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Gum gum-tool-delete-logic

Reference guide for Gum's delete architecture. Load this when working on delete commands, IEditCommands delete methods, IDeleteLogic, DeleteLogic, DeleteOptionsWindow, HandleDeleteCommand, AskToDeleteState, AskToDeleteStateCategory, or DeleteSelection.

install
source · Clone the upstream repo
git clone https://github.com/vchelaru/Gum
Claude Code · Install into ~/.claude/skills/
T=$(mktemp -d) && git clone --depth=1 https://github.com/vchelaru/Gum "$T" && mkdir -p ~/.claude/skills && cp -r "$T/.claude/skills/gum-tool-delete-logic" ~/.claude/skills/vchelaru-gum-gum-tool-delete-logic && rm -rf "$T"
manifest: .claude/skills/gum-tool-delete-logic/SKILL.md
tags
#delete-logic#ui-integration#object-deletion#gum-framework#delete-flow
source content

Gum Delete Logic Reference

Two Delete Patterns

There are two distinct delete flows depending on the object type being deleted.

Pattern 1 — AskTo* (states and categories)

Used for states and state categories. These types have blocking conditions that must be checked before any dialog is shown, so they have their own typed methods on 

IEditCommands
.

Flow: 

IEditCommands.AskTo*
→ validate (behavior deps, plugin hooks, default-state check) → simple Yes/No dialog → undo lock → 
IDeleteLogic.Remove*

Entry points:

  • IEditCommands.AskToDeleteState(stateSave, stateContainer)
  • IEditCommands.AskToDeleteStateCategory(category, container)

Why not DeleteOptionsWindow: States and categories are in-memory only — no XML files, no child hierarchy — so plugins have nothing to contribute to the delete dialog.

Pattern 2 — DeleteSelection (elements, behaviors, instances)

Used for screens, components, behaviors, and instances. All go through one shared entry point that dispatches based on what is currently selected.

Flow: 

IEditCommands.DeleteSelection
→ undo lock → 
IDeleteLogic.HandleDeleteCommand
→ 
DoDeletingLogic
→ 
ShowDeleteDialog
(creates 
DeleteOptionsWindow
) → 
IDeleteLogic.Remove*

Entry point: 

IEditCommands.DeleteSelection()

Why DeleteOptionsWindow: Plugins contribute runtime UI to this dialog (e.g. 

DeleteObjectPlugin
adds "Delete XML file?" and "Delete children?" options via the 
DeleteOptionsWindowShow
plugin event).

Responsibility Split

ClassResponsibility
IEditCommands
/ 
EditCommands
All user-triggered deletes. Shows dialogs, acquires undo locks, then delegates to 
IDeleteLogic
. Only entry point callers should use.
IDeleteLogic
/ 
DeleteLogic
Pure data mutation after confirmation. 
Remove*
methods do not show dialogs. 
HandleDeleteCommand
is the exception — it orchestrates the DeleteOptionsWindow flow and is only called from 
EditCommands.DeleteSelection
.

Callers

All delete actions funnel through 

IEditCommands
:

  • Delete key → 
    HotkeyManager
    → 
    IEditCommands.DeleteSelection
  • Element tree right-click Delete → 
    ElementTreeViewManager
    → 
    IEditCommands.DeleteSelection
  • State tree right-click Delete state → 
    StateTreeViewRightClickService
    → 
    IEditCommands.AskToDeleteState
  • State tree right-click Delete category → 
    StateTreeViewRightClickService
    → 
    IEditCommands.AskToDeleteStateCategory
  • Menu strip Remove > Element → 
    MenuStripManager
    → 
    IEditCommands.DeleteSelection
  • Menu strip Remove > State/Category → 
    MenuStripManager
    → 
    IEditCommands.AskToDeleteState
    / 
    AskToDeleteStateCategory

Do not call 

IDeleteLogic
methods directly from UI code — always go through 
IEditCommands
.

Testability

ShowDeleteDialog
creates a WPF 
DeleteOptionsWindow
and calls 
ShowDialog()
— it cannot be unit-tested directly. The 
internal BuildDeleteDialogMessage(Array, List<InstanceSave>?)
method on 
DeleteLogic
is the testable seam for asserting dialog message content (
InternalsVisibleTo("GumToolUnitTests")
is already configured).

Key Files

FilePurpose
Gum/Commands/IEditCommands.cs
Interface with architecture overview comment
Gum/Commands/EditCommands.cs
Implementation; AskTo* dialog logic lives here
Gum/Managers/IDeleteLogic.cs
Interface for pure data-mutation operations
Gum/Managers/DeleteLogic.cs
Data mutation + DeleteOptionsWindow orchestration
Gum/Logic/RenameLogic.cs
ElementReferences
class; 
GetDeleteImpactDetails()
and 
ExcludeContainersBeingDeleted()
used to build impact warnings in the delete dialog
Gum/Plugins/InternalPlugins/Delete/DeleteObjectPlugin.cs
Contributes "Delete XML?" and "Delete children?" to DeleteOptionsWindow
Gum/Plugins/InternalPlugins/StatePlugin/StateTreeViewRightClickService.cs
State/category right-click menu; calls AskTo* methods
Gum/Plugins/InternalPlugins/TreeView/ElementTreeViewManager.RightClick.cs
Element tree right-click; calls DeleteSelection
Gum/Managers/HotkeyManager.cs
Delete key handler; calls DeleteSelection