Add m-esr52 at 52.6.0

1 files changed, 179 insertions, 0 deletions

diff --git a/layout/generic/nsPlaceholderFrame.h b/layout/generic/nsPlaceholderFrame.h
new file mode 100644
index 000000000..0c23a4f75
--- /dev/null
+++ b/layout/generic/nsPlaceholderFrame.h
@@ -0,0 +1,179 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * rendering object for the point that anchors out-of-flow rendering
+ * objects such as floats and absolutely positioned elements
+ */
+
+/*
+ * Destruction of a placeholder and its out-of-flow must observe the
+ * following constraints:
+ *
+ * - The mapping from the out-of-flow to the placeholder must be
+ *   removed from the frame manager before the placeholder is destroyed.
+ * - The mapping from the out-of-flow to the placeholder must be
+ *   removed from the frame manager before the out-of-flow is destroyed.
+ * - The placeholder must be removed from the frame tree, or have the
+ *   mapping from it to its out-of-flow cleared, before the out-of-flow
+ *   is destroyed (so that the placeholder will not point to a destroyed
+ *   frame while it's in the frame tree).
+ *
+ * Furthermore, some code assumes that placeholders point to something
+ * useful, so placeholders without an associated out-of-flow should not
+ * remain in the tree.
+ *
+ * The placeholder's Destroy() implementation handles the destruction of
+ * the placeholder and its out-of-flow. To avoid crashes, frame removal
+ * and destruction code that works with placeholders must not assume
+ * that the placeholder points to its out-of-flow.
+ */
+
+#ifndef nsPlaceholderFrame_h___
+#define nsPlaceholderFrame_h___
+
+#include "mozilla/Attributes.h"
+#include "nsFrame.h"
+#include "nsGkAtoms.h"
+
+nsIFrame* NS_NewPlaceholderFrame(nsIPresShell* aPresShell,
+                                 nsStyleContext* aContext,
+                                 nsFrameState aTypeBit);
+
+#define PLACEHOLDER_TYPE_MASK    (PLACEHOLDER_FOR_FLOAT | \
+                                  PLACEHOLDER_FOR_ABSPOS | \
+                                  PLACEHOLDER_FOR_FIXEDPOS | \
+                                  PLACEHOLDER_FOR_POPUP | \
+                                  PLACEHOLDER_FOR_TOPLAYER)
+
+/**
+ * Implementation of a frame that's used as a placeholder for a frame that
+ * has been moved out of the flow.
+ */
+class nsPlaceholderFrame final : public nsFrame {
+public:
+  NS_DECL_FRAMEARENA_HELPERS
+#ifdef DEBUG
+  NS_DECL_QUERYFRAME_TARGET(nsPlaceholderFrame)
+  NS_DECL_QUERYFRAME
+#endif
+
+  /**
+   * Create a new placeholder frame.  aTypeBit must be one of the
+   * PLACEHOLDER_FOR_* constants above.
+   */
+  friend nsIFrame* NS_NewPlaceholderFrame(nsIPresShell* aPresShell,
+                                          nsStyleContext* aContext,
+                                          nsFrameState aTypeBit);
+  nsPlaceholderFrame(nsStyleContext* aContext, nsFrameState aTypeBit)
+    : nsFrame(aContext)
+  {
+    NS_PRECONDITION(aTypeBit == PLACEHOLDER_FOR_FLOAT ||
+                    aTypeBit == PLACEHOLDER_FOR_ABSPOS ||
+                    aTypeBit == PLACEHOLDER_FOR_FIXEDPOS ||
+                    aTypeBit == PLACEHOLDER_FOR_POPUP ||
+                    aTypeBit == PLACEHOLDER_FOR_TOPLAYER,
+                    "Unexpected type bit");
+    AddStateBits(aTypeBit);
+  }
+
+  // Get/Set the associated out of flow frame
+  nsIFrame*  GetOutOfFlowFrame() const { return mOutOfFlowFrame; }
+  void       SetOutOfFlowFrame(nsIFrame* aFrame) {
+               NS_ASSERTION(!aFrame || !aFrame->GetPrevContinuation(),
+                            "OOF must be first continuation");
+               mOutOfFlowFrame = aFrame;
+             }
+
+  // nsIFrame overrides
+  // We need to override GetXULMinSize and GetXULPrefSize because XUL uses
+  // placeholders not within lines.
+  virtual void AddInlineMinISize(nsRenderingContext* aRenderingContext,
+                                 InlineMinISizeData* aData) override;
+  virtual void AddInlinePrefISize(nsRenderingContext* aRenderingContext,
+                                  InlinePrefISizeData* aData) override;
+  virtual nsSize GetXULMinSize(nsBoxLayoutState& aBoxLayoutState) override;
+  virtual nsSize GetXULPrefSize(nsBoxLayoutState& aBoxLayoutState) override;
+  virtual nsSize GetXULMaxSize(nsBoxLayoutState& aBoxLayoutState) override;
+
+  virtual void Reflow(nsPresContext* aPresContext,
+                      ReflowOutput& aDesiredSize,
+                      const ReflowInput& aReflowInput,
+                      nsReflowStatus& aStatus) override;
+
+  virtual void DestroyFrom(nsIFrame* aDestructRoot) override;
+
+#if defined(DEBUG) || (defined(MOZ_REFLOW_PERF_DSP) && defined(MOZ_REFLOW_PERF))
+  virtual void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
+                                const nsRect&           aDirtyRect,
+                                const nsDisplayListSet& aLists) override;
+#endif // DEBUG || (MOZ_REFLOW_PERF_DSP && MOZ_REFLOW_PERF)
+  
+#ifdef DEBUG_FRAME_DUMP
+  void List(FILE* out = stderr, const char* aPrefix = "", uint32_t aFlags = 0) const override;
+  virtual nsresult GetFrameName(nsAString& aResult) const override;
+#endif // DEBUG
+
+  /**
+   * Get the "type" of the frame
+   *
+   * @see nsGkAtoms::placeholderFrame
+   */
+  virtual nsIAtom* GetType() const override;
+
+  virtual bool IsEmpty() override { return true; }
+  virtual bool IsSelfEmpty() override { return true; }
+
+  virtual bool CanContinueTextRun() const override;
+
+#ifdef ACCESSIBILITY
+  virtual mozilla::a11y::AccType AccessibleType() override
+  {
+    nsIFrame* realFrame = GetRealFrameForPlaceholder(this);
+    return realFrame ? realFrame->AccessibleType() :
+                       nsFrame::AccessibleType();
+  }
+#endif
+
+  virtual nsStyleContext* GetParentStyleContext(nsIFrame** aProviderFrame) const override;
+
+  bool RenumberFrameAndDescendants(int32_t* aOrdinal,
+                                   int32_t aDepth,
+                                   int32_t aIncrement,
+                                   bool aForCounting) override
+  {
+    return mOutOfFlowFrame->
+      RenumberFrameAndDescendants(aOrdinal, aDepth, aIncrement, aForCounting);
+  }
+
+  /**
+   * @return the out-of-flow for aFrame if aFrame is a placeholder; otherwise
+   * aFrame
+   */
+  static nsIFrame* GetRealFrameFor(nsIFrame* aFrame) {
+    NS_PRECONDITION(aFrame, "Must have a frame to work with");
+    if (aFrame->GetType() == nsGkAtoms::placeholderFrame) {
+      return GetRealFrameForPlaceholder(aFrame);
+    }
+    return aFrame;
+  }
+
+  /**
+   * @return the out-of-flow for aFrame, which is known to be a placeholder
+   */
+  static nsIFrame* GetRealFrameForPlaceholder(nsIFrame* aFrame) {
+    NS_PRECONDITION(aFrame->GetType() == nsGkAtoms::placeholderFrame,
+                    "Must have placeholder frame as input");
+    nsIFrame* outOfFlow =
+      static_cast<nsPlaceholderFrame*>(aFrame)->GetOutOfFlowFrame();
+    NS_ASSERTION(outOfFlow, "Null out-of-flow for placeholder?");
+    return outOfFlow;
+  }
+
+protected:
+  nsIFrame* mOutOfFlowFrame;
+};
+
+#endif /* nsPlaceholderFrame_h___ */