From 1757b2dc576a28ef28715c7f2ab1c5c64a781328 2015-09-30 07:44:27
From: Miikka Heikkinen <miikka.heikkinen@theqtcompany.com>
Date: 2015-09-30 07:44:27
Subject: [PATCH] Use empty rect for gl series instead of small dummy rect

Empty rect triggers the changed signal just as well, and has less
change of triggering other updates on the underlying scene.

Change-Id: Ifa6a477c14ca74a178657464a1da0f765a880412
Reviewed-by: Titta Heikkala <titta.heikkala@theqtcompany.com>

---

diff --git a/src/charts/linechart/linechartitem.cpp b/src/charts/linechart/linechartitem.cpp
index f0b0a57..a6b4da9 100644
--- a/src/charts/linechart/linechartitem.cpp
+++ b/src/charts/linechart/linechartitem.cpp
@@ -70,12 +70,11 @@ QPainterPath LineChartItem::shape() const
 
 void LineChartItem::updateGeometry()
 {
-    static const QRectF dummyRect = QRectF(0.0, 0.0, 0.001, 0.001);
     if (m_series->useOpenGL()) {
-        // Fake a miniscule region, so we trigger changed signal.
-        if (m_rect.width() != dummyRect.width()) {
+        if (!m_rect.isEmpty()) {
             prepareGeometryChange();
-            m_rect = dummyRect;
+            // Changed signal seems to trigger even with empty region
+            m_rect = QRectF();
         }
         update();
         return;
diff --git a/src/charts/scatterchart/scatterchartitem.cpp b/src/charts/scatterchart/scatterchartitem.cpp
index e8e4fe4..e84b712 100644
--- a/src/charts/scatterchart/scatterchartitem.cpp
+++ b/src/charts/scatterchart/scatterchartitem.cpp
@@ -130,14 +130,13 @@ void ScatterChartItem::markerDoubleClicked(QGraphicsItem *marker)
 
 void ScatterChartItem::updateGeometry()
 {
-    static const QRectF dummyRect = QRectF(0.0, 0.0, 0.001, 0.001);
     if (m_series->useOpenGL()) {
         if (m_items.childItems().count())
             deletePoints(m_items.childItems().count());
-        // Fake a miniscule region, so we trigger changed signal.
-        if (m_rect.width() != dummyRect.width()) {
+        if (!m_rect.isEmpty()) {
             prepareGeometryChange();
-            m_rect = dummyRect;
+            // Changed signal seems to trigger even with empty region
+            m_rect = QRectF();
         }
         update();
         return;