Update QgsColorButton so it shows a color chooser on click

python/gui/qgscolorbutton.sip

@@ -7,15 +7,79 @@ class QgsColorButton : QToolButton
 %End
 
   public:
-    QgsColorButton( QWidget *parent = 0 );
+    /**
+     * Construct a new color button.
+     *
+     * @param parent The parent QWidget for the dialog
+     * @param cdt The title to show in the color chooser dialog
+     * @param cdo Options for the color chooser dialog
+     * @note changed in 1.9
+     */
+    QgsColorButton( QWidget *parent = 0, QString cdt = "Select Color", QColorDialog::ColorDialogOptions cdo = 0 );
     ~QgsColorButton();
 
+    /**
+     * Specify the current color. Will emit a colorChanged signal if the color is different to the previous.
+     *
+     * @param color the new color
+     * @note added in 1.9
+     */
     void setColor( const QColor &color );
+    /**
+     * Return the currently selected color.
+     *
+     * @return the currently selected color
+     * @note added in 1.9
+     */
     QColor color() const;
 
+    /**
+     * Specify the options for the color chooser dialog (e.g. alpha).
+     *
+     * @param cdo Options for the color chooser dialog
+     * @note added in 1.9
+     */
+    void setColorDialogOptions( QColorDialog::ColorDialogOptions cdo );
+
+    /**
+     * Returns the options for the color chooser dialog.
+     *
+     * @return Options for the color chooser dialog
+     * @note added in 1.9
+     */
+    QColorDialog::ColorDialogOptions colorDialogOptions();
+
+    /**
+     * Set the title, which the color chooser dialog will show.
+     *
+     * @param cdt Title for the color chooser dialog
+     * @note added in 1.9
+     */
+    void setColorDialogTitle( QString cdt );
+
+    /**
+     * Returns the title, which the color chooser dialog shows.
+     *
+     * @return Title for the color chooser dialog
+     * @note added in 1.9
+     */
+    QString colorDialogTitle();
+
   protected:
     void paintEvent( QPaintEvent *e );
 
+  public slots:
+    void onButtonClicked();
+
+  signals:
+    /**
+     * Is emitted, whenever a new color is accepted. The color is always valid.
+     * In case the new color is the same, no signal is emitted, to avoid infinite loops.
+     *
+     * @param color New color
+     * @note added in 1.9
+     */
+    void colorChanged( const QColor &color );
 };
 
 

src/gui/CMakeLists.txt

@@ -113,6 +113,8 @@ ENDIF (WITH_TOUCH)
 
 SET(QGIS_GUI_MOC_HDRS
 
+qgscolorbutton.h
+
 raster/qgsrasterminmaxwidget.h
 raster/qgspalettedrendererwidget.h
 raster/qgsmultibandcolorrendererwidget.h
@@ -203,7 +205,6 @@ SET(QGIS_GUI_HDRS
 qgisgui.h
 qgisinterface.h
 qgscharacterselectdialog.h
-qgscolorbutton.h
 qgscursors.h
 qgsencodingfiledialog.h
 qgsfiledropedit.h

src/gui/qgscolorbutton.cpp

@@ -31,15 +31,31 @@
   by Qt Designer to do the same thing.
 */
 
-QgsColorButton::QgsColorButton( QWidget *parent )
+QgsColorButton::QgsColorButton( QWidget *parent, QString cdt, QColorDialog::ColorDialogOptions cdo )
     : QToolButton( parent )
+    , mColorDialogTitle( cdt )
+    , mColorDialogOptions( cdo )
 {
   setToolButtonStyle( Qt::ToolButtonTextOnly ); // decrease default button height
+  connect( this, SIGNAL( clicked() ), this, SLOT( onButtonClicked() ) );
 }
 
 QgsColorButton::~QgsColorButton()
 {}
 
+void QgsColorButton::onButtonClicked()
+{
+#if QT_VERSION >= 0x040500
+  QColor newColor = QColorDialog::getColor( color(), 0, mColorDialogTitle, mColorDialogOptions );
+#else
+  QColor newColor = QColorDialog::getColor( color() );
+#endif
+  if ( newColor.isValid() )
+  {
+    setColor( newColor );
+  }
+}
+
 /*!
   Paints button in response to a paint event.
 */
@@ -62,10 +78,41 @@ void QgsColorButton::paintEvent( QPaintEvent *e )
 
 void QgsColorButton::setColor( const QColor &color )
 {
+  QColor oldColor = mColor;
+
   mColor = color;
   update();
+
+  if ( oldColor != mColor )
+  {
+    emit( colorChanged( mColor ) );
+  }
 }
 
+QColor QgsColorButton::color() const
+{
+  return mColor;
+}
+
+void QgsColorButton::setColorDialogOptions( QColorDialog::ColorDialogOptions cdo )
+{
+  mColorDialogOptions = cdo;
+}
+
+QColorDialog::ColorDialogOptions QgsColorButton::colorDialogOptions()
+{
+  return mColorDialogOptions;
+}
+
+void QgsColorButton::setColorDialogTitle( QString cdt )
+{
+  mColorDialogTitle = cdt;
+}
+
+QString QgsColorButton::colorDialogTitle()
+{
+  return mColorDialogTitle;
+}
 
 //////////////////
 

src/gui/qgscolorbutton.h

@@ -15,26 +15,96 @@
 #ifndef QGSCOLORBUTTON_H
 #define QGSCOLORBUTTON_H
 
+#include <QColorDialog>
 #include <QToolButton>
 #include <QPushButton>
 
 /** \ingroup gui
- * A cross platform button subclass for selecting colors.
+ * A cross platform button subclass for selecting colors. Will open a color chooser dialog when clicked.
  */
 class GUI_EXPORT QgsColorButton: public QToolButton
 {
+  Q_OBJECT
+
   public:
-    QgsColorButton( QWidget *parent = 0 );
+    /**
+     * Construct a new color button.
+     *
+     * @param parent The parent QWidget for the dialog
+     * @param cdt The title to show in the color chooser dialog
+     * @param cdo Options for the color chooser dialog
+     * @note changed in 1.9
+     */
+    QgsColorButton( QWidget *parent = 0, QString cdt = tr( "Select Color" ), QColorDialog::ColorDialogOptions cdo = 0 );
     ~QgsColorButton();
 
+    /**
+     * Specify the current color. Will emit a colorChanged signal if the color is different to the previous.
+     *
+     * @param color the new color
+     * @note added in 1.9
+     */
     void setColor( const QColor &color );
-    QColor color() const { return mColor; }
+    /**
+     * Return the currently selected color.
+     *
+     * @return the currently selected color
+     * @note added in 1.9
+     */
+    QColor color() const;
+
+    /**
+     * Specify the options for the color chooser dialog (e.g. alpha).
+     *
+     * @param cdo Options for the color chooser dialog
+     * @note added in 1.9
+     */
+    void setColorDialogOptions( QColorDialog::ColorDialogOptions cdo );
+
+    /**
+     * Returns the options for the color chooser dialog.
+     *
+     * @return Options for the color chooser dialog
+     * @note added in 1.9
+     */
+    QColorDialog::ColorDialogOptions colorDialogOptions();
+
+    /**
+     * Set the title, which the color chooser dialog will show.
+     *
+     * @param cdt Title for the color chooser dialog
+     * @note added in 1.9
+     */
+    void setColorDialogTitle( QString cdt );
+
+    /**
+     * Returns the title, which the color chooser dialog shows.
+     *
+     * @return Title for the color chooser dialog
+     * @note added in 1.9
+     */
+    QString colorDialogTitle();
 
   protected:
     void paintEvent( QPaintEvent *e );
 
+  public slots:
+    void onButtonClicked();
+
+  signals:
+    /**
+     * Is emitted, whenever a new color is accepted. The color is always valid.
+     * In case the new color is the same, no signal is emitted, to avoid infinite loops.
+     *
+     * @param color New color
+     * @note added in 1.9
+     */
+    void colorChanged( const QColor &color );
+
   private:
+    QString mColorDialogTitle;
     QColor mColor;
+    QColorDialog::ColorDialogOptions mColorDialogOptions;
 };