Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 201 insertions, 0 deletions

diff --git a/layout/generic/nsColumnSetFrame.h b/layout/generic/nsColumnSetFrame.h
new file mode 100644
index 0000000000..20df72a07d
--- /dev/null
+++ b/layout/generic/nsColumnSetFrame.h
@@ -0,0 +1,201 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#ifndef nsColumnSetFrame_h___
+#define nsColumnSetFrame_h___
+
+/* rendering object for css3 multi-column layout */
+
+#include "mozilla/Attributes.h"
+#include "nsContainerFrame.h"
+
+class nsCSSBorderRenderer;
+
+/**
+ * nsColumnSetFrame implements CSS multi-column layout.
+ * @note nsColumnSetFrame keeps true overflow containers in the normal flow
+ * child lists (i.e. the principal and overflow lists).
+ */
+class nsColumnSetFrame final : public nsContainerFrame {
+ public:
+  NS_DECL_FRAMEARENA_HELPERS(nsColumnSetFrame)
+
+  explicit nsColumnSetFrame(ComputedStyle* aStyle, nsPresContext* aPresContext);
+
+  void Reflow(nsPresContext* aPresContext, ReflowOutput& aDesiredSize,
+              const ReflowInput& aReflowInput,
+              nsReflowStatus& aStatus) override;
+
+#ifdef DEBUG
+  void SetInitialChildList(ChildListID aListID,
+                           nsFrameList&& aChildList) override;
+  void AppendFrames(ChildListID aListID, nsFrameList&& aFrameList) override;
+  void InsertFrames(ChildListID aListID, nsIFrame* aPrevFrame,
+                    const nsLineList::iterator* aPrevFrameLine,
+                    nsFrameList&& aFrameList) override;
+  void RemoveFrame(DestroyContext&, ChildListID, nsIFrame*) override;
+#endif
+
+  nscoord GetMinISize(gfxContext* aRenderingContext) override;
+  nscoord GetPrefISize(gfxContext* aRenderingContext) override;
+
+  nsContainerFrame* GetContentInsertionFrame() override {
+    nsIFrame* frame = PrincipalChildList().FirstChild();
+
+    // if no children return nullptr
+    if (!frame) return nullptr;
+
+    return frame->GetContentInsertionFrame();
+  }
+
+  void BuildDisplayList(nsDisplayListBuilder* aBuilder,
+                        const nsDisplayListSet& aLists) override;
+
+  /**
+   * Similar to nsBlockFrame::DrainOverflowLines. Locate any columns not
+   * handled by our prev-in-flow, and any columns sitting on our own
+   * overflow list, and put them in our primary child list for reflowing.
+   */
+  void DrainOverflowColumns();
+
+  // Return the column-content frame.
+  void AppendDirectlyOwnedAnonBoxes(nsTArray<OwnedAnonBox>& aResult) override;
+
+#ifdef DEBUG_FRAME_DUMP
+  nsresult GetFrameName(nsAString& aResult) const override {
+    return MakeFrameName(u"ColumnSet"_ns, aResult);
+  }
+#endif
+
+  void CreateBorderRenderers(nsTArray<nsCSSBorderRenderer>& aBorderRenderers,
+                             gfxContext* aCtx, const nsRect& aDirtyRect,
+                             const nsPoint& aPt);
+
+  Maybe<nscoord> GetNaturalBaselineBOffset(
+      mozilla::WritingMode aWM, BaselineSharingGroup aBaselineGroup,
+      BaselineExportContext aExportContext) const override;
+
+ protected:
+  nscoord mLastBalanceBSize;
+  nsReflowStatus mLastFrameStatus;
+
+  /**
+   * These are the parameters that control the layout of columns.
+   */
+  struct ReflowConfig {
+    // The optimal number of columns that we want to use. This is computed from
+    // column-count, column-width, available inline-size, etc.
+    int32_t mUsedColCount = INT32_MAX;
+
+    // The inline-size of each individual column.
+    nscoord mColISize = NS_UNCONSTRAINEDSIZE;
+
+    // The amount of inline-size that is expected to be left over after all the
+    // columns and column gaps are laid out.
+    nscoord mExpectedISizeLeftOver = 0;
+
+    // The width (inline-size) of each column gap.
+    nscoord mColGap = NS_UNCONSTRAINEDSIZE;
+
+    // The available block-size of each individual column. This parameter is set
+    // during each iteration of the binary search for the best column
+    // block-size.
+    nscoord mColBSize = NS_UNCONSTRAINEDSIZE;
+
+    // A boolean controlling whether or not we are balancing.
+    bool mIsBalancing = false;
+
+    // A boolean controlling whether or not we are forced to fill columns
+    // sequentially.
+    bool mForceAuto = false;
+
+    // A boolean indicates whether or not we are in the last attempt to reflow
+    // columns. We set it to true at the end of FindBestBalanceBSize().
+    bool mIsLastBalancingReflow = false;
+
+    // The last known column block-size that was 'feasible'. A column bSize is
+    // feasible if all child content fits within the specified bSize.
+    nscoord mKnownFeasibleBSize = NS_UNCONSTRAINEDSIZE;
+
+    // The last known block-size that was 'infeasible'. A column bSize is
+    // infeasible if not all child content fits within the specified bSize.
+    nscoord mKnownInfeasibleBSize = 0;
+  };
+
+  // Collect various block-size data calculated in ReflowChildren(), which are
+  // mainly used for column balancing. This is the output of ReflowChildren()
+  // and ReflowColumns().
+  struct ColumnBalanceData {
+    // The maximum "content block-size" of any column
+    nscoord mMaxBSize = 0;
+
+    // The sum of the "content block-size" for all columns
+    nscoord mSumBSize = 0;
+
+    // The "content block-size" of the last column
+    nscoord mLastBSize = 0;
+
+    // The maximum "content block-size" of all columns that overflowed
+    // their available block-size
+    nscoord mMaxOverflowingBSize = 0;
+
+    // The number of columns (starting from 1 because we have at least one
+    // column). It can be less than ReflowConfig::mUsedColCount.
+    int32_t mColCount = 1;
+
+    // This flag indicates the content that was reflowed fits into the
+    // mColMaxBSize in ReflowConfig.
+    bool mFeasible = false;
+  };
+
+  ColumnBalanceData ReflowColumns(ReflowOutput& aDesiredSize,
+                                  const ReflowInput& aReflowInput,
+                                  nsReflowStatus& aStatus,
+                                  const ReflowConfig& aConfig,
+                                  bool aUnboundedLastColumn);
+
+  /**
+   * The basic reflow strategy is to call this function repeatedly to
+   * obtain specific parameters that determine the layout of the
+   * columns. This function will compute those parameters from the CSS
+   * style. This function will also be responsible for implementing
+   * the state machine that controls column balancing.
+   */
+  ReflowConfig ChooseColumnStrategy(const ReflowInput& aReflowInput,
+                                    bool aForceAuto) const;
+
+  /**
+   * Perform the binary search for the best balance block-size for this column
+   * set.
+   *
+   * @param aReflowInput The input parameters for the current reflow iteration.
+   * @param aPresContext The presentation context in which the current reflow
+   *        iteration is occurring.
+   * @param aConfig The ReflowConfig object associated with this column set
+   *        frame, generated by ChooseColumnStrategy().
+   * @param aColData A data structure used to keep track of data needed between
+   *        successive iterations of the balancing process.
+   * @param aDesiredSize The final output size of the column set frame (output
+   *        of reflow procedure).
+   * @param aUnboundedLastColumn A boolean value indicating that the last column
+   *        can be of any block-size. Used during the first iteration of the
+   *        balancing procedure to measure the block-size of all content in
+   *        descendant frames of the column set.
+   * @param aStatus A final reflow status of the column set frame, passed in as
+   *        an output parameter.
+   */
+  void FindBestBalanceBSize(const ReflowInput& aReflowInput,
+                            nsPresContext* aPresContext, ReflowConfig& aConfig,
+                            ColumnBalanceData aColData,
+                            ReflowOutput& aDesiredSize,
+                            bool aUnboundedLastColumn, nsReflowStatus& aStatus);
+
+  void ForEachColumnRule(
+      const std::function<void(const nsRect& lineRect)>& aSetLineRect,
+      const nsPoint& aPt) const;
+};
+
+#endif  // nsColumnSetFrame_h___