gecko-dev/layout/generic/ScrollSnap.h
Daniel Holbert 680815cd6e Bug 1412346 part 5: (automated patch) Switch a bunch of C++ files in layout to use our standard mode lines. r=jfkthame
This patch was generated automatically by the "modeline.py" script, available
here: https://github.com/amccreight/moz-source-tools/blob/master/modeline.py

For every file that is modified in this patch, the changes are as follows:
 (1) The patch changes the file to use the exact C++ mode lines from the
     Mozilla coding style guide, available here:
https://developer.mozilla.org/en-US/docs/Mozilla/Developer_guide/Coding_Style#Mode_Line

 (2) The patch deletes any blank lines between the mode line & the MPL
     boilerplate comment.

 (3) If the file previously had the mode lines and MPL boilerplate in a
     single contiguous C++ comment, then the patch splits them into
     separate C++ comments, to match the boilerplate in the coding style.

MozReview-Commit-ID: EuRsDue63tK

--HG--
extra : rebase_source : 3356d4b80ff6213935192e87cdbc9103fec6084c
2017-10-27 10:33:53 -07:00

46 lines
1.7 KiB
C++

/* -*- 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 "mozilla/Maybe.h"
#include "nsIScrollableFrame.h"
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|, |aScrollPortSize|, 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 mozilla::Maybe<nsPoint> GetSnapPointForDestination(
const layers::ScrollSnapInfo& aSnapInfo,
nsIScrollableFrame::ScrollUnit aUnit,
const nsSize& aScrollPortSize,
const nsRect& aScrollRange,
const nsPoint& aStartPos,
const nsPoint& aDestination);
};
} // namespace mozilla
#endif // mozilla_layout_ScrollSnap_h_