nt

button.go (5579B)

---

 package tview
 
 import (
 	"github.com/gdamore/tcell/v2"
 )
 
 // Button is labeled box that triggers an action when selected.
 //
 // See https://github.com/rivo/tview/wiki/Button for an example.
 type Button struct {
 	*Box
 
 	// If set to true, the button cannot be activated.
 	disabled bool
 
 	// The text to be displayed inside the button.
 	text string
 
 	// The button's style (when deactivated).
 	style tcell.Style
 
 	// The button's style (when activated).
 	activatedStyle tcell.Style
 
 	// The button's style (when disabled).
 	disabledStyle tcell.Style
 
 	// An optional function which is called when the button was selected.
 	selected func()
 
 	// An optional function which is called when the user leaves the button. A
 	// key is provided indicating which key was pressed to leave (tab or
 	// backtab).
 	exit func(tcell.Key)
 }
 
 // NewButton returns a new input field.
 func NewButton(label string) *Button {
 	box := NewBox()
 	box.SetRect(0, 0, TaggedStringWidth(label)+4, 1)
 	return &Button{
 		Box:            box,
 		text:           label,
 		style:          tcell.StyleDefault.Background(Styles.ContrastBackgroundColor).Foreground(Styles.PrimaryTextColor),
 		activatedStyle: tcell.StyleDefault.Background(Styles.PrimaryTextColor).Foreground(Styles.InverseTextColor),
 		disabledStyle:  tcell.StyleDefault.Background(Styles.ContrastBackgroundColor).Foreground(Styles.ContrastSecondaryTextColor),
 	}
 }
 
 // SetLabel sets the button text.
 func (b *Button) SetLabel(label string) *Button {
 	b.text = label
 	return b
 }
 
 // GetLabel returns the button text.
 func (b *Button) GetLabel() string {
 	return b.text
 }
 
 // SetLabelColor sets the color of the button text.
 func (b *Button) SetLabelColor(color tcell.Color) *Button {
 	b.style = b.style.Foreground(color)
 	return b
 }
 
 // SetStyle sets the style of the button used when it is not focused.
 func (b *Button) SetStyle(style tcell.Style) *Button {
 	b.style = style
 	return b
 }
 
 // SetLabelColorActivated sets the color of the button text when the button is
 // in focus.
 func (b *Button) SetLabelColorActivated(color tcell.Color) *Button {
 	b.activatedStyle = b.activatedStyle.Foreground(color)
 	return b
 }
 
 // SetBackgroundColorActivated sets the background color of the button text when
 // the button is in focus.
 func (b *Button) SetBackgroundColorActivated(color tcell.Color) *Button {
 	b.activatedStyle = b.activatedStyle.Background(color)
 	return b
 }
 
 // SetActivatedStyle sets the style of the button used when it is focused.
 func (b *Button) SetActivatedStyle(style tcell.Style) *Button {
 	b.activatedStyle = style
 	return b
 }
 
 // SetDisabledStyle sets the style of the button used when it is disabled.
 func (b *Button) SetDisabledStyle(style tcell.Style) *Button {
 	b.disabledStyle = style
 	return b
 }
 
 // SetDisabled sets whether or not the button is disabled. Disabled buttons
 // cannot be activated.
 //
 // If the button is part of a form, you should set focus to the form itself
 // after calling this function to set focus to the next non-disabled form item.
 func (b *Button) SetDisabled(disabled bool) *Button {
 	b.disabled = disabled
 	return b
 }
 
 // IsDisabled returns whether or not the button is disabled.
 func (b *Button) IsDisabled() bool {
 	return b.disabled
 }
 
 // SetSelectedFunc sets a handler which is called when the button was selected.
 func (b *Button) SetSelectedFunc(handler func()) *Button {
 	b.selected = handler
 	return b
 }
 
 // SetExitFunc sets a handler which is called when the user leaves the button.
 // The callback function is provided with the key that was pressed, which is one
 // of the following:
 //
 //   - KeyEscape: Leaving the button with no specific direction.
 //   - KeyTab: Move to the next field.
 //   - KeyBacktab: Move to the previous field.
 func (b *Button) SetExitFunc(handler func(key tcell.Key)) *Button {
 	b.exit = handler
 	return b
 }
 
 // Draw draws this primitive onto the screen.
 func (b *Button) Draw(screen tcell.Screen) {
 	// Draw the box.
 	style := b.style
 	if b.disabled {
 		style = b.disabledStyle
 	}
 	if b.HasFocus() && !b.disabled {
 		style = b.activatedStyle
 	}
 	_, backgroundColor, _ := style.Decompose()
 	b.SetBackgroundColor(backgroundColor)
 	b.Box.DrawForSubclass(screen, b)
 
 	// Draw label.
 	x, y, width, height := b.GetInnerRect()
 	if width > 0 && height > 0 {
 		y = y + height/2
 		printWithStyle(screen, b.text, x, y, 0, width, AlignCenter, style, true)
 	}
 }
 
 // InputHandler returns the handler for this primitive.
 func (b *Button) InputHandler() func(event *tcell.EventKey, setFocus func(p Primitive)) {
 	return b.WrapInputHandler(func(event *tcell.EventKey, setFocus func(p Primitive)) {
 		if b.disabled {
 			return
 		}
 
 		// Process key event.
 		switch key := event.Key(); key {
 		case tcell.KeyEnter: // Selected.
 			if b.selected != nil {
 				b.selected()
 			}
 		case tcell.KeyBacktab, tcell.KeyTab, tcell.KeyEscape: // Leave. No action.
 			if b.exit != nil {
 				b.exit(key)
 			}
 		}
 	})
 }
 
 // MouseHandler returns the mouse handler for this primitive.
 func (b *Button) MouseHandler() func(action MouseAction, event *tcell.EventMouse, setFocus func(p Primitive)) (consumed bool, capture Primitive) {
 	return b.WrapMouseHandler(func(action MouseAction, event *tcell.EventMouse, setFocus func(p Primitive)) (consumed bool, capture Primitive) {
 		if b.disabled {
 			return false, nil
 		}
 
 		if !b.InRect(event.Position()) {
 			return false, nil
 		}
 
 		// Process mouse event.
 		if action == MouseLeftDown {
 			setFocus(b)
 			consumed = true
 		} else if action == MouseLeftClick {
 			if b.selected != nil {
 				b.selected()
 			}
 			consumed = true
 		}
 
 		return
 	})
 }