tmf: Bug 484422: Fix inconsistent vertical zoom

In GTK3, after changing the tree font, the tree item bounds are not
updated until the tree has been painted. The alignment of tree items
should be done after a paint event has occurred.

Change-Id: I47617b881d3f0f981bdacf3ddda572c296dffaf7
Signed-off-by: Patrick Tasse <patrick.tasse@gmail.com>
Reviewed-on: https://git.eclipse.org/r/62876
Reviewed-by: Hudson CI
Reviewed-by: Francis Giraldeau <francis.giraldeau@gmail.com>

diff --git a/tmf/org.eclipse.tracecompass.tmf.ui/src/org/eclipse/tracecompass/tmf/ui/widgets/timegraph/TimeGraphCombo.java b/tmf/org.eclipse.tracecompass.tmf.ui/src/org/eclipse/tracecompass/tmf/ui/widgets/timegraph/TimeGraphCombo.java
index 71d42fa368020492b61f1e0f8906c5e49d05a615..745d156a42d20d27accf12ae859b488d588bb40e 100644 (file)
--- a/tmf/org.eclipse.tracecompass.tmf.ui/src/org/eclipse/tracecompass/tmf/ui/widgets/timegraph/TimeGraphCombo.java
+++ b/tmf/org.eclipse.tracecompass.tmf.ui/src/org/eclipse/tracecompass/tmf/ui/widgets/timegraph/TimeGraphCombo.java
@@ -732,7 +732,6 @@ public class TimeGraphCombo extends Composite {
         fTimeGraphViewer.setHeaderHeight(tree.getHeaderHeight());
         fTimeGraphViewer.setItemHeight(getItemHeight(tree, true));
         alignTreeItems(false);
-        redraw();
         return true;
     }
 
@@ -748,7 +747,6 @@ public class TimeGraphCombo extends Composite {
         fTimeGraphViewer.setHeaderHeight(tree.getHeaderHeight());
         fTimeGraphViewer.setItemHeight(getItemHeight(tree, true));
         alignTreeItems(false);
-        redraw();
     }
 
     private void sendTimeViewAlignmentChanged() {
@@ -1240,6 +1238,31 @@ public class TimeGraphCombo extends Composite {
         TreeItem item = treeItems.get(topIndex);
         tree.setTopItem(item);
 
+        /*
+         * In GTK3, the bounds of the tree items are only sure to be correct
+         * after the tree has been painted.
+         */
+        tree.addPaintListener(new PaintListener() {
+            @Override
+            public void paintControl(PaintEvent e) {
+                tree.removePaintListener(this);
+                doAlignTreeItems();
+                redraw();
+            }
+        });
+        /* Make sure the paint event is triggered. */
+        tree.redraw();
+    }
+
+    private void doAlignTreeItems() {
+        Tree tree = fTreeViewer.getTree();
+        List<TreeItem> treeItems = getVisibleExpandedItems(tree, false);
+        int topIndex = fTimeGraphViewer.getTopIndex();
+        if (topIndex >= treeItems.size()) {
+            return;
+        }
+        TreeItem item = treeItems.get(topIndex);
+
         // get the first filler item so we can calculate the last item's height
         TreeItem fillerItem = null;
         for (TreeItem treeItem : fTreeViewer.getTree().getItems()) {
@@ -1272,16 +1295,8 @@ public class TimeGraphCombo extends Composite {
          * newly visible items at the top of the viewer are also aligned.
          */
         fTimeGraphViewer.setTopIndex(topIndex);
-        item = treeItems.get(topIndex);
-        tree.setTopItem(item);
-        while (fTimeGraphViewer.getTopIndex() < topIndex) {
-            TreeItem nextItem = item;
-            topIndex--;
-            item = treeItems.get(topIndex);
-            tree.setTopItem(item);
-            bounds = item.getBounds();
-            alignTreeItem(item, bounds, nextItem);
-            fTimeGraphViewer.setTopIndex(topIndex);
+        if (fTimeGraphViewer.getTopIndex() != topIndex) {
+            alignTreeItems(false);
         }
     }