layout/mathml/nsMathMLmsqrtFrame.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 #ifndef nsMathMLmsqrtFrame_h___
   8 #define nsMathMLmsqrtFrame_h___
   9
  10 #include "mozilla/Attributes.h"
  11 #include "nsMathMLmencloseFrame.h"
  12
  13 namespace mozilla {
  14 class PresShell;
  15 }  // namespace mozilla
  16
  17 //
  18 // <msqrt> -- form a radical
  19 //
  20
  21 /*
  22 The MathML REC describes:
  23
  24 The <msqrt> element is used to display square roots.
  25 The syntax for <msqrt> is:
  26   <msqrt> base </msqrt>
  27
  28 Attributes of <msqrt> and <mroot>:
  29
  30 None (except the attributes allowed for all MathML elements, listed in Section
  31 2.3.4).
  32
  33 The <mroot> element increments scriptlevel by 2, and sets displaystyle to
  34 "false", within index, but leaves both attributes unchanged within base. The
  35 <msqrt> element leaves both attributes unchanged within all its arguments.
  36 These attributes are inherited by every element from its rendering environment,
  37 but can be set explicitly only on <mstyle>. (See Section 3.3.4.)
  38 */
  39
  40 // XXXfredw: This class should share its layout logic with nsMathMLmrootFrame
  41 // when the menclose "radical" notation is removed.
  42 // See https://bugzilla.mozilla.org/show_bug.cgi?id=1548522
  43 class nsMathMLmsqrtFrame final : public nsMathMLmencloseFrame {
  44  public:
  45   NS_DECL_FRAMEARENA_HELPERS(nsMathMLmsqrtFrame)
  46
  47   friend nsIFrame* NS_NewMathMLmsqrtFrame(mozilla::PresShell* aPresShell,
  48                                           ComputedStyle* aStyle);
  49
  50   virtual void Init(nsIContent* aContent, nsContainerFrame* aParent,
  51                     nsIFrame* aPrevInFlow) override;
  52
  53   NS_IMETHOD
  54   InheritAutomaticData(nsIFrame* aParent) override;
  55
  56   virtual nsresult AttributeChanged(int32_t aNameSpaceID, nsAtom* aAttribute,
  57                                     int32_t aModType) override;
  58
  59   virtual bool IsMrowLike() override {
  60     return mFrames.FirstChild() != mFrames.LastChild() || !mFrames.FirstChild();
  61   }
  62
  63  protected:
  64   explicit nsMathMLmsqrtFrame(ComputedStyle* aStyle,
  65                               nsPresContext* aPresContext);
  66   virtual ~nsMathMLmsqrtFrame();
  67 };
  68
  69 #endif /* nsMathMLmsqrtFrame_h___ */