add load json from file keybinding

gui/gui.go

@@ -1,7 +1,11 @@
 package gui
 
 import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
 	"log"
+	"os"
 
 	"github.com/gdamore/tcell"
 	"github.com/rivo/tview"
@@ -46,6 +50,22 @@ func (g *Gui) Modal(p tview.Primitive, width, height int) tview.Primitive {
 		AddItem(p, 1, 1, 1, 1, 0, 0, true)
 }
 
+func (g *Gui) Message(message, page string, doneFunc func()) {
+	doneLabel := "ok"
+	modal := tview.NewModal().
+		SetText(message).
+		AddButtons([]string{doneLabel}).
+		SetDoneFunc(func(buttonIndex int, buttonLabel string) {
+			g.Pages.RemovePage("message")
+			g.Pages.SwitchToPage(page)
+			if buttonLabel == doneLabel {
+				doneFunc()
+			}
+		})
+
+	g.Pages.AddAndSwitchToPage("message", g.Modal(modal, 80, 29), true).ShowPage("main")
+}
+
 func (g *Gui) Input(text string, doneFunc func(text string)) {
 	input := tview.NewInputField().SetText(text)
 	input.SetBorder(true)
@@ -58,3 +78,40 @@ func (g *Gui) Input(text string, doneFunc func(text string)) {
 
 	g.Pages.AddAndSwitchToPage("input", g.Modal(input, 0, 3), true).ShowPage("main")
 }
+
+func (g *Gui) LoadJSON() {
+	width := 30
+	pageName := "read_from_file"
+	form := tview.NewForm()
+	form.AddInputField("file", "", width, nil, nil).
+		AddButton("read", func() {
+			file := form.GetFormItem(0).(*tview.InputField).GetText()
+			file = os.ExpandEnv(file)
+			b, err := ioutil.ReadFile(file)
+			if err != nil {
+				msg := fmt.Sprintf("can't read file: %s", err)
+				log.Println(msg)
+				g.Message(msg, "main", func() {})
+				return
+			}
+
+			var i interface{}
+			if err := json.Unmarshal(b, &i); err != nil {
+				msg := fmt.Sprintf("can't read file: %s", err)
+				log.Println(msg)
+				g.Message(msg, "main", func() {})
+				return
+			}
+
+			g.Tree.UpdateView(g, i)
+			g.Pages.RemovePage(pageName)
+		}).
+		AddButton("cancel", func() {
+			g.Pages.RemovePage(pageName)
+		})
+
+	form.SetBorder(true).SetTitle("read from file").
+		SetTitleAlign(tview.AlignLeft)
+
+	g.Pages.AddAndSwitchToPage(pageName, g.Modal(form, 0, 8), true).ShowPage("main")
+}

gui/tree.go

@@ -86,6 +86,8 @@ func (t *Tree) SetKeybindings(g *Gui) {
 			t.GetRoot().ExpandAll()
 		case 'l':
 			t.GetCurrentNode().SetExpanded(true)
+		case 'r':
+			g.LoadJSON()
 		}
 
 		return event