[packagechooser] Initial support for appstream items

- Use *appstream* as key in one of the items for the package-
   chooser to load data from the AppStream cache in the system.
 - Usable for some applications; for DE-selection not so much.
 - Currently unimplemented.

src/modules/packagechooser/CMakeLists.txt

@@ -23,6 +23,7 @@ set_package_properties(
 if ( AppStreamQt_FOUND )
     add_definitions( -DHAVE_APPSTREAM )
     list( APPEND _extra_libraries AppStreamQt )
+    list( APPEND _extra_src ItemAppStream.cpp )
 endif()
 
 calamares_add_plugin( packagechooser

src/modules/packagechooser/ItemAppStream.cpp

@@ -0,0 +1,33 @@
+/* === This file is part of Calamares - <https://github.com/calamares> ===
+ *
+ *   Copyright 2019, Adriaan de Groot <groot@kde.org>
+ *
+ *   Calamares is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   Calamares is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with Calamares. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @brief Loading items from AppData XML files.
+ *
+ * Only used if QtXML is found, implements PackageItem::fromAppData().
+ */
+#include "PackageModel.h"
+
+#include "utils/Logger.h"
+#include "utils/Variant.h"
+
+PackageItem
+PackageItem::fromAppStream( const QVariantMap& map )
+{
+    cWarning() << "AppStream loading not implemented.";
+    return PackageItem();
+}

src/modules/packagechooser/PackageChooserViewStep.cpp

@@ -219,6 +219,10 @@ PackageChooserViewStep::fillModel( const QVariantList& items )
         {
             m_model->addPackage( PackageItem::fromAppData( item_map ) );
         }
+        else if ( item_map.contains( "appstream" ) )
+        {
+            m_model->addPackage( PackageItem::fromAppStream( item_map ) );
+        }
         else
         {
             m_model->addPackage( PackageItem( item_map ) );

src/modules/packagechooser/PackageModel.cpp

@@ -98,6 +98,15 @@ PackageItem::fromAppData( const QVariantMap& item_map )
 }
 #endif
 
+#ifndef HAVE_APPSTREAM
+PackageItem
+PackageItem::fromAppStream( const QVariantMap& item_map )
+{
+    cWarning() << "Loading AppStream data is not supported.";
+    return PackageItem();
+}
+#endif
+
 
 PackageListModel::PackageListModel( QObject* parent )
     : QAbstractListModel( parent )

src/modules/packagechooser/PackageModel.h

@@ -93,6 +93,20 @@ struct PackageItem
      * return invalid PackageItems.
      */
     static PackageItem fromAppData( const QVariantMap& map );
+
+    /** @brief Loads an item from AppStream data.
+     *
+     * The @p map must have a key *appstream*. That is used as the
+     * primary source of information from the AppStream cache, but
+     * keys *id* and *screenshotPath* may be used to override parts
+     * of the AppStream data -- so that the ID is under the control
+     * of Calamares, and the screenshot can be forced to a local path
+     * available on the installation medium.
+     *
+     * Requires AppStreamQt, if not present will return invalid
+     * PackageItems.
+     */
+    static PackageItem fromAppStream( const QVariantMap& map );
 };
 
 using PackageList = QVector< PackageItem >;

src/modules/packagechooser/packagechooser.conf

@@ -20,14 +20,15 @@
 # or one-or-more).
 mode: required
 
-# Items to display in the chooser. In general, this should be a 
+# Items to display in the chooser. In general, this should be a
 # pretty short list to avoid overwhelming the UI. This is a list
 # of objects, and the items are displayed in list order.
 #
 # Either provide the data for an item in the list (using the keys
-# below), or use existing AppData XML files as a source for the data.
+# below), or use existing AppData XML files, or use AppStream cache
+# as a source for the data.
 #
-# For data provided by the list: the item has an id, which is used in 
+# For data provided by the list: the item has an id, which is used in
 # setting the value of *packagechooser_<module-id>*). The following fields
 # are mandatory:
 #
@@ -60,6 +61,14 @@ mode: required
 # be loaded and the screenshot will be missing. An item with *appdata*
 # **may** specify an ID or screenshot path, as above. This will override
 # the settings from AppData.
+#
+# For data provided by AppStream cache: the item has an *appstream*
+# key which matches the AppStream identifier in the cache (e.g.
+# *org.kde.kwrite.desktop*). Data is retrieved from the AppStream
+# cache for that ID. The package name is set from the AppStream data.
+#
+# An item for AppStream may also contain an *id* and a *screenshot*
+# key which will override the data from AppStream.
 items:
     - id: ""
       package: ""
@@ -81,4 +90,5 @@ items:
     - id: calamares
       appdata: ../io.calamares.calamares.appdata.xml
       screenshot: ":/images/calamares.png"
-
+    - id: kate
+      appstream: org.kde.kwrite.desktop