Valid drop targets must be explicit during drag
Aliases: drop target · drag feedback · drop feedback
What it is
Drag-and-drop target feedback explicitly shows, while an object is dragged, which locations can accept it, whether the current location is valid, and what dropping will do. Destinations should not be guesses; this is continuing navigation information during transport.
Why it happens
After pickup, visual attention shifts from source to destination. The system can calculate acceptable targets from object type, permission, and position, then communicate the result with highlighting, insertion lines, cursor state, or previews. Clear feedback reduces invalid releases and trial-and-error while people can still correct their route.
Studying it
Compare no cue, valid-target-only cues, and outcome-preview conditions. Record invalid drops, path backtracking, target-search time, cancellation, and completion. Test object types, scrolling regions, and dense lists separately; one obvious destination hides the problem.
Where it stops holding
Highlighting every target can become visual noise, especially on large canvases or when most positions are valid; local candidates or cursor state can communicate more economically. If permissions, network state, or rules change during drag, feedback must update rather than promise a now-invalid drop.
Applying it
- On drag entry, show pickup and distinguish valid, invalid, and current candidate destinations.
- For reordering, show an exact insertion position and outcome preview rather than highlighting only a container.
- Log invalid drops and repeated pre-drop passes to find unclear or lagging targets.
Related
- Same group: C1.08.1 Drag and drop has three phases: pickup, transport, and drop · C1.08.2 Drag-start thresholds prevent a click from becoming a drag · C1.08.4 Auto-scroll when dragging to an edge · C1.08.5 Drag and drop can be cancelled and returned to origin · C1.08.6 Drag and drop needs a non-drag equivalent
- Nearby: C1.05 Cursor hotspots and hit testing · D1 Output and feedback channels
- Search terms:
drag feedback·drop target·feedforward