From: Soeren Apel <redacted>
Date: Sun, 3 Apr 2016 18:34:50 +0000 (+0200)
Subject: TraceTreeItemOwner: Change behavior for empty containers
X-Git-Tag: pulseview-0.4.0~324
X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=d9177e6cfafcbb3bdca8f8529e7c74f6a56d0a1a;p=pulseview.git

TraceTreeItemOwner: Change behavior for empty containers

An empty TraceTreeItemOwner's v_extents are no longer
[INT_MAX, INT_MIN] but [0, 0] instead. As new items were added
relative to the view's own v_extents, items were added at
positions close to the over-/underflow margin. This messed up
the scrollbar among other things. Returning [0, 0] instead
allows for better handling of such cases.
---

diff --git a/pv/view/tracetreeitemowner.cpp b/pv/view/tracetreeitemowner.cpp
index 24174794..1449d813 100644
--- a/pv/view/tracetreeitemowner.cpp
+++ b/pv/view/tracetreeitemowner.cpp
@@ -87,13 +87,16 @@ void TraceTreeItemOwner::remove_child_item(std::shared_ptr<TraceTreeItem> item)
 
 pair<int, int> TraceTreeItemOwner::v_extents() const
 {
-	pair<int, int> extents(INT_MAX, INT_MIN);
+	bool has_children = false;
 
+	pair<int, int> extents(INT_MAX, INT_MIN);
 	for (const shared_ptr<TraceTreeItem> t : trace_tree_child_items()) {
 		assert(t);
 		if (!t->enabled())
 			continue;
 
+		has_children = true;
+
 		const int child_offset = t->layout_v_offset();
 		const pair<int, int> child_extents = t->v_extents();
 		extents.first = min(child_extents.first + child_offset,
@@ -102,6 +105,9 @@ pair<int, int> TraceTreeItemOwner::v_extents() const
 			extents.second);
 	}
 
+	if (!has_children)
+		extents = make_pair(0, 0);
+
 	return extents;
 }