layout/generic/nsFlexContainerFrame.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=2 et sw=2 tw=80: */
   3
   4 /* This Source Code is subject to the terms of the Mozilla Public License
   5  * version 2.0 (the "License"). You can obtain a copy of the License at
   6  * http://mozilla.org/MPL/2.0/. */
   7
   8 /* rendering object for CSS "display: flex" */
   9
  10 #ifndef nsFlexContainerFrame_h___
  11 #define nsFlexContainerFrame_h___
  12
  13 #include "nsContainerFrame.h"
  14
  15 nsIFrame* NS_NewFlexContainerFrame(nsIPresShell* aPresShell,
  16                                    nsStyleContext* aContext);
  17
  18 typedef nsContainerFrame nsFlexContainerFrameSuper;
  19
  20 class FlexItem;
  21 class FlexboxAxisTracker;
  22 class MainAxisPositionTracker;
  23 class SingleLineCrossAxisPositionTracker;
  24 template <class T> class nsTArray;
  25
  26 class nsFlexContainerFrame : public nsFlexContainerFrameSuper {
  27   NS_DECL_FRAMEARENA_HELPERS
  28   NS_DECL_QUERYFRAME_TARGET(nsFlexContainerFrame)
  29   NS_DECL_QUERYFRAME
  30
  31   // Factory method:
  32   friend nsIFrame* NS_NewFlexContainerFrame(nsIPresShell* aPresShell,
  33                                             nsStyleContext* aContext);
  34
  35 public:
  36   // nsIFrame overrides
  37   virtual void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
  38                                 const nsRect&           aDirtyRect,
  39                                 const nsDisplayListSet& aLists) MOZ_OVERRIDE;
  40
  41   NS_IMETHOD Reflow(nsPresContext*           aPresContext,
  42                     nsHTMLReflowMetrics&     aDesiredSize,
  43                     const nsHTMLReflowState& aReflowState,
  44                     nsReflowStatus&          aStatus) MOZ_OVERRIDE;
  45
  46   virtual nscoord
  47     GetMinWidth(nsRenderingContext* aRenderingContext) MOZ_OVERRIDE;
  48   virtual nscoord
  49     GetPrefWidth(nsRenderingContext* aRenderingContext) MOZ_OVERRIDE;
  50
  51   virtual nsIAtom* GetType() const MOZ_OVERRIDE;
  52 #ifdef DEBUG
  53   NS_IMETHOD GetFrameName(nsAString& aResult) const MOZ_OVERRIDE;
  54 #endif // DEBUG
  55   // Flexbox-specific public methods
  56   bool IsHorizontal();
  57
  58 protected:
  59   // Protected constructor & destructor
  60   nsFlexContainerFrame(nsStyleContext* aContext) :
  61     nsFlexContainerFrameSuper(aContext),
  62     mChildrenHaveBeenReordered(false)
  63   {}
  64   virtual ~nsFlexContainerFrame();
  65
  66   /**
  67    * Checks whether our child-frame list "mFrames" is sorted, using the given
  68    * IsLessThanOrEqual function, and sorts it if it's not already sorted.
  69    *
  70    * XXXdholbert Once we support pagination, we need to make this function
  71    * check our continuations as well (or wrap it in a function that does).
  72    *
  73    * @return true if we had to sort mFrames, false if it was already sorted.
  74    */
  75   template<bool IsLessThanOrEqual(nsIFrame*, nsIFrame*)>
  76   bool SortChildrenIfNeeded();
  77
  78   // Protected flex-container-specific methods / member-vars
  79 #ifdef DEBUG
  80   void SanityCheckAnonymousFlexItems() const;
  81 #endif // DEBUG
  82
  83   FlexItem GenerateFlexItemForChild(nsPresContext* aPresContext,
  84                                     nsIFrame* aChildFrame,
  85                                     const nsHTMLReflowState& aParentReflowState,
  86                                     const FlexboxAxisTracker& aAxisTracker);
  87
  88   // Returns nsresult because we might have to reflow aFlexItem.Frame() (to
  89   // get its vertical intrinsic size in a vertical flexbox), and if that
  90   // reflow fails (returns a failure nsresult), we want to bail out.
  91   nsresult ResolveFlexItemMaxContentSizing(nsPresContext* aPresContext,
  92                                            FlexItem& aFlexItem,
  93                                            const nsHTMLReflowState& aParentReflowState,
  94                                            const FlexboxAxisTracker& aAxisTracker);
  95
  96   // Runs the "resolve the flexible lengths" algorithm, distributing
  97   // |aFlexContainerMainSize| among the |aItems| and freezing them.
  98   void ResolveFlexibleLengths(const FlexboxAxisTracker& aAxisTracker,
  99                               nscoord aFlexContainerMainSize,
 100                               nsTArray<FlexItem>& aItems);
 101
 102   nsresult GenerateFlexItems(nsPresContext* aPresContext,
 103                              const nsHTMLReflowState& aReflowState,
 104                              const FlexboxAxisTracker& aAxisTracker,
 105                              nsTArray<FlexItem>& aItems);
 106
 107   nscoord ComputeFlexContainerMainSize(const nsHTMLReflowState& aReflowState,
 108                                        const FlexboxAxisTracker& aAxisTracker,
 109                                        const nsTArray<FlexItem>& aFlexItems);
 110
 111   void PositionItemInMainAxis(MainAxisPositionTracker& aMainAxisPosnTracker,
 112                               FlexItem& aItem);
 113
 114   nsresult SizeItemInCrossAxis(nsPresContext* aPresContext,
 115                                const FlexboxAxisTracker& aAxisTracker,
 116                                nsHTMLReflowState& aChildReflowState,
 117                                FlexItem& aItem);
 118
 119   void PositionItemInCrossAxis(
 120     nscoord aLineStartPosition,
 121     SingleLineCrossAxisPositionTracker& aLineCrossAxisPosnTracker,
 122     FlexItem& aItem);
 123
 124   bool mChildrenHaveBeenReordered; // Have we ever had to reorder our kids
 125                                    // to satisfy their 'order' values?
 126 };
 127
 128 #endif /* nsFlexContainerFrame_h___ */