Commited dependencies

vendor/github.com/juju/ansiterm/writer.go

@@ -0,0 +1,74 @@
+// Copyright 2016 Canonical Ltd.
+// Licensed under the LGPLv3, see LICENCE file for details.
+
+package ansiterm
+
+import (
+	"fmt"
+	"io"
+)
+
+// Writer allows colors and styles to be specified. If the io.Writer
+// is not a terminal capable of color, all attempts to set colors or
+// styles are no-ops.
+type Writer struct {
+	io.Writer
+
+	noColor bool
+}
+
+// NewWriter returns a Writer that allows the caller to specify colors and
+// styles. If the io.Writer is not a terminal capable of color, all attempts
+// to set colors or styles are no-ops.
+func NewWriter(w io.Writer) *Writer {
+	writer, colorCapable := colorEnabledWriter(w)
+	return &Writer{
+		Writer:  writer,
+		noColor: !colorCapable,
+	}
+}
+
+// SetColorCapable forces the writer to either write the ANSI escape color
+// if capable is true, or to not write them if capable is false.
+func (w *Writer) SetColorCapable(capable bool) {
+	w.noColor = !capable
+}
+
+// SetForeground sets the foreground color.
+func (w *Writer) SetForeground(c Color) {
+	w.writeSGR(c.foreground())
+}
+
+// SetBackground sets the background color.
+func (w *Writer) SetBackground(c Color) {
+	w.writeSGR(c.background())
+}
+
+// SetStyle sets the text style.
+func (w *Writer) SetStyle(s Style) {
+	w.writeSGR(s.enable())
+}
+
+// ClearStyle clears the text style.
+func (w *Writer) ClearStyle(s Style) {
+	w.writeSGR(s.disable())
+}
+
+// Reset returns the default foreground and background colors with no styles.
+func (w *Writer) Reset() {
+	w.writeSGR(reset)
+}
+
+type sgr interface {
+	// sgr returns the combined escape sequence for the Select Graphic Rendition.
+	sgr() string
+}
+
+// writeSGR takes the appropriate integer SGR parameters
+// and writes out the ANIS escape code.
+func (w *Writer) writeSGR(value sgr) {
+	if w.noColor {
+		return
+	}
+	fmt.Fprint(w, value.sgr())
+}