tcell-widgets/wdgt_form.go

/*
Copyright © Brian Buller <brian@bullercodeworks.com>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
package widgets

import (
	"fmt"

	wh "git.bullercodeworks.com/brian/tcell-widgets/helpers"
	"github.com/gdamore/tcell"
)

type Form struct {
	id    string
	style tcell.Style

	cursor    int
	visible   bool
	active    bool
	focusable bool
	x, y      int
	w, h      int

	title  string
	border []rune
	fields []Widget

	submit    *Button
	cancel    *Button
	hasSubmit bool
	hasCancel bool

	keyMap, customKeyMap KeyMap
}

var _ Widget = (*Form)(nil)

func NewForm(id string, style tcell.Style) *Form {
	f := &Form{}
	f.Init(id, style)
	return f
}

func (w *Form) Init(id string, style tcell.Style) {
	w.id = id
	w.style = style
	w.visible = true
	w.focusable = true
	w.submit = NewButton(fmt.Sprintf("%s-submit", id), style)
	w.cancel = NewButton(fmt.Sprintf("%s-cancel", id), style)
	w.keyMap = BlankKeyMap()
	w.customKeyMap = BlankKeyMap()
}

func (w *Form) Id() string { return w.id }
func (w *Form) HandleResize(ev *tcell.EventResize) {
	w.w, w.h = ev.Size()
	y := 0
	for i := range w.fields {
		w.fields[i].SetPos(Coord{X: 0, Y: y})
		wantH := w.fields[i].WantH()
		w.fields[i].HandleResize(Coord{X: w.w, Y: wantH}.ResizeEvent())
		y += wantH
	}
	half := w.w / 2
	if w.hasCancel && w.hasSubmit {
		w.cancel.SetPos(Coord{X: 0, Y: y})
		w.cancel.SetSize(Coord{X: half, Y: 3})
		w.submit.SetPos(Coord{X: 0, Y: y})
		w.submit.SetSize(Coord{X: half, Y: 3})
	} else if w.hasCancel {
		w.cancel.SetPos(Coord{X: half, Y: y})
		w.cancel.SetSize(Coord{X: half, Y: 3})
	} else if w.hasSubmit {
		w.submit.SetPos(Coord{X: w.w / 2, Y: y})
		w.submit.SetSize(Coord{X: half, Y: 3})
	}
}

func (w *Form) SetKeyMap(km KeyMap, def bool) {
	if def {
		w.keyMap = km
	} else {
		w.customKeyMap = km
	}
}
func (w *Form) AddToKeyMap(km KeyMap) { w.customKeyMap.Merge(km) }
func (w *Form) RemoveFromKeyMap(km KeyMap) {
	for k := range km.Keys {
		w.customKeyMap.Remove(k)
	}
	for r := range km.Runes {
		w.customKeyMap.RemoveRune(r)
	}
}

func (w *Form) HandleKey(ev *tcell.EventKey) bool {
	if !w.active {
		return false
	}
	if w.getActive().HandleKey(ev) {
		return true
	}
	if ev.Key() == tcell.KeyTab {
		fldCnt := len(w.fields)
		if w.hasCancel {
			fldCnt += 1
		}
		if w.hasSubmit {
			fldCnt += 1
		}
		pre := w.cursor
		w.cursor = (w.cursor + 1) % fldCnt
		w.updateWidgets()
		return w.cursor > pre
	}
	b1 := w.keyMap.Handle(ev)
	b2 := w.customKeyMap.Handle(ev)
	return b1 || b2
}
func (w *Form) HandleTime(ev *tcell.EventTime) {}
func (w *Form) Draw(screen tcell.Screen) {
	if !w.visible {
		return
	}
	useStyle := w.style.Dim(!w.active)
	if len(w.title) > 0 {
		wh.TitledBorderFilled(w.x, w.y, w.x+w.w, w.y+w.h, w.title, w.border, useStyle, screen)
	} else {
		wh.BorderFilled(w.x, w.y, w.x+w.w, w.y+w.h, w.border, useStyle, screen)
	}
	p := w.GetPos()
	for _, wdgt := range w.fields {
		if !w.Active() {
			wdAct := wdgt.Active()
			wdgt.SetActive(false)
			p.DrawOffset(wdgt, screen)
			wdgt.SetActive(wdAct)
		} else {
			p.DrawOffset(wdgt, screen)
		}
	}
	if w.hasCancel {
		p.DrawOffset(w.cancel, screen)
	}
	if w.hasSubmit {
		p.DrawOffset(w.submit, screen)
	}
}

func (w *Form) Active() bool { return w.active }
func (w *Form) SetActive(a bool) {
	w.active = a
	w.updateWidgets()
}
func (w *Form) Visible() bool     { return w.visible }
func (w *Form) SetVisible(a bool) { w.visible = a }
func (w *Form) SetX(x int)        { w.x = x }
func (w *Form) SetY(y int)        { w.y = y }
func (w *Form) GetX() int         { return w.x }
func (w *Form) GetY() int         { return w.y }
func (w *Form) GetPos() Coord     { return Coord{X: w.x, Y: w.y} }
func (w *Form) SetPos(c Coord)    { w.x, w.y = c.X, c.Y }
func (w *Form) SetW(wd int)       { w.w = wd }
func (w *Form) SetH(h int)        { w.h = h }
func (w *Form) GetW() int         { return w.w }
func (w *Form) GetH() int         { return w.h }
func (w *Form) WantW() int {
	var ret int
	if len(w.border) > 0 {
		ret += 2
	}
	maxFld := wh.MaxFor(func(f Widget) int { return f.WantW() }, w.fields...)
	ret += maxFld.WantW()

	return 1
}

func (w *Form) WantH() int {
	var ret int
	if len(w.border) > 0 {
		ret += 2
	}
	for i := range w.fields {
		ret += w.fields[i].WantH()
	}
	if w.hasSubmit || w.hasCancel {
		ret += 3
	}

	return ret
}

func (w *Form) SetSize(c Coord) {
	w.SetW(c.X)
	w.SetH(c.Y)
}
func (w *Form) Focusable() bool     { return w.focusable }
func (w *Form) SetFocusable(b bool) { w.focusable = b }
func (w *Form) MinW() int           { return 1 }
func (w *Form) MinH() int           { return 1 }

// Non-Widget Functions
func (w *Form) updateWidgets() {
	for i := 0; i < len(w.fields); i++ {
		w.fields[i].SetActive(w.Active() && i == w.cursor)
	}
	if w.hasCancel {
		w.cancel.SetActive(w.Active() && w.cursor == len(w.fields))
		if w.hasSubmit {
			w.submit.SetActive(w.Active() && w.cursor == len(w.fields)+1)
		}
	} else if w.hasSubmit {
		w.submit.SetActive(w.Active() && w.cursor == len(w.fields))
	}
}

func (w *Form) getActive() Widget {
	if w.cursor < len(w.fields) {
		return w.fields[w.cursor]
	}
	if w.cursor == len(w.fields) {
		if w.hasCancel {
			return w.cancel
		}
		if w.hasSubmit {
			return w.submit
		}
	} else if w.cursor > len(w.fields) && w.hasSubmit {
		return w.submit
	}
	return nil
}

func (w *Form) IndexOf(n Widget) int {
	for i := range w.fields {
		if w.fields[i] == n {
			return i
		}
	}
	return -1
}
func (w *Form) Contains(n Widget) bool { return w.IndexOf(n) >= 0 }
func (w *Form) Replace(n, with Widget) {
	idx := w.IndexOf(n)
	if idx == -1 {
		return
	}
	w.Delete(n)
	w.Insert(with, idx)
}

func (w *Form) Add(n Widget) {
	if w.Contains(n) {
		// If the widget is already in the layout, move it to the end
		w.Delete(n)
	}
	w.fields = append(w.fields, n)
}

func (w *Form) Insert(n Widget, idx int) {
	if idx >= len(w.fields) {
		w.Add(n)
		return
	}
	if pos := w.IndexOf(n); pos >= 0 {
		if pos < idx {
			idx--
		}
		w.Delete(n)
	}
	w.fields = append(w.fields[:idx], append([]Widget{n}, w.fields[idx:]...)...)
}

func (w *Form) Delete(n Widget) {
	for i := 0; i < len(w.fields); i++ {
		if w.fields[i] == n {
			w.DeleteIndex(i)
			return
		}
	}
}

func (w *Form) DeleteIndex(idx int) {
	if idx < len(w.fields) {
		w.fields = append(w.fields[:idx], w.fields[idx+1:]...)
	}
}
func (w *Form) Clear() { w.fields = []Widget{} }

func (w *Form) SetTitle(ttl string) { w.title = ttl }
func (w *Form) SetBorder(b []rune)  { w.border = b }

func (w *Form) SetSubmitLabel(lbl string) { w.submit.SetLabel(lbl) }
func (w *Form) SetOnSubmit(sb func() bool) {
	w.submit.SetOnPressed(sb)
	w.hasSubmit = sb != nil
}
func (w *Form) SetCancelLabel(lbl string) { w.cancel.SetLabel(lbl) }
func (w *Form) SetOnCancel(sb func() bool) {
	w.cancel.SetOnPressed(sb)
	w.hasCancel = sb != nil
}