main.go

Documentation: github.com/rivo/tview/demos/primitive

     1  // Demo code which illustrates how to implement your own primitive.
     2  package main
     3  
     4  import (
     5  	"fmt"
     6  
     7  	"github.com/gdamore/tcell/v2"
     8  	"github.com/rivo/tview"
     9  )
    10  
    11  // RadioButtons implements a simple primitive for radio button selections.
    12  type RadioButtons struct {
    13  	*tview.Box
    14  	options       []string
    15  	currentOption int
    16  }
    17  
    18  // NewRadioButtons returns a new radio button primitive.
    19  func NewRadioButtons(options []string) *RadioButtons {
    20  	return &RadioButtons{
    21  		Box:     tview.NewBox(),
    22  		options: options,
    23  	}
    24  }
    25  
    26  // Draw draws this primitive onto the screen.
    27  func (r *RadioButtons) Draw(screen tcell.Screen) {
    28  	r.Box.DrawForSubclass(screen, r)
    29  	x, y, width, height := r.GetInnerRect()
    30  
    31  	for index, option := range r.options {
    32  		if index >= height {
    33  			break
    34  		}
    35  		radioButton := "\u25ef" // Unchecked.
    36  		if index == r.currentOption {
    37  			radioButton = "\u25c9" // Checked.
    38  		}
    39  		line := fmt.Sprintf(`%s[white]  %s`, radioButton, option)
    40  		tview.Print(screen, line, x, y+index, width, tview.AlignLeft, tcell.ColorYellow)
    41  	}
    42  }
    43  
    44  // InputHandler returns the handler for this primitive.
    45  func (r *RadioButtons) InputHandler() func(event *tcell.EventKey, setFocus func(p tview.Primitive)) {
    46  	return r.WrapInputHandler(func(event *tcell.EventKey, setFocus func(p tview.Primitive)) {
    47  		switch event.Key() {
    48  		case tcell.KeyUp:
    49  			r.currentOption--
    50  			if r.currentOption < 0 {
    51  				r.currentOption = 0
    52  			}
    53  		case tcell.KeyDown:
    54  			r.currentOption++
    55  			if r.currentOption >= len(r.options) {
    56  				r.currentOption = len(r.options) - 1
    57  			}
    58  		}
    59  	})
    60  }
    61  
    62  // MouseHandler returns the mouse handler for this primitive.
    63  func (r *RadioButtons) MouseHandler() func(action tview.MouseAction, event *tcell.EventMouse, setFocus func(p tview.Primitive)) (consumed bool, capture tview.Primitive) {
    64  	return r.WrapMouseHandler(func(action tview.MouseAction, event *tcell.EventMouse, setFocus func(p tview.Primitive)) (consumed bool, capture tview.Primitive) {
    65  		x, y := event.Position()
    66  		_, rectY, _, _ := r.GetInnerRect()
    67  		if !r.InRect(x, y) {
    68  			return false, nil
    69  		}
    70  
    71  		if action == tview.MouseLeftClick {
    72  			setFocus(r)
    73  			index := y - rectY
    74  			if index >= 0 && index < len(r.options) {
    75  				r.currentOption = index
    76  				consumed = true
    77  			}
    78  		}
    79  
    80  		return
    81  	})
    82  }
    83  
    84  func main() {
    85  	radioButtons := NewRadioButtons([]string{"Lions", "Elephants", "Giraffes"})
    86  	radioButtons.SetBorder(true).
    87  		SetTitle("Radio Button Demo").
    88  		SetRect(0, 0, 30, 5)
    89  	if err := tview.NewApplication().SetRoot(radioButtons, false).EnableMouse(true).Run(); err != nil {
    90  		panic(err)
    91  	}
    92  }
    93
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