layout/generic/nsLeafFrame.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 /* base class for rendering objects that do not have child lists */
   7
   8 #ifndef nsLeafFrame_h___
   9 #define nsLeafFrame_h___
  10
  11 #include "mozilla/Attributes.h"
  12 #include "nsFrame.h"
  13 #include "nsDisplayList.h"
  14
  15 /**
  16  * Abstract class that provides simple fixed-size layout for leaf objects
  17  * (e.g. images, form elements, etc.). Deriviations provide the implementation
  18  * of the GetDesiredSize method. The rendering method knows how to render
  19  * borders and backgrounds.
  20  */
  21 class nsLeafFrame : public nsFrame {
  22 public:
  23   NS_DECL_FRAMEARENA_HELPERS
  24
  25   // nsIFrame replacements
  26   virtual void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
  27                                 const nsRect&           aDirtyRect,
  28                                 const nsDisplayListSet& aLists) MOZ_OVERRIDE {
  29     DO_GLOBAL_REFLOW_COUNT_DSP("nsLeafFrame");
  30     DisplayBorderBackgroundOutline(aBuilder, aLists);
  31   }
  32
  33   /**
  34    * Both GetMinISize and GetPrefISize will return whatever GetIntrinsicISize
  35    * returns.
  36    */
  37   virtual nscoord GetMinISize(nsRenderingContext *aRenderingContext) MOZ_OVERRIDE;
  38   virtual nscoord GetPrefISize(nsRenderingContext *aRenderingContext) MOZ_OVERRIDE;
  39
  40   /**
  41    * Our auto size is just intrinsic width and intrinsic height.
  42    */
  43   virtual mozilla::LogicalSize
  44   ComputeAutoSize(nsRenderingContext *aRenderingContext,
  45                   mozilla::WritingMode aWritingMode,
  46                   const mozilla::LogicalSize& aCBSize,
  47                   nscoord aAvailableISize,
  48                   const mozilla::LogicalSize& aMargin,
  49                   const mozilla::LogicalSize& aBorder,
  50                   const mozilla::LogicalSize& aPadding,
  51                   bool aShrinkWrap) MOZ_OVERRIDE;
  52
  53   /**
  54    * Reflow our frame.  This will use the computed width plus borderpadding for
  55    * the desired width, and use the return value of GetIntrinsicBSize plus
  56    * borderpadding for the desired height.  Ascent will be set to the height,
  57    * and descent will be set to 0.
  58    */
  59   virtual void Reflow(nsPresContext*      aPresContext,
  60                       nsHTMLReflowMetrics& aDesiredSize,
  61                       const nsHTMLReflowState& aReflowState,
  62                       nsReflowStatus&      aStatus) MOZ_OVERRIDE;
  63
  64   /**
  65    * This method does most of the work that Reflow() above need done.
  66    */
  67   virtual void DoReflow(nsPresContext*      aPresContext,
  68                         nsHTMLReflowMetrics& aDesiredSize,
  69                         const nsHTMLReflowState& aReflowState,
  70                         nsReflowStatus&      aStatus);
  71
  72   virtual bool IsFrameOfType(uint32_t aFlags) const MOZ_OVERRIDE
  73   {
  74     // We don't actually contain a block, but we do always want a
  75     // computed width, so tell a little white lie here.
  76     return nsFrame::IsFrameOfType(aFlags & ~(nsIFrame::eReplacedContainsBlock));
  77   }
  78
  79 protected:
  80   explicit nsLeafFrame(nsStyleContext* aContext) : nsFrame(aContext) {}
  81   virtual ~nsLeafFrame();
  82
  83   /**
  84    * Return the intrinsic width of the frame's content area. Note that this
  85    * should not include borders or padding and should not depend on the applied
  86    * styles.
  87    */
  88   virtual nscoord GetIntrinsicISize() = 0;
  89
  90   /**
  91    * Return the intrinsic height of the frame's content area.  This should not
  92    * include border or padding.  This will only matter if the specified height
  93    * is auto.  Note that subclasses must either implement this or override
  94    * Reflow and ComputeAutoSize; the default Reflow and ComputeAutoSize impls
  95    * call this method.
  96    */
  97   virtual nscoord GetIntrinsicBSize();
  98
  99   /**
 100    * Subroutine to add in borders and padding
 101    */
 102   void AddBordersAndPadding(const nsHTMLReflowState& aReflowState,
 103                             mozilla::LogicalSize& aDesiredSize);
 104
 105   /**
 106    * Set aDesiredSize to be the available size
 107    */
 108   void SizeToAvailSize(const nsHTMLReflowState& aReflowState,
 109                        nsHTMLReflowMetrics& aDesiredSize);
 110 };
 111
 112 #endif /* nsLeafFrame_h___ */