WebCore/platform/ScrollView.h
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/platform/ScrollView.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,354 @@
+/*
+ * Copyright (C) 2004, 2006, 2007, 2008 Apple Inc. All rights reserved.
+ * Copyright (C) 2009 Holger Hans Peter Freyther
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#ifndef ScrollView_h
+#define ScrollView_h
+
+#include "IntRect.h"
+#include "Scrollbar.h"
+#include "ScrollbarClient.h"
+#include "ScrollTypes.h"
+#include "Widget.h"
+
+#include <wtf/HashSet.h>
+
+#if PLATFORM(MAC) && defined __OBJC__
+@protocol WebCoreFrameScrollView;
+#endif
+
+#if PLATFORM(GTK)
+typedef struct _GtkAdjustment GtkAdjustment;
+#endif
+
+#if PLATFORM(WX)
+class wxScrollWinEvent;
+#endif
+
+namespace WebCore {
+
+class HostWindow;
+class PlatformWheelEvent;
+class Scrollbar;
+
+class ScrollView : public Widget, public ScrollbarClient {
+public:
+    ~ScrollView();
+
+    // ScrollbarClient function. FrameView overrides the other two.
+    virtual void valueChanged(Scrollbar*);
+    
+    // The window thats hosts the ScrollView. The ScrollView will communicate scrolls and repaints to the
+    // host window in the window's coordinate space.
+    virtual HostWindow* hostWindow() const = 0;
+
+    // Returns a clip rect in host window coordinates. Used to clip the blit on a scroll.
+    virtual IntRect windowClipRect(bool clipToContents = true) const = 0;
+
+    // Functions for child manipulation and inspection.
+    const HashSet<RefPtr<Widget> >* children() const { return &m_children; }
+    void addChild(PassRefPtr<Widget>);
+    void removeChild(Widget*);
+    
+    // If the scroll view does not use a native widget, then it will have cross-platform Scrollbars. These functions
+    // can be used to obtain those scrollbars.
+    Scrollbar* horizontalScrollbar() const { return m_horizontalScrollbar.get(); }
+    Scrollbar* verticalScrollbar() const { return m_verticalScrollbar.get(); }
+    bool isScrollViewScrollbar(const Widget* child) const { return horizontalScrollbar() == child || verticalScrollbar() == child; }
+
+    // Functions for setting and retrieving the scrolling mode in each axis (horizontal/vertical). The mode has values of
+    // AlwaysOff, AlwaysOn, and Auto. AlwaysOff means never show a scrollbar, AlwaysOn means always show a scrollbar.
+    // Auto means show a scrollbar only when one is needed.
+    // Note that for platforms with native widgets, these modes are considered advisory. In other words the underlying native
+    // widget may choose not to honor the requested modes.
+    void setScrollbarModes(ScrollbarMode horizontalMode, ScrollbarMode verticalMode, bool horizontalLock = false, bool verticalLock = false);
+    void setHorizontalScrollbarMode(ScrollbarMode mode, bool lock = false) { setScrollbarModes(mode, verticalScrollbarMode(), lock, verticalScrollbarLock()); }
+    void setVerticalScrollbarMode(ScrollbarMode mode, bool lock = false) { setScrollbarModes(horizontalScrollbarMode(), mode, horizontalScrollbarLock(), lock); };
+    void scrollbarModes(ScrollbarMode& horizontalMode, ScrollbarMode& verticalMode) const;
+    ScrollbarMode horizontalScrollbarMode() const { ScrollbarMode horizontal, vertical; scrollbarModes(horizontal, vertical); return horizontal; }
+    ScrollbarMode verticalScrollbarMode() const { ScrollbarMode horizontal, vertical; scrollbarModes(horizontal, vertical); return vertical; }
+
+    void setHorizontalScrollbarLock(bool lock = true) { m_horizontalScrollbarLock = lock; }
+    bool horizontalScrollbarLock() const { return m_horizontalScrollbarLock; }
+    void setVerticalScrollbarLock(bool lock = true) { m_verticalScrollbarLock = lock; }
+    bool verticalScrollbarLock() const { return m_verticalScrollbarLock; }
+
+    void setScrollingModesLock(bool lock = true) { m_horizontalScrollbarLock = m_verticalScrollbarLock = lock; }
+
+    virtual void setCanHaveScrollbars(bool);
+    bool canHaveScrollbars() const { return horizontalScrollbarMode() != ScrollbarAlwaysOff || verticalScrollbarMode() != ScrollbarAlwaysOff; }
+
+    virtual bool avoidScrollbarCreation() { return false; }
+
+    // By default you only receive paint events for the area that is visible. In the case of using a
+    // tiled backing store, this function can be set, so that the view paints the entire contents.
+    bool paintsEntireContents() const { return m_paintsEntireContents; }
+    void setPaintsEntireContents(bool);
+
+    // Overridden by FrameView to create custom CSS scrollbars if applicable.
+    virtual PassRefPtr<Scrollbar> createScrollbar(ScrollbarOrientation);
+
+    // If the prohibits scrolling flag is set, then all scrolling in the view (even programmatic scrolling) is turned off.
+    void setProhibitsScrolling(bool b) { m_prohibitsScrolling = b; }
+    bool prohibitsScrolling() const { return m_prohibitsScrolling; }
+
+    // Whether or not a scroll view will blit visible contents when it is scrolled. Blitting is disabled in situations
+    // where it would cause rendering glitches (such as with fixed backgrounds or when the view is partially transparent).
+    void setCanBlitOnScroll(bool);
+    bool canBlitOnScroll() const;
+
+    // The visible content rect has a location that is the scrolled offset of the document. The width and height are the viewport width
+    // and height. By default the scrollbars themselves are excluded from this rectangle, but an optional boolean argument allows them to be
+    // included.
+    IntRect visibleContentRect(bool includeScrollbars = false) const;
+    int visibleWidth() const { return visibleContentRect().width(); }
+    int visibleHeight() const { return visibleContentRect().height(); }
+
+    // Functions for getting/setting the size webkit should use to layout the contents. By default this is the same as the visible
+    // content size. Explicitly setting a layout size value will cause webkit to layout the contents using this size instead.
+    int layoutWidth() const;
+    int layoutHeight() const;
+    IntSize fixedLayoutSize() const;
+    void setFixedLayoutSize(const IntSize&);
+    bool useFixedLayout() const;
+    void setUseFixedLayout(bool enable);
+    
+    // Functions for getting/setting the size of the document contained inside the ScrollView (as an IntSize or as individual width and height
+    // values).
+    IntSize contentsSize() const; // Always at least as big as the visibleWidth()/visibleHeight().
+    int contentsWidth() const { return contentsSize().width(); }
+    int contentsHeight() const { return contentsSize().height(); }
+    virtual void setContentsSize(const IntSize&);
+   
+    // Functions for querying the current scrolled position (both as a point, a size, or as individual X and Y values).
+    IntPoint scrollPosition() const { return visibleContentRect().location(); }
+    IntSize scrollOffset() const { return visibleContentRect().location() - IntPoint(); } // Gets the scrolled position as an IntSize. Convenient for adding to other sizes.
+    IntPoint maximumScrollPosition() const; // The maximum position we can be scrolled to.
+    int scrollX() const { return scrollPosition().x(); }
+    int scrollY() const { return scrollPosition().y(); }
+    
+    // Functions for scrolling the view.
+    void setScrollPosition(const IntPoint&);
+    void scrollBy(const IntSize& s) { return setScrollPosition(scrollPosition() + s); }
+
+    // This function scrolls by lines, pages or pixels.
+    bool scroll(ScrollDirection, ScrollGranularity);
+        
+    // Scroll the actual contents of the view (either blitting or invalidating as needed).
+    void scrollContents(const IntSize& scrollDelta);
+
+    // This gives us a means of blocking painting on our scrollbars until the first layout has occurred.
+    void setScrollbarsSuppressed(bool suppressed, bool repaintOnUnsuppress = false);
+    bool scrollbarsSuppressed() const { return m_scrollbarsSuppressed; }
+
+    // Event coordinates are assumed to be in the coordinate space of a window that contains
+    // the entire widget hierarchy. It is up to the platform to decide what the precise definition
+    // of containing window is. (For example on Mac it is the containing NSWindow.)
+    IntPoint windowToContents(const IntPoint&) const;
+    IntPoint contentsToWindow(const IntPoint&) const;
+    IntRect windowToContents(const IntRect&) const;
+    IntRect contentsToWindow(const IntRect&) const;
+
+    // Functions for converting to and from screen coordinates.
+    IntRect contentsToScreen(const IntRect&) const;
+    IntPoint screenToContents(const IntPoint&) const;
+
+    // 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
+    // we know that we are either not in a window right now or if that window is not visible.
+    bool isOffscreen() const;
+    
+    // These functions are used to enable scrollbars to avoid window resizer controls that overlap the scroll view. This happens on Mac
+    // for example.
+    virtual IntRect windowResizerRect() const { return IntRect(); }
+    bool containsScrollbarsAvoidingResizer() const;
+    void adjustScrollbarsAvoidingResizerCount(int overlapDelta);
+    virtual void setParent(ScrollView*); // Overridden to update the overlapping scrollbar count.
+
+    // Called when our frame rect changes (or the rect/scroll position of an ancestor changes).
+    virtual void frameRectsChanged();
+    
+    // Widget override to update our scrollbars and notify our contents of the resize.
+    virtual void setFrameRect(const IntRect&);
+
+    // For platforms that need to hit test scrollbars from within the engine's event handlers (like Win32).
+    Scrollbar* scrollbarAtPoint(const IntPoint& windowPoint);
+
+    // This function exists for scrollviews that need to handle wheel events manually.
+    // On Mac the underlying NSScrollView just does the scrolling, but on other platforms
+    // (like Windows), we need this function in order to do the scroll ourselves.
+    void wheelEvent(PlatformWheelEvent&);
+
+    IntPoint convertChildToSelf(const Widget* child, const IntPoint& point) const
+    {
+        IntPoint newPoint = point;
+        if (!isScrollViewScrollbar(child))
+            newPoint = point - scrollOffset();
+        newPoint.move(child->x(), child->y());
+        return newPoint;
+    }
+
+    IntPoint convertSelfToChild(const Widget* child, const IntPoint& point) const
+    {
+        IntPoint newPoint = point;
+        if (!isScrollViewScrollbar(child))
+            newPoint = point + scrollOffset();
+        newPoint.move(-child->x(), -child->y());
+        return newPoint;
+    }
+
+    // Widget override. Handles painting of the contents of the view as well as the scrollbars.
+    virtual void paint(GraphicsContext*, const IntRect&);
+    void paintScrollbars(GraphicsContext*, const IntRect&);
+
+    // Widget overrides to ensure that our children's visibility status is kept up to date when we get shown and hidden.
+    virtual void show();
+    virtual void hide();
+    virtual void setParentVisible(bool);
+    
+    // Pan scrolling.
+    static const int noPanScrollRadius = 15;
+    void addPanScrollIcon(const IntPoint&);
+    void removePanScrollIcon();
+    void paintPanScrollIcon(GraphicsContext*);
+
+    virtual bool isPointInScrollbarCorner(const IntPoint&);
+    virtual bool scrollbarCornerPresent() const;
+
+    virtual IntRect convertFromScrollbarToContainingView(const Scrollbar*, const IntRect&) const;
+    virtual IntRect convertFromContainingViewToScrollbar(const Scrollbar*, const IntRect&) const;
+    virtual IntPoint convertFromScrollbarToContainingView(const Scrollbar*, const IntPoint&) const;
+    virtual IntPoint convertFromContainingViewToScrollbar(const Scrollbar*, const IntPoint&) const;
+
+protected:
+    ScrollView();
+
+    virtual void repaintContentRectangle(const IntRect&, bool now = false);
+    virtual void paintContents(GraphicsContext*, const IntRect& damageRect) = 0;
+    
+    virtual void contentsResized() = 0;
+    virtual void visibleContentsResized() = 0;
+
+    // These functions are used to create/destroy scrollbars.
+    void setHasHorizontalScrollbar(bool);
+    void setHasVerticalScrollbar(bool);
+
+    IntRect scrollCornerRect() const;
+    virtual void updateScrollCorner();
+    virtual void paintScrollCorner(GraphicsContext*, const IntRect& cornerRect);
+
+    // Scroll the content by blitting the pixels
+    virtual bool scrollContentsFastPath(const IntSize& scrollDelta, const IntRect& rectToScroll, const IntRect& clipRect);
+
+private:
+    RefPtr<Scrollbar> m_horizontalScrollbar;
+    RefPtr<Scrollbar> m_verticalScrollbar;
+    ScrollbarMode m_horizontalScrollbarMode;
+    ScrollbarMode m_verticalScrollbarMode;
+
+    bool m_horizontalScrollbarLock;
+    bool m_verticalScrollbarLock;
+
+    bool m_prohibitsScrolling;
+
+    HashSet<RefPtr<Widget> > m_children;
+
+    // This bool is unused on Mac OS because we directly ask the platform widget
+    // whether it is safe to blit on scroll.
+    bool m_canBlitOnScroll;
+
+    IntSize m_scrollOffset; // FIXME: Would rather store this as a position, but we will wait to make this change until more code is shared.
+    IntSize m_fixedLayoutSize;
+    IntSize m_contentsSize;
+
+    int m_scrollbarsAvoidingResizer;
+    bool m_scrollbarsSuppressed;
+
+    bool m_inUpdateScrollbars;
+    unsigned m_updateScrollbarsPass;
+
+    IntPoint m_panScrollIconPoint;
+    bool m_drawPanScrollIcon;
+    bool m_useFixedLayout;
+
+    bool m_paintsEntireContents;
+
+    void init();
+    void destroy();
+
+    // Called to update the scrollbars to accurately reflect the state of the view.
+    void updateScrollbars(const IntSize& desiredOffset);
+
+    // Called when the scroll position within this view changes.  FrameView overrides this to generate repaint invalidations.
+    virtual void repaintFixedElementsAfterScrolling() {}
+
+    void platformInit();
+    void platformDestroy();
+    void platformAddChild(Widget*);
+    void platformRemoveChild(Widget*);
+    void platformSetScrollbarModes();
+    void platformScrollbarModes(ScrollbarMode& horizontal, ScrollbarMode& vertical) const;
+    void platformSetCanBlitOnScroll(bool);
+    bool platformCanBlitOnScroll() const;
+    IntRect platformVisibleContentRect(bool includeScrollbars) const;
+    IntSize platformContentsSize() const;
+    void platformSetContentsSize();
+    IntRect platformContentsToScreen(const IntRect&) const;
+    IntPoint platformScreenToContents(const IntPoint&) const;
+    void platformSetScrollPosition(const IntPoint&);
+    bool platformScroll(ScrollDirection, ScrollGranularity);
+    void platformSetScrollbarsSuppressed(bool repaintOnUnsuppress);
+    void platformRepaintContentRectangle(const IntRect&, bool now);
+    bool platformIsOffscreen() const;
+
+#if PLATFORM(MAC) && defined __OBJC__
+public:
+    NSView* documentView() const;
+
+private:
+    NSScrollView<WebCoreFrameScrollView>* scrollView() const;
+#endif
+
+#if PLATFORM(GTK)
+public:
+    void setGtkAdjustments(GtkAdjustment* hadj, GtkAdjustment* vadj, bool resetValues = true);
+    GtkAdjustment* m_horizontalAdjustment;
+    GtkAdjustment* m_verticalAdjustment;
+    void setScrollOffset(const IntSize& offset) { m_scrollOffset = offset; }
+#endif
+
+#if PLATFORM(WX)
+public:
+    virtual void setPlatformWidget(wxWindow*);
+    void adjustScrollbars(int x = -1, int y = -1, bool refresh = true);
+private:
+    class ScrollViewPrivate;
+    ScrollViewPrivate* m_data;
+#endif
+
+}; // class ScrollView
+
+} // namespace WebCore
+
+#endif // ScrollView_h