Textfield class

function _M.newTextField(params)
    local group = params.group
    local back = display.newImageRect(group, 'images/login_field.png', 281, 36)
    game:setRP(back, 'TopCenter')
    local x = params.x or 0
    back.x, back.y = x, params.y
    local text = params.text or ''
    --local title = _M.newLabel{text = text, x = x + -132, y = params.y + 14, font = native.systemFont, size = 22, color = _COLORS.black, align = 'CenterLeft', flat = true}
    local title = _M.newLabel{text = text, x = x + -132, y = params.y + 20, font = _FONTNAME_HEAVY_CONDENSED, size = 22, color = _COLORS.black, align = 'CenterLeft', flat = true}
    group:insert(title)
    back.title = title

    function back:touch(event)
        if event.phase == 'began' then
            if type(params.onclick) == 'function' then
                params.onclick(self, 'up')
            else
                self:showTextField()
            end
        end
        return true
    end
    back:addEventListener('touch', back)

    function back:showTextField()
        if self.title.isVisible then
            self.title.isVisible = false
            local w, h = 260, 28
            local x, y = back:localToContent(0, 0)
            self.textField = native.newTextField(x - 132, y - 13, w, h)
            if self.current_text and self.current_text ~= params.title then
                self.textField.text = self.current_text
            end
            if params.password then
                self.textField.isSecure = params.password
            end
            self.textField.hasBackground = false
            self.textField.size = 22--math.floor(22 * display.pixelWidth / (_R - _L))
            self.textField.font = native.newFont(_FONTNAME_HEAVY_CONDENSED, 22)
            if params.mode then
                self.textField.inputType = params.mode
            end
            if params.userInput then
                self.textField:addEventListener('userInput', params.userInput)
            end
            native.setKeyboardFocus(self.textField)
        end
    end

    function back:hideTextField()
        if not self.title.isVisible then
            self.title.isVisible = true
            self.current_text = self.textField.text:sub(1, 45)
            self.title:setText(self.textField.text:sub(1, 45))
            self.title:setTextColor(0, 0, 0)
            if params.password then
                local s = string.gsub(self.title.text, '.', '●')
                self.title:setText(s)
            end
            native.setKeyboardFocus(nil)
            if params.userInput then
                self.textField:removeEventListener('userInput', params.userInput)
            end
            display.remove(self.textField)
        end
    end

    function back:checkEmpty()
        if (self.textField and self.textField.text) or self.current_text then
            local text = (self.textField and self.textField.text) or self.current_text
            if text:len() > 5 then
                if params.mode == 'email' then
                    if text:match("[A-Za-z0-9%.%%%+%-]+@[A-Za-z0-9%.%%%+%-]+%.%w%w%w?%w?") then
                        return true
                    else
                        native.showAlert(_APP_NAME, params.title .. ' is not valid.', {'OK'})
                    end
                else
                    return true
                end
            else
                native.showAlert(_APP_NAME, params.title .. ' must be at least 6 characters long.', {'OK'})
            end
        else
            native.showAlert(_APP_NAME, 'Please enter ' .. params.title, {'OK'})
        end
        return false
    end

    function back:getText()
        return (self.textField and self.textField.text) or self.current_text
    end

    return back
end