layout/generic/nsPageContentFrame.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 #ifndef nsPageContentFrame_h___
   7 #define nsPageContentFrame_h___
   8
   9 #include "mozilla/Attributes.h"
  10 #include "mozilla/ViewportFrame.h"
  11
  12 class nsPageFrame;
  13 class nsSharedPageData;
  14
  15 namespace mozilla {
  16 class PresShell;
  17 }  // namespace mozilla
  18
  19 // Page content frame class. Represents a page's content, in paginated mode.
  20 class nsPageContentFrame final : public mozilla::ViewportFrame {
  21  public:
  22   NS_DECL_FRAMEARENA_HELPERS(nsPageContentFrame)
  23
  24   friend nsPageContentFrame* NS_NewPageContentFrame(
  25       mozilla::PresShell* aPresShell, ComputedStyle* aStyle,
  26       already_AddRefed<const nsAtom> aPageName);
  27   friend class nsPageFrame;
  28
  29   // nsIFrame
  30   void Reflow(nsPresContext* aPresContext, ReflowOutput& aReflowOutput,
  31               const ReflowInput& aReflowInput,
  32               nsReflowStatus& aStatus) override;
  33
  34   const nsAtom* GetPageName() const { return mPageName; }
  35
  36   void SetSharedPageData(nsSharedPageData* aPD) { mPD = aPD; }
  37
  38   ComputeTransformFunction GetTransformGetter() const override;
  39   void BuildDisplayList(nsDisplayListBuilder*,
  40                         const nsDisplayListSet&) override;
  41
  42   /**
  43    * Return our canvas frame.
  44    */
  45   void AppendDirectlyOwnedAnonBoxes(nsTArray<OwnedAnonBox>& aResult) override;
  46
  47   void EnsurePageName();
  48
  49   // The default implementation of FirstContinuation in nsSplittableFrame is
  50   // implemented in linear time, walking back through the linked list of
  51   // continuations via mPrevContinuation.
  52   // For nsPageContentFrames, we can find the first continuation through the
  53   // frame tree structure in constant time.
  54   nsIFrame* FirstContinuation() const final;
  55
  56 #ifdef DEBUG_FRAME_DUMP
  57   // Debugging
  58   nsresult GetFrameName(nsAString& aResult) const override;
  59   void ExtraContainerFrameInfo(nsACString& aTo) const override;
  60 #endif
  61
  62  protected:
  63   explicit nsPageContentFrame(ComputedStyle* aStyle,
  64                               nsPresContext* aPresContext,
  65                               already_AddRefed<const nsAtom> aPageName)
  66       : ViewportFrame(aStyle, aPresContext, kClassID), mPageName(aPageName) {}
  67
  68   RefPtr<const nsAtom> mPageName;
  69
  70   // Note: this will be set before reflow, and it's strongly owned by our
  71   // nsPageSequenceFrame, which outlives us.
  72   nsSharedPageData* mPD = nullptr;
  73
  74   // The combined InkOverflow from the previous and current page that does not
  75   // yet have space allocated for it.
  76   nscoord mRemainingOverflow = 0;
  77 };
  78
  79 #endif /* nsPageContentFrame_h___ */