Gestures and drag-and-drop

Use a recognizer when the meaning is dragging, holding, multi-tapping, or a two-pointer transform. Raw pointer notifications are useful for observation, but should not become a second scrolling or capture system.

Respond to recognized movement

#include <huxerui/huxerui.h>

using namespace huxerui;

[[huxerui::composable]]
View DragReadout() {
  auto distance = UseState(0.0F);
  auto active = UseState(false);
  return Text::Format("Distance: {} - dragging: {}", distance, active)
      .With(Padding(24.0F), DragGesture{.axis = Axis::Horizontal})
      .On<DragEvents::Started>([active](const DragEvent&) { active = true; })
      .On<DragEvents::Changed>([distance](const DragEvent& event) { distance = event.translation.x; })
      .On<DragEvents::Ended>([active](const DragEvent&) { active = false; })
      .On<DragEvents::Canceled>([active](const DragEvent&) { active = false; });
}

The example shows values rather than introducing a second animation controller. For a moving object, apply the gesture to stable geometry and drive presentation from the same owned value. Total translation and incremental delta are different inputs; do not add total translation on every event.

Keep touch, mouse, and keyboard alternatives

Long press and multi-touch cannot be assumed on every device. Give essential commands an ordinary button, menu, or keyboard path. MultiTapGesture recognizes repeated physical taps without suppressing normal Click output; use it for an additional action whose first click is harmless.

For pinch/rotate, TransformGesture emits incremental scale and rotation. Clamp your application’s zoom range and honor reduced-motion policy in any follow-up animation.

Transfer domain values

Attach DragSource(record_id) to a source and DropTarget::Accepts<RecordId>() to a destination. Handle DropEvents<RecordId>::Dropped to mutate application state; hover is not a completed transfer. A preview factory is optional and should return display content.

This operation stays within HuxerUI. Receiving files from another application uses FileDropTarget, which returns access-bearing FileReference values.

Read the gesture example source or consult the gesture API for thresholds, coordinates, and cancellation.