michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: // vim:cindent:ts=2:et:sw=2:
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: /* class that a parent frame uses to reflow a block frame */
michael@0: 
michael@0: #ifndef nsBlockReflowContext_h___
michael@0: #define nsBlockReflowContext_h___
michael@0: 
michael@0: #include "nsIFrame.h"
michael@0: #include "nsHTMLReflowMetrics.h"
michael@0: 
michael@0: class nsBlockReflowState;
michael@0: struct nsHTMLReflowState;
michael@0: class nsLineBox;
michael@0: class nsPresContext;
michael@0: class nsLineLayout;
michael@0: struct nsBlockHorizontalAlign;
michael@0: 
michael@0: /**
michael@0:  * An encapsulation of the state and algorithm for reflowing block frames.
michael@0:  */
michael@0: class nsBlockReflowContext {
michael@0: public:
michael@0:   nsBlockReflowContext(nsPresContext* aPresContext,
michael@0:                        const nsHTMLReflowState& aParentRS);
michael@0:   ~nsBlockReflowContext() { }
michael@0: 
michael@0:   nsresult ReflowBlock(const nsRect&       aSpace,
michael@0:                        bool                aApplyTopMargin,
michael@0:                        nsCollapsingMargin& aPrevMargin,
michael@0:                        nscoord             aClearance,
michael@0:                        bool                aIsAdjacentWithTop,
michael@0:                        nsLineBox*          aLine,
michael@0:                        nsHTMLReflowState&  aReflowState,
michael@0:                        nsReflowStatus&     aReflowStatus,
michael@0:                        nsBlockReflowState& aState);
michael@0: 
michael@0:   bool PlaceBlock(const nsHTMLReflowState& aReflowState,
michael@0:                   bool                     aForceFit,
michael@0:                   nsLineBox*               aLine,
michael@0:                   nsCollapsingMargin&      aBottomMarginResult /* out */,
michael@0:                   nsOverflowAreas&         aOverflowAreas,
michael@0:                   nsReflowStatus           aReflowStatus,
michael@0:                   nscoord                  aContainerWidth);
michael@0: 
michael@0:   nsCollapsingMargin& GetCarriedOutBottomMargin() {
michael@0:     return mMetrics.mCarriedOutBottomMargin;
michael@0:   }
michael@0: 
michael@0:   nscoord GetTopMargin() const {
michael@0:     return mTopMargin.get();
michael@0:   }
michael@0: 
michael@0:   const nsHTMLReflowMetrics& GetMetrics() const {
michael@0:     return mMetrics;
michael@0:   }
michael@0: 
michael@0:   /**
michael@0:    * Computes the collapsed top margin for a block whose reflow state is in aRS.
michael@0:    * The computed margin is added into aMargin.
michael@0:    * If aClearanceFrame is null then this is the first optimistic pass which shall assume
michael@0:    * that no frames have clearance, and we clear the HasClearance on all frames encountered.
michael@0:    * If non-null, this is the second pass and
michael@0:    * the caller has decided aClearanceFrame needs clearance (and we will
michael@0:    * therefore stop collapsing there); also, this function is responsible for marking
michael@0:    * it with SetHasClearance.
michael@0:    * If in the optimistic pass any frame is encountered that might possibly need
michael@0:    * clearance (i.e., if we really needed the optimism assumption) then we set aMayNeedRetry
michael@0:    * to true.
michael@0:    * We return true if we changed the clearance state of any line and marked it dirty.
michael@0:    */
michael@0:   static bool ComputeCollapsedTopMargin(const nsHTMLReflowState& aRS,
michael@0:                                           nsCollapsingMargin* aMargin, nsIFrame* aClearanceFrame,
michael@0:                                           bool* aMayNeedRetry, bool* aIsEmpty = nullptr);
michael@0: 
michael@0: protected:
michael@0:   nsPresContext* mPresContext;
michael@0:   const nsHTMLReflowState& mOuterReflowState;
michael@0: 
michael@0:   nsIFrame* mFrame;
michael@0:   nsRect mSpace;
michael@0: 
michael@0:   nscoord mX, mY;
michael@0:   nsHTMLReflowMetrics mMetrics;
michael@0:   nsCollapsingMargin mTopMargin;
michael@0: };
michael@0: 
michael@0: #endif /* nsBlockReflowContext_h___ */