create scale widget (scale combo box + button to set scale from map canvas)

python/gui/gui.sip

@@ -100,6 +100,7 @@
 %Include qgsrubberband.sip
 %Include qgsscalecombobox.sip
 %Include qgsscalerangewidget.sip
+%Include qgsscalewidget.sip
 %Include qgsscalevisibilitydialog.sip
 %Include qgssearchquerybuilder.sip
 %Include qgstextannotationitem.sip

python/gui/qgsscalewidget.sip

@@ -0,0 +1,47 @@
+
+/** A combobox which lets the user select map scale from predefined list
+ * and highlights nearest to current scale value
+ */
+class QgsScaleWidget : QWidget
+{
+%TypeHeaderCode
+#include <qgsscalewidget.h>
+%End
+
+  public:
+    QgsScaleWidget( QWidget* parent = 0 );
+    ~QgsScaleWidget();
+    
+    //! shows a button to set the scale to the current scale of the map canvas next to the combobox
+    //! @note the map canvas must be defined to show the button
+    void setShowCurrentScaleButton( bool showCurrentScaleButton );
+    bool showCurrentScaleButton();
+
+    //! set the map canvas associated to the current button
+    void setMapCanvas( QgsMapCanvas* canvas );
+
+    //! Function to read the selected scale as text
+    QString scaleString();
+    //! Function to set the selected scale from text
+    bool setScaleString( QString scaleTxt );
+    //! Function to read the selected scale as double
+    double scale();
+    //! Function to set the selected scale from double
+    void setScale( double scale );
+
+    //! Helper function to convert a double to scale string
+    // Performs rounding, so an exact representation is not to
+    // be expected.
+    static QString toString( double scale );
+    //! Helper function to convert a scale string to double
+    static double toDouble( QString scaleString, bool *ok = NULL );
+
+  signals:
+    //! Signal is emitted when *user* has finished editing/selecting a new scale.
+    void scaleChanged();
+
+  public slots:
+    void updateScales( const QStringList &scales = QStringList() );
+
+};
+

src/gui/CMakeLists.txt

@@ -215,6 +215,7 @@ qgsrubberband.cpp
 qgsscalecombobox.cpp
 qgsscalerangewidget.cpp
 qgsscalevisibilitydialog.cpp
+qgsscalewidget.cpp
 qgssearchquerybuilder.cpp
 qgsslider.cpp
 qgssublayersdialog.cpp
@@ -412,6 +413,7 @@ qgsrelationmanagerdialog.h
 qgsscalecombobox.h
 qgsscalerangewidget.h
 qgsscalevisibilitydialog.h
+qgsscalewidget.h
 qgssearchquerybuilder.h
 qgsslider.h
 qgssublayersdialog.h
@@ -491,6 +493,7 @@ qgsrubberband.h
 qgsscalecombobox.h
 qgsscalerangewidget.h
 qgsscalevisibilitydialog.h
+qgsscalewidget.h
 qgssearchquerybuilder.h
 qgsslider.h
 qgssublayersdialog.h

src/gui/qgsscalewidget.cpp

@@ -0,0 +1,69 @@
+/***************************************************************************
+   qgsscalewidget.cpp
+    --------------------------------------
+   Date                 : 08.01.2015
+   Copyright            : (C) 2014 Denis Rouzaud
+   Email                : denis.rouzaud@gmail.com
+***************************************************************************
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+***************************************************************************/
+
+#include <QHBoxLayout>
+
+#include "qgsapplication.h"
+#include "qgsscalewidget.h"
+#include "qgsmapcanvas.h"
+
+QgsScaleWidget::QgsScaleWidget( QWidget *parent )
+    : QWidget( parent )
+    , mShowCurrentScaleButton( false )
+    , mCanvas( NULL )
+{
+  QHBoxLayout* layout = new QHBoxLayout( this );
+  layout->setContentsMargins( 0, 0, 0, 0 );
+  layout->setSpacing( 2 );
+
+  mScaleComboBox = new QgsScaleComboBox( this );
+  layout->addWidget( mScaleComboBox );
+
+  mCurrentScaleButton = new QToolButton( this );
+  mCurrentScaleButton->setIcon( QgsApplication::getThemeIcon( "/mActionMapIdentification.svg" ) );
+  layout->addWidget( mCurrentScaleButton );
+  mCurrentScaleButton->hide();
+
+  connect( mScaleComboBox, SIGNAL( scaleChanged() ), this, SIGNAL( scaleChanged() ) );
+  connect( mCurrentScaleButton, SIGNAL( clicked() ), this, SLOT( setScaleFromCanvas() ) );
+}
+
+
+QgsScaleWidget::~QgsScaleWidget()
+{
+}
+
+void QgsScaleWidget::setShowCurrentScaleButton( bool showCurrentScaleButton )
+{
+  mShowCurrentScaleButton = showCurrentScaleButton;
+  mCurrentScaleButton->setVisible( mShowCurrentScaleButton && mCanvas );
+}
+
+void QgsScaleWidget::setMapCanvas( QgsMapCanvas* canvas )
+{
+  mCanvas = canvas;
+  mCurrentScaleButton->setVisible( mShowCurrentScaleButton && mCanvas );
+}
+
+void QgsScaleWidget::setScaleFromCanvas()
+{
+  if ( !mCanvas )
+    return;
+
+  setScale( mCanvas->scale() );
+}
+
+
+

src/gui/qgsscalewidget.h

@@ -0,0 +1,82 @@
+/***************************************************************************
+   qgsscalewidget.h
+    --------------------------------------
+   Date                 : 08.01.2015
+   Copyright            : (C) 2014 Denis Rouzaud
+   Email                : denis.rouzaud@gmail.com
+***************************************************************************
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+***************************************************************************/
+
+#ifndef QGSSCALEWIDGET_H
+#define QGSSCALEWIDGET_H
+
+#include <QWidget>
+#include <QToolButton>
+
+
+#include "qgsscalecombobox.h"
+
+class QgsMapCanvas;
+
+/** \ingroup gui
+ * A combobox which lets the user select map scale from predefined list
+ * and highlights nearest to current scale value
+ **/
+class GUI_EXPORT QgsScaleWidget : public QWidget
+{
+    Q_OBJECT
+    Q_PROPERTY( bool showCurrentScaleButton READ showCurrentScaleButton WRITE setShowCurrentScaleButton )
+
+  public:
+    explicit QgsScaleWidget(QWidget *parent = 0);
+
+    virtual ~QgsScaleWidget();
+
+    //! shows a button to set the scale to the current scale of the map canvas next to the combobox
+    //! @note the map canvas must be defined to show the button
+    void setShowCurrentScaleButton( bool showCurrentScaleButton );
+    bool showCurrentScaleButton(){ return mShowCurrentScaleButton;}
+
+    //! set the map canvas associated to the current button
+    void setMapCanvas( QgsMapCanvas* canvas );
+
+    //! Function to read the selected scale as text
+    QString scaleString(){return mScaleComboBox->scaleString();}
+    //! Function to set the selected scale from text
+    bool setScaleString( QString scaleTxt ){return mScaleComboBox->setScaleString(scaleTxt);}
+    //! Function to read the selected scale as double
+    double scale(){return mScaleComboBox->scale();}
+    //! Function to set the selected scale from double
+    void setScale( double scale ){return mScaleComboBox->setScale(scale);}
+
+    //! Helper function to convert a double to scale string
+    // Performs rounding, so an exact representation is not to
+    // be expected.
+    static QString toString( double scale ){return QgsScaleComboBox::toString(scale);}
+    //! Helper function to convert a scale string to double
+    static double toDouble( QString scaleString, bool *ok = NULL ){return QgsScaleComboBox::toDouble(scaleString, ok);}
+
+  public slots:
+    void updateScales( const QStringList &scales = QStringList() ){return mScaleComboBox->updateScales(scales);}
+
+    //! assign the current scale from the map canvas
+    void setScaleFromCanvas();
+
+  signals:
+    //! Signal is emitted when *user* has finished editing/selecting a new scale.
+    void scaleChanged();
+
+  private:
+    QgsScaleComboBox* mScaleComboBox;
+    QToolButton* mCurrentScaleButton;
+    QgsMapCanvas* mCanvas;
+    bool mShowCurrentScaleButton;
+};
+
+#endif // QGSSCALEWIDGET_H