manage cursor based on current peer position

Signed-off-by: Jakub Sokołowski <jakub@status.im>

keys.go

@@ -11,37 +11,12 @@ type Binding struct {
 }
 
 func (vc *ViewController) CursorUp(g *gocui.Gui, v *gocui.View) error {
-	return MoveCursor(-1, vc, g, v)
+	vc.State.SetCurrent(vc.State.GetState().Current - 1)
+	return nil
 }
 
 func (vc *ViewController) CursorDown(g *gocui.Gui, v *gocui.View) error {
-	return MoveCursor(1, vc, g, v)
-}
-
-func MoveCursor(mod int, vc *ViewController, g *gocui.Gui, v *gocui.View) error {
-	if v == nil {
-		return nil
-	}
-	cx, cy := v.Cursor()
-	// get peers
-	ps := vc.State.GetState()
-	peers := ps.Peers
-	// Don't go beyond available list of peers
-	if cy+mod >= len(peers) || cy+mod < 0 {
-		return nil
-	}
-	// update currently selected peer in the list
-	vc.State.SetCurrent(cy + mod)
-
-	if err := v.SetCursor(cx, cy+mod); err != nil {
-		if mod == -1 {
-			return nil
-		}
-		ox, oy := v.Origin()
-		if err := v.SetOrigin(ox, oy+mod); err != nil {
-			return err
-		}
-	}
+	vc.State.SetCurrent(vc.State.GetState().Current + 1)
 	return nil
 }
 

model.go

@@ -15,6 +15,9 @@ type Model struct {
 }
 
 func (m *Model) Current(state PeersState, peerIndex int) PeersState {
+	if peerIndex < 0 || peerIndex >= len(state.Peers) {
+		return state
+	}
 	return PeersState{
 		Peers:   state.Peers,
 		Current: peerIndex,

render.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"log"
 	"strings"
 
 	"github.com/jroimartin/gocui"
@@ -10,12 +11,13 @@ import (
 func GenRenderFunc(g *gocui.Gui, state *State) func() {
 	return func() {
 		ps := state.GetState()
-		renderPeers(g, ps.Peers)
+		renderPeerList(g, ps.Peers)
 		renderPeerInfo(g, state.GetCurrent())
+		updatePeerCursor(g, ps.Current)
 	}
 }
 
-func renderPeers(g *gocui.Gui, peers []Peer) {
+func renderPeerList(g *gocui.Gui, peers []Peer) {
 	if len(peers) == 0 {
 		return
 	}
@@ -56,11 +58,18 @@ func renderPeerInfo(g *gocui.Gui, peer *Peer) {
 	})
 }
 
-func boolToString(v bool, yes string, no string) string {
-	if v {
-		return yes
-	} else {
-		return no
+func updatePeerCursor(g *gocui.Gui, current int) {
+	v, err := g.View("main")
+	if err != nil {
+		log.Panicln("unable to find main view")
+	}
+	cx, _ := v.Cursor()
+
+	if err := v.SetCursor(cx, current); err != nil {
+		ox, _ := v.Origin()
+		if err := v.SetOrigin(ox, current); err != nil {
+			log.Panicln("unable to scroll")
+		}
 	}
 }
 
@@ -77,3 +86,11 @@ func (p Peer) AsTable(maxWidth int) string {
 		boolToString(p.Network.Trusted, "trusted", "normal"),
 		boolToString(p.Network.Static, "static", "dynamic"))
 }
+
+func boolToString(v bool, yes string, no string) string {
+	if v {
+		return yes
+	} else {
+		return no
+	}
+}