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/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
/* 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/. */
/* Per-block-formatting-context manager of font size inflation for pan and zoom UI. */
#ifndef nsFontInflationData_h_
#define nsFontInflationData_h_
#include "nsIFrame.h"
#include "nsLayoutUtils.h"
#include "nsBlockFrame.h"
struct nsHTMLReflowState;
class nsFontInflationData
{
public:
static nsFontInflationData* FindFontInflationDataFor(const nsIFrame *aFrame);
// Returns whether the effective width changed (which requires the
// caller to mark its descendants dirty
static bool
UpdateFontInflationDataWidthFor(const nsHTMLReflowState& aReflowState);
static void MarkFontInflationDataTextDirty(nsIFrame *aFrame);
bool InflationEnabled() {
if (mTextDirty) {
ScanText();
}
return mInflationEnabled;
}
nscoord EffectiveWidth() const {
return mNCAWidth;
}
private:
nsFontInflationData(nsIFrame* aBFCFrame);
nsFontInflationData(const nsFontInflationData&) MOZ_DELETE;
void operator=(const nsFontInflationData&) MOZ_DELETE;
void UpdateWidth(const nsHTMLReflowState &aReflowState);
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 width 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->GetStateBits() & NS_FRAME_FONT_INFLATION_FLOW_ROOT)) {
aFrame = aFrame->GetParent();
}
return aFrame;
}
nsIFrame *mBFCFrame;
nscoord mNCAWidth;
nscoord mTextAmount, mTextThreshold;
bool mInflationEnabled; // for this BFC
bool mTextDirty;
};
#endif /* !defined(nsFontInflationData_h_) */
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