feat(animation): animate loading prompt

2 files changed, 51 insertions, 1 deletions

diff --git a/animation.go b/animation.go
new file mode 100644
index 0000000..226f309
--- /dev/null
+++ b/animation.go
@@ -0,0 +1,49 @@
+package main
+
+import (
+	"fmt"
+	"time"
+	"strings"
+	"github.com/fatih/color"
+)
+
+var loadingDone chan bool
+
+func showLoadingPrompt(msg string) {
+	if loadingDone != nil {
+		return
+	}
+
+	loadingDone = make(chan bool)
+	go func() {
+		white := color.New(color.FgWhite)
+		for {
+			select {
+			case <-loadingDone:
+				fmt.Print("\r") // move cursor to line start
+				fmt.Print(strings.Repeat(" ", len(msg)+4))
+				fmt.Print("\r") // clear line
+				return
+			default:
+				white.Printf("\r%s", msg)
+				for i := range 4 {
+					if i == 3 {
+						white.Print("?")
+					} else {
+						white.Print(".")
+					}
+					time.Sleep(700 * time.Millisecond)
+				}
+			}
+		}
+	}()
+}
+
+// hideLoadingPrompt stops the animation cleanly.
+func hideLoadingPrompt() {
+	if loadingDone != nil {
+		close(loadingDone)
+		loadingDone = nil
+		fmt.Print("\r\033[2K")
+	}
+}
diff --git a/main.go b/main.go
index 6ea7ed7..5b7147c 100644
--- a/main.go
+++ b/main.go
@@ -25,10 +25,11 @@ func main() {
         	}
          	pkgName := cmd.Args().First()
          	// prompt
-          	color.White("What the heck is \"%s\" ...?", pkgName)
+          	showLoadingPrompt(fmt.Sprintf("What the heck is \"%s\"", pkgName))
          	// search and print
          	formulae, cask := GetBrewInfo(pkgName)
           	data := UnifyInfo(formulae, cask, pkgName)
+          	hideLoadingPrompt()
           	PrintInfo(data)
             return nil
         },