User interface toolkit for Go with support for SDL2 and HTML Canvas render targets.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

43 lines
1.0 KiB

package ui
// DragDrop is a state machine to manage draggable UI components.
type DragDrop struct {
isDragging bool
// If the subject of the drag is a widget, it can store itself here.
widget Widget
// NewDragDrop initializes the DragDrop struct. Normally your Supervisor
// will manage the drag/drop object, but you can use your own if you don't
// use a Supervisor.
func NewDragDrop() *DragDrop {
return &DragDrop{}
// IsDragging returns whether the drag state is active.
func (dd *DragDrop) IsDragging() bool {
return dd.isDragging
// SetWidget attaches the widget to the drag state, but does not start the
// drag; you call Start() after this if the subject is a widget.
func (dd *DragDrop) SetWidget(w Widget) {
dd.widget = w
// Widget returns the attached widget or nil.
func (dd *DragDrop) Widget() Widget {
return dd.widget
// Start the drag state.
func (dd *DragDrop) Start() {
dd.isDragging = true
// Stop dragging. This will also clear the stored widget, if any.
func (dd *DragDrop) Stop() {
dd.isDragging = false
dd.widget = nil