gecko-dev/layout/generic/nsFontInflationData.h

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/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the font size inflation manager.
*
* The Initial Developer of the Original Code is the Mozilla Foundation.
* Portions created by the Initial Developer are Copyright (C) 2012
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* L. David Baron <dbaron@dbaron.org>, Mozilla Corporation (original author)
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/* 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);
static void
UpdateFontInflationDataWidthFor(const nsHTMLReflowState& aReflowState);
static void MarkFontInflationDataTextDirty(nsIFrame *aFrame);
bool InflationEnabled() {
if (mTextDirty) {
ScanText();
}
return mInflationEnabled;
}
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 mTextAmount, mTextThreshold;
bool mInflationEnabled; // for this BFC
bool mTextDirty;
};
#endif /* !defined(nsFontInflationData_h_) */