package ui import ( "fmt" "git.kirsle.net/go/render" "git.kirsle.net/go/ui/theme" ) // SelectBox is a kind of MenuButton which allows choosing a value from a list. type SelectBox struct { MenuButton name string // Configurables after SelectBox creation. AlwaysChange bool // always call the Change event, even if selection not changed. // Child widgets specific to the SelectBox. frame *Frame label *Label arrow *Image // Data storage. textVariable string values []SelectValue } // SelectValue holds a mapping between a text label for a SelectBox and // its underlying value (an arbitrary data type). type SelectValue struct { Label string Value interface{} } // NewSelectBox creates a new SelectBox. // // The Label configuration passed in should be used to set font styles // and padding; the Text, TextVariable and IntVariable of the Label will // all be ignored, as SelectBox will handle the values internally. func NewSelectBox(name string, withLabel Label) *SelectBox { w := &SelectBox{ name: name, textVariable: "Choose one", values: []SelectValue{}, } // Ensure the label has no text of its own. withLabel.Text = "" withLabel.TextVariable = &w.textVariable withLabel.IntVariable = nil w.frame = NewFrame(name + " Frame") w.Button.child = w.frame w.label = NewLabel(withLabel) w.frame.Pack(w.label, Pack{ Side: W, }) // arrow, _ := GetGlyph(GlyphDownArrow9x9) // w.image = ImageFromImage(arrow, ) // Configure the button's appearance. w.Button.Configure(Config{ BorderSize: 2, BorderStyle: BorderSunken, Background: render.White, }) // Set sensible default padding on the label. if w.label.Font.Padding == 0 && w.label.Font.PadX == 0 && w.label.Font.PadY == 0 { w.label.Font.PadX = 4 w.label.Font.PadY = 2 } w.IDFunc(func() string { return fmt.Sprintf("SelectBox<%s>", name) }) w.setup() return w } // AddItem adds a new option to the SelectBox's menu. // The label is the text value to display. // The value is the underlying value (string or int) for the TextVariable or IntVariable. // The function callback runs when the option is picked. func (w *SelectBox) AddItem(label string, value interface{}, f func()) { // Add this label and its value mapping to the SelectBox. w.values = append(w.values, SelectValue{ Label: label, Value: value, }) // Call the inherited MenuButton.AddItem. w.MenuButton.AddItem(label, func() { // Set the bound label. var changed = w.textVariable != label w.textVariable = label if changed || w.AlwaysChange { w.Event(Change, EventData{ Supervisor: w.MenuButton.supervisor, }) } }) // If the current text label isn't in the options, pick // the first option. if _, ok := w.GetValue(); !ok { w.textVariable = w.values[0].Label } } // TODO: RemoveItem() // Value returns the currently selected item in the SelectBox. // // Returns the SelectValue and true on success, and the Label or underlying Value // can be read from the SelectValue struct. If no valid option is selected, the // bool value returns false. func (w *SelectBox) GetValue() (SelectValue, bool) { for _, row := range w.values { if w.textVariable == row.Label { return row, true } } return SelectValue{}, false } // Compute to re-evaluate the button state (in the case of radio buttons where // a different button will affect the state of this one when clicked). func (w *SelectBox) Compute(e render.Engine) { w.MenuButton.Compute(e) } // setup the UI components and event handlers. func (w *SelectBox) setup() { w.Configure(Config{ BorderSize: 1, BorderStyle: BorderSunken, Background: theme.InputBackgroundColor, }) w.Handle(MouseOver, func(ed EventData) error { w.hovering = true w.SetBackground(theme.ButtonHoverColor) return nil }) w.Handle(MouseOut, func(ed EventData) error { w.hovering = false w.SetBackground(theme.InputBackgroundColor) return nil }) w.Handle(MouseDown, func(ed EventData) error { w.clicked = true w.SetBackground(theme.ButtonBackgroundColor) return nil }) w.Handle(MouseUp, func(ed EventData) error { w.clicked = false w.SetBackground(theme.InputBackgroundColor) return nil }) w.Handle(Click, func(ed EventData) error { // Are we properly configured? if w.supervisor != nil && w.menu != nil { w.menu.Show() w.supervisor.PushModal(w.menu) } return nil }) }