WebCore/ScrollView.h

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