Polish the Tablet example

- Introduce Qt 5 signal-slot connection syntax.
- Merge MainWindow::createMenus()/createActions()
  into MainWindow::createMenus(), removing the need
  to store the actions as member variables.
  Use QMenu::addAction() for brevity.
- For actions in QActionGroups, carry the Valuator enum
  in QAction::data so that the slot to handle the selection
  does not need to compare the QAction pointer itself.
- Use a non-modal QColorDialog, so that the user
  can change colors more easily while drawing.
- Choose saner shortcut keys: control-Q should not
  override the default usage for quitting the application,
  and using shortcuts for About dialogs is anyway dubious.
- Improve the example documentation.

Change-Id: I57aaf5f5b885c13a953482dbcc41275dd3d6bff4
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Topi Reiniö <topi.reinio@theqtcompany.com>

1 files changed, 21 insertions, 25 deletions

diff --git a/examples/widgets/widgets/tablet/tabletcanvas.h b/examples/widgets/widgets/tablet/tabletcanvas.h
index a7335dbaf0..6044884d32 100644
--- a/examples/widgets/widgets/tablet/tabletcanvas.h
+++ b/examples/widgets/widgets/tablet/tabletcanvas.h
@@ -61,27 +61,26 @@ class TabletCanvas : public QWidget
     Q_OBJECT
 
 public:
-    enum AlphaChannelType { AlphaPressure, AlphaTangentialPressure, AlphaTilt, NoAlpha };
-    enum ColorSaturationType { SaturationVTilt, SaturationHTilt,
-                               SaturationPressure, NoSaturation };
-    enum LineWidthType { LineWidthPressure, LineWidthTilt, NoLineWidth };
+    enum Valuator { PressureValuator, TangentialPressureValuator,
+                    TiltValuator, VTiltValuator, HTiltValuator, NoValuator };
+    Q_ENUM(Valuator)
 
     TabletCanvas();
 
     bool saveImage(const QString &file);
     bool loadImage(const QString &file);
-    void setAlphaChannelType(AlphaChannelType type)
-        { alphaChannelType = type; }
-    void setColorSaturationType(ColorSaturationType type)
-        { colorSaturationType = type; }
-    void setLineWidthType(LineWidthType type)
-        { lineWidthType = type; }
-    void setColor(const QColor &color)
-        { myColor = color; }
+    void setAlphaChannelValuator(Valuator type)
+        { m_alphaChannelValuator = type; }
+    void setColorSaturationValuator(Valuator type)
+        { m_colorSaturationValuator = type; }
+    void setLineWidthType(Valuator type)
+        { m_lineWidthValuator = type; }
+    void setColor(const QColor &c)
+        { if (c.isValid()) m_color = c; }
     QColor color() const
-        { return myColor; }
+        { return m_color; }
     void setTabletDevice(QTabletEvent *event)
-        { myTabletDevice = event->device(); updateCursor(event); }
+        { updateCursor(event); }
     int maximum(int a, int b)
         { return a > b ? a : b; }
 
@@ -97,17 +96,14 @@ private:
     void updateBrush(const QTabletEvent *event);
     void updateCursor(const QTabletEvent *event);
 
-    AlphaChannelType alphaChannelType;
-    ColorSaturationType colorSaturationType;
-    LineWidthType lineWidthType;
-    QTabletEvent::PointerType pointerType;
-    QTabletEvent::TabletDevice myTabletDevice;
-    QColor myColor;
-
-    QPixmap pixmap;
-    QBrush myBrush;
-    QPen myPen;
-    bool deviceDown;
+    Valuator m_alphaChannelValuator;
+    Valuator m_colorSaturationValuator;
+    Valuator m_lineWidthValuator;
+    QColor m_color;
+    QPixmap m_pixmap;
+    QBrush m_brush;
+    QPen m_pen;
+    bool m_deviceDown;
 
     struct Point {
         QPointF pos;