init

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

@@ -0,0 +1,271 @@
+package survey
+
+import (
+	"errors"
+	"strings"
+
+	"gopkg.in/AlecAivazis/survey.v1/core"
+	"gopkg.in/AlecAivazis/survey.v1/terminal"
+)
+
+/*
+Select 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 string.
+
+	color := ""
+	prompt := &survey.Select{
+		Message: "Choose a color:",
+		Options: []string{"red", "blue", "green"},
+	}
+	survey.AskOne(prompt, &color, nil)
+*/
+type Select struct {
+	core.Renderer
+	Message       string
+	Options       []string
+	Default       string
+	Help          string
+	PageSize      int
+	VimMode       bool
+	FilterMessage string
+	filter        string
+	selectedIndex int
+	useDefault    bool
+	showingHelp   bool
+}
+
+// the data available to the templates when processing
+type SelectTemplateData struct {
+	Select
+	PageEntries   []string
+	SelectedIndex int
+	Answer        string
+	ShowAnswer    bool
+	ShowHelp      bool
+}
+
+var SelectQuestionTemplate = `
+{{- if .ShowHelp }}{{- color "cyan"}}{{ HelpIcon }} {{ .Help }}{{color "reset"}}{{"\n"}}{{end}}
+{{- color "green+hb"}}{{ QuestionIcon }} {{color "reset"}}
+{{- color "default+hb"}}{{ .Message }}{{ .FilterMessage }}{{color "reset"}}
+{{- if .ShowAnswer}}{{color "cyan"}} {{.Answer}}{{color "reset"}}{{"\n"}}
+{{- else}}
+  {{- "  "}}{{- color "cyan"}}[Use arrows to move, type to filter{{- if and .Help (not .ShowHelp)}}, {{ HelpInputRune }} for more help{{end}}]{{color "reset"}}
+  {{- "\n"}}
+  {{- range $ix, $choice := .PageEntries}}
+    {{- if eq $ix $.SelectedIndex}}{{color "cyan+b"}}{{ SelectFocusIcon }} {{else}}{{color "default+hb"}}  {{end}}
+    {{- $choice}}
+    {{- color "reset"}}{{"\n"}}
+  {{- end}}
+{{- end}}`
+
+// OnChange is called on every keypress.
+func (s *Select) OnChange(line []rune, pos int, key rune) (newLine []rune, newPos int, ok bool) {
+	options := s.filterOptions()
+	oldFilter := s.filter
+
+	// if the user pressed the enter key
+	if key == terminal.KeyEnter {
+		if s.selectedIndex < len(options) {
+			return []rune(options[s.selectedIndex]), 0, true
+		}
+		// if the user pressed the up arrow or 'k' to emulate vim
+	} else if key == terminal.KeyArrowUp || (s.VimMode && key == 'k') {
+		s.useDefault = false
+
+		// if we are at the top of the list
+		if s.selectedIndex == 0 {
+			// start from the button
+			s.selectedIndex = len(options) - 1
+		} else {
+			// otherwise we are not at the top of the list so decrement the selected index
+			s.selectedIndex--
+		}
+		// if the user pressed down or 'j' to emulate vim
+	} else if key == terminal.KeyArrowDown || (s.VimMode && key == 'j') {
+		s.useDefault = false
+		// if we are at the bottom of the list
+		if s.selectedIndex == len(options)-1 {
+			// start from the top
+			s.selectedIndex = 0
+		} else {
+			// increment the selected index
+			s.selectedIndex++
+		}
+		// only show the help message if we have one
+	} else if key == core.HelpInputRune && s.Help != "" {
+		s.showingHelp = true
+		// if the user wants to toggle vim mode on/off
+	} else if key == terminal.KeyEscape {
+		s.VimMode = !s.VimMode
+		// if the user hits any of the keys that clear the filter
+	} else if key == terminal.KeyDeleteWord || key == terminal.KeyDeleteLine {
+		s.filter = ""
+		// if the user is deleting a character in the filter
+	} else if key == terminal.KeyDelete || key == terminal.KeyBackspace {
+		// if there is content in the filter to delete
+		if s.filter != "" {
+			// subtract a line from the current filter
+			s.filter = s.filter[0 : len(s.filter)-1]
+			// we removed the last value in the filter
+		}
+	} else if key >= terminal.KeySpace {
+		s.filter += string(key)
+		// make sure vim mode is disabled
+		s.VimMode = false
+		// make sure that we use the current value in the filtered list
+		s.useDefault = false
+	}
+
+	s.FilterMessage = ""
+	if s.filter != "" {
+		s.FilterMessage = " " + s.filter
+	}
+	if oldFilter != s.filter {
+		// filter changed
+		options = s.filterOptions()
+		if len(options) > 0 && len(options) <= s.selectedIndex {
+			s.selectedIndex = len(options) - 1
+		}
+	}
+
+	// figure out the options and index to render
+
+	// TODO if we have started filtering and were looking at the end of a list
+	// and we have modified the filter then we should move the page back!
+	opts, idx := paginate(s.PageSize, options, s.selectedIndex)
+
+	// render the options
+	s.Render(
+		SelectQuestionTemplate,
+		SelectTemplateData{
+			Select:        *s,
+			SelectedIndex: idx,
+			ShowHelp:      s.showingHelp,
+			PageEntries:   opts,
+		},
+	)
+
+	// if we are not pressing ent
+	if len(options) <= s.selectedIndex {
+		return []rune{}, 0, false
+	}
+	return []rune(options[s.selectedIndex]), 0, true
+}
+
+func (s *Select) filterOptions() []string {
+	filter := strings.ToLower(s.filter)
+	if filter == "" {
+		return s.Options
+	}
+	answer := []string{}
+	for _, o := range s.Options {
+		if strings.Contains(strings.ToLower(o), filter) {
+			answer = append(answer, o)
+		}
+	}
+	return answer
+}
+
+func (s *Select) Prompt() (interface{}, error) {
+	// if there are no options to render
+	if len(s.Options) == 0 {
+		// we failed
+		return "", errors.New("please provide options to select from")
+	}
+
+	// start off with the first option selected
+	sel := 0
+	// if there is a default
+	if s.Default != "" {
+		// find the choice
+		for i, opt := range s.Options {
+			// if the option correponds to the default
+			if opt == s.Default {
+				// we found our initial value
+				sel = i
+				// stop looking
+				break
+			}
+		}
+	}
+	// save the selected index
+	s.selectedIndex = sel
+
+	// figure out the options and index to render
+	opts, idx := paginate(s.PageSize, s.Options, sel)
+
+	// ask the question
+	err := s.Render(
+		SelectQuestionTemplate,
+		SelectTemplateData{
+			Select:        *s,
+			PageEntries:   opts,
+			SelectedIndex: idx,
+		},
+	)
+	if err != nil {
+		return "", err
+	}
+
+	// by default, use the default value
+	s.useDefault = true
+
+	rr := s.NewRuneReader()
+	rr.SetTermMode()
+	defer rr.RestoreTermMode()
+
+	cursor := s.NewCursor()
+	cursor.Hide()       // hide the cursor
+	defer cursor.Show() // show the cursor when we're done
+
+	// start waiting for input
+	for {
+		r, _, err := rr.ReadRune()
+		if err != nil {
+			return "", err
+		}
+		if r == '\r' || r == '\n' {
+			break
+		}
+		if r == terminal.KeyInterrupt {
+			return "", terminal.InterruptErr
+		}
+		if r == terminal.KeyEndTransmission {
+			break
+		}
+		s.OnChange(nil, 0, r)
+	}
+	options := s.filterOptions()
+	s.filter = ""
+	s.FilterMessage = ""
+
+	var val string
+	// if we are supposed to use the default value
+	if s.useDefault || s.selectedIndex >= len(options) {
+		// if there is a default value
+		if s.Default != "" {
+			// use the default value
+			val = s.Default
+		} else if len(options) > 0 {
+			// there is no default value so use the first
+			val = options[0]
+		}
+		// otherwise the selected index points to the value
+	} else if s.selectedIndex < len(options) {
+		// the
+		val = options[s.selectedIndex]
+	}
+	return val, err
+}
+
+func (s *Select) Cleanup(val interface{}) error {
+	return s.Render(
+		SelectQuestionTemplate,
+		SelectTemplateData{
+			Select:     *s,
+			Answer:     val.(string),
+			ShowAnswer: true,
+		},
+	)
+}