layout/generic/nsLeafFrame.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /* base class for rendering objects that do not have child lists */
   8
   9 #ifndef nsLeafFrame_h___
  10 #define nsLeafFrame_h___
  11
  12 #include "mozilla/Attributes.h"
  13 #include "nsIFrame.h"
  14 #include "nsDisplayList.h"
  15
  16 /**
  17  * Abstract class that provides simple fixed-size layout for leaf objects
  18  * (e.g. images, form elements, etc.). Deriviations provide the implementation
  19  * of the GetDesiredSize method. The rendering method knows how to render
  20  * borders and backgrounds.
  21  */
  22 class nsLeafFrame : public nsIFrame {
  23  public:
  24   NS_DECL_ABSTRACT_FRAME(nsLeafFrame)
  25
  26   // nsIFrame replacements
  27   void BuildDisplayList(nsDisplayListBuilder* aBuilder,
  28                         const nsDisplayListSet& aLists) override;
  29
  30   /**
  31    * Both GetMinISize and GetPrefISize will return whatever GetIntrinsicISize
  32    * returns.
  33    */
  34   virtual nscoord GetMinISize(gfxContext* aRenderingContext) override;
  35   virtual nscoord GetPrefISize(gfxContext* aRenderingContext) override;
  36
  37   /**
  38    * Our auto size is just intrinsic width and intrinsic height.
  39    */
  40   mozilla::LogicalSize ComputeAutoSize(
  41       gfxContext* aRenderingContext, mozilla::WritingMode aWM,
  42       const mozilla::LogicalSize& aCBSize, nscoord aAvailableISize,
  43       const mozilla::LogicalSize& aMargin,
  44       const mozilla::LogicalSize& aBorderPadding,
  45       const mozilla::StyleSizeOverrides& aSizeOverrides,
  46       mozilla::ComputeSizeFlags aFlags) override;
  47
  48   /**
  49    * Each of our subclasses should provide its own Reflow impl:
  50    */
  51   virtual void Reflow(nsPresContext* aPresContext, ReflowOutput& aDesiredSize,
  52                       const ReflowInput& aReflowInput,
  53                       nsReflowStatus& aStatus) override = 0;
  54
  55   virtual bool IsFrameOfType(uint32_t aFlags) const override {
  56     // We don't actually contain a block, but we do always want a
  57     // computed width, so tell a little white lie here.
  58     return nsIFrame::IsFrameOfType(aFlags &
  59                                    ~(nsIFrame::eReplacedContainsBlock));
  60   }
  61
  62  protected:
  63   nsLeafFrame(ComputedStyle* aStyle, nsPresContext* aPresContext, ClassID aID)
  64       : nsIFrame(aStyle, aPresContext, aID) {}
  65
  66   virtual ~nsLeafFrame();
  67
  68   /**
  69    * Return the intrinsic isize of the frame's content area. Note that this
  70    * should not include borders or padding and should not depend on the applied
  71    * styles.
  72    */
  73   virtual nscoord GetIntrinsicISize() = 0;
  74
  75   /**
  76    * Return the intrinsic bsize of the frame's content area.  This should not
  77    * include border or padding.  This will only matter if the specified bsize
  78    * is auto.  Note that subclasses must either implement this or override
  79    * Reflow and ComputeAutoSize; the default Reflow and ComputeAutoSize impls
  80    * call this method.
  81    */
  82   virtual nscoord GetIntrinsicBSize();
  83
  84   /**
  85    * Set aDesiredSize to be the available size
  86    */
  87   void SizeToAvailSize(const ReflowInput& aReflowInput,
  88                        ReflowOutput& aDesiredSize);
  89 };
  90
  91 #endif /* nsLeafFrame_h___ */