[packagechooser] Remove 'id' configuration setting

- Setting 'id' (which changes the Global Storage key that
  gets used) is a kludge when the existing module-instance
  name can be used instead -- and **was** already used, as
  a fallback when 'id' is not set. There's no point in having
  two places to set a particular name.
- Rip out the docs for 'id' as well.
- Add documentation on the difference between single-selection
  (the QML implementation) and model-selection (what the Widgets
  version does).

src/modules/packagechooser/Config.cpp

@@ -95,6 +95,12 @@ Config::introductionPackage() const
     return *defaultIntroduction;
 }
 
+static inline QString
+make_gs_key( const Calamares::ModuleSystem::InstanceKey& key )
+{
+    return QStringLiteral( "packagechooser_" ) + key.id();
+}
+
 void
 Config::updateGlobalStorage( const QStringList& selected ) const
 {
@@ -105,8 +111,8 @@ Config::updateGlobalStorage( const QStringList& selected ) const
     if ( m_method == PackageChooserMethod::Legacy )
     {
         QString value = selected.join( ',' );
-        Calamares::JobQueue::instance()->globalStorage()->insert( m_id, value );
-        cDebug() << m_id << "selected" << value;
+        Calamares::JobQueue::instance()->globalStorage()->insert( make_gs_key( m_defaultId ), value );
+        cDebug() << m_defaultId << "selected" << value;
     }
     else if ( m_method == PackageChooserMethod::Packages )
     {
@@ -133,11 +139,11 @@ Config::updateGlobalStorage() const
         auto* gs = Calamares::JobQueue::instance()->globalStorage();
         if ( m_packageChoice.has_value() )
         {
-            gs->insert( m_id, m_packageChoice.value() );
+            gs->insert( make_gs_key( m_defaultId ), m_packageChoice.value() );
         }
         else
         {
-            gs->remove( m_id );
+            gs->remove( make_gs_key( m_defaultId ) );
         }
     }
     else if ( m_method == PackageChooserMethod::Packages )
@@ -240,26 +246,7 @@ Config::setConfigurationMap( const QVariantMap& configurationMap )
 
     if ( m_method == PackageChooserMethod::Legacy )
     {
-        const QString configId = CalamaresUtils::getString( configurationMap, "id" );
-        const QString base = QStringLiteral( "packagechooser_" );
-        if ( configId.isEmpty() )
-        {
-            if ( m_defaultId.id().isEmpty() )
-            {
-                // We got nothing to work with
-                m_id = base;
-            }
-            else
-            {
-                m_id = base + m_defaultId.id();
-            }
-            cDebug() << "Using default ID" << m_id << "from" << m_defaultId.toString();
-        }
-        else
-        {
-            m_id = base + configId;
-            cDebug() << "Using configured ID" << m_id;
-        }
+        cDebug() << "Using module ID" << m_defaultId;
     }
 
     if ( configurationMap.contains( "items" ) )

src/modules/packagechooser/Config.h

@@ -110,8 +110,6 @@ private:
     PackageChooserMode m_mode = PackageChooserMode::Optional;
     /// How this module stores to GS
     PackageChooserMethod m_method = PackageChooserMethod::Legacy;
-    /// Id (used to identify settings from this module in GS)
-    QString m_id;
     /// Value to use for id if none is set in the config file
     Calamares::ModuleSystem::InstanceKey m_defaultId;
     /** @brief QML selection (for single-selection approaches)

src/modules/packagechooser/packagechooser.conf

@@ -15,11 +15,10 @@ mode: required
 #
 # - "legacy" or "custom" or "contextualprocess"
 #   When set to "legacy", writes a GlobalStorage value for the choice that
-#   has been made. The key is *packagechooser_<id>*. Normally, the module's
+#   has been made. The key is *packagechooser_<id>*. The module's
 #   instance name is used; see the *instances* section of `settings.conf`.
 #   If there is just one packagechooser module, and no special instance is set,
-#   resulting GS key is probably *packagechooser@packagechooser*.
-#   You can set *id* to change that, but it is not recommended.
+#   resulting GS key is probably *packagechooser_packagechooser*.
 #
 #   The GS value is a comma-separated list of the IDs of the selected
 #   packages, or an empty string if none is selected.
@@ -33,15 +32,12 @@ mode: required
 #   consumption by the *packages* module (which should appear later
 #   in the `exec` section. These package settings will then be handed
 #   off to whatever package manager is configured there.
-#   The *id* key is not used.
 #
 # There is no need to put this module in the `exec` section. There
 # are no jobs that this module provides. You should put **other**
 # modules, either *contextualprocess* or *packages* or some custom
 # module, in the `exec` section to do the actual work.
 method: legacy
-# The *id* key is used only in "legacy" mode
-# id: ""
 
 
 # Human-visible strings in this module. These are all optional.
@@ -51,13 +47,13 @@ method: legacy
 # Each key can have a [locale] added to it, which is used as
 # the translated string for that locale. For the strings
 # associated with the "no-selection" item, see *items*, below
-# with the explicit id "".
+# with the explicit item-*id* "".
 #
 labels:
     step: "Packages"
     step[nl]: "Pakketten"
 
-# (Optional) 'id' of pre-selected list-view item.
+# (Optional) item-*id* of pre-selected list-view item.
 # Pre-selects one of the items below.
 # default: kde
 

src/modules/packagechooserq/packagechooserq.conf

@@ -1,23 +1,26 @@
 # SPDX-FileCopyrightText: no
 # SPDX-License-Identifier: CC0-1.0
 #
-# Configuration for the low-density software chooser
----
-# Software selection mode, to set whether the software packages
-# can be chosen singly, or multiply.
+# Configuration for the low-density software chooser, QML implementation
+#
+# The example QML implementation uses single-selection, rather than
+# a model for the available packages. That makes it simpler: the
+# QML itself codes the available options, descriptions and images
+# -- after all, this is **low density** selection, so a custom UI
+# can make sense for the few choices that need to be made.
+#
 #
-# The example QML module does not use a model, and ignores this value.
-mode: required
 
+---
 # Software installation method:
 #
 # - "legacy" or "custom" or "contextualprocess"
 #   When set to "legacy", writes a GlobalStorage value for the choice that
-#   has been made. The key is *packagechooser_<id>*. Normally, the module's
+#   has been made. The key is *packagechooser_<id>*. The module's
 #   instance name is used; see the *instances* section of `settings.conf`.
-#   If there is just one packagechooser module, and no special instance is set,
-#   resulting GS key is probably *packagechooser@packagechooser*.
-#   You can set *id* to change that, but it is not recommended.
+#   If there is just one packagechooserq module, and no special instance is set,
+#   resulting GS key is probably *packagechooser_packagechooserq*.
+#   (Do note that the prefix of the GS key remains "packagechooser_")
 #
 #   The GS value is a comma-separated list of the IDs of the selected
 #   packages, or an empty string if none is selected.
@@ -31,19 +34,13 @@ mode: required
 #   consumption by the *packages* module (which should appear later
 #   in the `exec` section. These package settings will then be handed
 #   off to whatever package manager is configured there.
-#   The *id* key is not used.
 #
 # There is no need to put this module in the `exec` section. There
 # are no jobs that this module provides. You should put **other**
 # modules, either *contextualprocess* or *packages* or some custom
 # module, in the `exec` section to do the actual work.
-method: legacy
-
-# The *id* key is used only in "legacy" mode and changes the GlobalStorage
-# key used to store the package choices. It is not recommended to use
-# this, since the module instance key does the same job.
 #
-# id: ""
+method: legacy
 
 # The *packageChoice* value is used for setting the default selection
 # in the QML view; this should match one of the keys used in the QML