move the code to model

- added tests

src/lib/registration/addon.rb

@@ -105,5 +105,18 @@ def label
       (friendly_name && !friendly_name.empty?) ? friendly_name : name
     end
 
+    # can be the addon selected in UI or should it be disabled?
+    # return [Boolean] true if it should be enabled
+    def selectable?
+      # Do not support unregister
+      return false if registered?
+      # Do not allow to select child without selected or already registered parent
+      return false if depends_on && !(depends_on.selected? || depends_on.registered?)
+      # Do not allow to unselect parent if any children is selected
+      return false if children.any?(&:selected?)
+
+      return true
+    end
+
   end
 end

src/lib/registration/ui/addon_selection_dialog.rb

@@ -180,21 +180,10 @@ def show_addon_details(addon)
 
       def reactivate_dependencies
         @addons.each do |addon|
-          Yast::UI.ChangeWidget(Id(addon.identifier), :Enabled, enable_addon?(addon))
+          Yast::UI.ChangeWidget(Id(addon.identifier), :Enabled, addon.selectable?)
         end
       end
 
-      def enable_addon?(addon)
-        # Do not support unregister
-        return false if addon.registered?
-        # Do not allow to select child without selected or already registered parent
-        return false if addon.depends_on && (!addon.depends_on.selected? || !addon.depends_on.registered?)
-        # Do not allow to unselect parent if any children is selected
-        return false if addon.children.any?(&:selected?)
-
-        return true
-      end
-
       # the maximum number of reg. codes displayed vertically,
       # this is the limit for 80x25 textmode UI
       MAX_REGCODES_PER_COLUMN = 8

test/addon_spec.rb

@@ -116,4 +116,41 @@
     end
   end
 
+  describe "#selectable?" do
+    let(:addons) do
+      Registration::Addon.find_all(double(:get_addon_list => [addon_with_child_generator]))
+    end
+
+    let(:parent) { addons.first }
+    let(:child) { parent.children.first }
+
+    it "cannot be selected when the addon has been already registered" do
+      addon.registered
+      expect(addon.selectable?).to be_false
+    end
+
+    it "can be selected when the addon has not been already registered" do
+      expect(addon.selectable?).to be_true
+    end
+
+    it "cannot be selected when the parent is not selected or registered" do
+      expect(child.selectable?).to be_false
+    end
+
+    it "can be selected when the parent is selected" do
+      parent.selected
+      expect(child.selectable?).to be_true
+    end
+
+    it "can be selected when the parent is registered" do
+      parent.registered
+      expect(child.selectable?).to be_true
+    end
+
+    it "cannot be changed when any child is selected" do
+      child.selected
+      expect(parent.selectable?).to be_false
+    end
+  end
+
 end