ebiten/examples/textinput/main.go
2023-11-17 01:19:05 +09:00

368 lines
8.7 KiB
Go

// Copyright 2023 The Ebitengine Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package main
import (
"image"
"image/color"
"log"
"math"
"runtime"
"strings"
"unicode/utf8"
"github.com/hajimehoshi/bitmapfont/v3"
"github.com/hajimehoshi/ebiten/v2"
"github.com/hajimehoshi/ebiten/v2/exp/textinput"
"github.com/hajimehoshi/ebiten/v2/inpututil"
"github.com/hajimehoshi/ebiten/v2/text/v2"
"github.com/hajimehoshi/ebiten/v2/vector"
)
var fontFace = text.NewStdFace(bitmapfont.FaceEA)
const (
screenWidth = 640
screenHeight = 480
)
type TextField struct {
bounds image.Rectangle
multilines bool
text string
selectionStart int
selectionEnd int
focused bool
ch chan textinput.State
end func()
state textinput.State
}
func NewTextField(bounds image.Rectangle, multilines bool) *TextField {
return &TextField{
bounds: bounds,
multilines: multilines,
}
}
func (t *TextField) Contains(x, y int) bool {
return image.Pt(x, y).In(t.bounds)
}
func (t *TextField) SetSelectionStartByCursorPosition(x, y int) bool {
idx, ok := t.textIndexByCursorPosition(x, y)
if !ok {
return false
}
t.selectionStart = idx
t.selectionEnd = idx
return true
}
func (t *TextField) textIndexByCursorPosition(x, y int) (int, bool) {
if !t.Contains(x, y) {
return 0, false
}
x -= t.bounds.Min.X
y -= t.bounds.Min.Y
px, py := textFieldPadding()
x -= px
y -= py
if x < 0 {
x = 0
}
if y < 0 {
y = 0
}
lineSpacingInPixels := int(fontFace.Metrics().Height)
var nlCount int
var lineStart int
var prevAdvance float64
for i, r := range t.text {
var x0, x1 int
currentAdvance := text.Advance(t.text[lineStart:i], fontFace)
if lineStart < i {
x0 = int((prevAdvance + currentAdvance) / 2)
}
if r == '\n' {
x1 = int(math.MaxInt32)
} else if i < len(t.text) {
nextI := i + 1
for !utf8.ValidString(t.text[i:nextI]) {
nextI++
}
nextAdvance := text.Advance(t.text[lineStart:nextI], fontFace)
x1 = int((currentAdvance + nextAdvance) / 2)
} else {
x1 = int(currentAdvance)
}
if x0 <= x && x < x1 && nlCount*lineSpacingInPixels <= y && y < (nlCount+1)*lineSpacingInPixels {
return i, true
}
prevAdvance = currentAdvance
if r == '\n' {
nlCount++
lineStart = i + 1
prevAdvance = 0
}
}
return len(t.text), true
}
func (t *TextField) Focus() {
t.focused = true
}
func (t *TextField) Blur() {
t.focused = false
}
func (t *TextField) Update() {
if !t.focused {
if t.end != nil {
t.end()
t.ch = nil
t.end = nil
t.state = textinput.State{}
}
return
}
var processed bool
// Text inputting can happen multiple times in one tick (1/60[s] by default).
// Handle all of them.
for {
if t.ch == nil {
x, y := t.bounds.Min.X, t.bounds.Min.Y
cx, cy := t.cursorPos()
px, py := textFieldPadding()
x += cx + px
y += cy + py + int(fontFace.Metrics().HAscent)
t.ch, t.end = textinput.Start(x, y)
// Start returns nil for non-supported envrionments.
if t.ch == nil {
return
}
}
readchar:
for {
select {
case state, ok := <-t.ch:
processed = true
if !ok {
t.ch = nil
t.end = nil
t.state = textinput.State{}
break readchar
}
if state.Committed {
t.text = t.text[:t.selectionStart] + state.Text + t.text[t.selectionEnd:]
t.selectionStart += len(state.Text)
t.selectionEnd = t.selectionStart
t.state = textinput.State{}
continue
}
t.state = state
default:
break readchar
}
}
if t.ch == nil {
continue
}
break
}
if processed {
return
}
switch {
case inpututil.IsKeyJustPressed(ebiten.KeyEnter):
if t.multilines {
t.text = t.text[:t.selectionStart] + "\n" + t.text[t.selectionEnd:]
t.selectionStart += 1
t.selectionEnd = t.selectionStart
}
case inpututil.IsKeyJustPressed(ebiten.KeyBackspace):
if t.selectionStart > 0 {
// TODO: Remove a grapheme instead of a code point.
_, l := utf8.DecodeLastRuneInString(t.text[:t.selectionStart])
t.text = t.text[:t.selectionStart-l] + t.text[t.selectionEnd:]
t.selectionStart -= l
}
t.selectionEnd = t.selectionStart
case inpututil.IsKeyJustPressed(ebiten.KeyLeft):
if t.selectionStart > 0 {
// TODO: Remove a grapheme instead of a code point.
_, l := utf8.DecodeLastRuneInString(t.text[:t.selectionStart])
t.selectionStart -= l
}
t.selectionEnd = t.selectionStart
case inpututil.IsKeyJustPressed(ebiten.KeyRight):
if t.selectionEnd < len(t.text) {
// TODO: Remove a grapheme instead of a code point.
_, l := utf8.DecodeRuneInString(t.text[t.selectionEnd:])
t.selectionEnd += l
}
t.selectionStart = t.selectionEnd
}
if !t.multilines {
orig := t.text
new := strings.ReplaceAll(orig, "\n", "")
if new != orig {
t.selectionStart -= strings.Count(orig[:t.selectionStart], "\n")
t.selectionEnd -= strings.Count(orig[:t.selectionEnd], "\n")
}
}
}
func (t *TextField) cursorPos() (int, int) {
var nlCount int
lastNLPos := -1
for i, r := range t.text[:t.selectionStart] {
if r == '\n' {
nlCount++
lastNLPos = i
}
}
txt := t.text[lastNLPos+1 : t.selectionStart]
if t.state.Text != "" {
txt += t.state.Text[:t.state.CompositionSelectionStartInBytes]
}
x := int(text.Advance(txt, fontFace))
y := nlCount * int(fontFace.Metrics().Height)
return x, y
}
func (t *TextField) Draw(screen *ebiten.Image) {
vector.DrawFilledRect(screen, float32(t.bounds.Min.X), float32(t.bounds.Min.Y), float32(t.bounds.Dx()), float32(t.bounds.Dy()), color.White, false)
var clr color.Color = color.Black
if t.focused {
clr = color.RGBA{0, 0, 0xff, 0xff}
}
vector.StrokeRect(screen, float32(t.bounds.Min.X), float32(t.bounds.Min.Y), float32(t.bounds.Dx()), float32(t.bounds.Dy()), 1, clr, false)
px, py := textFieldPadding()
if t.focused && t.selectionStart >= 0 {
x, y := t.bounds.Min.X, t.bounds.Min.Y
cx, cy := t.cursorPos()
x += px + cx
y += py + cy
h := int(fontFace.Metrics().Height)
vector.StrokeLine(screen, float32(x), float32(y), float32(x), float32(y+h), 1, color.Black, false)
}
shownText := t.text
if t.focused && t.state.Text != "" {
shownText = t.text[:t.selectionStart] + t.state.Text + t.text[t.selectionEnd:]
}
tx := t.bounds.Min.X + px
ty := t.bounds.Min.Y + py
op := &text.DrawOptions{}
op.GeoM.Translate(float64(tx), float64(ty))
op.ColorScale.ScaleWithColor(color.Black)
op.LineSpacingInPixels = fontFace.Metrics().Height
text.Draw(screen, shownText, fontFace, op)
}
const textFieldHeight = 24
func textFieldPadding() (int, int) {
m := fontFace.Metrics()
return 4, (textFieldHeight - int(m.Height)) / 2
}
type Game struct {
textFields []*TextField
}
func (g *Game) Update() error {
if g.textFields == nil {
g.textFields = append(g.textFields, NewTextField(image.Rect(16, 16, screenWidth-16, 16+textFieldHeight), false))
g.textFields = append(g.textFields, NewTextField(image.Rect(16, 48, screenWidth-16, 48+textFieldHeight), false))
g.textFields = append(g.textFields, NewTextField(image.Rect(16, 80, screenWidth-16, screenHeight-16), true))
}
if inpututil.IsMouseButtonJustPressed(ebiten.MouseButtonLeft) {
x, y := ebiten.CursorPosition()
for _, tf := range g.textFields {
if tf.Contains(x, y) {
tf.Focus()
tf.SetSelectionStartByCursorPosition(x, y)
} else {
tf.Blur()
}
}
}
for _, tf := range g.textFields {
tf.Update()
}
x, y := ebiten.CursorPosition()
var inTextField bool
for _, tf := range g.textFields {
if tf.Contains(x, y) {
inTextField = true
break
}
}
if inTextField {
ebiten.SetCursorShape(ebiten.CursorShapeText)
} else {
ebiten.SetCursorShape(ebiten.CursorShapeDefault)
}
return nil
}
func (g *Game) Draw(screen *ebiten.Image) {
screen.Fill(color.RGBA{0xcc, 0xcc, 0xcc, 0xff})
for _, tf := range g.textFields {
tf.Draw(screen)
}
}
func (g *Game) Layout(outsideWidth, outsideHeight int) (int, int) {
return screenWidth, screenHeight
}
func main() {
if runtime.GOOS != "darwin" && runtime.GOOS != "js" {
log.Printf("github.com/hajimehoshi/ebiten/v2/exp/textinput is not supported in this environment (GOOS=%s) yet", runtime.GOOS)
}
ebiten.SetWindowSize(screenWidth, screenHeight)
ebiten.SetWindowTitle("Text Input (Ebitengine Demo)")
if err := ebiten.RunGame(&Game{}); err != nil {
log.Fatal(err)
}
}