fix(dock): prevent tab loss on invalid drops and improve tree cleanup

This commit is contained in:
2026-03-28 14:39:26 +09:00
parent b194b57e4e
commit c6a71e599b

View File

@@ -389,18 +389,40 @@ public sealed partial class DockLayout : Control
return;
}
if (_currentDropPosition == DockPosition.None)
{
ClearDragOperationState();
return;
}
if (_sourceNode == targetNode && _currentDropPosition == DockPosition.Center)
{
ClearDragOperationState();
return; // Reordering within same tab is handled natively by TabView
}
// 1. Remove from source
// 1. Validate target for split
if (_currentDropPosition != DockPosition.Center && targetNode.Parent == null)
{
// If target has no parent, it must be the root (or wrapped in root).
// We can't split it without a parent group unless we wrap it.
if (ReferenceEquals(targetNode, Root) || (Root?.Children.Count == 1 && ReferenceEquals(Root.Children[0], targetNode)))
{
// This is allowed, we'll handle it by wrapping in a new group if needed
}
else
{
ClearDragOperationState();
return;
}
}
// 2. Remove from source
_sourceNode.Items.Remove(_draggedItem);
var sourceNodeCopy = _sourceNode; // Keep reference for cleanup
CleanupEmptyNodes(sourceNodeCopy);
// 2. Add to target
// 3. Add to target
if (_currentDropPosition == DockPosition.Center)
{
targetNode.Items.Add(_draggedItem);
@@ -408,12 +430,45 @@ public sealed partial class DockLayout : Control
else
{
// Split scenario
bool isHorizontalSplit = _currentDropPosition == DockPosition.Left || _currentDropPosition == DockPosition.Right;
bool isAfter = _currentDropPosition == DockPosition.Right || _currentDropPosition == DockPosition.Bottom;
var parentGroup = targetNode.Parent;
if (parentGroup != null)
if (parentGroup == null)
{
// Target is root or only child of root. Wrap it.
var newRoot = new DockGroupNode
{
Orientation = isHorizontalSplit ? Orientation.Horizontal : Orientation.Vertical
};
var newNode = new DockPanelNode();
newNode.Items.Add(_draggedItem);
if (ReferenceEquals(targetNode, Root))
{
Root = newRoot;
}
else if (Root != null && Root.Children.Count == 1 && ReferenceEquals(Root.Children[0], targetNode))
{
Root.RemoveChild(targetNode);
Root.AddChild(newRoot);
}
if (isAfter)
{
newRoot.AddChild(targetNode);
newRoot.AddChild(newNode);
}
else
{
newRoot.AddChild(newNode);
newRoot.AddChild(targetNode);
}
}
else
{
int targetIndex = parentGroup.Children.IndexOf(targetNode);
bool isHorizontalSplit = _currentDropPosition == DockPosition.Left || _currentDropPosition == DockPosition.Right;
bool isAfter = _currentDropPosition == DockPosition.Right || _currentDropPosition == DockPosition.Bottom;
if ((isHorizontalSplit && parentGroup.Orientation == Orientation.Horizontal) ||
(!isHorizontalSplit && parentGroup.Orientation == Orientation.Vertical))
@@ -455,44 +510,46 @@ public sealed partial class DockLayout : Control
ClearDragOperationState();
}
private void CleanupEmptyNodes(DockPanelNode panelNode)
private void CleanupEmptyNodes(DockNode node)
{
if (panelNode.Items.Count > 0) return;
if (node is DockPanelNode panelNode && panelNode.Items.Count > 0) return;
if (node is DockGroupNode groupNode && groupNode.Children.Count > 0 && groupNode.Children.Count != 1) return;
var parentGroup = panelNode.Parent;
if (parentGroup != null)
var parentGroup = node.Parent;
// Handle collapsing group with 1 child
if (node is DockGroupNode collapsingGroup && collapsingGroup.Children.Count == 1)
{
parentGroup.RemoveChild(panelNode);
// If group only has 1 child left, collapse it
if (parentGroup.Children.Count == 1)
var onlyChild = collapsingGroup.Children[0];
if (parentGroup != null)
{
var onlyChild = parentGroup.Children[0];
var grandParent = parentGroup.Parent;
if (grandParent != null)
int groupIndex = parentGroup.Children.IndexOf(collapsingGroup);
parentGroup.RemoveChild(collapsingGroup);
parentGroup.InsertChild(groupIndex, onlyChild);
CleanupEmptyNodes(parentGroup); // Recursively clean parent
}
else if (collapsingGroup == Root)
{
collapsingGroup.RemoveChild(onlyChild);
if (onlyChild is DockGroupNode newRootGroup)
{
int groupIndex = grandParent.Children.IndexOf(parentGroup);
grandParent.RemoveChild(parentGroup);
grandParent.InsertChild(groupIndex, onlyChild);
Root = newRootGroup;
}
else if (parentGroup == Root)
else
{
// If root is collapsing, the only child becomes the new root
parentGroup.RemoveChild(onlyChild);
if (onlyChild is DockGroupNode newRootGroup)
{
Root = newRootGroup;
}
else
{
// Wrap panel in a new group to keep Root as a GroupNode
var wrapperGroup = new DockGroupNode();
wrapperGroup.AddChild(onlyChild);
Root = wrapperGroup;
}
var wrapperGroup = new DockGroupNode();
wrapperGroup.AddChild(onlyChild);
Root = wrapperGroup;
}
}
return;
}
// Handle empty node (Panel or Group)
if (parentGroup != null)
{
parentGroup.RemoveChild(node);
CleanupEmptyNodes(parentGroup); // Recursively clean parent
}
}