Bug 1360500 - Allow custom colors on find selection type selections. r=jaws,masayuki,smaug

This patch implements chrome-only Selection#setColors and
Selection#resetColors methods, and use it to set the background color of
the preferences search highlight.

MozReview-Commit-ID: 2U92aBCAyeh

--HG--
extra : rebase_source : b07af1f37309d8184584b298a720cd5c1382929a

browser/components/preferences/in-content/findInPage.js

@@ -12,6 +12,7 @@ var gSearchResultsPane = {
   init() {
     let controller = this.getSelectionController();
     this.findSelection = controller.getSelection(Ci.nsISelectionController.SELECTION_FIND);
+    this.findSelection.setColors("currentColor", "#ffe900", "currentColor", "#540ead");
     this.searchResultsCategory = document.getElementById("category-search-results");
 
     this.searchInput = document.getElementById("searchInput");

dom/base/nsISelectionPrivate.idl

@@ -161,5 +161,35 @@ interface nsISelectionPrivate : nsISelection
      *                PR_FALSE if the new language is left-to-right.
      */
     [noscript] void selectionLanguageChange(in boolean langRTL);
+
+    /**
+     * setColors() sets custom colors for the selection.
+     * Currently, this is supported only when the selection type is SELECTION_FIND.
+     * Otherwise, throws an exception.
+     *
+     * @param aForegroundColor     The foreground color of the selection.
+     *                             If this is "currentColor", foreground color
+     *                             isn't changed by this selection.
+     * @param aBackgroundColor     The background color of the selection.
+     *                             If this is "transparent", background color is
+     *                             never painted.
+     * @param aAltForegroundColor  The alternative foreground color of the
+     *                             selection.
+     *                             If aBackgroundColor doesn't have sufficient
+     *                             contrast with its around or foreground color
+     *                             if "currentColor" is specified, alternative
+     *                             colors are used if it have higher contrast.
+     * @param aAltBackgroundColor  The alternative background color of the
+     *                             selection.
+     */
+    void setColors(in DOMString aForegroundColor,
+                   in DOMString aBackgroundColor,
+                   in DOMString aAltForegroundColor,
+                   in DOMString aAltBackgroundColor);
+
+    /**
+     * resetColors() forget the customized colors which were set by setColors().
+     */
+    void resetColors();
 };
 

dom/webidl/Selection.webidl

@@ -90,4 +90,11 @@ partial interface Selection {
 
   [ChromeOnly,Throws]
   void scrollIntoView(short aRegion, boolean aIsSynchronous, short aVPercent, short aHPercent);
+
+  [ChromeOnly,Throws]
+  void setColors(DOMString aForegroundColor, DOMString aBackgroundColor,
+                 DOMString aAltForegroundColor, DOMString aAltBackgroundColor);
+
+  [ChromeOnly,Throws]
+  void resetColors();
 };

layout/generic/Selection.h

@@ -30,6 +30,7 @@ class nsIHTMLEditor;
 class nsFrameSelection;
 class nsPIDOMWindowOuter;
 struct SelectionDetails;
+struct SelectionCustomColors;
 class nsCopySupport;
 class nsHTMLCopyEncoder;
 
@@ -251,6 +252,12 @@ public:
                       int16_t aVPercent, int16_t aHPercent,
                       mozilla::ErrorResult& aRv);
 
+  void SetColors(const nsAString& aForeColor, const nsAString& aBackColor,
+                 const nsAString& aAltForeColor, const nsAString& aAltBackColor,
+                 mozilla::ErrorResult& aRv);
+
+  void ResetColors(mozilla::ErrorResult& aRv);
+
   // Non-JS callers should use the following methods.
   void Collapse(nsINode& aNode, uint32_t aOffset, mozilla::ErrorResult& aRv);
   void CollapseToStart(mozilla::ErrorResult& aRv);
@@ -284,6 +291,8 @@ public:
     mSelectionType = aSelectionType;
   }
 
+  SelectionCustomColors* GetCustomColors() const { return mCustomColors.get(); }
+
   nsresult NotifySelectionListeners(bool aCalledByJS);
   nsresult NotifySelectionListeners();
 
@@ -418,9 +427,11 @@ private:
   RefPtr<nsAutoScrollTimer> mAutoScrollTimer;
   nsCOMArray<nsISelectionListener> mSelectionListeners;
   nsRevocableEventPtr<ScrollSelectionIntoViewEvent> mScrollEvent;
-  CachedOffsetForFrame *mCachedOffsetForFrame;
+  CachedOffsetForFrame* mCachedOffsetForFrame;
   nsDirection mDirection;
   SelectionType mSelectionType;
+  UniquePtr<SelectionCustomColors> mCustomColors;
+
   /**
    * True if the current selection operation was initiated by user action.
    * It determines whether we exclude -moz-user-select:none nodes or not,

layout/generic/nsFrameSelection.h

@@ -45,6 +45,24 @@ struct SelectionDetails
   mozilla::UniquePtr<SelectionDetails> mNext;
 };
 
+struct SelectionCustomColors
+{
+#ifdef NS_BUILD_REFCNT_LOGGING
+  SelectionCustomColors()
+  {
+    MOZ_COUNT_CTOR(SelectionCustomColors);
+  }
+  ~SelectionCustomColors()
+  {
+    MOZ_COUNT_DTOR(SelectionCustomColors);
+  }
+#endif
+  mozilla::Maybe<nscolor> mForegroundColor;
+  mozilla::Maybe<nscolor> mBackgroundColor;
+  mozilla::Maybe<nscolor> mAltForegroundColor;
+  mozilla::Maybe<nscolor> mAltBackgroundColor;
+};
+
 class nsIPresShell;
 
 /** PeekOffsetStruct is used to group various arguments (both input and output)

layout/generic/nsSelection.cpp

@@ -3490,6 +3490,7 @@ Selection::Selection()
   : mCachedOffsetForFrame(nullptr)
   , mDirection(eDirNext)
   , mSelectionType(SelectionType::eNormal)
+  , mCustomColors(nullptr)
   , mUserInitiated(false)
   , mCalledByJS(false)
   , mSelectionChangeBlockerCount(0)
@@ -3501,6 +3502,7 @@ Selection::Selection(nsFrameSelection* aList)
   , mCachedOffsetForFrame(nullptr)
   , mDirection(eDirNext)
   , mSelectionType(SelectionType::eNormal)
+  , mCustomColors(nullptr)
   , mUserInitiated(false)
   , mCalledByJS(false)
   , mSelectionChangeBlockerCount(0)
@@ -6821,6 +6823,102 @@ Selection::SelectionLanguageChange(bool aLangRTL)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+Selection::SetColors(const nsAString& aForegroundColor,
+                     const nsAString& aBackgroundColor,
+                     const nsAString& aAltForegroundColor,
+                     const nsAString& aAltBackgroundColor)
+{
+  ErrorResult result;
+  SetColors(aForegroundColor, aBackgroundColor,
+            aAltForegroundColor, aAltBackgroundColor, result);
+  return result.StealNSResult();
+}
+
+void
+Selection::SetColors(const nsAString& aForegroundColor,
+                     const nsAString& aBackgroundColor,
+                     const nsAString& aAltForegroundColor,
+                     const nsAString& aAltBackgroundColor,
+                     ErrorResult& aRv)
+{
+  if (mSelectionType != SelectionType::eFind) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return;
+  }
+
+  mCustomColors.reset(new SelectionCustomColors);
+
+  NS_NAMED_LITERAL_STRING(currentColorStr, "currentColor");
+  NS_NAMED_LITERAL_STRING(transparentStr, "transparent");
+
+  if (!aForegroundColor.Equals(currentColorStr)) {
+    nscolor foregroundColor;
+    nsAttrValue aForegroundColorValue;
+    aForegroundColorValue.ParseColor(aForegroundColor);
+    if (!aForegroundColorValue.GetColorValue(foregroundColor)) {
+      aRv.Throw(NS_ERROR_INVALID_ARG);
+      return;
+    }
+    mCustomColors->mForegroundColor = Some(foregroundColor);
+  } else {
+    mCustomColors->mForegroundColor = Nothing();
+  }
+
+  if (!aBackgroundColor.Equals(transparentStr)) {
+    nscolor backgroundColor;
+    nsAttrValue aBackgroundColorValue;
+    aBackgroundColorValue.ParseColor(aBackgroundColor);
+    if (!aBackgroundColorValue.GetColorValue(backgroundColor)) {
+      aRv.Throw(NS_ERROR_INVALID_ARG);
+      return;
+    }
+    mCustomColors->mBackgroundColor = Some(backgroundColor);
+  } else {
+    mCustomColors->mBackgroundColor = Nothing();
+  }
+
+  if (!aAltForegroundColor.Equals(currentColorStr)) {
+    nscolor altForegroundColor;
+    nsAttrValue aAltForegroundColorValue;
+    aAltForegroundColorValue.ParseColor(aAltForegroundColor);
+    if (!aAltForegroundColorValue.GetColorValue(altForegroundColor)) {
+      aRv.Throw(NS_ERROR_INVALID_ARG);
+      return;
+    }
+    mCustomColors->mAltForegroundColor = Some(altForegroundColor);
+  } else {
+    mCustomColors->mAltForegroundColor = Nothing();
+  }
+
+  if (!aAltBackgroundColor.Equals(transparentStr)) {
+    nscolor altBackgroundColor;
+    nsAttrValue aAltBackgroundColorValue;
+    aAltBackgroundColorValue.ParseColor(aAltBackgroundColor);
+    if (!aAltBackgroundColorValue.GetColorValue(altBackgroundColor)) {
+      aRv.Throw(NS_ERROR_INVALID_ARG);
+      return;
+    }
+    mCustomColors->mAltBackgroundColor = Some(altBackgroundColor);
+  } else {
+    mCustomColors->mAltBackgroundColor = Nothing();
+  }
+}
+
+NS_IMETHODIMP
+Selection::ResetColors()
+{
+  ErrorResult result;
+  ResetColors(result);
+  return result.StealNSResult();
+}
+
+void
+Selection::ResetColors(ErrorResult& aRv)
+{
+  mCustomColors = nullptr;
+}
+
 NS_IMETHODIMP_(nsDirection)
 Selection::GetSelectionDirection() {
   return mDirection;

layout/generic/nsTextFrame.cpp

@@ -3828,13 +3828,86 @@ nsTextPaintStyle::GetHighlightColors(nscolor* aForeColor,
   NS_ASSERTION(aForeColor, "aForeColor is null");
   NS_ASSERTION(aBackColor, "aBackColor is null");
 
-  nscolor backColor =
-    LookAndFeel::GetColor(LookAndFeel::eColorID_TextHighlightBackground);
-  nscolor foreColor =
-    LookAndFeel::GetColor(LookAndFeel::eColorID_TextHighlightForeground);
-  EnsureSufficientContrast(&foreColor, &backColor);
-  *aForeColor = foreColor;
-  *aBackColor = backColor;
+  const nsFrameSelection* frameSelection = mFrame->GetConstFrameSelection();
+  const Selection* selection =
+    frameSelection->GetSelection(SelectionType::eFind);
+  const SelectionCustomColors* customColors = nullptr;
+  if (selection) {
+    customColors = selection->GetCustomColors();
+  }
+
+  if (!customColors) {
+    nscolor backColor =
+      LookAndFeel::GetColor(LookAndFeel::eColorID_TextHighlightBackground);
+    nscolor foreColor =
+      LookAndFeel::GetColor(LookAndFeel::eColorID_TextHighlightForeground);
+    EnsureSufficientContrast(&foreColor, &backColor);
+    *aForeColor = foreColor;
+    *aBackColor = backColor;
+
+    return;
+  }
+
+  if (customColors->mForegroundColor && customColors->mBackgroundColor) {
+    nscolor foreColor = *customColors->mForegroundColor;
+    nscolor backColor = *customColors->mBackgroundColor;
+
+    if (EnsureSufficientContrast(&foreColor, &backColor) &&
+        customColors->mAltForegroundColor &&
+        customColors->mAltBackgroundColor) {
+      foreColor = *customColors->mAltForegroundColor;
+      backColor = *customColors->mAltBackgroundColor;
+    }
+
+    *aForeColor = foreColor;
+    *aBackColor = backColor;
+    return;
+  }
+
+  if (customColors->mBackgroundColor) {
+    // !mForegroundColor means "currentColor"; the current color of the text.
+    nscolor foreColor = GetTextColor();
+    nscolor backColor = *customColors->mBackgroundColor;
+
+    if (customColors->mAltBackgroundColor) {
+      int32_t foreLuminosityDifference =
+                NS_LUMINOSITY_DIFFERENCE(foreColor, backColor);
+
+      // The sufficient luminosity difference is based on the link color of
+      // about:preferences, so we don't invert the background color on these text.
+      // XXX: Make this more generic.
+      int32_t sufficientLuminosityDifference =
+                NS_LUMINOSITY_DIFFERENCE(NS_RGBA(23, 140, 229, 255), backColor);
+
+      if (foreLuminosityDifference < sufficientLuminosityDifference) {
+        backColor = *customColors->mAltBackgroundColor;
+      }
+    }
+
+    *aForeColor = foreColor;
+    *aBackColor = backColor;
+    return;
+  }
+
+  if (customColors->mForegroundColor) {
+    nscolor foreColor = *customColors->mForegroundColor;
+    // !mBackgroundColor means "transparent"; the current color of the background.
+    nscolor backColor = mFrameBackgroundColor;
+
+    if (customColors->mAltForegroundColor &&
+        EnsureSufficientContrast(&foreColor, &backColor)) {
+      foreColor = *customColors->mAltForegroundColor;
+      backColor = mFrameBackgroundColor;
+    }
+
+    *aForeColor = foreColor;
+    *aBackColor = backColor;
+    return;
+  }
+
+  // There are neither mForegroundColor nor mBackgroundColor.
+  *aForeColor = GetTextColor();
+  *aBackColor = NS_TRANSPARENT;
 }
 
 void

layout/generic/nsTextFrame.h

@@ -11,6 +11,7 @@
 #include "mozilla/gfx/2D.h"
 #include "mozilla/UniquePtr.h"
 #include "nsFrame.h"
+#include "nsFrameSelection.h"
 #include "nsSplittableFrame.h"
 #include "nsLineBox.h"
 #include "gfxSkipChars.h"