layout/generic/StickyScrollContainer.h

Wed, 31 Dec 2014 06:09:35 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Wed, 31 Dec 2014 06:09:35 +0100
changeset 0
6474c204b198
permissions
-rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

michael@0 1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0 2 /* vim: set ts=2 sts=2 et sw=2 tw=80: */
michael@0 3 /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0 4 * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0 6
michael@0 7 /**
michael@0 8 * compute sticky positioning, both during reflow and when the scrolling
michael@0 9 * container scrolls
michael@0 10 */
michael@0 11
michael@0 12 #ifndef StickyScrollContainer_h
michael@0 13 #define StickyScrollContainer_h
michael@0 14
michael@0 15 #include "nsPoint.h"
michael@0 16 #include "nsTArray.h"
michael@0 17 #include "nsIScrollPositionListener.h"
michael@0 18
michael@0 19 class nsRect;
michael@0 20 class nsIFrame;
michael@0 21 class nsIScrollableFrame;
michael@0 22
michael@0 23 namespace mozilla {
michael@0 24
michael@0 25 class StickyScrollContainer MOZ_FINAL : public nsIScrollPositionListener
michael@0 26 {
michael@0 27 public:
michael@0 28 /**
michael@0 29 * Find (and create if necessary) the StickyScrollContainer associated with
michael@0 30 * the scroll container of the given frame, if a scroll container exists.
michael@0 31 */
michael@0 32 static StickyScrollContainer* GetStickyScrollContainerForFrame(nsIFrame* aFrame);
michael@0 33
michael@0 34 /**
michael@0 35 * Find the StickyScrollContainer associated with the given scroll frame,
michael@0 36 * if it exists.
michael@0 37 */
michael@0 38 static StickyScrollContainer* GetStickyScrollContainerForScrollFrame(nsIFrame* aScrollFrame);
michael@0 39
michael@0 40 /**
michael@0 41 * aFrame may have moved into or out of a scroll frame's frame subtree.
michael@0 42 */
michael@0 43 static void NotifyReparentedFrameAcrossScrollFrameBoundary(nsIFrame* aFrame,
michael@0 44 nsIFrame* aOldParent);
michael@0 45
michael@0 46 void AddFrame(nsIFrame* aFrame) {
michael@0 47 mFrames.AppendElement(aFrame);
michael@0 48 }
michael@0 49 void RemoveFrame(nsIFrame* aFrame) {
michael@0 50 mFrames.RemoveElement(aFrame);
michael@0 51 }
michael@0 52
michael@0 53 nsIScrollableFrame* ScrollFrame() const {
michael@0 54 return mScrollFrame;
michael@0 55 }
michael@0 56
michael@0 57 // Compute the offsets for a sticky position element
michael@0 58 static void ComputeStickyOffsets(nsIFrame* aFrame);
michael@0 59
michael@0 60 /**
michael@0 61 * Compute the position of a sticky positioned frame, based on information
michael@0 62 * stored in its properties along with our scroll frame and scroll position.
michael@0 63 */
michael@0 64 nsPoint ComputePosition(nsIFrame* aFrame) const;
michael@0 65
michael@0 66 /**
michael@0 67 * Compute where a frame should not scroll with the page, represented by the
michael@0 68 * difference of two rectangles.
michael@0 69 */
michael@0 70 void GetScrollRanges(nsIFrame* aFrame, nsRect* aOuter, nsRect* aInner) const;
michael@0 71
michael@0 72 /**
michael@0 73 * Compute and set the position of a frame and its following continuations.
michael@0 74 */
michael@0 75 void PositionContinuations(nsIFrame* aFrame);
michael@0 76
michael@0 77 /**
michael@0 78 * Compute and set the position of all sticky frames, given the current
michael@0 79 * scroll position of the scroll frame. If not in reflow, aSubtreeRoot should
michael@0 80 * be null; otherwise, overflow-area updates will be limited to not affect
michael@0 81 * aSubtreeRoot or its ancestors.
michael@0 82 */
michael@0 83 void UpdatePositions(nsPoint aScrollPosition, nsIFrame* aSubtreeRoot);
michael@0 84
michael@0 85 // nsIScrollPositionListener
michael@0 86 virtual void ScrollPositionWillChange(nscoord aX, nscoord aY) MOZ_OVERRIDE;
michael@0 87 virtual void ScrollPositionDidChange(nscoord aX, nscoord aY) MOZ_OVERRIDE;
michael@0 88
michael@0 89 private:
michael@0 90 StickyScrollContainer(nsIScrollableFrame* aScrollFrame);
michael@0 91 ~StickyScrollContainer();
michael@0 92
michael@0 93 /**
michael@0 94 * Compute two rectangles that determine sticky positioning: |aStick|, based
michael@0 95 * on the scroll container, and |aContain|, based on the containing block.
michael@0 96 * Sticky positioning keeps the frame position (its upper-left corner) always
michael@0 97 * within |aContain| and secondarily within |aStick|.
michael@0 98 */
michael@0 99 void ComputeStickyLimits(nsIFrame* aFrame, nsRect* aStick,
michael@0 100 nsRect* aContain) const;
michael@0 101
michael@0 102 friend void DestroyStickyScrollContainer(void* aPropertyValue);
michael@0 103
michael@0 104 nsIScrollableFrame* const mScrollFrame;
michael@0 105 nsTArray<nsIFrame*> mFrames;
michael@0 106 nsPoint mScrollPosition;
michael@0 107 };
michael@0 108
michael@0 109 } // namespace mozilla
michael@0 110
michael@0 111 #endif /* StickyScrollContainer_h */

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