add and use event bus for UI progress

imgbom/presenter/text/presenter.go

@@ -10,17 +10,23 @@ import (
 )
 
 // Presenter holds the Present method to produce output
-type Presenter struct{}
+type Presenter struct {
+	img     *stereoscopeImg.Image
+	catalog *pkg.Catalog
+}
 
 // NewPresenter is a constructor for a Presenter
-func NewPresenter() *Presenter {
-	return &Presenter{}
+func NewPresenter(img *stereoscopeImg.Image, catalog *pkg.Catalog) *Presenter {
+	return &Presenter{
+		img:     img,
+		catalog: catalog,
+	}
 }
 
 // Present is a method that is in charge of writing to an output buffer
-func (pres *Presenter) Present(output io.Writer, img *stereoscopeImg.Image, catalog *pkg.Catalog) error {
-	tags := make([]string, len(img.Metadata.Tags))
-	for idx, tag := range img.Metadata.Tags {
+func (pres *Presenter) Present(output io.Writer) error {
+	tags := make([]string, len(pres.img.Metadata.Tags))
+	for idx, tag := range pres.img.Metadata.Tags {
 		tags[idx] = tag.String()
 	}
 
@@ -30,7 +36,7 @@ func (pres *Presenter) Present(output io.Writer, img *stereoscopeImg.Image, cata
 
 	fmt.Fprintln(w, "[Image]")
 
-	for idx, l := range img.Layers {
+	for idx, l := range pres.img.Layers {
 		fmt.Fprintln(w, " Layer:\t", idx)
 		fmt.Fprintln(w, " Digest:\t", l.Metadata.Digest)
 		fmt.Fprintln(w, " Size:\t", l.Metadata.Size)
@@ -40,7 +46,7 @@ func (pres *Presenter) Present(output io.Writer, img *stereoscopeImg.Image, cata
 	}
 
 	// populate artifacts...
-	for p := range catalog.Enumerate() {
+	for p := range pres.catalog.Enumerate() {
 		fmt.Fprintln(w, fmt.Sprintf("[%s]", p.Name))
 		fmt.Fprintln(w, " Version:\t", p.Version)
 		fmt.Fprintln(w, " Type:\t", p.Type.String())

imgbom/presenter/text/presenter_test.go

@@ -19,7 +19,6 @@ type PackageInfo struct {
 }
 
 func TestTextPresenter(t *testing.T) {
-	pres := NewPresenter()
 	var buffer bytes.Buffer
 
 	catalog := pkg.NewCatalog()
@@ -53,8 +52,9 @@ func TestTextPresenter(t *testing.T) {
 		l.Metadata.Digest = "sha256:ad8ecdc058976c07e7e347cb89fa9ad86a294b5ceaae6d09713fb035f84115abf3c4a2388a4af3aa60f13b94f4c6846930bdf53"
 	}
 
+	pres := NewPresenter(img, catalog)
 	// run presenter
-	err := pres.Present(&buffer, img, catalog)
+	err := pres.Present(&buffer)
 	if err != nil {
 		t.Fatal(err)
 	}