cview/form.go

201 lines
4.9 KiB
Go

package tview
import (
"strings"
"github.com/gdamore/tcell"
)
// Form is a Box which contains multiple input fields, one per row.
type Form struct {
Box
// The items of the form (one row per item).
items []*InputField
// The buttons of the form.
buttons []*Button
// The number of empty rows between items.
itemPadding int
// The index of the item or button which has focus. (Items are counted first,
// buttons are counted last.)
focusedElement int
// The label color.
labelColor tcell.Color
// The background color of the input area.
fieldBackgroundColor tcell.Color
// The text color of the input area.
fieldTextColor tcell.Color
}
// NewForm returns a new form.
func NewForm() *Form {
return &Form{
Box: *NewBox(),
itemPadding: 1,
labelColor: tcell.ColorYellow,
fieldBackgroundColor: tcell.ColorBlue,
fieldTextColor: tcell.ColorWhite,
}
}
// SetItemPadding sets the number of empty rows between form items.
func (f *Form) SetItemPadding(padding int) *Form {
f.itemPadding = padding
return f
}
// SetLabelColor sets the color of the labels.
func (f *Form) SetLabelColor(color tcell.Color) *Form {
f.labelColor = color
return f
}
// SetFieldBackgroundColor sets the background color of the input areas.
func (f *Form) SetFieldBackgroundColor(color tcell.Color) *Form {
f.fieldBackgroundColor = color
return f
}
// SetFieldTextColor sets the text color of the input areas.
func (f *Form) SetFieldTextColor(color tcell.Color) *Form {
f.fieldTextColor = color
return f
}
// AddItem adds a new item to the form. It has a label, an optional initial
// value, a field length (a value of 0 extends it as far as possible), and
// an optional accept function to validate the item's value (set to nil to
// accept any text).
func (f *Form) AddItem(label, value string, fieldLength int, accept func(textToCheck string, lastChar rune) bool) *Form {
f.items = append(f.items, NewInputField().
SetLabel(label).
SetText(value).
SetFieldLength(fieldLength).
SetAcceptanceFunc(accept))
return f
}
// AddButton adds a new button to the form. The "selected" function is called
// when the user selects this button. It may be nil.
func (f *Form) AddButton(label string, selected func()) *Form {
f.buttons = append(f.buttons, NewButton(label).SetSelectedFunc(selected))
return f
}
// Draw draws this primitive onto the screen.
func (f *Form) Draw(screen tcell.Screen) {
f.Box.Draw(screen)
// Determine the dimensions.
x := f.x
y := f.y
width := f.width
bottomLimit := f.y + f.height
if f.border {
x++
y++
width -= 2
bottomLimit -= 2
}
rightLimit := x + width
// Find the longest label.
var labelLength int
for _, inputField := range f.items {
label := strings.TrimSpace(inputField.GetLabel())
if len([]rune(label)) > labelLength {
labelLength = len([]rune(label))
}
}
labelLength++ // Add one space.
// Set up and draw the input fields.
for _, inputField := range f.items {
if y >= bottomLimit {
return // Stop here.
}
label := strings.TrimSpace(inputField.GetLabel())
inputField.SetLabelColor(f.labelColor).
SetFieldBackgroundColor(f.fieldBackgroundColor).
SetFieldTextColor(f.fieldTextColor).
SetLabel(label+strings.Repeat(" ", labelLength-len([]rune(label)))).
SetBackgroundColor(f.backgroundColor).
SetRect(x, y, width, 1)
inputField.Draw(screen)
y += 1 + f.itemPadding
}
// Draw the buttons.
if f.itemPadding == 0 {
y++
}
if y >= bottomLimit {
return // Stop here.
}
for _, button := range f.buttons {
space := rightLimit - x
if space < 1 {
return // No space for this button anymore.
}
buttonWidth := len([]rune(button.GetLabel())) + 4
if buttonWidth > space {
buttonWidth = space
}
button.SetRect(x, y, buttonWidth, 1)
button.Draw(screen)
x += buttonWidth + 2
}
}
// Focus is called by the application when the primitive receives focus.
func (f *Form) Focus(app *Application) {
f.Box.Focus(app)
if len(f.items)+len(f.buttons) == 0 {
return
}
// Hand on the focus to one of our child elements.
if f.focusedElement < 0 || f.focusedElement >= len(f.items)+len(f.buttons) {
f.focusedElement = 0
}
f.hasFocus = false
handler := func(key tcell.Key) {
switch key {
case tcell.KeyTab:
f.focusedElement++
case tcell.KeyBacktab:
f.focusedElement--
if f.focusedElement < 0 {
f.focusedElement = len(f.items) + len(f.buttons) - 1
}
case tcell.KeyEscape:
f.focusedElement = 0
}
f.Focus(app)
}
if f.focusedElement < len(f.items) {
// We're selecting an item.
inputField := f.items[f.focusedElement]
inputField.SetDoneFunc(handler)
app.SetFocus(inputField)
} else {
// We're selecting a button.
button := f.buttons[f.focusedElement-len(f.items)]
button.SetBlurFunc(handler)
app.SetFocus(button)
}
}
// InputHandler returns the handler for this primitive.
func (f *Form) InputHandler() func(event *tcell.EventKey) {
return func(event *tcell.EventKey) {}
}