1/*
2 * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
3 *
4 * Portions are Copyright (C) 1998 Netscape Communications Corporation.
5 *
6 * Other contributors:
7 *   Robert O'Callahan <roc+@cs.cmu.edu>
8 *   David Baron <dbaron@fas.harvard.edu>
9 *   Christian Biesinger <cbiesinger@web.de>
10 *   Randall Jesup <rjesup@wgate.com>
11 *   Roland Mainz <roland.mainz@informatik.med.uni-giessen.de>
12 *   Josh Soref <timeless@mac.com>
13 *   Boris Zbarsky <bzbarsky@mit.edu>
14 *
15 * This library is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU Lesser General Public
17 * License as published by the Free Software Foundation; either
18 * version 2.1 of the License, or (at your option) any later version.
19 *
20 * This library is distributed in the hope that it will be useful,
21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
23 * Lesser General Public License for more details.
24 *
25 * You should have received a copy of the GNU Lesser General Public
26 * License along with this library; if not, write to the Free Software
27 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
28 *
29 * Alternatively, the contents of this file may be used under the terms
30 * of either the Mozilla Public License Version 1.1, found at
31 * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public
32 * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html
33 * (the "GPL"), in which case the provisions of the MPL or the GPL are
34 * applicable instead of those above.  If you wish to allow use of your
35 * version of this file only under the terms of one of those two
36 * licenses (the MPL or the GPL) and not to allow others to use your
37 * version of this file under the LGPL, indicate your decision by
38 * deletingthe provisions above and replace them with the notice and
39 * other provisions required by the MPL or the GPL, as the case may be.
40 * If you do not delete the provisions above, a recipient may use your
41 * version of this file under any of the LGPL, the MPL or the GPL.
42 */
43
44#ifndef RenderLayerScrollableArea_h
45#define RenderLayerScrollableArea_h
46
47#include "platform/scroll/ScrollableArea.h"
48
49namespace WebCore {
50
51enum ResizerHitTestType {
52    ResizerForPointer,
53    ResizerForTouch
54};
55
56enum ForceNeedsCompositedScrollingMode {
57    DoNotForceCompositedScrolling = 0,
58    CompositedScrollingAlwaysOn = 1,
59    CompositedScrollingAlwaysOff = 2
60};
61
62class PlatformEvent;
63class RenderBox;
64class RenderLayer;
65class RenderScrollbarPart;
66
67class RenderLayerScrollableArea FINAL : public ScrollableArea {
68    friend class Internals;
69
70public:
71    RenderLayerScrollableArea(RenderBox*);
72    virtual ~RenderLayerScrollableArea();
73
74    bool hasHorizontalScrollbar() const { return horizontalScrollbar(); }
75    bool hasVerticalScrollbar() const { return verticalScrollbar(); }
76
77    virtual Scrollbar* horizontalScrollbar() const OVERRIDE { return m_hBar.get(); }
78    virtual Scrollbar* verticalScrollbar() const OVERRIDE { return m_vBar.get(); }
79    virtual ScrollableArea* enclosingScrollableArea() const OVERRIDE;
80
81    virtual GraphicsLayer* layerForScrolling() const OVERRIDE;
82    virtual GraphicsLayer* layerForHorizontalScrollbar() const OVERRIDE;
83    virtual GraphicsLayer* layerForVerticalScrollbar() const OVERRIDE;
84    virtual GraphicsLayer* layerForScrollCorner() const OVERRIDE;
85    virtual bool usesCompositedScrolling() const OVERRIDE;
86    virtual void invalidateScrollbarRect(Scrollbar*, const IntRect&) OVERRIDE;
87    virtual void invalidateScrollCornerRect(const IntRect&) OVERRIDE;
88    virtual bool isActive() const OVERRIDE;
89    virtual bool isScrollCornerVisible() const OVERRIDE;
90    virtual IntRect scrollCornerRect() const OVERRIDE;
91    virtual IntRect convertFromScrollbarToContainingView(const Scrollbar*, const IntRect&) const OVERRIDE;
92    virtual IntRect convertFromContainingViewToScrollbar(const Scrollbar*, const IntRect&) const OVERRIDE;
93    virtual IntPoint convertFromScrollbarToContainingView(const Scrollbar*, const IntPoint&) const OVERRIDE;
94    virtual IntPoint convertFromContainingViewToScrollbar(const Scrollbar*, const IntPoint&) const OVERRIDE;
95    virtual int scrollSize(ScrollbarOrientation) const OVERRIDE;
96    virtual void setScrollOffset(const IntPoint&) OVERRIDE;
97    virtual IntPoint scrollPosition() const OVERRIDE;
98    virtual IntPoint minimumScrollPosition() const OVERRIDE;
99    virtual IntPoint maximumScrollPosition() const OVERRIDE;
100    virtual IntRect visibleContentRect(IncludeScrollbarsInRect) const OVERRIDE;
101    virtual int visibleHeight() const OVERRIDE;
102    virtual int visibleWidth() const OVERRIDE;
103    virtual IntSize contentsSize() const OVERRIDE;
104    virtual IntSize overhangAmount() const OVERRIDE;
105    virtual IntPoint lastKnownMousePosition() const OVERRIDE;
106    virtual bool shouldSuspendScrollAnimations() const OVERRIDE;
107    virtual bool scrollbarsCanBeActive() const OVERRIDE;
108    virtual IntRect scrollableAreaBoundingBox() const OVERRIDE;
109    virtual bool userInputScrollable(ScrollbarOrientation) const OVERRIDE;
110    virtual bool shouldPlaceVerticalScrollbarOnLeft() const OVERRIDE;
111    virtual int pageStep(ScrollbarOrientation) const OVERRIDE;
112
113    int scrollXOffset() const { return m_scrollOffset.width() + scrollOrigin().x(); }
114    int scrollYOffset() const { return m_scrollOffset.height() + scrollOrigin().y(); }
115
116    IntSize scrollOffset() const { return m_scrollOffset; }
117
118    // FIXME: We shouldn't allow access to m_overflowRect outside this class.
119    LayoutRect overflowRect() const { return m_overflowRect; }
120
121    void scrollToOffset(const IntSize& scrollOffset, ScrollOffsetClamping = ScrollOffsetUnclamped);
122    void scrollToXOffset(int x, ScrollOffsetClamping clamp = ScrollOffsetUnclamped) { scrollToOffset(IntSize(x, scrollYOffset()), clamp); }
123    void scrollToYOffset(int y, ScrollOffsetClamping clamp = ScrollOffsetUnclamped) { scrollToOffset(IntSize(scrollXOffset(), y), clamp); }
124
125    void updateAfterLayout();
126    void updateAfterStyleChange(const RenderStyle*);
127
128    bool hasScrollbar() const { return m_hBar || m_vBar; }
129
130    // FIXME: This should be removed.
131    bool hasScrollCorner() const { return m_scrollCorner; }
132
133    void resize(const PlatformEvent&, const LayoutSize&);
134    IntSize offsetFromResizeCorner(const IntPoint& absolutePoint) const;
135
136    bool inResizeMode() const { return m_inResizeMode; }
137    void setInResizeMode(bool inResizeMode) { m_inResizeMode = inResizeMode; }
138
139    IntRect touchResizerCornerRect(const IntRect& bounds) const
140    {
141        return resizerCornerRect(bounds, ResizerForTouch);
142    }
143
144    int scrollWidth() const;
145    int scrollHeight() const;
146
147    int verticalScrollbarWidth(OverlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize) const;
148    int horizontalScrollbarHeight(OverlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize) const;
149
150    IntSize adjustedScrollOffset() const { return IntSize(scrollXOffset(), scrollYOffset()); }
151
152    void paintResizer(GraphicsContext*, const IntPoint& paintOffset, const IntRect& damageRect);
153    void paintOverflowControls(GraphicsContext*, const IntPoint& paintOffset, const IntRect& damageRect, bool paintingOverlayControls);
154    void paintScrollCorner(GraphicsContext*, const IntPoint&, const IntRect& damageRect);
155
156    // If IntSize is not given, then we must incur additional overhead to instantiate a RenderGeometryMap
157    // and compute the correct offset ourselves.
158    void positionOverflowControls();
159    void positionOverflowControls(const IntSize& offsetFromRoot);
160
161    // isPointInResizeControl() is used for testing if a pointer/touch position is in the resize control
162    // area.
163    bool isPointInResizeControl(const IntPoint& absolutePoint, ResizerHitTestType) const;
164    bool hitTestOverflowControls(HitTestResult&, const IntPoint& localPoint);
165
166    bool hitTestResizerInFragments(const LayerFragments&, const HitTestLocation&) const;
167
168    LayoutRect exposeRect(const LayoutRect&, const ScrollAlignment& alignX, const ScrollAlignment& alignY);
169
170    bool scrollsOverflow() const;
171
172    // Rectangle encompassing the scroll corner and resizer rect.
173    IntRect scrollCornerAndResizerRect() const;
174
175    bool needsCompositedScrolling() const;
176
177    // FIXME: This needs to be exposed as forced compositing scrolling is a RenderLayerScrollableArea
178    // concept and stacking container is a RenderLayerStackingNode concept.
179    bool adjustForForceCompositedScrollingMode(bool) const;
180
181private:
182    bool hasHorizontalOverflow() const;
183    bool hasVerticalOverflow() const;
184    bool hasScrollableHorizontalOverflow() const;
185    bool hasScrollableVerticalOverflow() const;
186
187    void computeScrollDimensions();
188
189    IntSize clampScrollOffset(const IntSize&) const;
190
191    void setScrollOffset(const IntSize& scrollOffset) { m_scrollOffset = scrollOffset; }
192
193    IntRect rectForHorizontalScrollbar(const IntRect& borderBoxRect) const;
194    IntRect rectForVerticalScrollbar(const IntRect& borderBoxRect) const;
195    LayoutUnit verticalScrollbarStart(int minX, int maxX) const;
196    LayoutUnit horizontalScrollbarStart(int minX) const;
197    IntSize scrollbarOffset(const Scrollbar*) const;
198
199    PassRefPtr<Scrollbar> createScrollbar(ScrollbarOrientation);
200    void destroyScrollbar(ScrollbarOrientation);
201
202    void setHasHorizontalScrollbar(bool hasScrollbar);
203    void setHasVerticalScrollbar(bool hasScrollbar);
204
205    void updateScrollCornerStyle();
206
207    // See comments on isPointInResizeControl.
208    IntRect resizerCornerRect(const IntRect&, ResizerHitTestType) const;
209    bool overflowControlsIntersectRect(const IntRect& localRect) const;
210    void updateResizerAreaSet();
211    void updateResizerStyle();
212    void drawPlatformResizerImage(GraphicsContext*, IntRect resizerCornerRect);
213
214    RenderLayer* layer() const;
215
216    void updateScrollableAreaSet(bool hasOverflow);
217
218    void updateCompositingLayersAfterScroll();
219    virtual void updateNeedsCompositedScrolling() OVERRIDE;
220    bool setNeedsCompositedScrolling(bool);
221
222    virtual void updateHasVisibleNonLayerContent() OVERRIDE;
223
224    void setForceNeedsCompositedScrolling(ForceNeedsCompositedScrollingMode);
225
226    RenderBox* m_box;
227
228    // Keeps track of whether the layer is currently resizing, so events can cause resizing to start and stop.
229    unsigned m_inResizeMode : 1;
230
231    unsigned m_scrollDimensionsDirty : 1;
232    unsigned m_inOverflowRelayout : 1;
233
234    unsigned m_needsCompositedScrolling : 1;
235    unsigned m_willUseCompositedScrollingHasBeenRecorded : 1;
236
237    unsigned m_isScrollableAreaHasBeenRecorded : 1;
238
239    ForceNeedsCompositedScrollingMode m_forceNeedsCompositedScrolling;
240
241    // The width/height of our scrolled area.
242    LayoutRect m_overflowRect;
243
244    // This is the (scroll) offset from scrollOrigin().
245    IntSize m_scrollOffset;
246
247    IntPoint m_cachedOverlayScrollbarOffset;
248
249    // For areas with overflow, we have a pair of scrollbars.
250    RefPtr<Scrollbar> m_hBar;
251    RefPtr<Scrollbar> m_vBar;
252
253    // Renderers to hold our custom scroll corner.
254    RenderScrollbarPart* m_scrollCorner;
255
256    // Renderers to hold our custom resizer.
257    RenderScrollbarPart* m_resizer;
258};
259
260} // Namespace WebCore
261
262#endif // RenderLayerScrollableArea_h
263