From d2b6847d0b6c54aa216160dc93b43d98e62d41bc Mon Sep 17 00:00:00 2001
From: Peter Hartmann <peter@edelhirsch.io>
Date: Mon, 8 Nov 2021 16:22:22 +0100
Subject: [PATCH] improve input handling

---
 examples/iotdashboard/LightDisplay.cpp        | 29 ++++++++++++-------
 examples/iotdashboard/LightDisplay.h          |  1 +
 examples/iotdashboard/LightDisplaySkinlet.cpp |  5 +---
 3 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/examples/iotdashboard/LightDisplay.cpp b/examples/iotdashboard/LightDisplay.cpp
index c613b7f4..2585986a 100644
--- a/examples/iotdashboard/LightDisplay.cpp
+++ b/examples/iotdashboard/LightDisplay.cpp
@@ -102,9 +102,11 @@ void LightDisplay::mouseMoveEvent( QMouseEvent* event )
         return;
     }
 
-    const qreal ratioX = ( mousePos.x() - rect.x() ) / rect.width();
-
-    setValueAsRatio( ratioX );
+    const QskArcMetrics metrics = arcMetricsHint( ColdAndWarmArc );
+    const qreal angle = angleFromPoint( rect, mousePos );
+    qDebug() << "angle:" << angle;
+    const qreal ratio = ( metrics.spanAngle() - angle * 16 ) / metrics.spanAngle();
+    setValueAsRatio( ratio );
 }
 
 void LightDisplay::mouseReleaseEvent( QMouseEvent* /*event*/ )
@@ -112,24 +114,31 @@ void LightDisplay::mouseReleaseEvent( QMouseEvent* /*event*/ )
     setSkinStateFlag( Pressed, false );
 }
 
+qreal LightDisplay::angleFromPoint( const QRectF& rect, const QPointF& point ) const
+{
+    QPointF circlePos( point.x() - rect.center().x(),
+                 rect.center().y() - point.y() );
+
+    const qreal atan = qAtan2( circlePos.y(), circlePos.x() );
+    const qreal angle = qRadiansToDegrees( atan );
+    return angle;
+}
+
 bool LightDisplay::arcContainsPoint( const QRectF& rect, const QPointF& point ) const
 {
     // putting this in an own function just because it might be useful
     // at other places in the future
 
     const QskArcMetrics metrics = arcMetricsHint( ColdAndWarmArc );
-    const int tolerance = 10;
+    const int tolerance = 20;
 
     // 1. check angle
     QPointF circlePos( point.x() - rect.center().x(),
                  rect.center().y() - point.y() );
 
-    const qreal atan = qAtan2( circlePos.y(), circlePos.x() );
-    const qreal angle = qRadiansToDegrees( atan );
-    // the qAbs() actually only works for the 180 degrees case,
-    // we might want to generalize this later:
-    const bool angleWithinRange = ( qAbs( angle ) + tolerance ) > metrics.startAngle()
-            && qAbs( angle ) < ( metrics.startAngle() + metrics.spanAngle() - tolerance );
+    const qreal angle = angleFromPoint( rect, point );
+    const bool angleWithinRange = ( angle + tolerance ) > metrics.startAngle()
+            && angle < ( metrics.startAngle() + metrics.spanAngle() - tolerance );
 
     // 2. check whether point is on arc
     const qreal radiusMax = rect.width() / 2;
diff --git a/examples/iotdashboard/LightDisplay.h b/examples/iotdashboard/LightDisplay.h
index 4f121a03..f310a736 100644
--- a/examples/iotdashboard/LightDisplay.h
+++ b/examples/iotdashboard/LightDisplay.h
@@ -37,6 +37,7 @@ class LightDisplay : public QskBoundedValueInput
     void mouseReleaseEvent( QMouseEvent* e ) override;
 
   private:
+    qreal angleFromPoint( const QRectF&, const QPointF& ) const;
     bool arcContainsPoint( const QRectF&, const QPointF& ) const;
 
     QskShadowMetrics m_shadow;
diff --git a/examples/iotdashboard/LightDisplaySkinlet.cpp b/examples/iotdashboard/LightDisplaySkinlet.cpp
index 2340bead..4cb96045 100644
--- a/examples/iotdashboard/LightDisplaySkinlet.cpp
+++ b/examples/iotdashboard/LightDisplaySkinlet.cpp
@@ -140,10 +140,7 @@ QSGNode* LightDisplaySkinlet::updateSubNode(
         }
         case ColdAndWarmArcRole:
         {
-            const qreal startAngle = 0;
-            const qreal spanAngle = 180 * 16;
-            return updateArcNode( skinnable, node, startAngle, spanAngle,
-                LightDisplay::ColdAndWarmArc );
+            return updateArcNode( skinnable, node, LightDisplay::ColdAndWarmArc );
         }
         case ValueTextRole:
         {