aboutsummaryrefslogtreecommitdiffstats
path: root/lib/ui/textinput.go
blob: 4a5308eb4867e5dbef15dae577c6de8408741a7b (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
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
package ui

import (
	"github.com/gdamore/tcell"
	"github.com/mattn/go-runewidth"
)

// TODO: Attach history and tab completion providers
// TODO: scrolling

type TextInput struct {
	Invalidatable
	cells  int
	ctx    *Context
	focus  bool
	index  int
	prompt string
	scroll int
	text   []rune
	change []func(ti *TextInput)
}

// Creates a new TextInput. TextInputs will render a "textbox" in the entire
// context they're given, and process keypresses to build a string from user
// input.
func NewTextInput(text string) *TextInput {
	return &TextInput{
		cells: -1,
		text:  []rune(text),
		index: len([]rune(text)),
	}
}

func (ti *TextInput) Prompt(prompt string) *TextInput {
	ti.prompt = prompt
	return ti
}

func (ti *TextInput) String() string {
	return string(ti.text)
}

func (ti *TextInput) Set(value string) {
	ti.text = []rune(value)
}

func (ti *TextInput) Invalidate() {
	ti.DoInvalidate(ti)
}

func (ti *TextInput) Draw(ctx *Context) {
	ti.ctx = ctx // gross
	ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', tcell.StyleDefault)
	ctx.Printf(0, 0, tcell.StyleDefault, "%s%s", ti.prompt, string(ti.text))
	cells := runewidth.StringWidth(string(ti.text[:ti.index]) + ti.prompt)
	if cells != ti.cells && ti.focus {
		ctx.SetCursor(cells, 0)
	}
}

func (ti *TextInput) Focus(focus bool) {
	ti.focus = focus
	if focus && ti.ctx != nil {
		cells := runewidth.StringWidth(string(ti.text[:ti.index]))
		ti.ctx.SetCursor(cells+1, 0)
	} else if !focus && ti.ctx != nil {
		ti.ctx.HideCursor()
	}
}

func (ti *TextInput) insert(ch rune) {
	left := ti.text[:ti.index]
	right := ti.text[ti.index:]
	ti.text = append(left, append([]rune{ch}, right...)...)
	ti.index++
	ti.Invalidate()
	ti.onChange()
}

func (ti *TextInput) deleteWord() {
	// TODO: Break on any of / " '
	if len(ti.text) == 0 {
		return
	}
	i := ti.index - 1
	if ti.text[i] == ' ' {
		i--
	}
	for ; i >= 0; i-- {
		if ti.text[i] == ' ' {
			break
		}
	}
	ti.text = append(ti.text[:i+1], ti.text[ti.index:]...)
	ti.index = i + 1
	ti.Invalidate()
	ti.onChange()
}

func (ti *TextInput) deleteChar() {
	if len(ti.text) > 0 && ti.index != len(ti.text) {
		ti.text = append(ti.text[:ti.index], ti.text[ti.index+1:]...)
		ti.Invalidate()
		ti.onChange()
	}
}

func (ti *TextInput) backspace() {
	if len(ti.text) > 0 && ti.index != 0 {
		ti.text = append(ti.text[:ti.index-1], ti.text[ti.index:]...)
		ti.index--
		ti.Invalidate()
		ti.onChange()
	}
}

func (ti *TextInput) onChange() {
	for _, change := range ti.change {
		change(ti)
	}
}

func (ti *TextInput) OnChange(onChange func(ti *TextInput)) {
	ti.change = append(ti.change, onChange)
}

func (ti *TextInput) Event(event tcell.Event) bool {
	switch event := event.(type) {
	case *tcell.EventKey:
		switch event.Key() {
		case tcell.KeyBackspace, tcell.KeyBackspace2:
			ti.backspace()
		case tcell.KeyCtrlD, tcell.KeyDelete:
			ti.deleteChar()
		case tcell.KeyCtrlB, tcell.KeyLeft:
			if ti.index > 0 {
				ti.index--
				ti.Invalidate()
			}
		case tcell.KeyCtrlF, tcell.KeyRight:
			if ti.index < len(ti.text) {
				ti.index++
				ti.Invalidate()
			}
		case tcell.KeyCtrlA, tcell.KeyHome:
			ti.index = 0
			ti.Invalidate()
		case tcell.KeyCtrlE, tcell.KeyEnd:
			ti.index = len(ti.text)
			ti.Invalidate()
		case tcell.KeyCtrlW:
			ti.deleteWord()
		case tcell.KeyRune:
			ti.insert(event.Rune())
		}
	}
	return true
}