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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /layout/generic/ScrollSnap.h | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | layout/generic/ScrollSnap.h | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/layout/generic/ScrollSnap.h b/layout/generic/ScrollSnap.h new file mode 100644 index 0000000000..a5817543fa --- /dev/null +++ b/layout/generic/ScrollSnap.h @@ -0,0 +1,94 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef mozilla_layout_ScrollSnap_h_ +#define mozilla_layout_ScrollSnap_h_ + +#include <memory> +#include "mozilla/ScrollTypes.h" +#include "mozilla/ScrollSnapTargetId.h" +#include "mozilla/Maybe.h" + +class nsIContent; +class nsIFrame; +struct nsPoint; +struct nsRect; +struct nsSize; + +namespace mozilla { + +namespace layers { +struct ScrollSnapInfo; +} + +struct ScrollSnapUtils { + /** + * GetSnapPointForDestination determines which point to snap to after + * scrolling. |aStartPos| gives the position before scrolling and + * |aDestination| gives the position after scrolling, with no snapping. + * Behaviour is dependent on the value of |aUnit|. + * |aSnapInfo| and |aScrollRange| are characteristics of the scroll frame for + * which snapping is being performed. + * If a suitable snap point could be found, it is returned. Otherwise, an + * empty Maybe is returned. + * IMPORTANT NOTE: This function is designed to be called both on and off + * the main thread. If modifying its implementation, be sure + * not to touch main-thread-only data structures without + * appropriate locking. + */ + static Maybe<SnapTarget> GetSnapPointForDestination( + const layers::ScrollSnapInfo& aSnapInfo, ScrollUnit aUnit, + ScrollSnapFlags aSnapFlags, const nsRect& aScrollRange, + const nsPoint& aStartPos, const nsPoint& aDestination); + + /** + * Similar to above GetSnapPointForDestination but for re-snapping. + * + * |aCurrentPosition| are the snap point(s) last time when we scrolled. + * |aLastSnapTargetIds| are the snap point(s) last time when we scrolled if + * exists. + * |aFocusedContent| is the focused content in the document if exists. + * Other parameters are same as GetSnapPointForDestination. + */ + + static mozilla::Maybe<mozilla::SnapTarget> GetSnapPointForResnap( + const layers::ScrollSnapInfo& aSnapInfo, const nsRect& aScrollRange, + const nsPoint& aCurrentPosition, + const UniquePtr<ScrollSnapTargetIds>& aLastSnapTargetIds, + const nsIContent* aFocusedContent); + + static ScrollSnapTargetId GetTargetIdFor(const nsIFrame* aFrame); + + // Post a pending re-snap request if the given |aFrame| is one of the snap + // points on the last scroll operation. + static void PostPendingResnapIfNeededFor(nsIFrame* aFrame); + + // Similar to above PostPendingResnapIfNeededFor but post a pending re-snap + // request even if the given |aFrame| is not one of the last snap point. + // This is basically used for cases there was no valid snap point on the last + // scroll operation but the given |aFrame| might be a valid snap point now, + // e.g changing the scroll-snap-align property from `none` to something. + static void PostPendingResnapFor(nsIFrame* aFrame); + + // Returns true if the writing-mode of the snap target element needs to be + // respected to resolve scroll-snap-align property. + // Note that usually the scroll container's writing-mode is used for resolving + // the property but there's a special case defined in the CSS scroll snap + // spec. + static bool NeedsToRespectTargetWritingMode(const nsSize& aSnapAreaSize, + const nsSize& aSnapportSize); + + // Returns the scroll snap area for the snap target frame |aFrame| inside the + // nearest scroll container |aScrolledFrame| and its scrolled rect + // |aScrolledRect|. + static nsRect GetSnapAreaFor(const nsIFrame* aFrame, + const nsIFrame* aScrolledFrame, + const nsRect& aScrolledRect); +}; + +} // namespace mozilla + +#endif // mozilla_layout_ScrollSnap_h_ |