Scala学习整理[第三十二章 GUI编程]<Programming In Scala>

第三十二章 GUI编程

package SecondWithProgrammingInScalaimport java.io.Fileimport scala.swing.{TextField, _}import scala.swing.event.{ButtonClicked, EditDone}/**  * GUI 编程  * 大致的使用和实际效果和JavaSwing没啥区别  * 之前使用过Swing和Vaadin(Java->Html/js) ,相比浏览器流派 ,Java客户端适用性还是低一些的  *  *  * 使用swing时候出现了版本问题  * scala在2.10以后对模块进行了比较大的划分 ,不少包被拆分成了不同的模块  * 使用maven关联要注意  * 以scala-library为核心 ,核心版本号2.12去关联其他模块包  * 官方还提供了一个scala-lang-all ,包括了之前拆分出去的包  *  */object ScalaSwingApp extends SimpleSwingApplication {  /**    * 和Java编写方式不同 ,Java大多将参数通过构造函数传递进去    * Button okBtn = new Button(text = ok)    * scala而多是使用{}直接重载里面的属性(实质是匿名子类) ,更符合实际 ,不同功能的按钮就是不同的类.    * val okBtn = new Button{override text = ok}    * :  new OkButton{override text = ok} extends Button    */  //设置程序主窗口  override def top: Frame = new MainFrame {    //窗口标题    title = "Scala Swing App"    //注册组件    val clickBtn = new Button {      text = "Click me"    }    val clickBlueBtn = new Button {      background = java.awt.Color.BLUE      text = "Click me"    }    val tipL = new Label {      text = "No button clicks registered"    }    //设置窗口内容(布局){组件}    contents = new BoxPanel(Orientation.Vertical) {      //这里的contents是指BoxPanel布局的内容      contents += clickBtn      contents += clickBlueBtn      contents += tipL      border = Swing.EmptyBorder(30, 30, 10, 30)    }    //设置监听    listenTo(clickBtn, clickBlueBtn)    //设置监听回调函数    var nClicks = 0    reactions += {      case ButtonClicked(btn) => {        nClicks += 1        if (btn == clickBlueBtn) tipL.text = "You just Click the Blue Button:" + nClicks        else tipL.text = "Number of button Clicks:" + nClicks      }    }  }}/**  * 简单计算器  */object Calculation extends SimpleSwingApplication {  override def top: Frame = new MainFrame {    title = "简单计算器"    //文本组件    object Elem1 extends TextField {      columns = 5    }    object Elem2 extends TextField {      columns = 5    }    object Func extends TextField {      columns = 2    }    object Result extends TextField {      columns = 20    }    //提示组件    val tips_defualt = "请输入要计算的值[0-9]和运算符[+-*/]"    val tipsL = new Label(tips_defualt)    //设置布局    contents = new BoxPanel(Orientation.Vertical) {      //设置提示      contents += tipsL      //设置输入框      contents += new BoxPanel(Orientation.Horizontal) {        contents += Elem1        contents += new Label("     ")        contents += Func        contents += new Label("     ")        contents += Elem2      }      //设置结果      contents += Result      border = Swing.EmptyBorder(30, 30, 30, 30)    }    //设置动作    var errors = 0    listenTo(Elem1, Elem2, Func)    reactions += {      //输入完成      case EditDone(_) => calculate    }    //设置计算函数    def calculate: Unit = {      try {        //复原提示        tipsL.text = tips_defualt        //检查运算符并试图转换数值        Func.text match {          case "+" => Result.text = (Elem1.text.toInt + Elem2.text.toInt).toString          case "-" => Result.text = (Elem1.text.toInt - Elem2.text.toInt).toString          case "*" => Result.text = (Elem1.text.toInt * Elem2.text.toInt).toString          case "/" => Result.text = (Elem1.text.toInt / Elem2.text.toInt).toString          case _ => tipsL.text_=("运算符输入错误 ,请重新输入")        }      } catch {        //数值转换出错        case e: NumberFormatException => tipsL.text_=("数值输出错误 ,请重新输入")        case e => tipsL.text_=(e.getMessage)      }    }  }}