kdeui: simplify highlighter management of KTextEdit

instead of virtual method for creating one and a setter now there is only
a setter with ownership of the highlighter belonging to the parent (the
case for the default-created highlighter) or caller of
KTextEdit::setHighlighter()

Signed-off-by: Ivailo Monev <xakepa10@gmail.com>

kdeui/widgets/ktextedit.cpp

@@ -128,7 +128,6 @@ class KTextEdit::Private
     bool checkSpellingEnabled;
     bool findReplaceEnabled;
     bool showTabAction;
-    QString spellCheckingLanguage;
     KSpellHighlighter *highlighter;
     KFindDialog *findDlg;
     KFind *find;
@@ -184,10 +183,6 @@ QRect KTextEdit::Private::clickMessageRect() const
 void KTextEdit::Private::init()
 {
     KCursor::setAutoHideCursor(parent, true, false);
-    parent->connect(
-        parent, SIGNAL(languageChanged(QString)),
-        parent, SLOT(setSpellCheckingLanguage(QString))
-    );
 }
 
 KTextEdit::KTextEdit(const QString &text, QWidget *parent)
@@ -209,24 +204,6 @@ KTextEdit::~KTextEdit()
     delete d;
 }
 
-const QString& KTextEdit::spellCheckingLanguage() const
-{
-    return d->spellCheckingLanguage;
-}
-
-void KTextEdit::setSpellCheckingLanguage(const QString &_language)
-{
-    if (highlighter()) {
-        highlighter()->setCurrentLanguage(_language);
-        highlighter()->rehighlight();
-    }
-
-    if (_language != d->spellCheckingLanguage) {
-        d->spellCheckingLanguage = _language;
-        emit languageChanged(_language);
-    }
-}
-
 bool KTextEdit::event(QEvent* ev)
 {
     if (ev->type() == QEvent::ShortcutOverride) {
@@ -535,11 +512,6 @@ void KTextEdit::contextMenuEvent(QContextMenuEvent *event)
     }
 }
 
-void KTextEdit::createHighlighter()
-{
-    setHighlighter(new KSpellHighlighter(KGlobal::config().data(), this));
-}
-
 KSpellHighlighter* KTextEdit::highlighter() const
 {
     return d->highlighter;
@@ -547,7 +519,6 @@ KSpellHighlighter* KTextEdit::highlighter() const
 
 void KTextEdit::setHighlighter(KSpellHighlighter *highLighter)
 {
-    delete d->highlighter;
     d->highlighter = highLighter;
 }
 
@@ -564,14 +535,15 @@ void KTextEdit::setCheckSpellingEnabled(bool check)
     d->checkSpellingEnabled = check;
     if (check) {
         if (!isReadOnly() && !d->highlighter) {
-            createHighlighter();
-            if (!d->spellCheckingLanguage.isEmpty()) {
-                setSpellCheckingLanguage(d->spellCheckingLanguage);
-            }
+            d->highlighter = new KSpellHighlighter(KGlobal::config().data(), this);
+        }
+        if (d->highlighter) {
+            d->highlighter->setDocument(document());
         }
     } else {
-        delete d->highlighter;
-        d->highlighter = nullptr;
+        if (d->highlighter) {
+            d->highlighter->setDocument(nullptr);
+        }
     }
 
     emit checkSpellingChanged(check);
@@ -589,9 +561,6 @@ void KTextEdit::setReadOnly(bool readOnly)
     }
 
     if (readOnly) {
-        delete d->highlighter;
-        d->highlighter = nullptr;
-
         d->customPalette = testAttribute(Qt::WA_SetPalette);
         QPalette p = palette();
         QColor color = p.color(QPalette::Disabled, QPalette::Background);
@@ -608,16 +577,11 @@ void KTextEdit::setReadOnly(bool readOnly)
         } else {
             setPalette(QPalette());
         }
-
-        if (d->checkSpellingEnabled && !d->highlighter) {
-            createHighlighter();
-            if (!d->spellCheckingLanguage.isEmpty()) {
-                setSpellCheckingLanguage(d->spellCheckingLanguage);
-            }
-        }
     }
 
     QTextEdit::setReadOnly(readOnly);
+
+    setCheckSpellingEnabled(!readOnly);
 }
 
 void KTextEdit::highlightWord(int length, int pos)

kdeui/widgets/ktextedit.h

@@ -49,7 +49,6 @@ class KDEUI_EXPORT KTextEdit : public QTextEdit
     Q_OBJECT
     Q_PROPERTY(QString clickMessage READ clickMessage WRITE setClickMessage)
     Q_PROPERTY(bool checkSpellingEnabled READ checkSpellingEnabled WRITE setCheckSpellingEnabled)
-    Q_PROPERTY(QString spellCheckingLanguage READ spellCheckingLanguage WRITE setSpellCheckingLanguage)
 
 public:
     /**
@@ -78,9 +77,6 @@ public:
      * Turns background spell checking for this text edit on or off.
      * Note that spell checking is only available in read-writable KTextEdits.
      *
-     * Enabling spell checking will set back the current highlighter to the one
-     * returned by createHighlighter().
-     *
      * @see checkSpellingEnabled()
      * @see isReadOnly()
      * @see setReadOnly()
@@ -108,43 +104,23 @@ public:
     void highlightWord(int length, int pos);
 
     /**
-     * Allows to create a specific highlighter if reimplemented.
-     *
-     * By default, it creates a normal highlighter.
-     *
-     * This highlighter is set each time spell checking is toggled on by
-     * calling setCheckSpellingEnabled(), but can later be overridden by calling
-     * setHighlighter().
+     * Returns the current highlighter, may be null if spell checking is not
+     * enabled. The default highlighter might be overridden by setHighlighter().
      *
      * @see setHighlighter()
-     * @see highlighter()
-     */
-    virtual void createHighlighter();
-
-    /**
-     * Returns the current highlighter, which is 0 if spell checking is disabled.
-     * The default highlighter is the one created by createHighlighter(), but
-     * might be overridden by setHighlighter().
-     *
-     * @see setHighlighter()
-     * @see createHighlighter()
      */
     KSpellHighlighter* highlighter() const;
 
     /**
      * Sets a custom backgound spell highlighter for this text edit.
-     * Normally, the highlighter returned by createHighlighter() will be
-     * used to detect and highlight incorrectly spelled words, but this
-     * function allows to set a custom highlighter.
-     *
-     * This has to be called after enabling spell checking with
-     * setCheckSpellingEnabled(), otherwise it has no effect.
+     * Normally, the highlighter is created when spell checking is enabled but
+     * this function allows to set a custom highlighter. Note that ownership
+     * of the highlighter belongs to the caller.
      *
      * @see highlighter()
-     * @see createHighlighter()
      * @param highLighter the new highlighter which will be used now
      */
-    void setHighlighter(KSpellHighlighter *_highLighter);
+    void setHighlighter(KSpellHighlighter *highLighter);
 
     /**
      * Return standard KTextEdit popupMenu
@@ -159,14 +135,6 @@ public:
      */
     void enableFindReplace(bool enabled);
 
-    /**
-     * @return the spell checking language which was set by
-     *         setSpellCheckingLanguage(), the spellcheck dialog or the spellcheck
-     *         config dialog, or an empty string if that has never been called.
-     * @since 4.2
-     */
-    const QString& spellCheckingLanguage() const;
-
     /**
      * This makes the text edit display a grayed-out hinting text as long as
      * the user didn't enter any text. It is often used as indication about
@@ -192,15 +160,7 @@ Q_SIGNALS:
      *
      * @since 4.1
      */
-     void checkSpellingChanged( bool );
-
-     /**
-      * Emitted when calling setSpellCheckingLanguage().
-      *
-      * @param language the new language the user selected
-      * @since 4.1
-      */
-     void languageChanged(const QString &language);
+     void checkSpellingChanged(bool check);
 
     /**
      * Emitted before the context menu is displayed.
@@ -218,16 +178,6 @@ Q_SIGNALS:
     void aboutToShowContextMenu(QMenu *menu);
 
 public Q_SLOTS:
-    /**
-     * Set the spell check language which will be used for highlighting spelling
-     * mistakes and for the spellcheck dialog.
-     * The languageChanged() signal will be emitted when the new language is
-     * different from the old one.
-     *
-     * @since 4.1
-     */
-    void setSpellCheckingLanguage(const QString &language);
-
     /**
      * Create replace dialogbox
      * @since 4.1