[libcalamaresui] Warnings-- for Qt 5.15 deprecations

Introduce a GUI-oriented compatibility header that introduces aliases
for some enum values that are deprecated in Qt 5.15

src/libcalamaresui/utils/QtCompat.h

@@ -0,0 +1,42 @@
+/* === This file is part of Calamares - <https://calamares.io> ===
+ *
+ *   SPDX-FileCopyrightText: 2020 Adriaan de Groot <groot@kde.org>
+ *   SPDX-License-Identifier: GPL-3.0-or-later
+ *   Calamares is Free Software: see the License-Identifier above.
+ *
+ */
+
+/**@file Handle compatibility and deprecations across Qt versions
+ *
+ * Since Calamares is supposed to work with Qt 5.9 or later, it covers a
+ * lot of changes in the Qt API. Especially the later Qt 5.15 (last LTS)
+ * versions deprecate a number of enum values and parts of the QWidgets
+ * API. This file adjusts for that by introducing suitable aliases
+ * and workaround-functions.
+ *
+ * For a similar approach for QtCore, see libcalamares/utils/String.h
+ */
+
+#ifndef UTILS_QTCOMPAT_H
+#define UTILS_QTCOMPAT_H
+
+#include <QPalette>
+
+/* Avoid warnings about QPalette changes */
+constexpr static const auto WindowBackground =
+#if QT_VERSION < QT_VERSION_CHECK( 5, 15, 0 )
+    QPalette::Background
+#else
+    QPalette::Window
+#endif
+    ;
+
+constexpr static const auto WindowText =
+#if QT_VERSION < QT_VERSION_CHECK( 5, 15, 0 )
+    QPalette::Foreground
+#else
+    QPalette::WindowText
+#endif
+    ;
+
+#endif

src/modules/license/LicenseWidget.cpp

@@ -13,6 +13,7 @@
 #include "LicenseWidget.h"
 
 #include "utils/Logger.h"
+#include "utils/QtCompat.h"
 
 #include <QDesktopServices>
 #include <QFile>
@@ -48,7 +49,7 @@ LicenseWidget::LicenseWidget( LicenseEntry entry, QWidget* parent )
     , m_isExpanded( m_entry.expandByDefault() )
 {
     QPalette pal( palette() );
-    pal.setColor( QPalette::Background, palette().window().color().lighter( 108 ) );
+    pal.setColor( WindowBackground, palette().window().color().lighter( 108 ) );
 
     setObjectName( "licenseItem" );
 

src/modules/partition/gui/BootInfoWidget.cpp

@@ -12,6 +12,7 @@
 #include "core/PartUtils.h"
 
 #include "utils/CalamaresUtilsGui.h"
+#include "utils/QtCompat.h"
 #include "utils/Retranslator.h"
 
 #include <QDir>
@@ -45,7 +46,7 @@ BootInfoWidget::BootInfoWidget( QWidget* parent )
     m_bootLabel->setAlignment( Qt::AlignCenter );
 
     QPalette palette;
-    palette.setBrush( QPalette::Foreground, QColor( "#4D4D4D" ) );  //dark grey
+    palette.setBrush( WindowText, QColor( "#4D4D4D" ) );  //dark grey
 
     m_bootIcon->setAutoFillBackground( true );
     m_bootLabel->setAutoFillBackground( true );

src/modules/partition/gui/DeviceInfoWidget.cpp

@@ -7,13 +7,13 @@
  *
  */
 
-
 #include "DeviceInfoWidget.h"
 
 #include "GlobalStorage.h"
 #include "JobQueue.h"
 #include "utils/CalamaresUtilsGui.h"
 #include "utils/Logger.h"
+#include "utils/QtCompat.h"
 #include "utils/Retranslator.h"
 
 #include <QDir>
@@ -47,7 +47,7 @@ DeviceInfoWidget::DeviceInfoWidget( QWidget* parent )
     m_ptLabel->setAlignment( Qt::AlignCenter );
 
     QPalette palette;
-    palette.setBrush( QPalette::Foreground, QColor( "#4D4D4D" ) );  //dark grey
+    palette.setBrush( WindowText, QColor( "#4D4D4D" ) );  //dark grey
 
     m_ptIcon->setAutoFillBackground( true );
     m_ptLabel->setAutoFillBackground( true );

src/modules/partition/gui/PartitionViewStep.cpp

@@ -34,6 +34,7 @@
 #include "utils/CalamaresUtilsGui.h"
 #include "utils/Logger.h"
 #include "utils/NamedEnum.h"
+#include "utils/QtCompat.h"
 #include "utils/Retranslator.h"
 #include "utils/Variant.h"
 #include "widgets/WaitingWidget.h"
@@ -273,7 +274,7 @@ PartitionViewStep::createSummaryWidget() const
         jobsLabel->setText( jobsLines.join( "<br/>" ) );
         jobsLabel->setMargin( CalamaresUtils::defaultFontHeight() / 2 );
         QPalette pal;
-        pal.setColor( QPalette::Background, pal.window().color().lighter( 108 ) );
+        pal.setColor( WindowBackground, pal.window().color().lighter( 108 ) );
         jobsLabel->setAutoFillBackground( true );
         jobsLabel->setPalette( pal );
     }

src/modules/summary/SummaryPage.cpp

@@ -19,6 +19,7 @@
 
 #include "utils/CalamaresUtilsGui.h"
 #include "utils/Logger.h"
+#include "utils/QtCompat.h"
 #include "utils/Retranslator.h"
 #include "viewpages/ExecutionViewStep.h"
 
@@ -183,7 +184,7 @@ SummaryPage::createBodyLabel( const QString& text ) const
     QLabel* label = new QLabel;
     label->setMargin( CalamaresUtils::defaultFontHeight() / 2 );
     QPalette pal( palette() );
-    pal.setColor( QPalette::Background, palette().window().color().lighter( 108 ) );
+    pal.setColor( WindowBackground, palette().window().color().lighter( 108 ) );
     label->setAutoFillBackground( true );
     label->setPalette( pal );
     label->setText( text );