Nicer behaviour of QgsCharacterSelectorDialog

python/gui/auto_generated/qgscharacterselectordialog.sip.in

@@ -23,7 +23,13 @@ A dialog for selecting a single character from a single font
     QgsCharacterSelectorDialog( QWidget *parent /TransferThis/ = 0, Qt::WindowFlags fl = QgsGuiUtils::ModalDialogFlags );
 
   public slots:
-    const QChar &selectCharacter( bool *gotChar, const QFont &font, const QString &style );
+
+    QChar selectCharacter( bool *gotChar, const QFont &font, const QString &style, QChar initialSelection = QChar() );
+%Docstring
+Opens the dialog modally and returns when the user has selected a character.
+
+If ``initialSelection`` is specified, then that character will be initially selected in the dialog.
+%End
 
   protected:
 };

src/gui/qgscharacterselectordialog.cpp

@@ -29,14 +29,16 @@ QgsCharacterSelectorDialog::QgsCharacterSelectorDialog( QWidget *parent, Qt::Win
   connect( mCharWidget, &CharacterWidget::characterSelected, this, &QgsCharacterSelectorDialog::setCharacter );
 }
 
-const QChar &QgsCharacterSelectorDialog::selectCharacter( bool *gotChar, const QFont &font, const QString &style )
+QChar QgsCharacterSelectorDialog::selectCharacter( bool *gotChar, const QFont &font, const QString &style, QChar initialSelection )
 {
   mCharSelectLabelFont->setText( QStringLiteral( "%1 %2" ).arg( font.family(), style ) );
   mCharWidget->setFont( font );
   mCharWidget->setFontStyle( style );
   mCharWidget->setFontSize( 22.0 );
   mCharSelectScrollArea->viewport()->update();
 
+  mCharWidget->setCharacter( initialSelection );
+
   QApplication::setOverrideCursor( Qt::ArrowCursor );
   int res = exec();
   QApplication::restoreOverrideCursor();

src/gui/qgscharacterselectordialog.h

@@ -39,7 +39,13 @@ class GUI_EXPORT QgsCharacterSelectorDialog : public QDialog, private Ui::QgsCha
     QgsCharacterSelectorDialog( QWidget *parent SIP_TRANSFERTHIS = nullptr, Qt::WindowFlags fl = QgsGuiUtils::ModalDialogFlags );
 
   public slots:
-    const QChar &selectCharacter( bool *gotChar, const QFont &font, const QString &style );
+
+    /**
+     * Opens the dialog modally and returns when the user has selected a character.
+     *
+     * If \a initialSelection is specified, then that character will be initially selected in the dialog.
+     */
+    QChar selectCharacter( bool *gotChar, const QFont &font, const QString &style, QChar initialSelection = QChar() );
 
   private slots:
     void setCharacter( QChar chr );

src/gui/qgstextformatwidget.cpp

@@ -1411,7 +1411,9 @@ void QgsTextFormatWidget::mPreviewBackgroundBtn_colorChanged( const QColor &colo
 void QgsTextFormatWidget::mDirectSymbLeftToolBtn_clicked()
 {
   bool gotChar = false;
-  QChar dirSymb = mCharDlg->selectCharacter( &gotChar, mRefFont, mFontDB.styleString( mRefFont ) );
+
+  const QChar initial = !mDirectSymbLeftLineEdit->text().isEmpty() ? mDirectSymbLeftLineEdit->text().at( 0 ) : QChar();
+  QChar dirSymb = mCharDlg->selectCharacter( &gotChar, mRefFont, mFontDB.styleString( mRefFont ), initial );
 
   if ( !gotChar )
     return;
@@ -1423,7 +1425,8 @@ void QgsTextFormatWidget::mDirectSymbLeftToolBtn_clicked()
 void QgsTextFormatWidget::mDirectSymbRightToolBtn_clicked()
 {
   bool gotChar = false;
-  QChar dirSymb = mCharDlg->selectCharacter( &gotChar, mRefFont, mFontDB.styleString( mRefFont ) );
+  const QChar initial = !mDirectSymbRightLineEdit->text().isEmpty() ? mDirectSymbRightLineEdit->text().at( 0 ) : QChar();
+  QChar dirSymb = mCharDlg->selectCharacter( &gotChar, mRefFont, mFontDB.styleString( mRefFont ), initial );
 
   if ( !gotChar )
     return;

src/gui/symbology/characterwidget.cpp

@@ -112,7 +112,7 @@ void CharacterWidget::setColumns( int columns )
 void CharacterWidget::setCharacter( QChar character )
 {
   const bool changed = character != mLastKey;
-  mLastKey = character.unicode();
+  mLastKey = character.isNull() ? -1 : character.unicode();
   QWidget *widget = parentWidget();
   if ( widget )
   {
@@ -123,7 +123,7 @@ void CharacterWidget::setCharacter( QChar character )
     }
   }
   if ( changed )
-    emit characterSelected( mLastKey );
+    emit characterSelected( mLastKey >= 0 ? QChar( mLastKey ) : QChar() );
 
   update();
 }