Fix crash after importing a watch-only wallet and clicking the send b…

…utton (#200)

* fix crash when import watch-only wallet and click send

* add listen mixer notification and check nil when delete watch-only wallet

* update logic nitices for user when they have only watch-only wallet

* clean code

* update new logic for check when click button send

* change warning text when the app have only watch-only wallet

libwallet/assets/dcr/wallet.go

@@ -155,7 +155,8 @@ func CreateWatchOnlyWallet(walletName, extendedPublicKey string, params *sharedW
 		syncData: &SyncData{
 			syncProgressListeners: make(map[string]sharedW.SyncProgressListener),
 		},
-		txAndBlockNotificationListeners: make(map[string]sharedW.TxAndBlockNotificationListener),
+		txAndBlockNotificationListeners:  make(map[string]sharedW.TxAndBlockNotificationListener),
+		accountMixerNotificationListener: make(map[string]AccountMixerNotificationListener),
 	}
 
 	dcrWallet.SetNetworkCancelCallback(dcrWallet.SafelyCancelSync)

ui/cryptomaterial/slider.go

@@ -57,8 +57,12 @@ func (s *Slider) Layout(gtx C, items []layout.Widget) D {
 		s.items = items
 		s.isSliderItemsSet = true
 	}
-	s.handleClickEvent()
 
+	if len(s.items) == 0 {
+		return D{}
+	}
+
+	s.handleClickEvent()
 	gtx.Constraints.Max = s.items[s.selected](gtx).Size
 	return layout.Stack{Alignment: layout.S}.Layout(gtx,
 		layout.Expanded(s.items[s.selected]),
@@ -138,10 +142,6 @@ func (s *Slider) containerLayout(gtx C, content layout.Widget) D {
 	return s.card.Layout(gtx, content)
 }
 
-func (s *Slider) centerLayout(gtx C, content layout.Widget) D {
-	return layout.Center.Layout(gtx, content)
-}
-
 func (s *Slider) RefreshItems() {
 	s.isSliderItemsSet = false
 }

ui/page/root/home_page.go

@@ -40,7 +40,6 @@ type HomePage struct {
 	appLevelSettingsButton *cryptomaterial.Clickable
 	appNotificationButton  *cryptomaterial.Clickable
 	hideBalanceButton      *cryptomaterial.Clickable
-	checkBox               cryptomaterial.CheckBoxStyle
 	infoButton             cryptomaterial.IconButton // TOD0: use *cryptomaterial.Clickable
 
 	bottomNavigationBar  components.BottomNavigationBar
@@ -215,6 +214,17 @@ func (hp *HomePage) HandleUserInteractions() {
 			case values.StrReceive:
 				hp.ParentWindow().ShowModal(components.NewReceiveModal(hp.Load))
 			case values.StrSend:
+				allWallets := hp.WL.AssetsManager.AllWallets()
+				isSendAvailable := false
+				for _, wallet := range allWallets {
+					if !wallet.IsWatchingOnlyWallet() {
+						isSendAvailable = true
+					}
+				}
+				if !isSendAvailable {
+					hp.showWarningNoWallet()
+					return
+				}
 				hp.ParentWindow().ShowModal(send.NewSendPage(hp.Load, true))
 			}
 		}
@@ -277,6 +287,16 @@ func (hp *HomePage) HandleUserInteractions() {
 	}
 }
 
+func (hp *HomePage) showWarningNoWallet() {
+	go func() {
+		info := modal.NewCustomModal(hp.Load).
+			PositiveButtonStyle(hp.Theme.Color.Primary, hp.Theme.Color.Surface).
+			SetContentAlignment(layout.W, layout.W, layout.Center).
+			Body(values.String(values.StrNoWalletsAvailable))
+		hp.ParentWindow().ShowModal(info)
+	}()
+}
+
 // KeysToHandle returns an expression that describes a set of key combinations
 // that this page wishes to capture. The HandleKeyPress() method will only be
 // called when any of these key combinations is pressed.

ui/values/localizable/en.go

@@ -787,4 +787,5 @@ const EN = `
 "bondStrengthErrMsg" = "Bond Strength must be a valid number"
 "minimumBondStrength" = "Minimum Bond Strength is %d"
 "assets" = "Assets"
+"noWalletsAvailable" = "You cannot spend from a watch only wallet, try creating another wallet."
 `

ui/values/strings.go

@@ -897,4 +897,5 @@ const (
 	StrBondStrengthErrMsg              = "bondStrengthErrMsg"
 	StrMinimumBondStrength             = "minimumBondStrength"
 	StrAssets                          = "assets"
+	StrNoWalletsAvailable              = "noWalletsAvailable"
 )

ui/window.go

@@ -282,6 +282,9 @@ func (win *Window) prepareToDisplayUI(evt system.FrameEvent) *op.Ops {
 		if modal := win.navigator.TopModal(); modal != nil {
 			gtx = gtx.Disabled()
 		}
+		if win.navigator.CurrentPage() == nil {
+			win.navigator.Display(page.NewStartPage(win.load))
+		}
 		return win.navigator.CurrentPage().Layout(gtx)
 	})