Added static helper functions and more tests

src/gui/qgsscalecombobox.cpp

@@ -19,7 +19,9 @@
 #include "qgsscalecombobox.h"
 
 #include <QAbstractItemView>
+#include <QLocale>
 #include <QSettings>
+#include <QLineEdit>
 
 QgsScaleComboBox::QgsScaleComboBox( QWidget* parent ) : QComboBox( parent )
 {
@@ -28,6 +30,8 @@ QgsScaleComboBox::QgsScaleComboBox( QWidget* parent ) : QComboBox( parent )
   setEditable( true );
   setInsertPolicy( QComboBox::NoInsert );
   setCompleter( 0 );
+  connect( this, SIGNAL( currentIndexChanged( const QString & ) ), this, SLOT( fixupScale() ) );
+  connect( lineEdit(), SIGNAL( editingFinished() ), this, SLOT( fixupScale() ) );
 }
 
 QgsScaleComboBox::~QgsScaleComboBox()
@@ -94,3 +98,99 @@ void QgsScaleComboBox::showPopup()
   view()->setCurrentIndex( model()->index( idx, 0 ) );
   blockSignals( false );
 }
+
+//! Function to read the selected scale as text
+// @note added in 2.0
+QString QgsScaleComboBox::scaleString()
+{
+  return toString( mScale );
+}
+//! Function to read the selected scale as double
+// @note added in 2.0
+double QgsScaleComboBox::scale()
+{
+  return mScale;
+}
+
+//! Slot called when QComboBox has changed
+void QgsScaleComboBox::fixupScale()
+{
+  double newScale;
+  bool ok;
+  QStringList txtList;
+
+  newScale = QLocale::system().toDouble( currentText(), &ok );
+  if ( ok )
+  {
+    // Create a text version and set that text and rescan again
+    // Idea is to get the same rounding.
+    setEditText( toString( newScale ) );
+  }
+  ok = false;
+  // Is now either X:Y or not valid
+  txtList = currentText().split( ':' );
+  if ( 2 == txtList.size() )
+  {
+    bool okX = false;
+    bool okY = false;
+    int x = QLocale::system().toInt( txtList[ 0 ], &okX );
+    int y = QLocale::system().toInt( txtList[ 1 ], &okY );
+    if ( okX && okY )
+    {
+      // New scale is fraction of x and y
+      // Text should be OK now.
+      // Just update the scale.
+      mScale = ( double )x / ( double )y;
+      // And emit a signal that something has changed.
+      emit scaleChanged();
+      ok = true;
+    }
+  }
+  if ( ! ok )
+  {
+    // Set to what it whas before
+    setEditText( toString( mScale ) );
+  }
+}
+
+QString QgsScaleComboBox::toString( double scale )
+{
+  if ( scale > 1 )
+  {
+    return QString( "%1:1" ).arg( qRound( scale ) );
+  }
+  else
+  {
+    return QString( "1:%1" ).arg( qRound( 1.0 / scale ) );
+  }
+}
+
+double QgsScaleComboBox::toDouble( QString scaleString, bool * returnOk )
+{
+  bool ok = false;
+  double scale = QLocale::system().toDouble( scaleString, &ok );
+  if ( ! ok )
+  {
+    // It wasn't a decimal scale
+    // It is now either X:Y or not valid
+    QStringList txtList = scaleString.split( ':' );
+    if ( 2 == txtList.size() )
+    {
+      bool okX = false;
+      bool okY = false;
+      int x = QLocale::system().toInt( txtList[ 0 ], &okX );
+      int y = QLocale::system().toInt( txtList[ 1 ], &okY );
+      if ( okX && okY )
+      {
+        // Scale is fraction of x and y
+        scale = ( double )x / ( double )y;
+        ok = true;
+      }
+    }
+  }
+  if ( returnOk )
+  {
+    *returnOk = ok;
+  }
+  return scale;
+}

src/gui/qgsscalecombobox.h

@@ -30,12 +30,38 @@ class GUI_EXPORT QgsScaleComboBox : public QComboBox
   public:
     QgsScaleComboBox( QWidget* parent = 0 );
     virtual ~QgsScaleComboBox();
+    //! Function to read the selected scale as text
+    // @note added in 2.0
+    QString scaleString();
+    //! Function to read the selected scale as double
+    // @note added in 2.0
+    double scale();
+    //! Helper function to convert a double to scale string
+    // Performs rounding, so an exact representation is not to
+    // be expected.
+    // @note added in 2.0
+    static QString toString( double scale );
+    //! Helper function to convert a scale string to double
+    // @note added in 2.0
+    static double toDouble( QString scaleString, bool *ok = NULL );
+
+    //! Signals is emited when user has finished editing/selecting a new scale.
+    // @note added in 2.0
+  signals:
+    void scaleChanged();
 
   public slots:
     void updateScales( const QStringList &scales = QStringList() );
 
+
   protected:
     void showPopup();
+
+  private slots:
+    void fixupScale();
+
+  private:
+    double mScale;
 };
 
 #endif // QGSSCALECOMBOBOX_H

tests/src/gui/testqgsscalecombobox.cpp

@@ -31,8 +31,9 @@ class TestQgsScaleComboBox: public QObject
     void init();// will be called before each testfunction is executed.
     void cleanup();// will be called after every testfunction.
     void basic();
+    void slot_test();
   private:
-    QgsScaleComboBox *mScaleEdit;
+    QgsScaleComboBox *s;
 };
 
 void TestQgsScaleComboBox::initTestCase()
@@ -41,12 +42,12 @@ void TestQgsScaleComboBox::initTestCase()
   QgsApplication::initQgis();
 
   // Create a combobox, and init with predefined scales.
-  mScaleEdit = new QgsScaleComboBox();
+  s = new QgsScaleComboBox();
 };
 
 void TestQgsScaleComboBox::cleanupTestCase()
 {
-  delete mScaleEdit;
+  delete s;
 };
 
 void TestQgsScaleComboBox::init()
@@ -55,11 +56,34 @@ void TestQgsScaleComboBox::init()
 
 void TestQgsScaleComboBox::basic()
 {
-  mScaleEdit->lineEdit()->setText( "" );
-  QTest::keyClicks( mScaleEdit->lineEdit(), "1:2345");
-  QCOMPARE( mScaleEdit->lineEdit()->text(), QString("1:2345"));
+  QLineEdit *l = s->lineEdit();
+
+  // Testing conversion from "1:nnn".
+  l->setText( "" );
+  QTest::keyClicks( l, "1:2345" );
+  QTest::keyClick( l, Qt::Key_Return );
+  QCOMPARE( s->scaleString(), QString( "1:2345" ) );
+  QCOMPARE( s->scale(), (( double ) 1.0 / ( double ) 2345.0 ) );
+
+  // Testing conversion from number to "1:x"
+  l->setText( "" );
+  QTest::keyClicks( l, QLocale::system().toString( 0.02 ) );
+  QTest::keyClick( l, Qt::Key_Return );
+  QCOMPARE( s->scaleString(), QString( "1:50" ) );
+  QCOMPARE( s->scale(), ( double ) 0.02 );
+
+  // Testing conversion from number to "x:1"
+  l->setText( "" );
+  QTest::keyClicks( l, QLocale::system().toString( 42 ) );
+  QTest::keyClick( l, Qt::Key_Return );
+  QCOMPARE( s->scaleString(), QString( "42:1" ) );
+  QCOMPARE( s->scale(), ( double ) 42 );
+
 };
- 
+
+void TestQgsScaleComboBox::slot_test()
+{
+}
 void TestQgsScaleComboBox::cleanup()
 {
 };