Simulate mouse interaction on Unity PlayMode UI.
Workflow
- Ensure Unity is in PlayMode (use
uloop control-play-mode --action Playif not) - Get UI element info:
uloop screenshot --capture-mode rendering --annotate-elements --elements-only - Use the
AnnotatedElementsarray to find the target element byPathorName(labels are ordered bySortingOrder/SiblingIndex, which can differ from the real draw order, so do not choose a target byA,B, ... alone). UseInteractionto distinguish click targets from drag/drop/text targets, then useSimX/SimYdirectly as--x/--ycoordinates. - Execute the needed
uloop simulate-mouse-uicommands - Inspect the result with the lightest useful evidence: runtime state, logs, or a screenshot
- When this UI input verifies a state transition, use Pause Point inspection from the section below as the standard frame proof
- Report what happened and which evidence was used
Tool Reference
uloop simulate-mouse-ui --action <action> --x <x> --y <y> [options]
Parameters
| Parameter | Type | Default | Description |
|---|---|---|---|
--action |
enum | Click |
Click - click at position, Drag - one-shot drag, DragStart - begin drag and hold, DragMove - move while holding drag, DragEnd - release drag, LongPress - press and hold for --duration seconds |
--x |
number | 0 |
Target X position in screen pixels (origin: top-left). For Drag action, this is the destination. |
--y |
number | 0 |
Target Y position in screen pixels (origin: top-left). For Drag action, this is the destination. |
--from-x |
number | 0 |
Start X position for Drag action (origin: top-left). Drag starts here and moves to --x,--y. |
--from-y |
number | 0 |
Start Y position for Drag action (origin: top-left). Drag starts here and moves to --x,--y. |
--drag-speed |
number | 2000 |
Drag speed in pixels per second (0 for instant). 2000 is fast (default), 200 is slow enough to watch. Applies to Drag, DragMove, and DragEnd actions. |
--duration |
number | 0.5 |
Hold duration in seconds for LongPress action (max 30). |
--button |
enum | Left |
Mouse button. Click and LongPress support Left, Right, and Middle. Drag actions support Left only; other buttons return an error. |
--bypass-raycast |
flag | - | For Click, LongPress, Drag, and DragStart, bypass EventSystem raycast and dispatch pointer events directly to --target-path. Use when a raycast-blocking overlay visually covers the intended target. |
--target-path |
string | "" |
Hierarchy path of the target GameObject, for example Canvas/Panel/Button. Required when --bypass-raycast is used with Click, LongPress, Drag, or DragStart; prefer AnnotatedElements[].Path from screenshot JSON. |
--drop-target-path |
string | "" |
Optional hierarchy path of a drop target for Drag or DragEnd, for example Canvas/DropZone. Use this when the drop zone is also behind a raycast blocker. |
Actions
| Action | Event Fired | Description |
|---|---|---|
Click |
PointerDown → PointerUp → PointerClick | Click at (x, y) with the selected --button |
LongPress |
PointerDown → (hold) → PointerUp | Press and hold at (x, y) for --duration seconds, then release. No PointerClick is fired. |
Drag |
BeginDrag → Drag×N → EndDrag | One-shot drag from (fromX, fromY) to (x, y) at the specified speed |
DragStart |
BeginDrag | Begin drag at (x, y) and hold |
DragMove |
Drag×N | Animate from current position to (x, y) at the specified speed |
DragEnd |
Drag×N → EndDrag | Animate to (x, y) at the specified speed, then release drag |
Split Drag Rules
DragStartmust be called beforeDragMoveorDragEndDragEndmust be called to release an active drag — failing to call it leaves drag state stuck- Calling
DragMoveorDragEndwithout an active drag returns an error
Coordinate System
- Origin is top-left (0, 0)
- All positions are in screen pixels
- Get coordinates from
AnnotatedElementsJSON (SimX/SimY) — do NOT look up GameObject positions --bypass-raycaststill uses coordinates for pointer event positions, but chooses the clicked, long-pressed, or dragged GameObject by--target-path- If
--target-pathor--drop-target-pathmatches multiple active GameObjects, the command fails instead of choosing an arbitrary duplicate - Device Simulator play view is supported. Prefer
uloop screenshot --capture-mode rendering --annotate-elementsfor coordinates; they use the simulated device resolution (Handles.GetMainGameViewSize()/Screen), not the Simulator chrome scale.
Pause Point Inspection (Standard for E2E)
For standard frame proof when this UI input drives a state transition, follow the uloop-pause-point skill — it covers line placement and interruption semantics. Tool-specific note: if InterruptedByPausePoint: true, Success: true only means the command ended cleanly; read Message first — it states whether the pointer event was already dispatched before the pause (only the overlay animation was interrupted) or the pause landed first (no pointer event was fired). Clear inspection-only pause points (uloop clear-pause-point --all) before final validation.
Examples
# Click a button at screen position
uloop simulate-mouse-ui --action Click --x 400 --y 300
# Force-click a button behind a raycast blocker by path
uloop simulate-mouse-ui --action Click --x 400 --y 300 --bypass-raycast --target-path "Canvas/Panel/Button"
# Force-drag and dispatch Drop to a blocked drop zone
uloop simulate-mouse-ui --action Drag --from-x 400 --from-y 300 --x 600 --y 300 --bypass-raycast --target-path "Canvas/Item" --drop-target-path "Canvas/DropZone"
# Long-press a button for 3 seconds
uloop simulate-mouse-ui --action LongPress --x 400 --y 300 --duration 3.0
# One-shot drag (start to end in one call)
uloop simulate-mouse-ui --action Drag --from-x 400 --from-y 300 --x 600 --y 300
# Slow drag for visual inspection
uloop simulate-mouse-ui --action Drag --from-x 400 --from-y 300 --x 600 --y 300 --drag-speed 200
# Split drag with hold (for inspection between steps)
uloop simulate-mouse-ui --action DragStart --x 400 --y 300
uloop screenshot --window-name Game
uloop simulate-mouse-ui --action DragMove --x 500 --y 300
uloop simulate-mouse-ui --action DragEnd --x 600 --y 300
Prerequisites
- Unity must be in PlayMode
- Target scene must have an EventSystem GameObject
- UI elements must have a GraphicRaycaster on their Canvas
- If you need runtime mouse input rather than UI pointer events,
simulate-mouse-inputassumes the project uses the New Input System; otherwise preferexecute-dynamic-code
Output
The response reports Success, Message, Action, HitGameObjectName, the used
coordinates, and InterruptedByPausePoint/PausePointHits. Two readings that matter:
Click/LongPress on empty space still return Success = true with
HitGameObjectName = null (drag actions on empty space fail), and on a pause-point
interruption Message states whether the pointer event fired before the pause.
Field-by-field semantics are in references/output.md. Verify the visual outcome with a
follow-up uloop screenshot --capture-mode rendering --annotate-elements.