package ui import ( "sync/atomic" "github.com/gdamore/tcell/v2" ) const ( DIRTY int32 = iota NOT_DIRTY ) var MsgChannel = make(chan AercMsg, 50) // QueueRedraw sends a nil message into the MsgChannel. Nothing will handle this // message, but a redraw will occur if the UI is marked as invalid func QueueRedraw() { MsgChannel <- nil } // dirty is the dirty state of the UI. Any value other than 0 means the UI is in // a dirty state. Dirty should only be accessed via atomic operations to // maintain thread safety var dirty int32 // Invalidate marks the entire UI as invalid. Invalidate can be called from any // goroutine func Invalidate() { atomic.StoreInt32(&dirty, DIRTY) } type UI struct { Content DrawableInteractive exit atomic.Value // bool ctx *Context screen tcell.Screen popover *Popover } func Initialize(content DrawableInteractive) (*UI, error) { screen, err := tcell.NewScreen() if err != nil { return nil, err } if err = screen.Init(); err != nil { return nil, err } screen.Clear() screen.HideCursor() screen.EnablePaste() width, height := screen.Size() state := UI{ Content: content, screen: screen, } state.ctx = NewContext(width, height, screen, state.onPopover) state.exit.Store(false) Invalidate() if beeper, ok := content.(DrawableInteractiveBeeper); ok { beeper.OnBeep(screen.Beep) } content.Focus(true) if root, ok := content.(RootDrawable); ok { root.Initialize(&state) } return &state, nil } func (state *UI) onPopover(p *Popover) { state.popover = p } func (state *UI) ShouldExit() bool { return state.exit.Load().(bool) } func (state *UI) Exit() { state.exit.Store(true) } func (state *UI) Close() { state.screen.Fini() } func (state *UI) Render() { dirtyState := atomic.SwapInt32(&dirty, NOT_DIRTY) if dirtyState == DIRTY { // reset popover for the next Draw state.popover = nil state.Content.Draw(state.ctx) if state.popover != nil { // if the Draw resulted in a popover, draw it state.popover.Draw(state.ctx) } state.screen.Show() } } func (state *UI) EnableMouse() { state.screen.EnableMouse() } func (state *UI) ChannelEvents() { go func() { for { MsgChannel <- state.screen.PollEvent() } }() } func (state *UI) HandleEvent(event tcell.Event) { if event, ok := event.(*tcell.EventResize); ok { state.screen.Clear() width, height := event.Size() state.ctx = NewContext(width, height, state.screen, state.onPopover) Invalidate() } // if we have a popover, and it can handle the event, it does so if state.popover == nil || !state.popover.Event(event) { // otherwise, we send the event to the main content state.Content.Event(event) } }