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
|
// Package tk is the toolkit for the cli package.
//
// This package defines three basic interfaces - Renderer, Handler and Widget -
// and numerous implementations of these interfaces.
package tk
import (
"src.elv.sh/pkg/cli/term"
)
// Widget is the basic component of UI; it knows how to handle events and how to
// render itself.
type Widget interface {
Renderer
MaxHeighter
Handler
}
// Renderer wraps the Render method.
type Renderer interface {
// Render renders onto a region of bound width and height.
Render(width, height int) *term.Buffer
}
// MaxHeighter wraps the MaxHeight method.
type MaxHeighter interface {
// MaxHeight returns the maximum height needed when rendering onto a region
// of bound width and height. The returned value may be larger than the
// height argument.
MaxHeight(width, height int) int
}
// Handler wraps the Handle method.
type Handler interface {
// Try to handle a terminal event and returns whether the event has been
// handled.
Handle(event term.Event) bool
}
// Bindings is the interface for key bindings.
type Bindings interface {
Handle(Widget, term.Event) bool
}
// DummyBindings is a trivial Bindings implementation.
type DummyBindings struct{}
// Handle always returns false.
func (DummyBindings) Handle(w Widget, event term.Event) bool {
return false
}
// MapBindings is a map-backed Bindings implementation.
type MapBindings map[term.Event]func(Widget)
// Handle handles the event by calling the function corresponding to the event
// in the map. If there is no corresponding function, it returns false.
func (m MapBindings) Handle(w Widget, event term.Event) bool {
fn, ok := m[event]
if ok {
fn(w)
}
return ok
}
// FuncBindings is a function-based Bindings implementation.
type FuncBindings func(Widget, term.Event) bool
// Handle handles the event by calling the function.
func (f FuncBindings) Handle(w Widget, event term.Event) bool {
return f(w, event)
}
|
