michael@0: /* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /* Per-block-formatting-context manager of font size inflation for pan and zoom UI. */
michael@0: 
michael@0: #ifndef nsFontInflationData_h_
michael@0: #define nsFontInflationData_h_
michael@0: 
michael@0: #include "nsIFrame.h"
michael@0: 
michael@0: struct nsHTMLReflowState;
michael@0: 
michael@0: class nsFontInflationData
michael@0: {
michael@0: public:
michael@0: 
michael@0:   static nsFontInflationData* FindFontInflationDataFor(const nsIFrame *aFrame);
michael@0: 
michael@0:   // Returns whether the effective width changed (which requires the
michael@0:   // caller to mark its descendants dirty
michael@0:   static bool
michael@0:     UpdateFontInflationDataWidthFor(const nsHTMLReflowState& aReflowState);
michael@0: 
michael@0:   static void MarkFontInflationDataTextDirty(nsIFrame *aFrame);
michael@0: 
michael@0:   bool InflationEnabled() {
michael@0:     if (mTextDirty) {
michael@0:       ScanText();
michael@0:     }
michael@0:     return mInflationEnabled;
michael@0:   }
michael@0: 
michael@0:   nscoord EffectiveWidth() const {
michael@0:     return mNCAWidth;
michael@0:   }
michael@0: 
michael@0: private:
michael@0: 
michael@0:   nsFontInflationData(nsIFrame* aBFCFrame);
michael@0: 
michael@0:   nsFontInflationData(const nsFontInflationData&) MOZ_DELETE;
michael@0:   void operator=(const nsFontInflationData&) MOZ_DELETE;
michael@0: 
michael@0:   void UpdateWidth(const nsHTMLReflowState &aReflowState);
michael@0:   enum SearchDirection { eFromStart, eFromEnd };
michael@0:   static nsIFrame* FindEdgeInflatableFrameIn(nsIFrame *aFrame,
michael@0:                                              SearchDirection aDirection);
michael@0: 
michael@0:   void MarkTextDirty() { mTextDirty = true; }
michael@0:   void ScanText();
michael@0:   // Scan text in the subtree rooted at aFrame.  Increment mTextAmount
michael@0:   // by multiplying the number of characters found by the font size
michael@0:   // (yielding the width that would be occupied by the characters if
michael@0:   // they were all em squares).  But stop scanning if mTextAmount
michael@0:   // crosses mTextThreshold.
michael@0:   void ScanTextIn(nsIFrame *aFrame);
michael@0: 
michael@0:   static const nsIFrame* FlowRootFor(const nsIFrame *aFrame)
michael@0:   {
michael@0:     while (!(aFrame->GetStateBits() & NS_FRAME_FONT_INFLATION_FLOW_ROOT)) {
michael@0:       aFrame = aFrame->GetParent();
michael@0:     }
michael@0:     return aFrame;
michael@0:   }
michael@0: 
michael@0:   nsIFrame *mBFCFrame;
michael@0:   nscoord mNCAWidth;
michael@0:   nscoord mTextAmount, mTextThreshold;
michael@0:   bool mInflationEnabled; // for this BFC
michael@0:   bool mTextDirty;
michael@0: };
michael@0: 
michael@0: #endif /* !defined(nsFontInflationData_h_) */