1 files changed, 161 insertions, 0 deletions
diff --git a/layout/generic/nsTextPaintStyle.h b/layout/generic/nsTextPaintStyle.h
new file mode 100644
index 0000000000..bbc5b62e65
--- /dev/null
+++ b/layout/generic/nsTextPaintStyle.h
@@ -0,0 +1,161 @@
+/* -*- 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 nsTextPaintStyle_h__
+#define nsTextPaintStyle_h__
+
+#include "mozilla/Attributes.h"
+#include "mozilla/ComputedStyle.h"
+#include "mozilla/Span.h"
+
+#include "nsAtom.h"
+#include "nsISelectionController.h"
+#include "nsTHashMap.h"
+
+class nsTextFrame;
+class nsPresContext;
+
+namespace mozilla {
+enum class StyleTextDecorationStyle : uint8_t;
+}
+
+/**
+ * This helper object computes colors used for painting, and also IME
+ * underline information. The data is computed lazily and cached as necessary.
+ * These live for just the duration of one paint operation.
+ */
+class MOZ_STACK_CLASS nsTextPaintStyle {
+  using ComputedStyle = mozilla::ComputedStyle;
+  using SelectionType = mozilla::SelectionType;
+  using StyleTextDecorationStyle = mozilla::StyleTextDecorationStyle;
+  using StyleSimpleShadow = mozilla::StyleSimpleShadow;
+
+ public:
+  explicit nsTextPaintStyle(nsTextFrame* aFrame);
+
+  void SetResolveColors(bool aResolveColors) {
+    mResolveColors = aResolveColors;
+  }
+
+  nscolor GetTextColor();
+
+  // SVG text has its own painting process, so we should never get its stroke
+  // property from here.
+  nscolor GetWebkitTextStrokeColor();
+  float GetWebkitTextStrokeWidth();
+
+  /**
+   * Compute the colors for normally-selected text. Returns false if
+   * the normal selection is not being displayed.
+   */
+  bool GetSelectionColors(nscolor* aForeColor, nscolor* aBackColor);
+  void GetHighlightColors(nscolor* aForeColor, nscolor* aBackColor);
+  // Computes colors for custom highlights.
+  // Returns false if there are no rules associated with `aHighlightName`.
+  bool GetCustomHighlightColors(const nsAtom* aHighlightName,
+                                nscolor* aForeColor, nscolor* aBackColor);
+  void GetURLSecondaryColor(nscolor* aForeColor);
+  void GetIMESelectionColors(int32_t aIndex, nscolor* aForeColor,
+                             nscolor* aBackColor);
+  // if this returns false, we don't need to draw underline.
+  bool GetSelectionUnderlineForPaint(int32_t aIndex, nscolor* aLineColor,
+                                     float* aRelativeSize,
+                                     StyleTextDecorationStyle* aStyle);
+
+  // if this returns false, we don't need to draw underline.
+  static bool GetSelectionUnderline(nsIFrame*, int32_t aIndex,
+                                    nscolor* aLineColor, float* aRelativeSize,
+                                    StyleTextDecorationStyle* aStyle);
+
+  // if this returns false, no text-shadow was specified for the selection
+  // and the *aShadow parameter was not modified.
+  bool GetSelectionShadow(mozilla::Span<const StyleSimpleShadow>* aShadows);
+
+  nsPresContext* PresContext() const { return mPresContext; }
+
+  enum {
+    eIndexRawInput = 0,
+    eIndexSelRawText,
+    eIndexConvText,
+    eIndexSelConvText,
+    eIndexSpellChecker
+  };
+
+  static int32_t GetUnderlineStyleIndexForSelectionType(
+      SelectionType aSelectionType) {
+    switch (aSelectionType) {
+      case SelectionType::eIMERawClause:
+        return eIndexRawInput;
+      case SelectionType::eIMESelectedRawClause:
+        return eIndexSelRawText;
+      case SelectionType::eIMEConvertedClause:
+        return eIndexConvText;
+      case SelectionType::eIMESelectedClause:
+        return eIndexSelConvText;
+      case SelectionType::eSpellCheck:
+        return eIndexSpellChecker;
+      default:
+        NS_WARNING("non-IME selection type");
+        return eIndexRawInput;
+    }
+  }
+
+  nscolor GetSystemFieldForegroundColor();
+  nscolor GetSystemFieldBackgroundColor();
+
+ protected:
+  nsTextFrame* mFrame;
+  nsPresContext* mPresContext;
+  bool mInitCommonColors;
+  bool mInitSelectionColorsAndShadow;
+  bool mResolveColors;
+
+  // Selection data
+
+  nscolor mSelectionTextColor;
+  nscolor mSelectionBGColor;
+  RefPtr<ComputedStyle> mSelectionPseudoStyle;
+  nsTHashMap<RefPtr<const nsAtom>, RefPtr<ComputedStyle>>
+      mCustomHighlightPseudoStyles;
+
+  // Common data
+
+  int32_t mSufficientContrast;
+  nscolor mFrameBackgroundColor;
+  nscolor mSystemFieldForegroundColor;
+  nscolor mSystemFieldBackgroundColor;
+
+  // selection colors and underline info, the colors are resolved colors if
+  // mResolveColors is true (which is the default), i.e., the foreground color
+  // and background color are swapped if it's needed. And also line color will
+  // be resolved from them.
+  struct nsSelectionStyle {
+    bool mInit;
+    nscolor mTextColor;
+    nscolor mBGColor;
+    nscolor mUnderlineColor;
+    StyleTextDecorationStyle mUnderlineStyle;
+    float mUnderlineRelativeSize;
+  };
+  nsSelectionStyle mSelectionStyle[5];
+
+  // Color initializations
+  void InitCommonColors();
+  bool InitSelectionColorsAndShadow();
+
+  nsSelectionStyle* GetSelectionStyle(int32_t aIndex);
+  void InitSelectionStyle(int32_t aIndex);
+
+  // Ensures sufficient contrast between the frame background color and the
+  // selection background color, and swaps the selection text and background
+  // colors accordingly.
+  bool EnsureSufficientContrast(nscolor* aForeColor, nscolor* aBackColor);
+
+  nscolor GetResolvedForeColor(nscolor aColor, nscolor aDefaultForeColor,
+                               nscolor aBackColor);
+};
+
+#endif  // nsTextPaintStyle_h__