all: rename the gioui.org/ui module to gioui.org

The "ui" is redundant and stutters.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

text/buffer.go

@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package text
+
+import (
+	"fmt"
+	"io"
+	"strings"
+	"unicode/utf8"
+)
+
+const bufferDebug = false
+
+// editBuffer implements a gap buffer for text editing.
+type editBuffer struct {
+	// caret is the caret position in bytes.
+	caret int
+	// pos is the byte position for Read and ReadRune.
+	pos int
+
+	// The gap start and end in bytes.
+	gapstart, gapend int
+	text             []byte
+
+	// changed tracks whether the buffer content
+	// has changed since the last call to Changed.
+	changed bool
+}
+
+const minSpace = 5
+
+func (e *editBuffer) Changed() bool {
+	c := e.changed
+	e.changed = false
+	return c
+}
+
+func (e *editBuffer) deleteRuneForward() {
+	e.moveGap(0)
+	_, s := utf8.DecodeRune(e.text[e.gapend:])
+	e.gapend += s
+	e.changed = e.changed || s > 0
+	e.dump()
+}
+
+func (e *editBuffer) deleteRune() {
+	e.moveGap(0)
+	_, s := utf8.DecodeLastRune(e.text[:e.gapstart])
+	e.gapstart -= s
+	e.caret -= s
+	e.changed = e.changed || s > 0
+	e.dump()
+}
+
+// moveGap moves the gap to the caret position. After returning,
+// the gap is guaranteed to be at least space bytes long.
+func (e *editBuffer) moveGap(space int) {
+	if e.gapLen() < space {
+		if space < minSpace {
+			space = minSpace
+		}
+		txt := make([]byte, e.len()+space)
+		// Expand to capacity.
+		txt = txt[:cap(txt)]
+		gaplen := len(txt) - e.len()
+		if e.caret > e.gapstart {
+			copy(txt, e.text[:e.gapstart])
+			copy(txt[e.caret+gaplen:], e.text[e.caret:])
+			copy(txt[e.gapstart:], e.text[e.gapend:e.caret+e.gapLen()])
+		} else {
+			copy(txt, e.text[:e.caret])
+			copy(txt[e.gapstart+gaplen:], e.text[e.gapend:])
+			copy(txt[e.caret+gaplen:], e.text[e.caret:e.gapstart])
+		}
+		e.text = txt
+		e.gapstart = e.caret
+		e.gapend = e.gapstart + gaplen
+	} else {
+		if e.caret > e.gapstart {
+			copy(e.text[e.gapstart:], e.text[e.gapend:e.caret+e.gapLen()])
+		} else {
+			copy(e.text[e.caret+e.gapLen():], e.text[e.caret:e.gapstart])
+		}
+		l := e.gapLen()
+		e.gapstart = e.caret
+		e.gapend = e.gapstart + l
+	}
+	e.dump()
+}
+
+func (e *editBuffer) len() int {
+	return len(e.text) - e.gapLen()
+}
+
+func (e *editBuffer) gapLen() int {
+	return e.gapend - e.gapstart
+}
+
+func (e *editBuffer) Read(p []byte) (int, error) {
+	if e.pos == e.len() {
+		return 0, io.EOF
+	}
+	var n int
+	if e.pos < e.gapstart {
+		n += copy(p, e.text[e.pos:e.gapstart])
+		p = p[n:]
+	}
+	n += copy(p, e.text[e.gapend:])
+	e.pos += n
+	return n, nil
+}
+
+func (e *editBuffer) ReadRune() (rune, int, error) {
+	if e.pos == e.len() {
+		return 0, 0, io.EOF
+	}
+	r, s := e.runeAt(e.pos)
+	e.pos += s
+	return r, s, nil
+}
+
+func (e *editBuffer) String() string {
+	var b strings.Builder
+	b.Grow(e.len())
+	b.Write(e.text[:e.gapstart])
+	b.Write(e.text[e.gapend:])
+	return b.String()
+}
+
+func (e *editBuffer) prepend(s string) {
+	e.moveGap(len(s))
+	copy(e.text[e.caret:], s)
+	e.gapstart += len(s)
+	e.changed = e.changed || len(s) > 0
+	e.dump()
+}
+
+func (e *editBuffer) dump() {
+	if bufferDebug {
+		fmt.Printf("len(e.text) %d e.len() %d e.gapstart %d e.gapend %d e.caret %d txt:\n'%+x'<-%d->'%+x'\n", len(e.text), e.len(), e.gapstart, e.gapend, e.caret, e.text[:e.gapstart], e.gapLen(), e.text[e.gapend:])
+	}
+}
+
+func (e *editBuffer) moveLeft() {
+	_, s := e.runeBefore(e.caret)
+	e.caret -= s
+	e.dump()
+}
+
+func (e *editBuffer) moveRight() {
+	_, s := e.runeAt(e.caret)
+	e.caret += s
+	e.dump()
+}
+
+func (e *editBuffer) runeBefore(idx int) (rune, int) {
+	if idx >= e.gapstart {
+		idx += e.gapLen()
+	}
+	return utf8.DecodeLastRune(e.text[:idx])
+}
+
+func (e *editBuffer) runeAt(idx int) (rune, int) {
+	if idx >= e.gapstart {
+		idx += e.gapLen()
+	}
+	return utf8.DecodeRune(e.text[idx:])
+}