tor-browser

The Tor Browser
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ReflowOutput.cpp (3023B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
      3 /* This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 /* struct containing the output from nsIFrame::Reflow */
      8 
      9 #include "mozilla/ReflowOutput.h"
     10 
     11 #include "mozilla/ReflowInput.h"
     12 #include "mozilla/WritingModes.h"
     13 
     14 namespace mozilla {
     15 
     16 static bool IsValidOverflowRect(const nsRect& aRect) {
     17  // The reason we can't simply use `nsRect::IsEmpty` is that any one dimension
     18  // being zero is considered empty by it - On the other hand, an overflow rect
     19  // is valid if it has non-negative dimensions and at least one of them is
     20  // non-zero.
     21  return aRect.Size() != nsSize{0, 0} && aRect.Width() >= 0 &&
     22         aRect.Height() >= 0;
     23 }
     24 
     25 /* static */
     26 nsRect OverflowAreas::GetOverflowClipRect(const nsRect& aRectToClip,
     27                                          const nsRect& aBounds,
     28                                          PhysicalAxes aClipAxes,
     29                                          const nsMargin& aOverflowMargin) {
     30  auto inflatedBounds = aBounds;
     31  inflatedBounds.Inflate(aOverflowMargin);
     32  auto clip = aRectToClip;
     33  if (aClipAxes.contains(PhysicalAxis::Vertical)) {
     34    clip.y = inflatedBounds.y;
     35    clip.height = inflatedBounds.height;
     36  }
     37  if (aClipAxes.contains(PhysicalAxis::Horizontal)) {
     38    clip.x = inflatedBounds.x;
     39    clip.width = inflatedBounds.width;
     40  }
     41  return clip;
     42 }
     43 
     44 /* static */
     45 void OverflowAreas::ApplyOverflowClippingOnRect(
     46    nsRect& aOverflowRect, const nsRect& aBounds, PhysicalAxes aClipAxes,
     47    const nsMargin& aOverflowMargin) {
     48  aOverflowRect = aOverflowRect.Intersect(
     49      GetOverflowClipRect(aOverflowRect, aBounds, aClipAxes, aOverflowMargin));
     50 }
     51 
     52 void OverflowAreas::UnionWith(const OverflowAreas& aOther) {
     53  if (IsValidOverflowRect(aOther.InkOverflow())) {
     54    InkOverflow().UnionRect(InkOverflow(), aOther.InkOverflow());
     55  }
     56  if (IsValidOverflowRect(aOther.ScrollableOverflow())) {
     57    ScrollableOverflow().UnionRect(ScrollableOverflow(),
     58                                   aOther.ScrollableOverflow());
     59  }
     60 }
     61 
     62 void OverflowAreas::UnionAllWith(const nsRect& aRect) {
     63  if (!IsValidOverflowRect(aRect)) {
     64    // Same as `UnionWith()` - avoid losing information.
     65    return;
     66  }
     67  InkOverflow().UnionRect(InkOverflow(), aRect);
     68  ScrollableOverflow().UnionRect(ScrollableOverflow(), aRect);
     69 }
     70 
     71 void OverflowAreas::SetAllTo(const nsRect& aRect) {
     72  InkOverflow() = aRect;
     73  ScrollableOverflow() = aRect;
     74 }
     75 
     76 ReflowOutput::ReflowOutput(const ReflowInput& aReflowInput)
     77    : ReflowOutput(aReflowInput.GetWritingMode()) {}
     78 
     79 void ReflowOutput::SetOverflowAreasToDesiredBounds() {
     80  mOverflowAreas.SetAllTo(nsRect(0, 0, Width(), Height()));
     81 }
     82 
     83 void ReflowOutput::UnionOverflowAreasWithDesiredBounds() {
     84  mOverflowAreas.UnionAllWith(nsRect(0, 0, Width(), Height()));
     85 }
     86 
     87 }  // namespace mozilla