[welcome] add optional branding banner to welcome page

src/branding/default/branding.desc

@@ -106,6 +106,11 @@ strings:
 
 # These images are loaded from the branding module directory.
 #
+# productBanner is an optional image, which if present, will be shown
+#       on the welcome page of the application, above the welcome text.
+#       It is intended to have a width much greater than height.
+#       It is displayed at 64px height (also on HiDPI).
+#       Recommended size is 64px tall, and up to 460px wide.
 # productIcon is used as the window icon, and will (usually) be used
 #       by the window manager to represent the application. This image
 #       should be square, and may be displayed by the window manager
@@ -121,8 +126,9 @@ strings:
 #
 # These filenames can also use substitutions from os-release (see above).
 images:
-    productLogo:         "squid.png"
+    productBanner:       "banner.png"
     productIcon:         "squid.png"
+    productLogo:         "squid.png"
     productWelcome:      "languages.png"
 
 # The slideshow is displayed during execution steps (e.g. when the

src/libcalamaresui/Branding.cpp

@@ -73,10 +73,11 @@ const QStringList Branding::s_stringEntryStrings =
 
 const QStringList Branding::s_imageEntryStrings =
 {
-    "productLogo",
+    "productBanner",
     "productIcon",
-    "productWelcome",
-    "productWallpaper"
+    "productLogo",
+    "productWallpaper",
+    "productWelcome"
 };
 
 const QStringList Branding::s_styleEntryStrings =

src/libcalamaresui/Branding.h

@@ -67,10 +67,11 @@ public:
 
     enum ImageEntry : short
     {
-        ProductLogo,
+        ProductBanner,
         ProductIcon,
-        ProductWelcome,
-        ProductWallpaper
+        ProductLogo,
+        ProductWallpaper,
+        ProductWelcome
     };
     Q_ENUM( ImageEntry )
 

src/modules/welcome/WelcomePage.cpp

@@ -51,7 +51,6 @@ WelcomePage::WelcomePage( Config* conf, QWidget* parent )
     , m_languages( nullptr )
     , m_conf( conf )
 {
-
     connect( Calamares::ModuleManager::instance(),
              &Calamares::ModuleManager::requirementsComplete,
              m_checkingWidget,
@@ -62,7 +61,8 @@ WelcomePage::WelcomePage( Config* conf, QWidget* parent )
              &CheckerContainer::requirementsProgress );
     ui->setupUi( this );
 
-    ui->verticalLayout->insertSpacing( 1, CalamaresUtils::defaultFontHeight() * 2 );
+    const int defaultFontHeight = CalamaresUtils::defaultFontHeight();
+    ui->verticalLayout->insertSpacing( 1, defaultFontHeight * 2 );
     initLanguages();
 
     ui->mainText->setAlignment( Qt::AlignCenter );
@@ -77,11 +77,29 @@ WelcomePage::WelcomePage( Config* conf, QWidget* parent )
     ui->aboutButton->setIcon( CalamaresUtils::defaultPixmap(
         CalamaresUtils::Information,
         CalamaresUtils::Original,
-        2 * QSize( CalamaresUtils::defaultFontHeight(), CalamaresUtils::defaultFontHeight() ) ) );
+        2 * QSize( defaultFontHeight, defaultFontHeight ) ) );
     connect( ui->aboutButton, &QPushButton::clicked, this, &WelcomePage::showAboutBox );
 
-    int welcome_text_idx = ui->verticalLayout->indexOf( ui->mainText );
+    // insert system-check widget below welcome text
+    const int welcome_text_idx = ui->verticalLayout->indexOf( ui->mainText );
     ui->verticalLayout->insertWidget( welcome_text_idx + 1, m_checkingWidget );
+
+    // insert optional logo banner image above welcome text
+    Calamares::Branding::ImageEntry bannerImage = Calamares::Branding::ProductBanner;
+    QString bannerPath = Calamares::Branding::instance()->imagePath( bannerImage );
+    if ( QFile::exists( bannerPath ) )
+    {
+        QPixmap bannerPixmap = QPixmap( bannerPath );
+        if ( !bannerPixmap.isNull() )
+        {
+            QLabel* bannerLabel = new QLabel;
+            bannerLabel->setPixmap( bannerPixmap );
+            bannerLabel->setMinimumHeight( 64 );
+            bannerLabel->setAlignment( Qt::AlignCenter );
+            ui->verticalLayout->insertSpacing( welcome_text_idx, defaultFontHeight );
+            ui->verticalLayout->insertWidget( welcome_text_idx, bannerLabel );
+        }
+    }
 }
 
 void