buffer file and dir previews for drawing

Mentioned in #5.

client.go

@@ -38,7 +38,7 @@ func client() {
 			app.ui.message = msg
 			log.Printf(msg)
 		} else {
-			app.ui.echoFileInfo(app.nav)
+			app.ui.loadFile(app.nav)
 		}
 		defer rcFile.Close()
 

eval.go

@@ -125,29 +125,29 @@ func (e *CallExpr) eval(app *App, args []string) {
 	switch e.name {
 	case "up":
 		app.nav.up(1)
-		app.ui.echoFileInfo(app.nav)
+		app.ui.loadFile(app.nav)
 	case "half-up":
 		app.nav.up(app.nav.height / 2)
-		app.ui.echoFileInfo(app.nav)
+		app.ui.loadFile(app.nav)
 	case "page-up":
 		app.nav.up(app.nav.height)
-		app.ui.echoFileInfo(app.nav)
+		app.ui.loadFile(app.nav)
 	case "down":
 		app.nav.down(1)
-		app.ui.echoFileInfo(app.nav)
+		app.ui.loadFile(app.nav)
 	case "half-down":
 		app.nav.down(app.nav.height / 2)
-		app.ui.echoFileInfo(app.nav)
+		app.ui.loadFile(app.nav)
 	case "page-down":
 		app.nav.down(app.nav.height)
-		app.ui.echoFileInfo(app.nav)
+		app.ui.loadFile(app.nav)
 	case "updir":
 		if err := app.nav.updir(); err != nil {
 			app.ui.message = err.Error()
 			log.Print(err)
 			return
 		}
-		app.ui.echoFileInfo(app.nav)
+		app.ui.loadFile(app.nav)
 	case "open":
 		dir := app.nav.currDir()
 
@@ -171,7 +171,7 @@ func (e *CallExpr) eval(app *App, args []string) {
 				log.Print(err)
 				return
 			}
-			app.ui.echoFileInfo(app.nav)
+			app.ui.loadFile(app.nav)
 			return
 		}
 
@@ -203,14 +203,13 @@ func (e *CallExpr) eval(app *App, args []string) {
 		gExitFlag = true
 	case "bot":
 		app.nav.bot()
-		app.ui.echoFileInfo(app.nav)
+		app.ui.loadFile(app.nav)
 	case "top":
 		app.nav.top()
-		app.ui.echoFileInfo(app.nav)
+		app.ui.loadFile(app.nav)
 	case "read":
 		s := app.ui.prompt(app.nav, ":")
 		if len(s) == 0 {
-			app.ui.echoFileInfo(app.nav)
 			return
 		}
 		log.Printf("command: %s", s)
@@ -224,23 +223,38 @@ func (e *CallExpr) eval(app *App, args []string) {
 		}
 	case "read-shell":
 		s := app.ui.prompt(app.nav, "$")
+		if len(s) == 0 {
+			return
+		}
 		log.Printf("shell: %s", s)
 		app.runShell(s, nil, false, false)
 	case "read-shell-wait":
 		s := app.ui.prompt(app.nav, "!")
+		if len(s) == 0 {
+			return
+		}
 		log.Printf("shell-wait: %s", s)
 		app.runShell(s, nil, true, false)
 	case "read-shell-async":
 		s := app.ui.prompt(app.nav, "&")
+		if len(s) == 0 {
+			return
+		}
 		log.Printf("shell-async: %s", s)
 		app.runShell(s, nil, false, true)
 	case "search":
 		s := app.ui.prompt(app.nav, "/")
+		if len(s) == 0 {
+			return
+		}
 		log.Printf("search: %s", s)
 		app.ui.message = "sorry, search is not implemented yet!"
 		// TODO: implement
 	case "search-back":
 		s := app.ui.prompt(app.nav, "?")
+		if len(s) == 0 {
+			return
+		}
 		log.Printf("search-back: %s", s)
 		app.ui.message = "sorry, search-back is not implemented yet!"
 		// TODO: implement
@@ -288,7 +302,7 @@ func (e *CallExpr) eval(app *App, args []string) {
 			log.Print(err)
 			return
 		}
-		app.ui.echoFileInfo(app.nav)
+		app.ui.loadFile(app.nav)
 	default:
 		cmd, ok := gOpts.cmds[e.name]
 		if !ok {
@@ -307,7 +321,7 @@ func (e *ExecExpr) eval(app *App, args []string) {
 		log.Printf("shell: %s -- %s", e, args)
 		app.ui.clearMsg()
 		app.runShell(e.expr, args, false, false)
-		app.ui.echoFileInfo(app.nav)
+		app.ui.loadFile(app.nav)
 	case "!":
 		log.Printf("shell-wait: %s -- %s", e, args)
 		app.runShell(e.expr, args, true, false)

ui.go

@@ -235,55 +235,14 @@ func (win *Win) printd(dir *Dir, marks map[string]bool) {
 	}
 }
 
-func (win *Win) printr(reg *os.File) error {
-	var reader io.ReadSeeker
-
-	if len(gOpts.previewer) != 0 {
-		cmd := exec.Command(gOpts.previewer, reg.Name(), strconv.Itoa(win.w), strconv.Itoa(win.h))
-
-		out, err := cmd.Output()
-		if err != nil {
-			log.Printf("previewing file: %s", err)
-		}
-
-		reader = bytes.NewReader(out)
-	} else {
-		reader = reg
-	}
-
+func (win *Win) printr(reg []string) {
 	fg, bg := termbox.ColorDefault, termbox.ColorDefault
 
-	buf := bufio.NewScanner(reader)
-
-	for i := 0; i < win.h && buf.Scan(); i++ {
-		for _, r := range buf.Text() {
-			if unicode.IsSpace(r) {
-				continue
-			}
-			if !unicode.IsPrint(r) && r != EscapeCode {
-				fg = termbox.AttrBold
-				win.print(0, 0, fg, bg, "binary")
-				return nil
-			}
-		}
+	for i, l := range reg {
+		win.print(2, i, fg, bg, l)
 	}
 
-	if buf.Err() != nil {
-		return fmt.Errorf("printing regular file: %s", buf.Err())
-	}
-
-	reader.Seek(0, 0)
-	buf = bufio.NewScanner(reader)
-
-	for i := 0; i < win.h && buf.Scan(); i++ {
-		win.print(2, i, fg, bg, buf.Text())
-	}
-
-	if buf.Err() != nil {
-		return fmt.Errorf("printing regular file: %s", buf.Err())
-	}
-
-	return nil
+	return
 }
 
 type UI struct {
@@ -292,6 +251,8 @@ type UI struct {
 	msgwin  *Win
 	menuwin *Win
 	message string
+	regprev []string
+	dirprev *Dir
 }
 
 func getWidths(wtot int) []int {
@@ -352,7 +313,7 @@ func (ui *UI) renew() {
 	ui.msgwin.renew(wtot, 1, 0, htot-1)
 }
 
-func (ui *UI) echoFileInfo(nav *Nav) {
+func (ui *UI) loadFile(nav *Nav) {
 	dir := nav.currDir()
 
 	if len(dir.fi) == 0 {
@@ -362,6 +323,65 @@ func (ui *UI) echoFileInfo(nav *Nav) {
 	curr := nav.currFile()
 
 	ui.message = fmt.Sprintf("%v %v %v", curr.Mode(), humanize(curr.Size()), curr.ModTime().Format(time.ANSIC))
+
+	if !gOpts.preview {
+		return
+	}
+
+	path := nav.currPath()
+
+	if curr.IsDir() {
+		dir := newDir(path)
+		dir.load(nav.inds[path], nav.poss[path], nav.height, nav.names[path])
+		ui.dirprev = dir
+	} else if curr.Mode().IsRegular() {
+		var reader io.Reader
+
+		if len(gOpts.previewer) != 0 {
+			cmd := exec.Command(gOpts.previewer, path, strconv.Itoa(nav.height))
+
+			out, err := cmd.Output()
+			if err != nil {
+				msg := fmt.Sprintf("previewing file: %s", err)
+				ui.message = msg
+				log.Print(msg)
+			}
+
+			reader = bytes.NewReader(out)
+		} else {
+			f, err := os.Open(path)
+			if err != nil {
+				msg := fmt.Sprintf("opening file: %s", err)
+				ui.message = msg
+				log.Print(msg)
+			}
+
+			reader = f
+		}
+
+		ui.regprev = nil
+
+		buf := bufio.NewScanner(reader)
+
+		for i := 0; i < nav.height && buf.Scan(); i++ {
+			for _, r := range buf.Text() {
+				if unicode.IsSpace(r) {
+					continue
+				}
+				if !unicode.IsPrint(r) && r != EscapeCode {
+					ui.regprev = []string{"binary"}
+					return
+				}
+			}
+			ui.regprev = append(ui.regprev, buf.Text())
+		}
+
+		if buf.Err() != nil {
+			msg := fmt.Sprintf("loading file: %s", buf.Err())
+			ui.message = msg
+			log.Print(msg)
+		}
+	}
 }
 
 func (ui *UI) clearMsg() {
@@ -418,21 +438,9 @@ func (ui *UI) draw(nav *Nav) {
 		}
 
 		if f.IsDir() {
-			dir := newDir(path)
-			dir.load(nav.inds[path], nav.poss[path], nav.height, nav.names[path])
-			preview.printd(dir, nav.marks)
+			preview.printd(ui.dirprev, nav.marks)
 		} else if f.Mode().IsRegular() {
-			file, err := os.Open(path)
-			if err != nil {
-				msg := fmt.Sprintf("opening file: %s", err)
-				ui.message = msg
-				log.Print(msg)
-			}
-
-			if err := preview.printr(file); err != nil {
-				ui.message = err.Error()
-				log.Print(err)
-			}
+			preview.printr(ui.regprev)
 		}
 	}
 }