diff -r ef075cd7ce55 -r f47e82cd6077 src/main/java/de/uapcore/lightpit/viewmodel/ProjectView.java
--- a/src/main/java/de/uapcore/lightpit/viewmodel/ProjectView.java	Sat Oct 17 15:21:56 2020 +0200
+++ b/src/main/java/de/uapcore/lightpit/viewmodel/ProjectView.java	Sat Oct 17 19:56:50 2020 +0200
@@ -8,11 +8,29 @@
 
 public class ProjectView {
 
+    public static final int SELECTED_PAGE_ISSUES = 0;
+    public static final int SELECTED_PAGE_VERSIONS = 1;
+    public static final int SELECTED_PAGE_COMPONENTS = 2;
+
+    public static final Version ALL_VERSIONS = new Version(0);
+    public static final Version NO_VERSION = new Version(-1);
+    public static final Component ALL_COMPONENTS = new Component(0);
+    public static final Component NO_COMPONENT = new Component(-1);
+
+    static {
+        ALL_VERSIONS.setNode("all-versions");
+        NO_VERSION.setNode("no-version");
+        ALL_COMPONENTS.setNode("all-components");
+        NO_COMPONENT.setNode("no-component");
+    }
+
     private final List<ProjectInfo> projectList = new ArrayList<>();
     private ProjectInfo projectInfo;
     private Version versionFilter;
     private Component componentFilter;
 
+    private int selectedPage = SELECTED_PAGE_ISSUES;
+
     public List<ProjectInfo> getProjectList() {
         return projectList;
     }
@@ -25,6 +43,14 @@
         this.projectInfo = projectInfo;
     }
 
+    public int getSelectedPage() {
+        return selectedPage;
+    }
+
+    public void setSelectedPage(int selectedPage) {
+        this.selectedPage = selectedPage;
+    }
+
     public Version getVersionFilter() {
         return versionFilter;
     }
@@ -40,4 +66,20 @@
     public void setComponentFilter(Component componentFilter) {
         this.componentFilter = componentFilter;
     }
+
+    public boolean isProjectInfoPresent() {
+        return projectInfo != null;
+    }
+
+    public boolean isVersionFilterValid() {
+        return projectInfo != null && versionFilter != null;
+    }
+
+    public boolean isComponentFilterValid() {
+        return projectInfo != null && componentFilter != null;
+    }
+
+    public boolean isEveryFilterValid() {
+        return projectInfo != null && versionFilter != null && componentFilter != null;
+    }
 }