Initial commit

app/fyne_demo/tutorials/bind.go

@@ -0,0 +1,111 @@
+package tutorials
+
+import (
+	"fmt"
+
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/container"
+	"fyne.io/fyne/v2/data/binding"
+	"fyne.io/fyne/v2/widget"
+)
+
+func bindingScreen(_ fyne.Window) fyne.CanvasObject {
+	f := 0.2
+	data := binding.BindFloat(&f)
+	label := widget.NewLabelWithData(binding.FloatToStringWithFormat(data, "Float value: %0.2f"))
+	entry := widget.NewEntryWithData(binding.FloatToString(data))
+	floats := container.NewGridWithColumns(2, label, entry)
+
+	slide := widget.NewSliderWithData(0, 1, data)
+	slide.Step = 0.01
+	bar := widget.NewProgressBarWithData(data)
+
+	buttons := container.NewGridWithColumns(4,
+		widget.NewButton("0%", func() {
+			data.Set(0)
+		}),
+		widget.NewButton("30%", func() {
+			data.Set(0.3)
+		}),
+		widget.NewButton("70%", func() {
+			data.Set(0.7)
+		}),
+		widget.NewButton("100%", func() {
+			data.Set(1)
+		}))
+
+	boolData := binding.NewBool()
+	check := widget.NewCheckWithData("Check me!", boolData)
+	checkLabel := widget.NewLabelWithData(binding.BoolToString(boolData))
+	checkEntry := widget.NewEntryWithData(binding.BoolToString(boolData))
+	checks := container.NewGridWithColumns(3, check, checkLabel, checkEntry)
+	item := container.NewVBox(floats, slide, bar, buttons, widget.NewSeparator(), checks, widget.NewSeparator())
+
+	dataList := binding.BindFloatList(&[]float64{0.1, 0.2, 0.3})
+
+	button := widget.NewButton("Append", func() {
+		dataList.Append(float64(dataList.Length()+1) / 10)
+	})
+
+	list := widget.NewListWithData(dataList,
+		func() fyne.CanvasObject {
+			return container.NewBorder(nil, nil, nil, widget.NewButton("+", nil),
+				widget.NewLabel("item x.y"))
+		},
+		func(item binding.DataItem, obj fyne.CanvasObject) {
+			f := item.(binding.Float)
+			text := obj.(*fyne.Container).Objects[0].(*widget.Label)
+			text.Bind(binding.FloatToStringWithFormat(f, "item %0.1f"))
+
+			btn := obj.(*fyne.Container).Objects[1].(*widget.Button)
+			btn.OnTapped = func() {
+				val, _ := f.Get()
+				_ = f.Set(val + 1)
+			}
+		})
+
+	formStruct := struct {
+		Name, Email string
+		Subscribe   bool
+	}{}
+
+	formData := binding.BindStruct(&formStruct)
+	form := newFormWithData(formData)
+	form.OnSubmit = func() {
+		fmt.Println("Struct:\n", formStruct)
+	}
+
+	listPanel := container.NewBorder(nil, button, nil, nil, list)
+	return container.NewBorder(item, nil, nil, nil, container.NewGridWithColumns(2, listPanel, form))
+}
+
+func newFormWithData(data binding.DataMap) *widget.Form {
+	keys := data.Keys()
+	items := make([]*widget.FormItem, len(keys))
+	for i, k := range keys {
+		data, err := data.GetItem(k)
+		if err != nil {
+			items[i] = widget.NewFormItem(k, widget.NewLabel(err.Error()))
+		}
+		items[i] = widget.NewFormItem(k, createBoundItem(data))
+	}
+
+	return widget.NewForm(items...)
+}
+
+func createBoundItem(v binding.DataItem) fyne.CanvasObject {
+	switch val := v.(type) {
+	case binding.Bool:
+		return widget.NewCheckWithData("", val)
+	case binding.Float:
+		s := widget.NewSliderWithData(0, 1, val)
+		s.Step = 0.01
+		return s
+	case binding.Int:
+		return widget.NewEntryWithData(binding.IntToString(val))
+	case binding.String:
+		return widget.NewEntryWithData(val)
+	default:
+		return widget.NewLabel("")
+	}
+}