Fix issues in tcell renderer and Windows build

- Fix display of CJK wide characters
- Fix horizontal offset of header lines
- Add support for keys with ALT modifier, shift-tab, page-up and down
- Fix util.ExecCommand to properly parse command-line arguments
- Fix redraw on resize
- Implement Pause/Resume for execute action
- Remove runtime check of GOOS
- Change exit status to 2 when tcell failed to start
- TBD: Travis CI build for tcell renderer
    - Pending. tcell cannot reliably ingest keys from tmux send-keys

9 files changed, 91 insertions, 28 deletions

diff --git a/.travis.yml b/.travis.yml
index 597c1f6e..a1a6497d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,10 @@
 language: ruby
-rvm:
-- 2.2.0
+matrix:
+  include:
+    - env: TAGS=
+      rvm: 2.2.0
+#   - env: TAGS=tcell
+#     rvm: 2.2.0
 
 install:
 - sudo apt-get update
diff --git a/src/Makefile b/src/Makefile
index edc77faf..15f4c736 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -52,7 +52,7 @@ android-build: $(SRCDIR)
 	rm -f $(RELEASEARM7)
 
 test: deps
-	SHELL=/bin/sh go test -v ./...
+	SHELL=/bin/sh go test -v -tags "$(TAGS)" ./...
 
 install: $(BINDIR)/fzf
 
diff --git a/src/reader.go b/src/reader.go
index 15a0f44e..7e8e2e01 100644
--- a/src/reader.go
+++ b/src/reader.go
@@ -4,7 +4,6 @@ import (
 	"bufio"
 	"io"
 	"os"
-	"runtime"
 
 	"github.com/junegunn/fzf/src/util"
 )
@@ -44,7 +43,7 @@ func (r *Reader) feed(src io.Reader) {
 		if len(bytea) > 0 {
 			if err == nil {
 				// get rid of carriage return if under Windows:
-				if runtime.GOOS == "windows" && byteaLen >= 2 && bytea[byteaLen-2] == byte('\r') {
+				if util.IsWindows() && byteaLen >= 2 && bytea[byteaLen-2] == byte('\r') {
 					bytea = bytea[:byteaLen-2]
 				} else {
 					bytea = bytea[:byteaLen-1]
diff --git a/src/terminal.go b/src/terminal.go
index 39c78239..6d1a1ab5 100644
--- a/src/terminal.go
+++ b/src/terminal.go
@@ -7,6 +7,7 @@ import (
 	"os/signal"
 	"regexp"
 	"sort"
+	"strconv"
 	"strings"
 	"sync"
 	"syscall"
@@ -919,6 +920,9 @@ func keyMatch(key int, event tui.Event) bool {
 }
 
 func quoteEntry(entry string) string {
+	if util.IsWindows() {
+		return strconv.Quote(strings.Replace(entry, "\"", "\\\"", -1))
+	}
 	return "'" + strings.Replace(entry, "'", "'\\''", -1) + "'"
 }
 
@@ -982,6 +986,9 @@ func (t *Terminal) executeCommand(template string, items []*Item) {
 	cmd.Stderr = os.Stderr
 	tui.Pause()
 	cmd.Run()
+	if tui.Resume() {
+		t.printAll()
+	}
 	t.refresh()
 }
 
diff --git a/src/tui/ncurses.go b/src/tui/ncurses.go
index 3f52f3f8..d55c1c87 100644
--- a/src/tui/ncurses.go
+++ b/src/tui/ncurses.go
@@ -138,6 +138,10 @@ func Pause() {
 	C.endwin()
 }
 
+func Resume() bool {
+	return false
+}
+
 func Close() {
 	C.endwin()
 	C.delscreen(_screen)
diff --git a/src/tui/tcell.go b/src/tui/tcell.go
index 591b366c..0bb06e95 100644
--- a/src/tui/tcell.go
+++ b/src/tui/tcell.go
@@ -13,6 +13,8 @@ import (
 
 	"github.com/gdamore/tcell"
 	"github.com/gdamore/tcell/encoding"
+
+	"github.com/junegunn/go-runewidth"
 )
 
 type ColorPair [2]Color
@@ -108,21 +110,32 @@ func (a Attr) Merge(b Attr) Attr {
 
 var (
 	_screen tcell.Screen
+	_mouse  bool
 )
 
-func Init(theme *ColorTheme, black bool, mouse bool) {
-	encoding.Register()
-
+func initScreen() {
 	s, e := tcell.NewScreen()
 	if e != nil {
 		fmt.Fprintf(os.Stderr, "%v\n", e)
-		os.Exit(1)
+		os.Exit(2)
 	}
 	if e = s.Init(); e != nil {
 		fmt.Fprintf(os.Stderr, "%v\n", e)
-		os.Exit(1)
+		os.Exit(2)
+	}
+	if _mouse {
+		s.EnableMouse()
+	} else {
+		s.DisableMouse()
 	}
 	_screen = s
+}
+
+func Init(theme *ColorTheme, black bool, mouse bool) {
+	encoding.Register()
+
+	_mouse = mouse
+	initScreen()
 
 	_color = theme != nil
 	if _color {
@@ -139,12 +152,6 @@ func Init(theme *ColorTheme, black bool, mouse bool) {
 	ColSelected = ColorPair{theme.Selected, theme.DarkBg}
 	ColHeader = ColorPair{theme.Header, theme.Bg}
 	ColBorder = ColorPair{theme.Border, theme.Bg}
-
-	if mouse {
-		_screen.EnableMouse()
-	} else {
-		_screen.DisableMouse()
-	}
 }
 
 func MaxX() int {
@@ -162,6 +169,7 @@ func (w *Window) win() *WindowTcell {
 }
 
 func Clear() {
+	_screen.Sync()
 	_screen.Clear()
 }
 
@@ -211,6 +219,7 @@ func GetChar() Event {
 
 		// process keyboard:
 	case *tcell.EventKey:
+		alt := (ev.Modifiers() & tcell.ModAlt) > 0
 		switch ev.Key() {
 		case tcell.KeyCtrlA:
 			return Event{CtrlA, 0, nil}
@@ -233,6 +242,9 @@ func GetChar() Event {
 		case tcell.KeyCtrlL:
 			return Event{CtrlL, 0, nil}
 		case tcell.KeyCtrlM:
+			if alt {
+				return Event{AltEnter, 0, nil}
+			}
 			return Event{CtrlM, 0, nil}
 		case tcell.KeyCtrlN:
 			return Event{CtrlN, 0, nil}
@@ -261,6 +273,9 @@ func GetChar() Event {
 		case tcell.KeyCtrlZ:
 			return Event{CtrlZ, 0, nil}
 		case tcell.KeyBackspace, tcell.KeyBackspace2:
+			if alt {
+				return Event{AltBS, 0, nil}
+			}
 			return Event{BSpace, 0, nil}
 
 		case tcell.KeyUp:
@@ -278,13 +293,15 @@ func GetChar() Event {
 			return Event{Del, 0, nil}
 		case tcell.KeyEnd:
 			return Event{End, 0, nil}
-		/*case tcell.KeyPgUp:
+		case tcell.KeyPgUp:
 			return Event{PgUp, 0, nil}
-		case tcell.KeyPgdn:
-			return Event{PgDn, 0, nil}*/
+		case tcell.KeyPgDn:
+			return Event{PgDn, 0, nil}
 
 		case tcell.KeyTab:
 			return Event{Tab, 0, nil}
+		case tcell.KeyBacktab:
+			return Event{BTab, 0, nil}
 
 		case tcell.KeyF1:
 			return Event{F1, 0, nil}
@@ -313,7 +330,19 @@ func GetChar() Event {
 
 		// ev.Ch doesn't work for some reason for space:
 		case tcell.KeyRune:
-			return Event{Rune, ev.Rune(), nil}
+			r := ev.Rune()
+			if alt {
+				switch r {
+				case ' ':
+					return Event{AltSpace, 0, nil}
+				case '/':
+					return Event{AltSlash, 0, nil}
+				}
+				if r >= 'a' && r <= 'z' {
+					return Event{AltA + int(r) - 'a', 0, nil}
+				}
+			}
+			return Event{Rune, r, nil}
 
 		case tcell.KeyEsc:
 			return Event{ESC, 0, nil}
@@ -325,7 +354,12 @@ func GetChar() Event {
 }
 
 func Pause() {
-	// TODO
+	_screen.Fini()
+}
+
+func Resume() bool {
+	initScreen()
+	return true
 }
 
 func Close() {
@@ -391,11 +425,10 @@ func (w *Window) Move(y int, x int) {
 
 func (w *Window) MoveAndClear(y int, x int) {
 	w.Move(y, x)
-	r, _ := utf8.DecodeRuneInString(" ")
 	for i := w.win().LastX; i < w.Width; i++ {
-		_screen.SetContent(i+w.Left, w.win().LastY+w.Top, r, nil, ColDefault.style())
+		_screen.SetContent(i+w.Left, w.win().LastY+w.Top, rune(' '), nil, ColDefault.style())
 	}
-	w.win().LastX = 0
+	w.win().LastX = x
 }
 
 func (w *Window) Print(text string) {
@@ -439,7 +472,7 @@ func (w *Window) PrintString(text string, pair ColorPair, a Attr) {
 			if xPos < (w.Left+w.Width) && yPos < (w.Top+w.Height) {
 				_screen.SetContent(xPos, yPos, r, nil, style)
 			}
-			lx++
+			lx += runewidth.RuneWidth(r)
 		}
 	}
 	w.win().LastX += lx
@@ -482,7 +515,7 @@ func (w *Window) FillString(text string, pair ColorPair, a Attr) bool {
 			}
 
 			_screen.SetContent(xPos, yPos, r, nil, style)
-			lx++
+			lx += runewidth.RuneWidth(r)
 		}
 	}
 	w.win().LastX += lx
diff --git a/src/util/util_unix.go b/src/util/util_unix.go
index dcc5cb5e..29e0d30d 100644
--- a/src/util/util_unix.go
+++ b/src/util/util_unix.go
@@ -15,3 +15,8 @@ func ExecCommand(command string) *exec.Cmd {
 	}
 	return exec.Command(shell, "-c", command)
 }
+
+// IsWindows returns true on Windows
+func IsWindows() bool {
+	return false
+}
diff --git a/src/util/util_windows.go b/src/util/util_windows.go
index a660f39e..3aa86606 100644
--- a/src/util/util_windows.go
+++ b/src/util/util_windows.go
@@ -5,6 +5,8 @@ package util
 import (
 	"os"
 	"os/exec"
+
+	"github.com/junegunn/go-shellwords"
 )
 
 // ExecCommand executes the given command with $SHELL
@@ -13,5 +15,14 @@ func ExecCommand(command string) *exec.Cmd {
 	if len(shell) == 0 {
 		shell = "cmd"
 	}
-	return exec.Command(shell, "/c", command)
+	args, _ := shellwords.Parse(command)
+	allArgs := make([]string, len(args)+1)
+	allArgs[0] = "/c"
+	copy(allArgs[1:], args)
+	return exec.Command(shell, allArgs...)
+}
+
+// IsWindows returns true on Windows
+func IsWindows() bool {
+	return true
 }
diff --git a/test/test_go.rb b/test/test_go.rb
index f34d8b32..3fdfddd6 100644
--- a/test/test_go.rb
+++ b/test/test_go.rb
@@ -1058,7 +1058,7 @@ class TestGoFZF < TestBase
   def test_invalid_term
     lines = `TERM=xxx #{FZF}`
     assert_equal 2, $?.exitstatus
-    assert lines.include?('Invalid $TERM: xxx')
+    assert lines.include?('Invalid $TERM: xxx') || lines.include?('terminal entry not found')
   end
 
   def test_invalid_option