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/* -*- 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_) */