Add better Null support to QgsFilterLineEdit

qgis · Sep 22, 2014 · b1474c8 · b1474c8
1 parent b90dba4
commit b1474c8
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Showing 2 changed files with 69 additions and 8 deletions.
diff --git a/src/gui/qgsfilterlineedit.cpp b/src/gui/qgsfilterlineedit.cpp
@@ -20,10 +20,12 @@
 
 #include <QToolButton>
 #include <QStyle>
+#include <QFocusEvent>
 
 QgsFilterLineEdit::QgsFilterLineEdit( QWidget* parent, QString nullValue )
     : QLineEdit( parent )
     , mNullValue( nullValue )
+    , mFocusInEvent( false )
 {
   btnClear = new QToolButton( this );
   btnClear->setIcon( QgsApplication::getThemeIcon( "/mIconClear.svg" ) );
@@ -35,17 +37,33 @@ QgsFilterLineEdit::QgsFilterLineEdit( QWidget* parent, QString nullValue )
   connect( btnClear, SIGNAL( clicked() ), this, SLOT( clear() ) );
   connect( btnClear, SIGNAL( clicked() ), this, SIGNAL( cleared() ) );
   connect( this, SIGNAL( textChanged( const QString& ) ), this,
-           SLOT( toggleClearButton( const QString& ) ) );
+           SLOT( onTextChanged( const QString& ) ) );
 
   int frameWidth = style()->pixelMetric( QStyle::PM_DefaultFrameWidth );
-  setStyleSheet( QString( "QLineEdit { padding-right: %1px; } " )
-                 .arg( btnClear->sizeHint().width() + frameWidth + 1 ) );
+  mStyleSheet = QString( "QLineEdit { padding-right: %1px; } " )
+                .arg( btnClear->sizeHint().width() + frameWidth + 1 );
 
   QSize msz = minimumSizeHint();
   setMinimumSize( qMax( msz.width(), btnClear->sizeHint().height() + frameWidth * 2 + 2 ),
                   qMax( msz.height(), btnClear->sizeHint().height() + frameWidth * 2 + 2 ) );
 }
 
+void QgsFilterLineEdit::mousePressEvent( QMouseEvent* e )
+{
+  if ( !mFocusInEvent )
+    QLineEdit::mousePressEvent( e );
+}
+
+void QgsFilterLineEdit::focusInEvent( QFocusEvent* e )
+{
+  QLineEdit::focusInEvent( e );
+  if ( e->reason() == Qt::MouseFocusReason && isNull() )
+  {
+    mFocusInEvent = true;
+    selectAll();
+  }
+}
+
 void QgsFilterLineEdit::resizeEvent( QResizeEvent * )
 {
   QSize sz = btnClear->sizeHint();
@@ -69,7 +87,18 @@ void QgsFilterLineEdit::changeEvent( QEvent *e )
     btnClear->setVisible( text() != mNullValue );
 }
 
-void QgsFilterLineEdit::toggleClearButton( const QString &text )
+void QgsFilterLineEdit::onTextChanged( const QString &text )
 {
   btnClear->setVisible( !isReadOnly() && text != mNullValue );
+
+  if ( isNull() )
+  {
+    setStyleSheet( QString( "QLineEdit { font: italic; color: gray; } %1" ).arg( mStyleSheet ) );
+    emit valueChanged( QString::null );
+  }
+  else
+  {
+    setStyleSheet( mStyleSheet );
+    emit valueChanged( text );
+  }
 }
diff --git a/src/gui/qgsfilterlineedit.h b/src/gui/qgsfilterlineedit.h
@@ -35,22 +35,54 @@ class GUI_EXPORT QgsFilterLineEdit : public QLineEdit
 
     void setNullValue( QString nullValue ) { mNullValue = nullValue; }
 
-    QString nullValue() const {return mNullValue;}
+    QString nullValue() const { return mNullValue; }
+
+    /**
+     * Sets the current text with NULL support
+     *
+     * @param value The text to set. If a Null string is provided, the text will match the nullValue.
+     */
+    void setValue( QString value ) { setText( value.isNull() ? mNullValue : value ); }
+
+    /**
+     * Returns the text of this edit with NULL support
+     *
+     * @return Current text (Null string if it matches the nullValue property )
+     */
+    QString value() { return isNull() ? QString::null : text(); }
+
+    /**
+     * Determine if the current text represents Null.
+     *
+     * @return True if the value is Null.
+     */
+    inline bool isNull() { return text() == mNullValue; }
 
   signals:
     void cleared();
 
+    /**
+     * Same as textChanged(const QString& ) but with support for Null values.
+     *
+     * @param value The current text or Null string if it matches the nullValue property.
+     */
+    void valueChanged( const QString& value );
+
   protected:
-    void resizeEvent( QResizeEvent * );
-    void changeEvent( QEvent * );
+    void mousePressEvent( QMouseEvent* e );
+    void focusInEvent( QFocusEvent* e );
+    void resizeEvent( QResizeEvent* e );
+    void changeEvent( QEvent* e );
 
   private slots:
     void clear();
-    void toggleClearButton( const QString &text );
+    void onTextChanged( const QString &text );
 
   private:
     QString mNullValue;
     QToolButton *btnClear;
+    QString mStyleSheet;
+    bool mFocusInEvent;
 };
 
 #endif // QGSFILTERLINEEDIT_H