Merge branch 'master' into PR-fix-start-panic

.travis.yml

@@ -1,7 +1,28 @@
 language: go
 sudo: false
+
+matrix:
+  include:
+    - go: 1.11.x
+      os: linux
+    - go: 1.12.x
+      os: linux
+    - go: 1.11.x
+      os: linux
+      env: CROSS_COMPILE=true
+    - go: 1.12.x
+      os: linux
+      env: CROSS_COMPILE=true
+    - go: 1.11.x
+      os: osx
+    - go: 1.12.x
+      os: osx
+
 install:
-  - go get ./...
-go:
-  - 1.4
-  - tip
+  - if [ "$TRAVIS_OS_NAME" = "linux" -a "$CROSS_COMPILE" = "true" ]; then go get github.com/mattn/go-isatty ; fi
+  - go get -t -v ./...
+
+script:
+  - go build
+  - go test
+  - if [ "$TRAVIS_OS_NAME" = "linux" -a "$CROSS_COMPILE" = "true" ]; then env GOOS=windows GOARCH=amd64 CGO_ENABLED=0 go build -v; fi

Makefile

@@ -0,0 +1,7 @@
+test:
+	@go test -race .
+
+examples:
+	@go run -race ./example
+
+.PHONY: test examples

example/main.go

@@ -13,14 +13,15 @@ func main() {
 	// start listening for updates and render
 	writer.Start()
 
-	for _, f := range []string{"Foo.zip", "Bar.iso"} {
+	for _, f := range [][]string{{"Foo.zip", "Bar.iso"}, {"Baz.tar.gz", "Qux.img"}} {
 		for i := 0; i <= 50; i++ {
-			fmt.Fprintf(writer, "Downloading %s.. (%d/%d) GB\n", f, i, 50)
+			_, _ = fmt.Fprintf(writer, "Downloading %s.. (%d/%d) GB\n", f[0], i, 50)
+			_, _ = fmt.Fprintf(writer.Newline(), "Downloading %s.. (%d/%d) GB\n", f[1], i, 50)
 			time.Sleep(time.Millisecond * 25)
 		}
-		fmt.Fprintf(writer.Bypass(), "Downloaded %s\n", f)
+		_, _ = fmt.Fprintf(writer.Bypass(), "Downloaded %s\n", f[0])
+		_, _ = fmt.Fprintf(writer.Bypass(), "Downloaded %s\n", f[1])
 	}
-
-	fmt.Fprintln(writer, "Finished: Downloaded 100GB")
+	_, _ = fmt.Fprintln(writer, "Finished: Downloaded 150GB")
 	writer.Stop() // flush and stop rendering
 }

go.mod

@@ -0,0 +1,3 @@
+module github.com/gosuri/uilive
+
+go 1.10

terminal_size.go

@@ -0,0 +1,37 @@
+// +build !windows
+
+package uilive
+
+import (
+	"os"
+	"runtime"
+	"syscall"
+	"unsafe"
+)
+
+type windowSize struct {
+	rows    uint16
+	cols    uint16
+}
+
+var out *os.File
+var err error
+var sz windowSize
+
+func getTermSize() (int, int) {
+	if runtime.GOOS == "openbsd" {
+		out, err = os.OpenFile("/dev/tty", os.O_RDWR, 0)
+		if err != nil {
+			return 0, 0
+		}
+
+	} else {
+		out, err = os.OpenFile("/dev/tty", os.O_WRONLY, 0)
+		if err != nil {
+			return 0, 0
+		}
+	}
+	_, _, _ = syscall.Syscall(syscall.SYS_IOCTL,
+		out.Fd(), uintptr(syscall.TIOCGWINSZ), uintptr(unsafe.Pointer(&sz)))
+	return int(sz.cols), int(sz.rows)
+}

terminal_size_windows.go

@@ -0,0 +1,24 @@
+// +build windows
+
+package uilive
+
+import (
+	"os"
+	"unsafe"
+)
+
+func getTermSize() (int, int) {
+	out, err := os.Open("CONOUT$")
+	if err != nil {
+		return 0, 0
+	}
+	defer out.Close()
+
+	var csbi consoleScreenBufferInfo
+	ret, _, _ := procGetConsoleScreenBufferInfo.Call(out.Fd(), uintptr(unsafe.Pointer(&csbi)))
+	if ret == 0 {
+		return 0, 0
+	}
+
+	return int(csbi.window.right - csbi.window.left + 1), int(csbi.window.bottom - csbi.window.top + 1)
+}

writer.go

@@ -15,8 +15,12 @@ const ESC = 27
 // RefreshInterval is the default refresh interval to update the ui
 var RefreshInterval = time.Millisecond
 
+var overFlowHandled bool
+
+var termWidth int
+
 // Out is the default output writer for the Writer
-var Out = os.Stdout
+var Out = io.Writer(os.Stdout)
 
 // ErrClosedPipe is the error returned when trying to writer is not listening
 var ErrClosedPipe = errors.New("uilive: read/write on closed pipe")
@@ -47,8 +51,17 @@ type bypass struct {
 	writer *Writer
 }
 
+type newline struct {
+	writer *Writer
+}
+
 // New returns a new Writer with defaults
 func New() *Writer {
+	termWidth, _ = getTermSize()
+	if termWidth != 0 {
+		overFlowHandled = true
+	}
+
 	return &Writer{
 		Out:             Out,
 		RefreshInterval: RefreshInterval,
@@ -64,16 +77,24 @@ func (w *Writer) Flush() error {
 	w.mtx.Lock()
 	defer w.mtx.Unlock()
 
-	// do nothing is  buffer is empty
+	// do nothing if buffer is empty
 	if len(w.buf.Bytes()) == 0 {
 		return nil
 	}
 	w.clearLines()
 
 	lines := 0
+	var currentLine bytes.Buffer
 	for _, b := range w.buf.Bytes() {
 		if b == '\n' {
 			lines++
+			currentLine.Reset()
+		} else {
+			currentLine.Write([]byte{b})
+			if overFlowHandled && currentLine.Len() > termWidth {
+				lines++
+				currentLine.Reset()
+			}
 		}
 	}
 	w.lineCount = lines
@@ -105,7 +126,7 @@ func (w *Writer) Listen() {
 		select {
 		case <-w.ticker.C:
 			if w.ticker != nil {
-				w.Flush()
+				_ = w.Flush()
 			}
 		case <-w.tdone:
 			w.mtx.Lock()
@@ -118,23 +139,35 @@ func (w *Writer) Listen() {
 	}
 }
 
-// Write save the contents of b to its buffers. The only errors returned are ones encountered while writing to the underlying buffer.
-func (w *Writer) Write(b []byte) (n int, err error) {
+// Write save the contents of buf to the writer b. The only errors returned are ones encountered while writing to the underlying buffer.
+func (w *Writer) Write(buf []byte) (n int, err error) {
 	w.mtx.Lock()
 	defer w.mtx.Unlock()
-	return w.buf.Write(b)
+	return w.buf.Write(buf)
 }
 
 // Bypass creates an io.Writer which allows non-buffered output to be written to the underlying output
 func (w *Writer) Bypass() io.Writer {
 	return &bypass{writer: w}
 }
 
-func (b *bypass) Write(p []byte) (n int, err error) {
+func (b *bypass) Write(p []byte) (int, error) {
 	b.writer.mtx.Lock()
 	defer b.writer.mtx.Unlock()
 
 	b.writer.clearLines()
 	b.writer.lineCount = 0
 	return b.writer.Out.Write(p)
 }
+
+// Newline creates an io.Writer which allows buffered output to be written to the underlying output. This enable writing
+// to multiple lines at once.
+func (w *Writer) Newline() io.Writer {
+	return &newline{writer: w}
+}
+
+func (n *newline) Write(p []byte) (int, error) {
+	n.writer.mtx.Lock()
+	defer n.writer.mtx.Unlock()
+	return n.writer.buf.Write(p)
+}

writer_posix.go

@@ -4,11 +4,12 @@ package uilive
 
 import (
 	"fmt"
+	"strings"
 )
 
+// clear the line and move the cursor up
+var clear = fmt.Sprintf("%c[%dA%c[2K", ESC, 1, ESC)
+
 func (w *Writer) clearLines() {
-	for i := 0; i < w.lineCount; i++ {
-		fmt.Fprintf(w.Out, "%c[2K", ESC)     // clear the line
-		fmt.Fprintf(w.Out, "%c[%dA", ESC, 1) // move the cursor up
-	}
+	_, _ = fmt.Fprint(w.Out, strings.Repeat(clear, w.lineCount))
 }

writer_test.go

@@ -12,10 +12,10 @@ func TestWriter(t *testing.T) {
 	w.Out = b
 	w.Start()
 	for i := 0; i < 2; i++ {
-		fmt.Fprintln(w, "foo")
+		_, _ = fmt.Fprintln(w, "foo")
 	}
 	w.Stop()
-	fmt.Fprintln(b, "bar")
+	_, _ = fmt.Fprintln(b, "bar")
 
 	want := "foo\nfoo\nbar\n"
 	if b.String() != want {

writer_windows.go

@@ -4,9 +4,10 @@ package uilive
 
 import (
 	"fmt"
-	"github.com/mattn/go-isatty"
+	"strings"
 	"syscall"
 	"unsafe"
+	"github.com/mattn/go-isatty"
 )
 
 var kernel32 = syscall.NewLazyDLL("kernel32.dll")
@@ -15,9 +16,11 @@ var (
 	procGetConsoleScreenBufferInfo = kernel32.NewProc("GetConsoleScreenBufferInfo")
 	procSetConsoleCursorPosition   = kernel32.NewProc("SetConsoleCursorPosition")
 	procFillConsoleOutputCharacter = kernel32.NewProc("FillConsoleOutputCharacterW")
-	procFillConsoleOutputAttribute = kernel32.NewProc("FillConsoleOutputAttribute")
 )
 
+// clear the line and move the cursor up
+var clear = fmt.Sprintf("%c[%dA%c[2K\r", ESC, 0, ESC)
+
 type short int16
 type dword uint32
 type word uint16
@@ -48,27 +51,24 @@ func (w *Writer) clearLines() {
 		ok = false
 	}
 	if !ok {
-		for i := 0; i < w.lineCount; i++ {
-			fmt.Fprintf(w.Out, "%c[%dA", ESC, 0) // move the cursor up
-			fmt.Fprintf(w.Out, "%c[2K\r", ESC)   // clear the line
-		}
+		_, _ = fmt.Fprint(w.Out, strings.Repeat(clear, w.lineCount))
 		return
 	}
 	fd := f.Fd()
 	var csbi consoleScreenBufferInfo
-	procGetConsoleScreenBufferInfo.Call(fd, uintptr(unsafe.Pointer(&csbi)))
+	_, _, _ = procGetConsoleScreenBufferInfo.Call(fd, uintptr(unsafe.Pointer(&csbi)))
 
 	for i := 0; i < w.lineCount; i++ {
 		// move the cursor up
 		csbi.cursorPosition.y--
-		procSetConsoleCursorPosition.Call(fd, uintptr(*(*int32)(unsafe.Pointer(&csbi.cursorPosition))))
+		_, _, _ = procSetConsoleCursorPosition.Call(fd, uintptr(*(*int32)(unsafe.Pointer(&csbi.cursorPosition))))
 		// clear the line
 		cursor := coord{
 			x: csbi.window.left,
 			y: csbi.window.top + csbi.cursorPosition.y,
 		}
 		var count, w dword
 		count = dword(csbi.size.x)
-		procFillConsoleOutputCharacter.Call(fd, uintptr(' '), uintptr(count), *(*uintptr)(unsafe.Pointer(&cursor)), uintptr(unsafe.Pointer(&w)))
+		_, _, _ = procFillConsoleOutputCharacter.Call(fd, uintptr(' '), uintptr(count), *(*uintptr)(unsafe.Pointer(&cursor)), uintptr(unsafe.Pointer(&w)))
 	}
 }