aboutsummaryrefslogtreecommitdiffstats
path: root/lib/ui/ui.go
blob: 073684cca7dc00a95468b3e2d5deda5657413212 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
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)
		state.Content.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)
	}
}