disable buttons if no row is selected

gui/griffon-app/controllers/com/muwire/gui/MainFrameController.groovy

@@ -49,7 +49,8 @@ class MainFrameController {
         def group = selected.getClientProperty("mvc-group")
         def table = selected.getClientProperty("results-table")
         int row = table.getSelectedRow()
-
+        if (row == -1)
+            return
         group.model.results[row]        
     }
     

gui/griffon-app/models/com/muwire/gui/MainFrameModel.groovy

@@ -37,11 +37,13 @@ class MainFrameModel {
     @Observable boolean coreInitialized = false
     
     def results = new ConcurrentHashMap<>()
-    @Observable def downloads = []
-    @Observable def uploads = []
-    @Observable def shared = []
+    def downloads = []
+    def uploads = []
+    def shared = []
+    
     @Observable int connections
     @Observable String me
+    @Observable boolean searchButtonsEnabled
     
     private final Set<InfoHash> infoHashes = new HashSet<>()
 

gui/griffon-app/views/com/muwire/gui/MainFrameView.groovy

@@ -69,9 +69,9 @@ class MainFrameView {
                                 borderLayout()
                                 tabbedPane(id : "result-tabs", constraints: BorderLayout.CENTER)
                                 panel(constraints : BorderLayout.SOUTH) {
-                                    button(text : "Download", downloadAction)
-                                    button(text : "Trust", trustAction)
-                                    button(text : "Distrust", distrustAction)
+                                    button(text : "Download", enabled : bind {model.searchButtonsEnabled}, downloadAction)
+                                    button(text : "Trust", enabled: bind {model.searchButtonsEnabled }, trustAction)
+                                    button(text : "Distrust", enabled : bind {model.searchButtonsEnabled}, distrustAction)
                                 }
                             }
                             panel (constraints : JSplitPane.BOTTOM) {

gui/griffon-app/views/com/muwire/gui/SearchTabView.groovy

@@ -4,6 +4,8 @@ import griffon.core.artifact.GriffonView
 import griffon.core.mvc.MVCGroup
 import griffon.inject.MVCMember
 import griffon.metadata.ArtifactProviderFor
+
+import javax.swing.ListSelectionModel
 import javax.swing.SwingConstants
 
 import java.awt.BorderLayout
@@ -39,6 +41,12 @@ class SearchTabView {
             this.pane = pane
             this.pane.putClientProperty("mvc-group", mvcGroup)
             this.pane.putClientProperty("results-table",resultsTable)
+            
+            def selectionModel = resultsTable.getSelectionModel()
+            selectionModel.setSelectionMode(ListSelectionModel.SINGLE_SELECTION)
+            selectionModel.addListSelectionListener( {
+                mvcGroup.parentGroup.model.searchButtonsEnabled = true
+            })
         }
     }
     
@@ -66,6 +74,7 @@ class SearchTabView {
     def closeTab = {
         int index = parent.indexOfTab(searchTerms)
         parent.removeTabAt(index)
+        mvcGroup.parentGroup.model.searchButtonsEnabled = false
         mvcGroup.destroy()
     }
 }