From 75dc26dacf421e7027e959643963af1efdf10986 Mon Sep 17 00:00:00 2001
From: Tuukka Lehtonen <tuukka.lehtonen@semantum.fi>
Date: Sat, 10 Nov 2018 12:43:08 +0200
Subject: [PATCH] Fixed GraphExplorerImpl to set selection upon keyboard-based
 selection

Previously scrolling the selection using the keyboard and then pressing
Enter to open the selected resource would result in the wrong resource
being opened because the selection hadn't yet propagated through the
postSelection event.

gitlab #184

Change-Id: Ib1f837b3cb8eb70b32508e4abee36cfa995886ed
---
 .../browsing/ui/swt/GraphExplorerImpl.java    | 36 +++++++++++++++----
 1 file changed, 29 insertions(+), 7 deletions(-)

diff --git a/bundles/org.simantics.browsing.ui.swt/src/org/simantics/browsing/ui/swt/GraphExplorerImpl.java b/bundles/org.simantics.browsing.ui.swt/src/org/simantics/browsing/ui/swt/GraphExplorerImpl.java
index 0168ad864..df4860d42 100644
--- a/bundles/org.simantics.browsing.ui.swt/src/org/simantics/browsing/ui/swt/GraphExplorerImpl.java
+++ b/bundles/org.simantics.browsing.ui.swt/src/org/simantics/browsing/ui/swt/GraphExplorerImpl.java
@@ -1552,10 +1552,12 @@ class GraphExplorerImpl extends GraphExplorerImplBase implements Listener, Graph
         });
 
         OpenStrategy os = new OpenStrategy(tree);
+        os.addSelectionListener(SelectionListener.widgetSelectedAdapter(e -> {
+            resetSelectionFromWidget();
+        }));
         os.addPostSelectionListener(SelectionListener.widgetSelectedAdapter(e -> {
             //System.out.println("OPENSTRATEGY: post selection changed: " + e);
-            resetSelection();
-            selectionProvider.firePostSelection(selectionProvider.getSelection());
+            resetSelectionFromWidgetAndFirePostSelection(true);
         }));
 
         // This listener takes care of updating the set of currently selected
@@ -1578,12 +1580,32 @@ class GraphExplorerImpl extends GraphExplorerImplBase implements Listener, Graph
         });
     }
 
-    private void resetSelection() {
-        final ISelection selection = getWidgetSelection();
+    /**
+     * @return the new selection if it was different from the old selection in
+     *         {@link #selectionProvider}
+     */
+    private ISelection resetSelectionFromWidget() {
+        ISelection widgetSelection = getWidgetSelection();
 //        System.out.println("resetSelection()");
 //        System.out.println("    provider selection: " + selectionProvider.getSelection());
-//        System.out.println("    widget selection:   " + selection);
-        selectionProvider.setAndFireNonEqualSelection(selection);
+//        System.out.println("    widget selection:   " + widgetSelection);
+        boolean equals = selectionProvider.selectionEquals(widgetSelection);
+        selectionProvider.setSelectionWithoutFiring(widgetSelection);
+        return equals ? null : widgetSelection;
+    }
+
+    /**
+     * @return the new selection if it was different from the old selection in
+     *         {@link #selectionProvider}
+     */
+    private boolean resetSelectionFromWidgetAndFirePostSelection(boolean force) {
+        ISelection s = resetSelectionFromWidget();
+        boolean fire = s != null || force;
+        if (fire) {
+            //System.out.println("FIRING POST-SELECTION: " + selectionProvider.getSelection());
+            selectionProvider.firePostSelection(selectionProvider.getSelection());
+        }
+        return fire;
     }
 
     protected void setDefaultProcessors() {
@@ -2300,7 +2322,7 @@ class GraphExplorerImpl extends GraphExplorerImplBase implements Listener, Graph
 //                    System.out.println("MODCOUNT: " + modCount + " vs. " + count);
                     if (modCount != count)
                         return;
-                    resetSelection();
+                    resetSelectionFromWidgetAndFirePostSelection(false);
                 }
             });
         }
-- 
2.43.2