doodle/shell.go
Noah Petherbridge 41e1838549 Add JS + History to Shell, Add Main Scene
* The shell now supports an "eval" command, or "$" for short.
  * Runs it in an Otto JavaScript VM.
  * Some global variables are available, like `d` is the Doodle object
    itself, `log`, `RGBA()` and `Point()`
* The shell supports paging through input history using the arrow keys.
* Added an initial Main Scene
2018-07-25 19:38:54 -07:00

320 lines
6.5 KiB
Go

package doodle
import (
"bytes"
"fmt"
"strings"
"git.kirsle.net/apps/doodle/balance"
"git.kirsle.net/apps/doodle/events"
"git.kirsle.net/apps/doodle/render"
"github.com/robertkrimen/otto"
)
// Flash a message to the user.
func (d *Doodle) Flash(template string, v ...interface{}) {
d.shell.Write(fmt.Sprintf(template, v...))
}
// Shell implements the developer console in-game.
type Shell struct {
parent *Doodle
Open bool
Prompt string
Text string
History []string
Output []string
Flashes []Flash
// Blinky cursor variables.
cursor byte // cursor symbol
cursorFlip uint64 // ticks until cursor flip
cursorRate uint64
// Paging through history variables.
historyPaging bool
historyIndex int
// JavaScript shell interpreter.
js *otto.Otto
}
// Flash holds a message to flash on screen.
type Flash struct {
Text string
Expires uint64 // tick that it expires
}
// NewShell initializes the shell helper (the "Shellper").
func NewShell(d *Doodle) Shell {
s := Shell{
parent: d,
History: []string{},
Output: []string{},
Flashes: []Flash{},
Prompt: ">",
cursor: '_',
cursorRate: balance.ShellCursorBlinkRate,
js: otto.New(),
}
// Make the Doodle instance available to the shell.
bindings := map[string]interface{}{
"d": d,
"log": log,
"RGBA": render.RGBA,
"Point": render.NewPoint,
}
for name, v := range bindings {
err := s.js.Set(name, v)
if err != nil {
log.Error("Failed to make `%s` available to JS shell: %s", name, err)
}
}
return s
}
// Close the shell, resetting its internal state.
func (s *Shell) Close() {
log.Debug("Shell: closing shell")
s.Open = false
s.Prompt = ">"
s.Text = ""
s.historyPaging = false
s.historyIndex = 0
}
// Execute a command in the shell.
func (s *Shell) Execute(input string) {
command := s.Parse(input)
if command.Raw != "" {
s.Output = append(s.Output, s.Prompt+command.Raw)
s.History = append(s.History, command.Raw)
}
if command.Command == "clear" {
s.Output = []string{}
} else {
err := command.Run(s.parent)
if err != nil {
s.Write(err.Error())
}
}
// Reset the text buffer in the shell.
s.Text = ""
}
// Write a line of output text to the console.
func (s *Shell) Write(line string) {
s.Output = append(s.Output, line)
s.Flashes = append(s.Flashes, Flash{
Text: line,
Expires: s.parent.ticks + balance.FlashTTL,
})
}
// Parse the command line.
func (s *Shell) Parse(input string) Command {
input = strings.TrimSpace(input)
if len(input) == 0 {
return Command{}
}
var (
inQuote bool
buffer = bytes.NewBuffer([]byte{})
words = []string{}
)
for i := 0; i < len(input); i++ {
char := input[i]
switch char {
case ' ':
if inQuote {
buffer.WriteByte(char)
continue
}
if word := buffer.String(); word != "" {
words = append(words, word)
buffer.Reset()
}
case '"':
if !inQuote {
// An opening quote character.
inQuote = true
} else {
// The closing quote.
inQuote = false
if word := buffer.String(); word != "" {
words = append(words, word)
buffer.Reset()
}
}
default:
buffer.WriteByte(char)
}
}
if remainder := buffer.String(); remainder != "" {
words = append(words, remainder)
}
return Command{
Raw: input,
Command: words[0],
Args: words[1:],
ArgsLiteral: strings.TrimSpace(input[len(words[0]):]),
}
}
// Draw the shell.
func (s *Shell) Draw(d *Doodle, ev *events.State) error {
if ev.EscapeKey.Read() {
s.Close()
return nil
} else if ev.EnterKey.Read() || ev.EscapeKey.Read() {
s.Execute(s.Text)
s.Close()
return nil
} else if (ev.Up.Now || ev.Down.Now) && len(s.History) > 0 {
// Paging through history.
if !s.historyPaging {
s.historyPaging = true
s.historyIndex = len(s.History)
}
// Consume the inputs and make convenient variables.
ev.Down.Read()
isUp := ev.Up.Read()
// Scroll through the input history.
if isUp {
s.historyIndex--
if s.historyIndex < 0 {
s.historyIndex = 0
}
} else {
s.historyIndex++
if s.historyIndex >= len(s.History) {
s.historyIndex = len(s.History) - 1
}
}
s.Text = s.History[s.historyIndex]
}
// Compute the line height we can draw.
lineHeight := balance.ShellFontSize + int(balance.ShellPadding)
// If the console is open, draw the console.
if s.Open {
// Cursor flip?
if d.ticks > s.cursorFlip {
s.cursorFlip = d.ticks + s.cursorRate
if s.cursor == ' ' {
s.cursor = '_'
} else {
s.cursor = ' '
}
}
// Read a character from the keyboard.
if key := ev.ReadKey(); key != "" {
// Backspace?
if key == `\b` {
if len(s.Text) > 0 {
s.Text = s.Text[:len(s.Text)-1]
}
} else {
s.Text += key
}
}
// How tall is the box?
boxHeight := int32(lineHeight*(balance.ShellHistoryLineCount+1)) + balance.ShellPadding
// Draw the background color.
d.Engine.DrawBox(
balance.ShellBackgroundColor,
render.Rect{
X: 0,
Y: d.height - boxHeight,
W: d.width,
H: boxHeight,
},
)
// Draw the recent commands.
outputY := d.height - int32(lineHeight*2)
for i := 0; i < balance.ShellHistoryLineCount; i++ {
if len(s.Output) > i {
line := s.Output[len(s.Output)-1-i]
d.Engine.DrawText(
render.Text{
Text: line,
Size: balance.ShellFontSize,
Color: render.Grey,
},
render.Point{
X: balance.ShellPadding,
Y: outputY,
},
)
}
outputY -= int32(lineHeight)
}
// Draw the command prompt.
d.Engine.DrawText(
render.Text{
Text: s.Prompt + s.Text + string(s.cursor),
Size: balance.ShellFontSize,
Color: balance.ShellForegroundColor,
},
render.Point{
X: balance.ShellPadding,
Y: d.height - int32(balance.ShellFontSize) - balance.ShellPadding,
},
)
} else if len(s.Flashes) > 0 {
// Otherwise, just draw flashed messages.
valid := false // Did we actually draw any?
outputY := d.height - int32(lineHeight*2)
for i := len(s.Flashes); i > 0; i-- {
flash := s.Flashes[i-1]
if d.ticks >= flash.Expires {
continue
}
d.Engine.DrawText(
render.Text{
Text: flash.Text,
Size: balance.ShellFontSize,
Color: render.SkyBlue,
Stroke: render.Grey,
Shadow: render.Black,
},
render.Point{
X: balance.ShellPadding,
Y: outputY,
},
)
outputY -= int32(lineHeight)
valid = true
}
// If we've exhausted all flashes, free up the memory.
if !valid {
s.Flashes = []Flash{}
}
}
return nil
}