rewrite checkpoint

vendor/github.com/AlecAivazis/survey/multiselect.go

@@ -0,0 +1,204 @@
+package survey
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/AlecAivazis/survey/core"
+	"github.com/AlecAivazis/survey/terminal"
+)
+
+/*
+MultiSelect is a prompt that presents a list of various options to the user
+for them to select using the arrow keys and enter. Response type is a slice of strings.
+
+	days := []string{}
+	prompt := &survey.MultiSelect{
+		Message: "What days do you prefer:",
+		Options: []string{"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"},
+	}
+	survey.AskOne(prompt, &days, nil)
+*/
+type MultiSelect struct {
+	core.Renderer
+	Message       string
+	Options       []string
+	Default       []string
+	Help          string
+	PageSize      int
+	selectedIndex int
+	checked       map[string]bool
+	showingHelp   bool
+}
+
+// data available to the templates when processing
+type MultiSelectTemplateData struct {
+	MultiSelect
+	Answer        string
+	ShowAnswer    bool
+	Checked       map[string]bool
+	SelectedIndex int
+	ShowHelp      bool
+	PageEntries   []string
+}
+
+var MultiSelectQuestionTemplate = `
+{{- if .ShowHelp }}{{- color "cyan"}}{{ HelpIcon }} {{ .Help }}{{color "reset"}}{{"\n"}}{{end}}
+{{- color "green+hb"}}{{ QuestionIcon }} {{color "reset"}}
+{{- color "default+hb"}}{{ .Message }}{{color "reset"}}
+{{- if .ShowAnswer}}{{color "cyan"}} {{.Answer}}{{color "reset"}}{{"\n"}}
+{{- else }}
+  {{- if and .Help (not .ShowHelp)}} {{color "cyan"}}[{{ HelpInputRune }} for help]{{color "reset"}}{{end}}
+  {{- "\n"}}
+  {{- range $ix, $option := .PageEntries}}
+    {{- if eq $ix $.SelectedIndex}}{{color "cyan"}}{{ SelectFocusIcon }}{{color "reset"}}{{else}} {{end}}
+    {{- if index $.Checked $option}}{{color "green"}} {{ MarkedOptionIcon }} {{else}}{{color "default+hb"}} {{ UnmarkedOptionIcon }} {{end}}
+    {{- color "reset"}}
+    {{- " "}}{{$option}}{{"\n"}}
+  {{- end}}
+{{- end}}`
+
+// OnChange is called on every keypress.
+func (m *MultiSelect) OnChange(line []rune, pos int, key rune) (newLine []rune, newPos int, ok bool) {
+	if key == terminal.KeyArrowUp {
+		// if we are at the top of the list
+		if m.selectedIndex == 0 {
+			// go to the bottom
+			m.selectedIndex = len(m.Options) - 1
+		} else {
+			// decrement the selected index
+			m.selectedIndex--
+		}
+	} else if key == terminal.KeyArrowDown {
+		// if we are at the bottom of the list
+		if m.selectedIndex == len(m.Options)-1 {
+			// start at the top
+			m.selectedIndex = 0
+		} else {
+			// increment the selected index
+			m.selectedIndex++
+		}
+		// if the user pressed down and there is room to move
+	} else if key == terminal.KeySpace {
+		if old, ok := m.checked[m.Options[m.selectedIndex]]; !ok {
+			// otherwise just invert the current value
+			m.checked[m.Options[m.selectedIndex]] = true
+		} else {
+			// otherwise just invert the current value
+			m.checked[m.Options[m.selectedIndex]] = !old
+		}
+		// only show the help message if we have one to show
+	} else if key == core.HelpInputRune && m.Help != "" {
+		m.showingHelp = true
+	}
+
+	// paginate the options
+	opts, idx := paginate(m.PageSize, m.Options, m.selectedIndex)
+
+	// render the options
+	m.Render(
+		MultiSelectQuestionTemplate,
+		MultiSelectTemplateData{
+			MultiSelect:   *m,
+			SelectedIndex: idx,
+			Checked:       m.checked,
+			ShowHelp:      m.showingHelp,
+			PageEntries:   opts,
+		},
+	)
+
+	// if we are not pressing ent
+	return line, 0, true
+}
+
+func (m *MultiSelect) Prompt() (interface{}, error) {
+	// compute the default state
+	m.checked = make(map[string]bool)
+	// if there is a default
+	if len(m.Default) > 0 {
+		for _, dflt := range m.Default {
+			for _, opt := range m.Options {
+				// if the option correponds to the default
+				if opt == dflt {
+					// we found our initial value
+					m.checked[opt] = true
+					// stop looking
+					break
+				}
+			}
+		}
+	}
+
+	// if there are no options to render
+	if len(m.Options) == 0 {
+		// we failed
+		return "", errors.New("please provide options to select from")
+	}
+
+	// hide the cursor
+	terminal.CursorHide()
+	// show the cursor when we're done
+	defer terminal.CursorShow()
+
+	// paginate the options
+	opts, idx := paginate(m.PageSize, m.Options, m.selectedIndex)
+
+	// ask the question
+	err := m.Render(
+		MultiSelectQuestionTemplate,
+		MultiSelectTemplateData{
+			MultiSelect:   *m,
+			SelectedIndex: idx,
+			Checked:       m.checked,
+			PageEntries:   opts,
+		},
+	)
+	if err != nil {
+		return "", err
+	}
+
+	rr := terminal.NewRuneReader(os.Stdin)
+	rr.SetTermMode()
+	defer rr.RestoreTermMode()
+
+	// start waiting for input
+	for {
+		r, _, _ := rr.ReadRune()
+		if r == '\r' || r == '\n' {
+			break
+		}
+		if r == terminal.KeyInterrupt {
+			return "", fmt.Errorf("interrupt")
+		}
+		if r == terminal.KeyEndTransmission {
+			break
+		}
+		m.OnChange(nil, 0, r)
+	}
+
+	answers := []string{}
+	for _, option := range m.Options {
+		if val, ok := m.checked[option]; ok && val {
+			answers = append(answers, option)
+		}
+	}
+
+	return answers, nil
+}
+
+// Cleanup removes the options section, and renders the ask like a normal question.
+func (m *MultiSelect) Cleanup(val interface{}) error {
+	// execute the output summary template with the answer
+	return m.Render(
+		MultiSelectQuestionTemplate,
+		MultiSelectTemplateData{
+			MultiSelect:   *m,
+			SelectedIndex: m.selectedIndex,
+			Checked:       m.checked,
+			Answer:        strings.Join(val.([]string), ", "),
+			ShowAnswer:    true,
+		},
+	)
+}