Allow aligning color wheel widget to the top

Instead of the center, since that may match expectations better
depending on where in the UI the wheel is placed. Various other widgets
tend to grow downwards, not in both directions, so this fits better in
with those. The default continues to be off.

src/desktop/bundled/QtColorWidgets/color_wheel.cpp

@@ -89,7 +89,12 @@ void ColorWheel::paintEvent(QPaintEvent * )
 
     QPainter painter(this);
     painter.setRenderHint(QPainter::Antialiasing);
-    painter.translate(geometry().width()/2,geometry().height()/2);
+
+    int width = geometry().width();
+    int height = geometry().height();
+    int x = width / 2;
+    int y = height > width && p->align_top ? x : height / 2;
+    painter.translate(x, y);
 
     // hue wheel
     if(p->hue_ring.isNull())
@@ -285,6 +290,11 @@ bool ColorWheel::mirroredSelector() const
     return p->mirrored_selector;
 }
 
+bool ColorWheel::alignTop() const
+{
+    return p->align_top;
+}
+
 
 void ColorWheel::setColorSpace(color_widgets::ColorWheel::ColorSpaceEnum space)
 {
@@ -351,6 +361,16 @@ void ColorWheel::setMirroredSelector(bool mirrored)
     }
 }
 
+void ColorWheel::setAlignTop(bool top)
+{
+    if ( top != p->align_top )
+    {
+        p->align_top = top;
+        update();
+        Q_EMIT alignTopChanged(top);
+    }
+}
+
 void ColorWheel::dragEnterEvent(QDragEnterEvent* event)
 {
     if ( event->mimeData()->hasColor() ||

src/desktop/bundled/QtColorWidgets/include/QtColorWidgets/color_wheel.hpp

@@ -33,6 +33,7 @@ class QCP_EXPORT ColorWheel : public QWidget
     Q_PROPERTY(bool rotatingSelector READ rotatingSelector WRITE setRotatingSelector NOTIFY rotatingSelectorChanged DESIGNABLE true )
     Q_PROPERTY(ColorSpaceEnum colorSpace READ colorSpace WRITE setColorSpace NOTIFY colorSpaceChanged DESIGNABLE true )
     Q_PROPERTY(bool mirroredSelector READ mirroredSelector WRITE setMirroredSelector NOTIFY mirroredSelectorChanged DESIGNABLE true )
+    Q_PROPERTY(bool alignTop READ alignTop WRITE setAlignTop NOTIFY alignTop DESIGNABLE false )
 
 public:
     enum ShapeEnum
@@ -93,6 +94,9 @@ class QCP_EXPORT ColorWheel : public QWidget
     /// Whether the internal selector's should be mirrored horizontally
     bool mirroredSelector() const;
 
+    /// Whether the color wheel is aligned to the top or the center
+    bool alignTop() const;
+
 public Q_SLOTS:
 
     /// Set current color
@@ -125,6 +129,9 @@ public Q_SLOTS:
     /// Sets whether the internal selector should be mirrored horizontally
     void setMirroredSelector(bool mirrored);
 
+    /// Sets whether the wheel should be aligned to the top or the center
+    void setAlignTop(bool top);
+
 Q_SIGNALS:
     /**
      * Emitted when the user selects a color or setColor is called
@@ -146,6 +153,8 @@ public Q_SLOTS:
 
     void mirroredSelectorChanged(bool mirrored);
 
+    void alignTopChanged(bool alignTop);
+
     /**
      * Emitted when the user releases from dragging
      */

src/desktop/bundled/QtColorWidgets/include/QtColorWidgets/color_wheel_private.hpp

@@ -44,6 +44,7 @@ class ColorWheel::Private
     QColor (*rainbow_from_hue)(qreal);
     int max_size = 128;
     bool mirrored_selector = false;
+    bool align_top = false;
     qreal device_pixel_ratio = 1.0;
 
     Private(ColorWheel *widget)
@@ -94,7 +95,11 @@ class ColorWheel::Private
     /// return line from center to given point
     QLineF line_to_point(const QPoint &p) const
     {
-        return QLineF (w->geometry().width()/2, w->geometry().height()/2, p.x(), p.y());
+        int width = w->geometry().width();
+        int height = w->geometry().height();
+        int x1 = width / 2;
+        int y1 = height > width && align_top ? x1 : height / 2;
+        return QLineF (x1, y1, p.x(), p.y());
     }
 
     /**