selection_input.go

package main

import (
	"strings"
)

/*/ / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / /
// EXAMPLE USAGE

fuzzyPicker := SelectionInput{} // (state.FuzzyPicker is an instance of `SelectionInput`, fyi)
fuzzyPicker.StringItems = []string{}
fuzzyPicker.Items = []interface{}

// Add corresponding items to `Items` and `StringItems`
// Their lengths need to be the same.
for i := 0; i < 10; i++ {
    fuzzyPicker.Items = append(state.FuzzyPicker.Items, i)
    fuzzyPicker.StringItems = append(state.FuzzyPicker.Items, string(i))
}

// Show the fuzzy picker, and provide a callback to be called when the user selects an item.
fuzzyPicker.Show(func(state *State) {
    log.Printf("I'm printed when the user selectd something.")
    log.Printf("Selected index = %d", state.FuzzyPicker.SelectedItem)
})

/ / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / /*/

// A struct that wraps a collection of string items and norma items, and sorts both based on the
// closeness of each of `StringItems` to `Needle`.
type SelectionInput struct {
	Visible bool

	Items       []interface{}
	StringItems []string
	Needle      string
	OnSelected  func(*State)
	OnResort    func(*State)

	SelectedItem int
	BottomItem   int

	// Number of characters at the start of the search string to disregard
	ThrowAwayPrefix int
}

func (p SelectionInput) Len() int {
	return len(p.StringItems)
}

func (p SelectionInput) Less(i, j int) bool {
	iItem := p.StringItems[i]
	jItem := p.StringItems[j]
	return p.Rank(iItem) > p.Rank(jItem)
}

func (p SelectionInput) Swap(i, j int) {
	p.Items[i], p.Items[j] = p.Items[j], p.Items[i]
	p.StringItems[i], p.StringItems[j] = p.StringItems[j], p.StringItems[i]
}

func (p SelectionInput) Rank(item string) int {
	var delta int = 0
	if len(item) > 0 && item[0] == '.' {
		delta -= 20
	}

	if len(p.Needle) < p.ThrowAwayPrefix {
		return strings.Index(item, p.Needle) + delta
	} else {
		return strings.Index(item, p.Needle[p.ThrowAwayPrefix:]) + delta
	}
}

// Show the fuzzy picker
func (p *SelectionInput) Show(callbackOnSelected func(*State)) {
	p.Visible = true
	p.OnSelected = callbackOnSelected
	p.SelectedItem = 0
	p.BottomItem = 0
}
func (p *SelectionInput) Resort(callbackOnResort func(*State)) {
	p.OnResort = callbackOnResort
}

// Hide the fuzzy picker and reset to initial state
func (p *SelectionInput) Hide() {
	p.Visible = false
	p.Items = []interface{}{}
	p.StringItems = []string{}
	p.ThrowAwayPrefix = 0
	p.OnSelected = nil
	p.OnResort = nil
}

type SelectionInputConnectionChannelItem struct {
	Channel    string
	Connection string
}