fix: [filter] fix #16

hashlookup.go

@@ -27,10 +27,9 @@ type (
 	}
 
 	HashlookupBloom struct {
-		hgui   *hgui
-		tabPtr *container.TabItem
-		B      *bloom.BloomFilter
-		path   string
+		hgui *hgui
+		B    *bloom.BloomFilter
+		path string
 		// if the download completed
 		Complete bool
 		// if the download was cancelled
@@ -108,7 +107,7 @@ func (c *Client) LookupSHA1(sha1 string) (resp *gabs.Container, err error) {
 func NewHashlookupBloom(path string, h *hgui) *HashlookupBloom {
 	tmpBloom := bloom.BloomFilter{}
 	counter := &WriteCounter{}
-	tmpChan := make(chan struct{})
+	tmpChan := make(chan struct{}, 1)
 	return &HashlookupBloom{
 		B:              &tmpBloom,
 		path:           path,
@@ -123,6 +122,8 @@ func NewHashlookupBloom(path string, h *hgui) *HashlookupBloom {
 // DownloadFilterToFilter downloads the bloom filter
 // and load it without touching the disk
 func (h *HashlookupBloom) DownloadFilterToFilter() error {
+	h.Complete = false
+	h.Ready = false
 	var err error
 	resp, err := http.Get(_bloomFilterDefaultUrl)
 	defer resp.Body.Close()
@@ -132,6 +133,10 @@ func (h *HashlookupBloom) DownloadFilterToFilter() error {
 		return err
 	}
 	ch := make(chan struct{})
+	// make sure the cancelChan is empty before starting
+	for len(h.cancelDownload) > 0 {
+		<-h.cancelDownload
+	}
 	go func() {
 		select {
 		case <-h.cancelDownload:
@@ -149,18 +154,20 @@ func (h *HashlookupBloom) DownloadFilterToFilter() error {
 		fmt.Println("Issue when reading from the remote %s: %s", _bloomFilterDefaultUrl, err)
 	} else {
 		h.Complete = true
+		h.GetFilterDetails()
+		h.Ready = true
+		h.StopBar()
+		h.hgui.setOffline()
 	}
 	ch <- struct{}{}
-	h.GetFilterDetails()
-	h.Ready = true
-	h.StopBar()
-	h.hgui.setOffline()
 	return nil
 }
 
 // DownloadFilterToFile downloads the bloom filter into
 // the file at path. Beware this is blocking and takes time
 func (h *HashlookupBloom) DownloadFilterToFile() error {
+	h.Complete = false
+	h.Ready = false
 	var err error
 	out, err := os.Create(h.path)
 	if err != nil {
@@ -169,6 +176,10 @@ func (h *HashlookupBloom) DownloadFilterToFile() error {
 	defer out.Close()
 	resp, err := http.Get(_bloomFilterDefaultUrl)
 	ch := make(chan struct{})
+	// make sure the cancelChan is empty before starting the routine
+	for len(h.cancelDownload) > 0 {
+		<-h.cancelDownload
+	}
 	go func() {
 		select {
 		case <-h.cancelDownload:
@@ -197,15 +208,18 @@ func (h *HashlookupBloom) DownloadFilterToFile() error {
 // LoadFilterFromFile loads the bloom filter from the file
 // located at path. Beware this is blocking and takes time
 func (h *HashlookupBloom) LoadFilterFromFile() error {
-	var err error
-	h.B, err = bloom.LoadFilter(h.path, _bloomFilterGzip)
-	h.GetFilterDetails()
-	if err != nil {
-		log.Fatal(err)
+	if !h.Cancelled {
+		h.Ready = false
+		var err error
+		h.B, err = bloom.LoadFilter(h.path, _bloomFilterGzip)
+		h.GetFilterDetails()
+		if err != nil {
+			log.Fatal(err)
+		}
+		h.Ready = true
+		h.StopBar()
+		h.hgui.setOffline()
 	}
-	h.Ready = true
-	h.StopBar()
-	h.hgui.setOffline()
 	return nil
 }
 
@@ -242,7 +256,8 @@ func (h *HashlookupBloom) Content() fyne.CanvasObject {
 	infinite := widget.NewProgressBarInfinite()
 	cancelBtn := widget.NewButtonWithIcon("Cancel", theme.CancelIcon(), func() {
 		h.cancelDownload <- struct{}{}
-		h.hgui.resultsTabs.Remove(h.tabPtr)
+		h.hgui.resultsTabs.Remove(h.hgui.bfTab.tab)
+		h.hgui.bfTab.isOpened = false
 		return
 	})
 	bottomHboxContainer := container.NewBorder(nil, nil, nil, cancelBtn, infinite)

hgui.go

@@ -19,6 +19,12 @@ type hashlookupTab struct {
 	uri fyne.URI
 }
 
+// bloofilterTab holds the hashlookup filter and its tab-related data
+type bloomfilterTab struct {
+	tab      *container.TabItem
+	isOpened bool
+}
+
 type hgui struct {
 	win              fyne.Window
 	app              *fyne.App
@@ -31,6 +37,7 @@ type hgui struct {
 	toolBar          *widget.Toolbar
 	// The Bloom filter is tied to the application
 	Filter *HashlookupBloom
+	bfTab  *bloomfilterTab
 }
 
 func (h *hgui) OpenHashlooker(u fyne.URI) {
@@ -75,6 +82,39 @@ func (h *hgui) OpenHashlooker(u fyne.URI) {
 // a special tab that presents the filter's details
 // as well as its download progress
 func (h *hgui) OpenBloomFilter(operation string) {
+	// TODO write a newBloomFilterTab function
+	if h.Filter == nil {
+		fmt.Println("filter is nil")
+		h.Filter = &HashlookupBloom{}
+	}
+	// There was no tab struct so let's create one
+	if h.bfTab == nil {
+		fmt.Println("bfTab is nil")
+		h.bfTab = &bloomfilterTab{nil, false}
+	}
+
+	// It opened, it already exist
+	if h.bfTab.isOpened {
+		fmt.Println("bfTab is isOpened")
+		// need to cancel what was happening
+		h.Filter.cancelDownload <- struct{}{}
+		// reselect the tab if already opened
+		for _, item := range h.resultsTabs.Items {
+			if item == h.bfTab.tab {
+				h.resultsTabs.Select(h.bfTab.tab)
+				h.bfTab.isOpened = true
+			}
+		}
+		// create fresh content
+		h.bfTab.tab.Content = h.Filter.Content()
+		// If not opened yet, we open it
+	} else {
+		h.bfTab.tab = container.NewTabItemWithIcon("Bloom filter", theme.InfoIcon(), h.Filter.Content())
+		h.resultsTabs.Append(h.bfTab.tab)
+		h.resultsTabs.Select(h.bfTab.tab)
+		h.bfTab.isOpened = true
+	}
+
 	switch operation {
 	case "download":
 		// Closing the tab won't kill it
@@ -85,6 +125,8 @@ func (h *hgui) OpenBloomFilter(operation string) {
 				time.Sleep(time.Second * 1)
 			}
 			if h.Filter.Cancelled {
+				// Reset the value in case of object reuse
+				h.Filter.Cancelled = false
 				return
 			}
 			if h.Filter.Complete {
@@ -97,13 +139,4 @@ func (h *hgui) OpenBloomFilter(operation string) {
 	case "remote":
 		go h.Filter.DownloadFilterToFilter()
 	}
-
-	newTab := container.NewTabItemWithIcon("Bloom filter", theme.InfoIcon(), h.Filter.Content())
-	h.Filter.tabPtr = newTab
-	h.resultsTabs.Append(newTab)
-	h.resultsTabs.Select(newTab)
-}
-
-func (d *hgui) doStuff(u fyne.URI) {
-	fmt.Println("I do stuff.")
 }

main.go

@@ -27,8 +27,7 @@ func main() {
 	w := a.NewWindow("Hashlookup-gui")
 	w.Resize(fyne.NewSize(1024, 768))
 
-	tmpBloom := HashlookupBloom{}
-	hgui := &hgui{win: w, offlineMode: false, Filter: &tmpBloom, app: &a}
+	hgui := &hgui{win: w, offlineMode: false, app: &a}
 	if len(os.Args) > 1 {
 		path, _ := filepath.Abs(os.Args[1])
 		root := storage.NewFileURI(path)