Fix window palette initialization in Chart Themes Example

The default window palette needs to be set to the application object
in initialization as the palette of the window is not valid by then.

Change-Id: Iad18c255600b31b18f0030094dd9e57757001fa1
Task-number: QTBUG-62824
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>

1 files changed, 35 insertions, 27 deletions

diff --git a/examples/charts/chartthemes/themewidget.cpp b/examples/charts/chartthemes/themewidget.cpp
index 28741443..bcdd2e7f 100644
--- a/examples/charts/chartthemes/themewidget.cpp
+++ b/examples/charts/chartthemes/themewidget.cpp
@@ -51,6 +51,7 @@
 #include <QtWidgets/QLabel>
 #include <QtCore/QRandomGenerator>
 #include <QtCharts/QBarCategoryAxis>
+#include <QtWidgets/QApplication>
 
 ThemeWidget::ThemeWidget(QWidget *parent) :
     QWidget(parent),
@@ -111,6 +112,13 @@ ThemeWidget::ThemeWidget(QWidget *parent) :
 
     // Set defaults
     m_antialiasCheckBox->setChecked(true);
+
+    // Set the colors from the light theme as default ones
+    QPalette pal = qApp->palette();
+    pal.setColor(QPalette::Window, QRgb(0xf0f0f0));
+    pal.setColor(QPalette::WindowText, QRgb(0x404044));
+    qApp->setPalette(pal);
+
     updateUI();
 }
 
@@ -332,35 +340,35 @@ void ThemeWidget::updateUI()
     if (m_charts.at(0)->chart()->theme() != theme) {
         for (QChartView *chartView : charts)
             chartView->chart()->setTheme(theme);
-    }
 
-    QPalette pal = window()->palette();
-    if (theme == QChart::ChartThemeLight) {
-        pal.setColor(QPalette::Window, QRgb(0xf0f0f0));
-        pal.setColor(QPalette::WindowText, QRgb(0x404044));
-    } else if (theme == QChart::ChartThemeDark) {
-        pal.setColor(QPalette::Window, QRgb(0x121218));
-        pal.setColor(QPalette::WindowText, QRgb(0xd6d6d6));
-    } else if (theme == QChart::ChartThemeBlueCerulean) {
-        pal.setColor(QPalette::Window, QRgb(0x40434a));
-        pal.setColor(QPalette::WindowText, QRgb(0xd6d6d6));
-    } else if (theme == QChart::ChartThemeBrownSand) {
-        pal.setColor(QPalette::Window, QRgb(0x9e8965));
-        pal.setColor(QPalette::WindowText, QRgb(0x404044));
-    } else if (theme == QChart::ChartThemeBlueNcs) {
-        pal.setColor(QPalette::Window, QRgb(0x018bba));
-        pal.setColor(QPalette::WindowText, QRgb(0x404044));
-    } else if (theme == QChart::ChartThemeHighContrast) {
-        pal.setColor(QPalette::Window, QRgb(0xffab03));
-        pal.setColor(QPalette::WindowText, QRgb(0x181818));
-    } else if (theme == QChart::ChartThemeBlueIcy) {
-        pal.setColor(QPalette::Window, QRgb(0xcee7f0));
-        pal.setColor(QPalette::WindowText, QRgb(0x404044));
-    } else {
-        pal.setColor(QPalette::Window, QRgb(0xf0f0f0));
-        pal.setColor(QPalette::WindowText, QRgb(0x404044));
+        QPalette pal = window()->palette();
+        if (theme == QChart::ChartThemeLight) {
+            pal.setColor(QPalette::Window, QRgb(0xf0f0f0));
+            pal.setColor(QPalette::WindowText, QRgb(0x404044));
+        } else if (theme == QChart::ChartThemeDark) {
+            pal.setColor(QPalette::Window, QRgb(0x121218));
+            pal.setColor(QPalette::WindowText, QRgb(0xd6d6d6));
+        } else if (theme == QChart::ChartThemeBlueCerulean) {
+            pal.setColor(QPalette::Window, QRgb(0x40434a));
+            pal.setColor(QPalette::WindowText, QRgb(0xd6d6d6));
+        } else if (theme == QChart::ChartThemeBrownSand) {
+            pal.setColor(QPalette::Window, QRgb(0x9e8965));
+            pal.setColor(QPalette::WindowText, QRgb(0x404044));
+        } else if (theme == QChart::ChartThemeBlueNcs) {
+            pal.setColor(QPalette::Window, QRgb(0x018bba));
+            pal.setColor(QPalette::WindowText, QRgb(0x404044));
+        } else if (theme == QChart::ChartThemeHighContrast) {
+            pal.setColor(QPalette::Window, QRgb(0xffab03));
+            pal.setColor(QPalette::WindowText, QRgb(0x181818));
+        } else if (theme == QChart::ChartThemeBlueIcy) {
+            pal.setColor(QPalette::Window, QRgb(0xcee7f0));
+            pal.setColor(QPalette::WindowText, QRgb(0x404044));
+        } else {
+            pal.setColor(QPalette::Window, QRgb(0xf0f0f0));
+            pal.setColor(QPalette::WindowText, QRgb(0x404044));
+        }
+        window()->setPalette(pal);
     }
-    window()->setPalette(pal);
 
     bool checked = m_antialiasCheckBox->isChecked();
     for (QChartView *chart : charts)