initial commit

uiterm/textview.go

@@ -0,0 +1,141 @@
+package uiterm
+
+import (
+	"strings"
+
+	"github.com/nsf/termbox-go"
+)
+
+type Textview struct {
+	Lines       []string
+	CurrentLine int
+	Fg          Attribute
+	Bg          Attribute
+
+	parsedLines    []string
+	x0, y0, x1, y1 int
+}
+
+func (t *Textview) SetActive(ui *Ui, active bool) {
+}
+
+func (t *Textview) SetBounds(ui *Ui, x0, y0, x1, y1 int) {
+	t.x0 = x0
+	t.y0 = y0
+	t.x1 = x1
+	t.y1 = y1
+	t.updateParsedLines()
+}
+
+func (t *Textview) ScrollUp() {
+	if newLine := t.CurrentLine + 1; newLine < len(t.parsedLines) {
+		t.CurrentLine = newLine
+	}
+}
+
+func (t *Textview) ScrollDown() {
+	if newLine := t.CurrentLine - 1; newLine >= 0 {
+		t.CurrentLine = newLine
+	}
+}
+
+func (t *Textview) ScrollTop() {
+	if newLine := len(t.parsedLines) - 1; newLine > 0 {
+		t.CurrentLine = newLine
+	} else {
+		t.CurrentLine = 0
+	}
+}
+
+func (t *Textview) ScrollBottom() {
+	t.CurrentLine = 0
+}
+
+func (t *Textview) updateParsedLines() {
+	width := t.x1 - t.x0 - 3
+
+	if t.Lines == nil || width <= 0 {
+		t.parsedLines = nil
+		return
+	}
+
+	parsed := make([]string, 0, len(t.Lines))
+	for _, line := range t.Lines {
+		current := ""
+		chars := 0
+		reader := strings.NewReader(line)
+		for {
+			if chars >= width {
+				parsed = append(parsed, current)
+				chars = 0
+				current = ""
+			}
+			if reader.Len() <= 0 {
+				if chars > 0 {
+					parsed = append(parsed, current)
+				}
+				break
+			}
+			if ch, _, err := reader.ReadRune(); err == nil {
+				current = current + string(ch)
+				chars++
+			}
+		}
+	}
+	t.parsedLines = parsed
+}
+
+func (t *Textview) AddLine(line string) {
+	t.Lines = append(t.Lines, line)
+	t.updateParsedLines()
+}
+
+func (t *Textview) Clear() {
+	t.Lines = nil
+	t.CurrentLine = 0
+	t.parsedLines = nil
+}
+
+func (t *Textview) Draw(ui *Ui) {
+	var reader *strings.Reader
+	line := len(t.parsedLines) - 1 - t.CurrentLine
+	if line < 0 {
+		line = 0
+	}
+	totalLines := len(t.parsedLines)
+	if totalLines == 0 {
+		totalLines = 1
+	}
+	currentScrollLine := t.y1 - 1 - int((float32(t.CurrentLine)/float32(totalLines))*float32(t.y1-t.y0))
+	for y := t.y1 - 1; y >= t.y0; y-- {
+		if t.parsedLines != nil && line >= 0 {
+			reader = strings.NewReader(t.parsedLines[line])
+		} else {
+			reader = nil
+		}
+		for x := t.x0; x < t.x1; x++ {
+			var chr rune = ' '
+			if x == t.x1-1 { // scrollbar
+				if y == currentScrollLine {
+					chr = '█'
+				} else {
+					chr = '░'
+				}
+			} else if x < t.x1-3 {
+				if reader != nil {
+					if ch, _, err := reader.ReadRune(); err == nil {
+						chr = ch
+					}
+				}
+			}
+			termbox.SetCell(x, y, chr, termbox.Attribute(t.Fg), termbox.Attribute(t.Bg))
+		}
+		line--
+	}
+}
+
+func (t *Textview) KeyEvent(ui *Ui, mod Modifier, key Key) {
+}
+
+func (t *Textview) CharacterEvent(ui *Ui, chr rune) {
+}