[plasmalnf] Demand-load image for a theme

src/modules/plasmalnf/CMakeLists.txt

@@ -10,22 +10,30 @@ find_package(ECM ${ECM_VERSION} REQUIRED NO_MODULE)
 set( lnf_ver 5.41 )
 
 find_package( KF5Config ${lnf_ver} )
-find_package( KF5Plasma ${lnf_ver} )
-find_package( KF5Package ${lnf_ver} )
 set_package_properties(
     KF5Config PROPERTIES
     PURPOSE "For finding default Plasma Look-and-Feel"
 )
+
+find_package( KF5Plasma ${lnf_ver} )
 set_package_properties(
     KF5Plasma PROPERTIES
     PURPOSE "For Plasma Look-and-Feel selection"
 )
+
+find_package( KF5Package ${lnf_ver} )
 set_package_properties(
     KF5Package PROPERTIES
     PURPOSE "For Plasma Look-and-Feel selection"
 )
 
-if ( KF5Plasma_FOUND AND KF5Package_FOUND )
+find_package( KF5ItemModels ${lnf_ver} )
+set_package_properties(
+    KF5ItemModels PROPERTIES
+    PURPOSE "For Plasma Look-and-Feel display"
+)
+
+if ( KF5Plasma_FOUND AND KF5Package_FOUND AND KF5ItemModels_FOUND )
     calamares_add_plugin( plasmalnf
         TYPE viewmodule
         EXPORT_MACRO PLUGINDLLEXPORT_PRO
@@ -43,6 +51,7 @@ if ( KF5Plasma_FOUND AND KF5Package_FOUND )
             page_plasmalnf.ui
         LINK_PRIVATE_LIBRARIES
             calamaresui
+            KF5::ItemModels
             KF5::Package
             KF5::Plasma
         SHARED_LIB

src/modules/plasmalnf/PlasmaLnfPage.cpp

@@ -17,10 +17,47 @@
 #include "utils/Logger.h"
 #include "utils/Retranslator.h"
 
+#include <KExtraColumnsProxyModel>
+
 #include <QHeaderView>
 #include <QStyledItemDelegate>
 #include <QTableView>
 
+class ThemeColumns : public KExtraColumnsProxyModel
+{
+public:
+    ThemeColumns( QObject* parent );
+
+    QVariant extraColumnData( const QModelIndex& parent, int row, int extraColumn, int role ) const override;
+};
+
+ThemeColumns::ThemeColumns( QObject* parent )
+    : KExtraColumnsProxyModel( parent )
+{
+    appendColumn();
+    appendColumn();
+}
+
+QVariant
+ThemeColumns::extraColumnData( const QModelIndex& parent, int row, int extraColumn, int role ) const
+{
+    if ( role != Qt::DisplayRole )
+    {
+        return QVariant();
+    }
+    switch ( extraColumn )
+    {
+    case 0:
+        return sourceModel()->data( sourceModel()->index( row, 0 ), ThemesModel::DescriptionRole );
+    case 1:
+        return sourceModel()->data( sourceModel()->index( row, 0 ), ThemesModel::ImageRole );
+    default:
+        return QVariant();
+    }
+    __builtin_unreachable();
+}
+
+
 PlasmaLnfPage::PlasmaLnfPage( Config* config, QWidget* parent )
     : QWidget( parent )
     , ui( new Ui::PlasmaLnfPage )
@@ -43,9 +80,11 @@ PlasmaLnfPage::PlasmaLnfPage( Config* config, QWidget* parent )
     connect( this, &PlasmaLnfPage::plasmaThemeSelected, config, &Config::setTheme );
 
     QTableView* view = new QTableView( this );
+    ThemeColumns* model = new ThemeColumns( this );
+    model->setSourceModel( m_config->themeModel() );
+    view->setModel( model );
     view->verticalHeader()->hide();
     view->horizontalHeader()->hide();
-    view->setModel( m_config->themeModel() );
     ui->verticalLayout->addWidget( view );
 
     connect( view->selectionModel(),
@@ -54,8 +93,9 @@ PlasmaLnfPage::PlasmaLnfPage( Config* config, QWidget* parent )
                  auto i = selected.indexes();
                  if ( !i.isEmpty() )
                  {
+                     auto row = i.first().row();
                      auto* model = m_config->themeModel();
-                     auto id = model->data( i.first(), ThemesModel::KeyRole ).toString();
+                     auto id = model->data( model->index( row, 0 ), ThemesModel::KeyRole ).toString();
                      cDebug() << "View selected" << selected << id;
                      if ( !id.isEmpty() )
                      {

src/modules/plasmalnf/ThemeInfo.cpp

@@ -8,9 +8,17 @@
  */
 #include "ThemeInfo.h"
 
+#include "Branding.h"
+#include "utils/CalamaresUtilsGui.h"
+#include "utils/Logger.h"
+
 #include <KPackage/Package>
 #include <KPackage/PackageLoader>
 
+#include <QDir>
+#include <QFileInfo>
+#include <QPixmap>
+
 /** @brief describes a single plasma LnF theme.
  *
  * A theme description has an id, which is really the name of the desktop
@@ -24,6 +32,7 @@ struct ThemeInfo
     QString name;
     QString description;
     QString imagePath;
+    mutable QPixmap pixmap;
     bool show = true;
 
     ThemeInfo() {}
@@ -42,6 +51,9 @@ struct ThemeInfo
     explicit ThemeInfo( const KPluginMetaData& );
 
     bool isValid() const { return !id.isEmpty(); }
+
+    /// @brief Fill in the pixmap member based on imagePath
+    QPixmap loadImage() const;
 };
 
 class ThemeInfoList : public QList< ThemeInfo >
@@ -128,6 +140,8 @@ ThemesModel::data( const QModelIndex& index, int role ) const
         return item.show;
     case DescriptionRole:
         return item.description;
+    case ImageRole:
+        return item.loadImage();
     default:
         return QVariant();
     }
@@ -198,6 +212,39 @@ ThemesModel::showOnlyThemes( const QMap< QString, QString >& onlyThese )
     emit dataChanged( index( 0, 0 ), index( m_themes->count() - 1 ), { ShownRole } );
 }
 
+/**
+ * Massage the given @p path to the most-likely
+ * path that actually contains a screenshot. For
+ * empty image paths, returns the QRC path for an
+ * empty screenshot. Returns blank if the path
+ * doesn't exist anywhere in the search paths.
+ */
+static QString
+munge_imagepath( const QString& path )
+{
+    if ( path.isEmpty() )
+    {
+        return ":/view-preview.png";
+    }
+
+    if ( path.startsWith( '/' ) )
+    {
+        return path;
+    }
+
+    if ( QFileInfo::exists( path ) )
+    {
+        return path;
+    }
+
+    QFileInfo fi( QDir( Calamares::Branding::instance()->componentDirectory() ), path );
+    if ( fi.exists() )
+    {
+        return fi.absoluteFilePath();
+    }
+
+    return QString();
+}
 
 ThemeInfo::ThemeInfo( const KPluginMetaData& data )
     : id( data.pluginId() )
@@ -205,3 +252,34 @@ ThemeInfo::ThemeInfo( const KPluginMetaData& data )
     , description( data.description() )
 {
 }
+
+QPixmap
+ThemeInfo::loadImage() const
+{
+    if ( pixmap.isNull() )
+    {
+
+        const QSize image_size { qMax( 12 * CalamaresUtils::defaultFontHeight(), 120 ),
+                                 qMax( 8 * CalamaresUtils::defaultFontHeight(), 80 ) };
+
+        const QString path = munge_imagepath( imagePath );
+        cDebug() << "Loading initial image for" << id << imagePath << "->" << path;
+        QPixmap image( path );
+        if ( image.isNull() )
+        {
+            // Not found or not specified, so convert the name into some (horrible, likely)
+            // color instead.
+            image = QPixmap( image_size );
+            auto hash_color = qHash( imagePath.isEmpty() ? id : imagePath );
+            cDebug() << Logger::SubEntry << "Theme image" << imagePath << "not found, hash" << hash_color;
+            image.fill( QColor( QRgb( hash_color ) ) );
+        }
+        else
+        {
+            cDebug() << Logger::SubEntry << "Theme image" << image.size();
+        }
+
+        pixmap = image.scaled( image_size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation );
+    }
+    return pixmap;
+}