listview.go

package rlyeh

import (
	"time"

	rl "github.com/gen2brain/raylib-go/raylib"
)

type ListView struct {
	OnClick       func(string)
	OnDoubleClick func(string)

	layout *HBox

	items []string

	visibles int
	upper    int
	current  int

	clicked int
	state   State
	time    time.Duration
}

func NewListView(items []string, visibles int) *ListView {
	self := &ListView{}

	self.layout = NewHBox(Auto, Both)

	self.visibles = visibles

	vbox := NewVBox(Auto, Both)

	for i := 0; i < visibles; i++ {
		vbox.Add(NewLabel(Left, None, ""))
	}

	self.layout.Add(vbox)

	self.layout.Add(NewScrollbar(Vertical, self))

	self.SetItems(items)

	return self
}

func (self *ListView) Scroll(times int) {
	if times < 0 {
		times = -times

		if times > self.current {
			times = self.current
		}

		if self.upper >= times {
			self.upper -= times
			self.current -= times
		} else {
			self.current -= times
		}
	} else if times > 0 {
		left := len(self.items) - self.current - 1

		if times > left {
			times = left
		}

		if self.upper < (len(self.items) - self.visibles) {
			self.current += times
			self.upper += times
		} else {
			self.current += times
		}
	}
}

func (self *ListView) GetCount() int {
	return len(self.items)
}

func (self *ListView) GetCurrent() int {
	return self.current
}

func (self *ListView) SetCurrent(index int) {
	if index < 0 {
		index = 0
	}
	if index >= self.GetCount() {
		index = self.GetCount() - 1
	}

	if index <= (self.GetCount() - self.visibles) {
		self.upper = index
	} else {
		self.upper = self.GetCount() - self.visibles
	}

	self.current = index
}

func (self *ListView) RemoveScrollbar() {
	self.layout.Widgets = self.layout.Widgets[:len(self.layout.Widgets)-1]
}

func (self *ListView) SetItems(items []string) {
	self.upper = 0
	self.current = 0
	self.state = Normal
	self.clicked = -1
	self.items = items

	labels := self.layout.GetWidgets()[0].(Layout).GetWidgets()
	for i := len(items); i < self.visibles; i++ {
		label := labels[i].(*Label)
		label.Text = ""
	}
}

func (self *ListView) GetCurrentItem() string {
	return self.items[self.current]
}

func (self *ListView) GetId() int32 {
	return self.layout.GetId()
}

func (self *ListView) SetId(id int32) {
	self.layout.SetId(id)
}

func (self *ListView) GetParent() Widget {
	return self.layout.GetParent()
}

func (self *ListView) SetParent(parent Widget) {
	self.layout.SetParent(parent)
}

func (self *ListView) GetBounds() rl.Rectangle {
	return self.layout.GetBounds()
}

func (self *ListView) SetBounds(bounds rl.Rectangle) {
	self.layout.SetBounds(bounds)
}

func (self *ListView) GetAlign() Align {
	return self.layout.GetAlign()
}

func (self *ListView) GetFill() Fill {
	return self.layout.GetFill()
}

func (self *ListView) GetDataSize() Size {
	return self.layout.GetDataSize()
}

func (self *ListView) Update(dt float32) {
	vbox := self.layout.GetWidgets()[0].(*VBox)
	labels := vbox.GetWidgets()

	self.time += time.Duration(1e9 * dt)

	for i := 0; i < self.visibles; i++ {
		label := labels[i].(*Label)

		j := self.upper + i
		if j < len(self.items) {
			text := self.items[j]
			label.Text = text

			switch GetState(label.GetBounds()) {
			case Released:
				if Pressed == self.state && j == self.current {
					self.time = 0
					self.clicked = j
					if nil != self.OnClick {
						self.OnClick(text)
					}
				}

				if Released != self.state {
					self.current = j
				}

				self.state = Released
				break
			case Pressed:
				if j == self.clicked && j == self.current {
					if (200*time.Millisecond) > self.time && nil != self.OnDoubleClick {
						self.OnDoubleClick(text)
						self.clicked = -1
					}
				}

				self.current = j
				self.state = Pressed
				break
			}

			if self.current == j {
				label.BackgroundColor = style.ListviewSelectedBackgroundColor
				label.TextColor = style.ListviewSelectedTextColor
			} else {
				label.BackgroundColor = style.GlobalBackgroundColor
				label.TextColor = style.ListviewTextColor
			}
		}
	}

	self.layout.Update(dt)
}

func (self *ListView) Draw() {
	self.layout.Draw()
}