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 function. 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     // Functions 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 functions

    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     // Functions 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, bool horizontalLock = false, bool verticalLock = false);

    87     void setHorizontalScrollbarMode(ScrollbarMode mode, bool lock = false) { setScrollbarModes(mode, verticalScrollbarMode(), lock, verticalScrollbarLock()); }

    88     void setVerticalScrollbarMode(ScrollbarMode mode, bool lock = false) { setScrollbarModes(horizontalScrollbarMode(), mode, horizontalScrollbarLock(), lock); };

    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 

    93     void setHorizontalScrollbarLock(bool lock = true) { m_horizontalScrollbarLock = lock; }

    94     bool horizontalScrollbarLock() const { return m_horizontalScrollbarLock; }

    95     void setVerticalScrollbarLock(bool lock = true) { m_verticalScrollbarLock = lock; }

    96     bool verticalScrollbarLock() const { return m_verticalScrollbarLock; }

    97 

    98     void setScrollingModesLock(bool lock = true) { m_horizontalScrollbarLock = m_verticalScrollbarLock = lock; }

    99 

   100     virtual void setCanHaveScrollbars(bool);

   101     bool canHaveScrollbars() const { return horizontalScrollbarMode() != ScrollbarAlwaysOff || verticalScrollbarMode() != ScrollbarAlwaysOff; }

   102 

   103     virtual bool avoidScrollbarCreation() { return false; }

   104 

   105     // By default you only receive paint events for the area that is visible. In the case of using a

   106     // tiled backing store, this function can be set, so that the view paints the entire contents.

   107     bool paintsEntireContents() const { return m_paintsEntireContents; }

   108     void setPaintsEntireContents(bool);

   109 

   110     // Overridden by FrameView to create custom CSS scrollbars if applicable.

   111     virtual PassRefPtr<Scrollbar> createScrollbar(ScrollbarOrientation);

   112 

   113     // If the prohibits scrolling flag is set, then all scrolling in the view (even programmatic scrolling) is turned off.

   114     void setProhibitsScrolling(bool b) { m_prohibitsScrolling = b; }

   115     bool prohibitsScrolling() const { return m_prohibitsScrolling; }

   116 

   117     // Whether or not a scroll view will blit visible contents when it is scrolled. Blitting is disabled in situations

   118     // where it would cause rendering glitches (such as with fixed backgrounds or when the view is partially transparent).

   119     void setCanBlitOnScroll(bool);

   120     bool canBlitOnScroll() const;

   121 

   122     // The visible content rect has a location that is the scrolled offset of the document. The width and height are the viewport width

   123     // and height. By default the scrollbars themselves are excluded from this rectangle, but an optional boolean argument allows them to be

   124     // included.

   125     IntRect visibleContentRect(bool includeScrollbars = false) const;

   126     int visibleWidth() const { return visibleContentRect().width(); }

   127     int visibleHeight() const { return visibleContentRect().height(); }

   128 

   129     // Functions for getting/setting the size webkit should use to layout the contents. By default this is the same as the visible

   130     // content size. Explicitly setting a layout size value will cause webkit to layout the contents using this size instead.

   131     int layoutWidth() const;

   132     int layoutHeight() const;

   133     IntSize fixedLayoutSize() const;

   134     void setFixedLayoutSize(const IntSize&);

   135     bool useFixedLayout() const;

   136     void setUseFixedLayout(bool enable);

   137     

   138     // Functions for getting/setting the size of the document contained inside the ScrollView (as an IntSize or as individual width and height

   139     // values).

   140     IntSize contentsSize() const; // Always at least as big as the visibleWidth()/visibleHeight().

   141     int contentsWidth() const { return contentsSize().width(); }

   142     int contentsHeight() const { return contentsSize().height(); }

   143     virtual void setContentsSize(const IntSize&);

   144    

   145     // Functions for querying the current scrolled position (both as a point, a size, or as individual X and Y values).

   146     IntPoint scrollPosition() const { return visibleContentRect().location(); }

   147     IntSize scrollOffset() const { return visibleContentRect().location() - IntPoint(); } // Gets the scrolled position as an IntSize. Convenient for adding to other sizes.

   148     IntPoint maximumScrollPosition() const; // The maximum position we can be scrolled to.

   149     int scrollX() const { return scrollPosition().x(); }

   150     int scrollY() const { return scrollPosition().y(); }

   151     

   152     // Functions for scrolling the view.

   153     void setScrollPosition(const IntPoint&);

   154     void scrollBy(const IntSize& s) { return setScrollPosition(scrollPosition() + s); }

   155 

   156     // This function scrolls by lines, pages or pixels.

   157     bool scroll(ScrollDirection, ScrollGranularity);

   158         

   159     // Scroll the actual contents of the view (either blitting or invalidating as needed).

   160     void scrollContents(const IntSize& scrollDelta);

   161 

   162     // This gives us a means of blocking painting on our scrollbars until the first layout has occurred.

   163     void setScrollbarsSuppressed(bool suppressed, bool repaintOnUnsuppress = false);

   164     bool scrollbarsSuppressed() const { return m_scrollbarsSuppressed; }

   165 

   166     // Event coordinates are assumed to be in the coordinate space of a window that contains

   167     // the entire widget hierarchy. It is up to the platform to decide what the precise definition

   168     // of containing window is. (For example on Mac it is the containing NSWindow.)

   169     IntPoint windowToContents(const IntPoint&) const;

   170     IntPoint contentsToWindow(const IntPoint&) const;

   171     IntRect windowToContents(const IntRect&) const;

   172     IntRect contentsToWindow(const IntRect&) const;

   173 

   174     // Functions for converting to and from screen coordinates.

   175     IntRect contentsToScreen(const IntRect&) const;

   176     IntPoint screenToContents(const IntPoint&) const;

   177 

   178     // The purpose of this function is to answer whether or not the scroll view is currently visible. Animations and painting updates can be suspended if

   179     // we know that we are either not in a window right now or if that window is not visible.

   180     bool isOffscreen() const;

   181     

   182     // These functions are used to enable scrollbars to avoid window resizer controls that overlap the scroll view. This happens on Mac

   183     // for example.

   184     virtual IntRect windowResizerRect() const { return IntRect(); }

   185     bool containsScrollbarsAvoidingResizer() const;

   186     void adjustScrollbarsAvoidingResizerCount(int overlapDelta);

   187     virtual void setParent(ScrollView*); // Overridden to update the overlapping scrollbar count.

   188 

   189     // Called when our frame rect changes (or the rect/scroll position of an ancestor changes).

   190     virtual void frameRectsChanged();

   191     

   192     // Widget override to update our scrollbars and notify our contents of the resize.

   193     virtual void setFrameRect(const IntRect&);

   194 

   195     // For platforms that need to hit test scrollbars from within the engine's event handlers (like Win32).

   196     Scrollbar* scrollbarAtPoint(const IntPoint& windowPoint);

   197 

   198     // This function exists for scrollviews that need to handle wheel events manually.

   199     // On Mac the underlying NSScrollView just does the scrolling, but on other platforms

   200     // (like Windows), we need this function in order to do the scroll ourselves.

   201     void wheelEvent(PlatformWheelEvent&);

   202 

   203     IntPoint convertChildToSelf(const Widget* child, const IntPoint& point) const

   204     {

   205         IntPoint newPoint = point;

   206         if (!isScrollViewScrollbar(child))

   207             newPoint = point - scrollOffset();

   208         newPoint.move(child->x(), child->y());

   209         return newPoint;

   210     }

   211 

   212     IntPoint convertSelfToChild(const Widget* child, const IntPoint& point) const

   213     {

   214         IntPoint newPoint = point;

   215         if (!isScrollViewScrollbar(child))

   216             newPoint = point + scrollOffset();

   217         newPoint.move(-child->x(), -child->y());

   218         return newPoint;

   219     }

   220 

   221     // Widget override. Handles painting of the contents of the view as well as the scrollbars.

   222     virtual void paint(GraphicsContext*, const IntRect&);

   223     void paintScrollbars(GraphicsContext*, const IntRect&);

   224 

   225     // Widget overrides to ensure that our children's visibility status is kept up to date when we get shown and hidden.

   226     virtual void show();

   227     virtual void hide();

   228     virtual void setParentVisible(bool);

   229     

   230     // Pan scrolling.

   231     static const int noPanScrollRadius = 15;

   232     void addPanScrollIcon(const IntPoint&);

   233     void removePanScrollIcon();

   234     void paintPanScrollIcon(GraphicsContext*);

   235 

   236     virtual bool isPointInScrollbarCorner(const IntPoint&);

   237     virtual bool scrollbarCornerPresent() const;

   238 

   239     virtual IntRect convertFromScrollbarToContainingView(const Scrollbar*, const IntRect&) const;

   240     virtual IntRect convertFromContainingViewToScrollbar(const Scrollbar*, const IntRect&) const;

   241     virtual IntPoint convertFromScrollbarToContainingView(const Scrollbar*, const IntPoint&) const;

   242     virtual IntPoint convertFromContainingViewToScrollbar(const Scrollbar*, const IntPoint&) const;

   243 

   244 protected:

   245     ScrollView();

   246 

   247     virtual void repaintContentRectangle(const IntRect&, bool now = false);

   248     virtual void paintContents(GraphicsContext*, const IntRect& damageRect) = 0;

   249     

   250     virtual void contentsResized() = 0;

   251     virtual void visibleContentsResized() = 0;

   252 

   253     // These functions are used to create/destroy scrollbars.

   254     void setHasHorizontalScrollbar(bool);

   255     void setHasVerticalScrollbar(bool);

   256 

   257     IntRect scrollCornerRect() const;

   258     virtual void updateScrollCorner();

   259     virtual void paintScrollCorner(GraphicsContext*, const IntRect& cornerRect);

   260 

   261     // Scroll the content by blitting the pixels

   262     virtual bool scrollContentsFastPath(const IntSize& scrollDelta, const IntRect& rectToScroll, const IntRect& clipRect);

   263 

   264 private:

   265     RefPtr<Scrollbar> m_horizontalScrollbar;

   266     RefPtr<Scrollbar> m_verticalScrollbar;

   267     ScrollbarMode m_horizontalScrollbarMode;

   268     ScrollbarMode m_verticalScrollbarMode;

   269 

   270     bool m_horizontalScrollbarLock;

   271     bool m_verticalScrollbarLock;

   272 

   273     bool m_prohibitsScrolling;

   274 

   275     HashSet<RefPtr<Widget> > m_children;

   276 

   277     // This bool is unused on Mac OS because we directly ask the platform widget

   278     // whether it is safe to blit on scroll.

   279     bool m_canBlitOnScroll;

   280 

   281     IntSize m_scrollOffset; // FIXME: Would rather store this as a position, but we will wait to make this change until more code is shared.

   282     IntSize m_fixedLayoutSize;

   283     IntSize m_contentsSize;

   284 

   285     int m_scrollbarsAvoidingResizer;

   286     bool m_scrollbarsSuppressed;

   287 

   288     bool m_inUpdateScrollbars;

   289     unsigned m_updateScrollbarsPass;

   290 

   291     IntPoint m_panScrollIconPoint;

   292     bool m_drawPanScrollIcon;

   293     bool m_useFixedLayout;

   294 

   295     bool m_paintsEntireContents;

   296 

   297     void init();

   298     void destroy();

   299 

   300     // Called to update the scrollbars to accurately reflect the state of the view.

   301     void updateScrollbars(const IntSize& desiredOffset);

   302 

   303     // Called when the scroll position within this view changes.  FrameView overrides this to generate repaint invalidations.

   304     virtual void repaintFixedElementsAfterScrolling() {}

   305 

   306     void platformInit();

   307     void platformDestroy();

   308     void platformAddChild(Widget*);

   309     void platformRemoveChild(Widget*);

   310     void platformSetScrollbarModes();

   311     void platformScrollbarModes(ScrollbarMode& horizontal, ScrollbarMode& vertical) const;

   312     void platformSetCanBlitOnScroll(bool);

   313     bool platformCanBlitOnScroll() const;

   314     IntRect platformVisibleContentRect(bool includeScrollbars) const;

   315     IntSize platformContentsSize() const;

   316     void platformSetContentsSize();

   317     IntRect platformContentsToScreen(const IntRect&) const;

   318     IntPoint platformScreenToContents(const IntPoint&) const;

   319     void platformSetScrollPosition(const IntPoint&);

   320     bool platformScroll(ScrollDirection, ScrollGranularity);

   321     void platformSetScrollbarsSuppressed(bool repaintOnUnsuppress);

   322     void platformRepaintContentRectangle(const IntRect&, bool now);

   323     bool platformIsOffscreen() const;

   324 

   325 #if PLATFORM(MAC) && defined __OBJC__

   326 public:

   327     NSView* documentView() const;

   328 

   329 private:

   330     NSScrollView<WebCoreFrameScrollView>* scrollView() const;

   331 #endif

   332 

   333 #if PLATFORM(GTK)

   334 public:

   335     void setGtkAdjustments(GtkAdjustment* hadj, GtkAdjustment* vadj, bool resetValues = true);

   336     GtkAdjustment* m_horizontalAdjustment;

   337     GtkAdjustment* m_verticalAdjustment;

   338     void setScrollOffset(const IntSize& offset) { m_scrollOffset = offset; }

   339 #endif

   340 

   341 #if PLATFORM(WX)

   342 public:

   343     virtual void setPlatformWidget(wxWindow*);

   344     void adjustScrollbars(int x = -1, int y = -1, bool refresh = true);

   345 private:

   346     class ScrollViewPrivate;

   347     ScrollViewPrivate* m_data;

   348 #endif

   349 

   350 }; // class ScrollView

   351 

   352 } // namespace WebCore

   353 

   354 #endif // ScrollView_h