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, 70 insertions, 0 deletions

diff --git a/layout/generic/nsFontInflationData.h b/layout/generic/nsFontInflationData.h
new file mode 100644
index 0000000000..80a422fe32
--- /dev/null
+++ b/layout/generic/nsFontInflationData.h
@@ -0,0 +1,70 @@
+/* -*- 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/. */
+
+/* Per-block-formatting-context manager of font size inflation for pan and zoom
+ * UI. */
+
+#ifndef nsFontInflationData_h_
+#define nsFontInflationData_h_
+
+#include "nsContainerFrame.h"
+
+class nsFontInflationData {
+  using ReflowInput = mozilla::ReflowInput;
+
+ public:
+  static nsFontInflationData* FindFontInflationDataFor(const nsIFrame* aFrame);
+
+  // Returns whether the usable width changed (which requires the
+  // caller to mark its descendants dirty)
+  static bool UpdateFontInflationDataISizeFor(const ReflowInput& aReflowInput);
+
+  static void MarkFontInflationDataTextDirty(nsIFrame* aFrame);
+
+  bool InflationEnabled() {
+    if (mTextDirty) {
+      ScanText();
+    }
+    return mInflationEnabled;
+  }
+
+  nscoord UsableISize() const { return mUsableISize; }
+
+ private:
+  explicit nsFontInflationData(nsIFrame* aBFCFrame);
+
+  nsFontInflationData(const nsFontInflationData&) = delete;
+  void operator=(const nsFontInflationData&) = delete;
+
+  void UpdateISize(const ReflowInput& aReflowInput);
+  enum SearchDirection { eFromStart, eFromEnd };
+  static nsIFrame* FindEdgeInflatableFrameIn(nsIFrame* aFrame,
+                                             SearchDirection aDirection);
+
+  void MarkTextDirty() { mTextDirty = true; }
+  void ScanText();
+  // Scan text in the subtree rooted at aFrame.  Increment mTextAmount
+  // by multiplying the number of characters found by the font size
+  // (yielding the inline-size that would be occupied by the characters if
+  // they were all em squares).  But stop scanning if mTextAmount
+  // crosses mTextThreshold.
+  void ScanTextIn(nsIFrame* aFrame);
+
+  static const nsIFrame* FlowRootFor(const nsIFrame* aFrame) {
+    while (!aFrame->HasAnyStateBits(NS_FRAME_FONT_INFLATION_FLOW_ROOT)) {
+      aFrame = aFrame->GetParent();
+    }
+    return aFrame;
+  }
+
+  nsIFrame* mBFCFrame;
+  nscoord mUsableISize;
+  nscoord mTextAmount, mTextThreshold;
+  bool mInflationEnabled;  // for this BFC
+  bool mTextDirty;
+};
+
+#endif /* !defined(nsFontInflationData_h_) */