gui-textbox

local self = getfenv()
internal = {}

function self.new(name,x,y,width)
    local txt = {}
    txt.name = name
    txt.x = math.floor(x)
    txt.y = math.floor(y)
    txt.width = math.floor(width)
    txt.value = ""
    txt.scrolled = 0
    txt.cursorAt = 1
    txt.active = false
    txt.scrollWhenInactive = false
    txt.scrolling = false
    txt.scrollSpeed = 0.3
    txt.lastScroll = 0
    txt.scrollReverse = false
    txt.placeHolder = nil
    txt.txtColor = colors.white
    txt.bgColor = colors.black

    setmetatable(txt,{__index=internal})
    return txt
end

function internal:setText(str)
    self.value = str
    if self.scrolling then
        self:initScroll()
    end
    self:draw()
end

function internal:updateScroll(dt)
    self.lastScroll = self.lastScroll+dt
    if self.lastScroll > self.scrollSpeed then
        self.lastScroll = self.lastScroll - self.scrollSpeed
        local add = self.scrollReverse and -1 or 1
        self.scrolled = self.scrolled+add
        if self.scrolled + self.width > #self.value then
            self.scrollReverse = not self.scrollReverse
            self.scrolled = self.scrolled-add
        end
        if self.scrolled < 0 then
            self.scrolled = 0
            self.scrollReverse = not self.scrollReverse
        end
    end
end

function internal:initScroll()
    if #self.value > self.width then
        self.scrolling = true
    end
    self.scrolled = 0
    self.lastScroll = 0
    self.scrollReverse = false
end

function internal:stopScroll()
    self.scrolling = false
end

function internal:resetScroll()
    self.scrolled = 0
    self:draw()
end

function internal:drawText()
    term.setBackgroundColor(self.bgColor)
    term.setTextColor(self.txtColor)
    term.setCursorPos(self.x,self.y)
    term.write(string.rep(" ",self.width))
    term.setCursorPos(self.x,self.y)
    local dStr = self.value:sub(self.scrolled+1,self.scrolled+self.width)
    if self.placeHolder then
        dStr = string.rep(self.placeHolder,#dStr)
    end
    term.write(dStr)
    if self.active then self:setCursor() end
end

function internal:getCursorScreenPos()
    return self.x+self.cursorAt-1-self.scrolled
end

function internal:setCursor()
    local cX = self:getCursorScreenPos()
    term.setCursorPos(cX,self.y)
end

function internal:update(dt)
    if self.scrolling then
        self:updateScroll(dt)
    end
end

function internal:draw()
    self:drawText()
end

function internal:key(p1)
    if p1 == keys.left then
        self.cursorAt = math.max(1,self.cursorAt-1)
        if self:scrollToCursor() then self:draw() else self:setCursor() end
    elseif p1 == keys.right then
        self.cursorAt = math.min(#self.value+1,self.cursorAt+1)
        if self:scrollToCursor() then self:draw() else self:setCursor() end
    elseif p1 == keys.backspace then
        if self.cursorAt > 1 then
            self.value = self.value:sub(0,self.cursorAt-2)..self.value:sub(self.cursorAt)
            self.cursorAt = math.max(self.cursorAt-1,1)

            self:scrollToCursor()
            self:draw()
        end
    elseif p1 == keys.home then
        self.cursorAt = 1
        self:scrollToCursor()
        self:draw()
    elseif p1 == keys["end"] then
        self.cursorAt = #self.value+1
        self:scrollToCursor()
        self:draw()
    end
end

function internal:scrollToCursor()
    local screenPos = self:getCursorScreenPos()
    if screenPos < self.x then
        local scrollSize = self.x - screenPos
        self.scrolled = math.max(0,self.scrolled - scrollSize)
        return true
    elseif screenPos > self.x + self.width - 1 then
        local scrollSize = screenPos - self.x - self.width + 1
        self.scrolled = self.scrolled + scrollSize
        return true
    end
    return false
end

function internal:char(p1)
    self.value = self.value:sub(0,self.cursorAt-1)..p1..self.value:sub(self.cursorAt,#self.value)
    self.cursorAt = self.cursorAt + 1
    self:scrollToCursor()
    self:draw()
end

function internal:checkClicked()
end

function internal:activate()
    gui.activateControl(self)
end

function internal:deactivate()
    gui.deactivateControl()
end

function internal:onDeactivate()
    self.active=false
    term.setCursorBlink(false)
    if self.scrollWhenInactive then
        self:initScroll()
    end
end

function internal:onActivate()
    self.active=true
    term.setCursorBlink(true)
    if self.scrolling then
        self:stopScroll()
    end
    self:scrollToCursor()
    self:draw()
    self:setCursor()
end