Bug 1951007 - Make style editing commands check whether the editing host is contenteditable="plaintext-only" to consider whether it's enabled r=m_kato

The style editing commands should be disabled in
`contenteditable="plaintext-only"`.  Currently, we return `false` from
`execCommand`, but we still claim that the commands are enabled for
`queryCommandEnabled`.

Differential Revision: https://phabricator.services.mozilla.com/D239985

editor/libeditor/HTMLEditor.cpp

@@ -486,6 +486,19 @@ void HTMLEditor::PreDestroy() {
   PreDestroyInternal();
 }
 
+bool HTMLEditor::IsStyleEditable() const {
+  if (IsInDesignMode()) {
+    return true;
+  }
+  if (IsPlaintextMailComposer()) {
+    return false;
+  }
+  const Element* const editingHost = ComputeEditingHost(LimitInBodyElement::No);
+  // Let's return true if there is no focused editing host for the backward
+  // compatibility.
+  return !editingHost || !editingHost->IsContentEditablePlainTextOnly();
+}
+
 NS_IMETHODIMP HTMLEditor::GetDocumentCharacterSet(nsACString& aCharacterSet) {
   nsresult rv = GetDocumentCharsetInternal(aCharacterSet);
   NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),

editor/libeditor/HTMLEditor.h

@@ -400,6 +400,11 @@ class HTMLEditor final : public EditorBase,
    */
   bool IsCSSEnabled() const { return mIsCSSPrefChecked; }
 
+  /**
+   * Return true when editing host is not plaintext-only.
+   */
+  [[nodiscard]] bool IsStyleEditable() const;
+
   /**
    * Enable/disable object resizers for <img> elements, <table> elements,
    * absolute positioned elements (required absolute position editor enabled).
@@ -418,7 +423,9 @@ class HTMLEditor final : public EditorBase,
     mIsObjectResizingEnabled = aEnable;
     RefreshEditingUI();
   }
-  bool IsObjectResizerEnabled() const { return mIsObjectResizingEnabled; }
+  bool IsObjectResizerEnabled() const {
+    return mIsObjectResizingEnabled && IsStyleEditable();
+  }
 
   Element* GetResizerTarget() const { return mResizedObject; }
 
@@ -441,7 +448,7 @@ class HTMLEditor final : public EditorBase,
     RefreshEditingUI();
   }
   bool IsInlineTableEditorEnabled() const {
-    return mIsInlineTableEditingEnabled;
+    return mIsInlineTableEditingEnabled && IsStyleEditable();
   }
 
   /**
@@ -464,7 +471,7 @@ class HTMLEditor final : public EditorBase,
     RefreshEditingUI();
   }
   bool IsAbsolutePositionEditorEnabled() const {
-    return mIsAbsolutelyPositioningEnabled;
+    return mIsAbsolutelyPositioningEnabled && IsStyleEditable();
   }
 
   /**

editor/libeditor/HTMLEditorCommands.cpp

@@ -52,7 +52,8 @@ bool StateUpdatingCommandBase::IsCommandEnabled(Command aCommand,
   if (!htmlEditor) {
     return false;
   }
-  if (!htmlEditor->IsModifiable() || !htmlEditor->IsSelectionEditable()) {
+  if (!htmlEditor->IsModifiable() || !htmlEditor->IsSelectionEditable() ||
+      !htmlEditor->IsStyleEditable()) {
     return false;
   }
   if (aCommand == Command::FormatAbsolutePosition) {
@@ -356,7 +357,8 @@ bool RemoveListCommand::IsCommandEnabled(Command aCommand,
   if (!htmlEditor) {
     return false;
   }
-  if (!htmlEditor->IsModifiable() || !htmlEditor->IsSelectionEditable()) {
+  if (!htmlEditor->IsModifiable() || !htmlEditor->IsSelectionEditable() ||
+      !htmlEditor->IsStyleEditable()) {
     return false;
   }
 
@@ -401,7 +403,8 @@ bool IndentCommand::IsCommandEnabled(Command aCommand,
   if (!htmlEditor) {
     return false;
   }
-  return htmlEditor->IsModifiable() && htmlEditor->IsSelectionEditable();
+  return htmlEditor->IsModifiable() && htmlEditor->IsSelectionEditable() &&
+         htmlEditor->IsStyleEditable();
 }
 
 nsresult IndentCommand::DoCommand(Command aCommand, EditorBase& aEditorBase,
@@ -434,7 +437,8 @@ bool OutdentCommand::IsCommandEnabled(Command aCommand,
   if (!htmlEditor) {
     return false;
   }
-  return htmlEditor->IsModifiable() && htmlEditor->IsSelectionEditable();
+  return htmlEditor->IsModifiable() && htmlEditor->IsSelectionEditable() &&
+         htmlEditor->IsStyleEditable();
 }
 
 nsresult OutdentCommand::DoCommand(Command aCommand, EditorBase& aEditorBase,
@@ -467,7 +471,8 @@ bool MultiStateCommandBase::IsCommandEnabled(Command aCommand,
     return false;
   }
   // should be disabled sometimes, like if the current selection is an image
-  return htmlEditor->IsModifiable() && htmlEditor->IsSelectionEditable();
+  return htmlEditor->IsModifiable() && htmlEditor->IsSelectionEditable() &&
+         htmlEditor->IsStyleEditable();
 }
 
 nsresult MultiStateCommandBase::DoCommand(Command aCommand,
@@ -966,7 +971,8 @@ bool DecreaseZIndexCommand::IsCommandEnabled(Command aCommand,
   if (!htmlEditor) {
     return false;
   }
-  if (!htmlEditor->IsAbsolutePositionEditorEnabled()) {
+  if (!htmlEditor->IsAbsolutePositionEditorEnabled() ||
+      !htmlEditor->IsStyleEditable()) {
     return false;
   }
   RefPtr<Element> positionedElement = htmlEditor->GetPositionedElement();
@@ -1008,7 +1014,8 @@ bool IncreaseZIndexCommand::IsCommandEnabled(Command aCommand,
   if (!htmlEditor) {
     return false;
   }
-  if (!htmlEditor->IsAbsolutePositionEditorEnabled()) {
+  if (!htmlEditor->IsAbsolutePositionEditorEnabled() ||
+      !htmlEditor->IsStyleEditable()) {
     return false;
   }
   return !!htmlEditor->GetPositionedElement();
@@ -1047,7 +1054,8 @@ bool RemoveStylesCommand::IsCommandEnabled(Command aCommand,
     return false;
   }
   // test if we have any styles?
-  return htmlEditor->IsModifiable() && htmlEditor->IsSelectionEditable();
+  return htmlEditor->IsModifiable() && htmlEditor->IsSelectionEditable() &&
+         htmlEditor->IsStyleEditable();
 }
 
 nsresult RemoveStylesCommand::DoCommand(Command aCommand,
@@ -1085,7 +1093,8 @@ bool IncreaseFontSizeCommand::IsCommandEnabled(Command aCommand,
     return false;
   }
   // test if we are at max size?
-  return htmlEditor->IsModifiable() && htmlEditor->IsSelectionEditable();
+  return htmlEditor->IsModifiable() && htmlEditor->IsSelectionEditable() &&
+         htmlEditor->IsStyleEditable();
 }
 
 nsresult IncreaseFontSizeCommand::DoCommand(Command aCommand,
@@ -1121,7 +1130,8 @@ bool DecreaseFontSizeCommand::IsCommandEnabled(Command aCommand,
     return false;
   }
   // test if we are at min size?
-  return htmlEditor->IsModifiable() && htmlEditor->IsSelectionEditable();
+  return htmlEditor->IsModifiable() && htmlEditor->IsSelectionEditable() &&
+         htmlEditor->IsStyleEditable();
 }
 
 nsresult DecreaseFontSizeCommand::DoCommand(Command aCommand,
@@ -1213,7 +1223,8 @@ bool InsertTagCommand::IsCommandEnabled(Command aCommand,
   if (!htmlEditor) {
     return false;
   }
-  return htmlEditor->IsModifiable() && htmlEditor->IsSelectionEditable();
+  return htmlEditor->IsModifiable() && htmlEditor->IsSelectionEditable() &&
+         htmlEditor->IsStyleEditable();
 }
 
 // corresponding STATE_ATTRIBUTE is: src (img) and href (a)

testing/web-platform/tests/editing/plaintext-only/styling-commands.html

@@ -61,6 +61,9 @@ addEventListener("load", () => {
       function onInput(event) {
         inputEvent = `input={inputType="${event.inputType}"}`;
       }
+      test(() => {
+        assert_false(document.queryCommandEnabled(testing.command));
+      }, `${t.name}: the command should be disabled`);
       let ret;
       try {
         editingHost.addEventListener("input", onInput);