author Dragana Damjanovic <>
Thu, 06 May 2021 18:10:45 +0000
changeset 578757 c9980e971a31b2bd47783dc4a9a26fca4a4c57d6
parent 537705 7680b2b4acbbd87f0d39cb2f984d269569e08584
permissions -rw-r--r--
Bug 1708678 - Adapt code to neqo 0.4.24 r=necko-reviewers,valentin Differential Revision:

/* -*- 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 */

/* Per-block-formatting-context manager of font size inflation for pan and zoom
 * UI. */

#ifndef nsFontInflationData_h_
#define nsFontInflationData_h_

#include "nsContainerFrame.h"

class nsFontInflationData {
  using ReflowInput = mozilla::ReflowInput;

  static nsFontInflationData* FindFontInflationDataFor(const nsIFrame* aFrame);

  // Returns whether the usable width changed (which requires the
  // caller to mark its descendants dirty)
  static bool UpdateFontInflationDataISizeFor(const ReflowInput& aReflowInput);

  static void MarkFontInflationDataTextDirty(nsIFrame* aFrame);

  bool InflationEnabled() {
    if (mTextDirty) {
    return mInflationEnabled;

  nscoord UsableISize() const { return mUsableISize; }

  explicit nsFontInflationData(nsIFrame* aBFCFrame);

  nsFontInflationData(const nsFontInflationData&) = delete;
  void operator=(const nsFontInflationData&) = delete;

  void UpdateISize(const ReflowInput& aReflowInput);
  enum SearchDirection { eFromStart, eFromEnd };
  static nsIFrame* FindEdgeInflatableFrameIn(nsIFrame* aFrame,
                                             SearchDirection aDirection);

  void MarkTextDirty() { mTextDirty = true; }
  void ScanText();
  // Scan text in the subtree rooted at aFrame.  Increment mTextAmount
  // by multiplying the number of characters found by the font size
  // (yielding the inline-size that would be occupied by the characters if
  // they were all em squares).  But stop scanning if mTextAmount
  // crosses mTextThreshold.
  void ScanTextIn(nsIFrame* aFrame);

  static const nsIFrame* FlowRootFor(const nsIFrame* aFrame) {
    while (!aFrame->HasAnyStateBits(NS_FRAME_FONT_INFLATION_FLOW_ROOT)) {
      aFrame = aFrame->GetParent();
    return aFrame;

  nsIFrame* mBFCFrame;
  nscoord mUsableISize;
  nscoord mTextAmount, mTextThreshold;
  bool mInflationEnabled;  // for this BFC
  bool mTextDirty;

#endif /* !defined(nsFontInflationData_h_) */