll() const;
 296     IntRect platformVisibleContentRect(bool includeScrollbars) const;
 297     IntSize platformContentsSize() const;
 298     void platformSetContentsSize();
 299     IntRect platformContentsToScreen(const IntRect&) const;
 300     IntPoint platformScreenToContents(const IntPoint&) const;
 301     void platformSetScrollPosition(const IntPoint&);
 302     bool platformScroll(ScrollDirection, ScrollGranularity);
 303     void platformSetScrollbarsSuppressed(bool repaintOnUnsuppress);
 304     void platformRepaintContentRectangle(const IntRect&, bool now);
 305     bool platformIsOffscreen() const;
 306
 307 #if PLATFORM(MAC) && defined __OBJC__
 308 public:
 309     NSView* documentView() const;
 310
 311 private:
 312     NSScrollView<WebCoreFrameScrollView>* scrollView() const;
 313 #endif
 314
 315 #if PLATFORM(QT)
 316 public:
 317     void adjustWidgetsPreventingBlittingCount(int delta);
 318 private:
 319     bool rootPreventsBlitting() const { return root()->m_widgetsPreventingBlitting > 0; }
 320     unsigned m_widgetsPreventingBlitting;
 321 #else
 322     bool rootPreventsBlitting() const { return false; }
 323 #endif
 324
 325 #if PLATFORM(GTK)
 326 public:
 327     void setGtkAdjustments(GtkAdjustment* hadj, GtkAdjustment* vadj);
 328     GtkAdjustment* m_horizontalAdjustment;
 329     GtkAdjustment* m_verticalAdjustment;
 330     void setScrollOffset(const IntSize& offset) { m_scrollOffset = offset; }
 331 #endif
 332
 333 #if PLATFORM(WX)
 334 public:
 335     virtual void setPlatformWidget(wxWindow*);
 336     void adjustScrollbars(int x = -1, int y = -1, bool refresh = true);
 337 private:
 338     class ScrollViewPrivate;
 339     ScrollViewPrivate* m_data;
 340 #endif
 341
 342 }; // class ScrollView
 343
 344 } // namespace WebCore
 345
 346 #endif // ScrollView_h