Kotlin 实现组合模式 - 第三周作业二

发布于: 2020 年 06 月 23 日

1. 组合模式的概念

组合模式(Composite), 将对象组合成属性结构以表示‘部分-整体’的层次结构。组合模式使得用户对单个对象和组合对象的使用具有一致性。

2. 实例

使用组合设计模式实现以下程序

2.1 类图

在这个视图层级中容器一定是ViewGroup,而且只有ViewGroup才能包含其他的View,比如Frame能包含TextBoxButtonLabel等,但是反过来Button是不能包含Frame的,因此将Button等直接继承于ViewFrame继承与ViewGroup,这样的设计对于使用方来说将会更加的安全。

2.2 代码实现

最近Kotlin使用的比较多,写出来也比较简洁,就酱紫

abstract class View {
abstract val text: String
open fun draw() = println("Print View($text)")
}
abstract class ViewGroup : View() {
val viewGroup = arrayListOf<View>()
fun addView(view: View) = viewGroup.add(view)
fun addView(block: () -> View) = viewGroup.add(block())
fun removeView(view: View) = viewGroup.remove(view)
fun getView(index: Int) = viewGroup[index]
}
class WinForm(override val text: String) : ViewGroup() {
override fun draw() {
println("Print WinForm($text)")
viewGroup.map {
it.draw()
}
}
}
class Frame(override val text: String) : ViewGroup() {
override fun draw() {
println("Print Frame($text)")
viewGroup.map {
it.draw()
}
}
}
class Picture(override val text: String) : View() {
override fun draw() = println("Print Picture($text)")
}
class Button(override val text: String) : View() {
override fun draw() = println("Print Button($text)")
}
class Label(override val text: String) : View() {
override fun draw() = println("Print Label($text)")
}
class TextBox(override val text: String) : View() {
override fun draw() = println("Print TextBox($text)")
}
class PasswordBox(override val text: String) : View() {
override fun draw() = println("Print PasswordBox($text)")
}
class CheckBox(override val text: String) : View() {
override fun draw() = println("Print CheckBox($text)")
}
class LinkLabel(override val text: String) : View() {
override fun draw() = println("Print LinkLabel($text)")
}

调用构建界面:

fun main() {
WinForm("WINDOW窗口").apply {
addView(Picture("LOGO图片"))
addView(Button("登陆"))
addView(Button("注册"))
addView { //用高阶函数实现类DSL的方式让代码结构层次看起来比较清晰
Frame("FRAME1").apply {
addView(Label("用户名"))
addView(TextBox("文本框"))
addView(Label("密码"))
addView(PasswordBox("密码框"))
addView(CheckBox("复选框"))
addView(TextBox("记住用户名"))
addView(LinkLabel("记住密码"))
}
}
}.draw()
}

运行打印输出:

/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/bin/java -javaagent:/Applications/IntelliJ IDEA.app/Contents/lib/idea_rt.jar=63131:/Applications/IntelliJ IDEA.app/Contents/bin -Dfile.encoding=UTF-8 -classpath /Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/charsets.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/deploy.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/ext/cldrdata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/ext/dnsns.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/ext/jaccess.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/ext/jfxrt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/ext/localedata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/ext/nashorn.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/ext/sunec.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/ext/sunjce_provider.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/ext/sunpkcs11.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/ext/zipfs.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/javaws.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/jce.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/jfr.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/jfxswt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/jsse.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/management-agent.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/plugin.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/resources.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/jre/lib/rt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/lib/ant-javafx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/lib/dt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/lib/javafx-mx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/lib/jconsole.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/lib/packager.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/lib/sa-jdi.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_212.jdk/Contents/Home/lib/tools.jar:/Users/Acker/Desktop/架构师训练营/代码项目/architecture-exercise/out/production/classes:/Users/Acker/.gradle/caches/modules-2/files-2.1/org.jetbrains.kotlin/kotlin-stdlib-jdk8/1.3.72/916d54b9eb6442b615e6f1488978f551c0674720/kotlin-stdlib-jdk8-1.3.72.jar:/Users/Acker/.gradle/caches/modules-2/files-2.1/org.jetbrains.kotlin/kotlin-stdlib-jdk7/1.3.72/3adfc2f4ea4243e01204be8081fe63bde6b12815/kotlin-stdlib-jdk7-1.3.72.jar:/Users/Acker/.gradle/caches/modules-2/files-2.1/org.jetbrains.kotlin/kotlin-stdlib/1.3.72/8032138f12c0180bc4e51fe139d4c52b46db6109/kotlin-stdlib-1.3.72.jar:/Users/Acker/.gradle/caches/modules-2/files-2.1/org.jetbrains.kotlin/kotlin-stdlib-common/1.3.72/6ca8bee3d88957eaaaef077c41c908c9940492d8/kotlin-stdlib-common-1.3.72.jar:/Users/Acker/.gradle/caches/modules-2/files-2.1/org.jetbrains/annotations/13.0/919f0dfe192fb4e063e7dacadee7f8bb9a2672a9/annotations-13.0.jar com.sk.architect.week3.composite.ViewKt
Print WinForm(WINDOW窗口)
Print Picture(LOGO图片)
Print Button(登陆)
Print Button(注册)
Print Frame(FRAME1)
Print Label(用户名)
Print TextBox(文本框)
Print Label(密码)
Print PasswordBox(密码框)
Print CheckBox(复选框)
Print TextBox(记住用户名)
Print LinkLabel(记住密码)
Process finished with exit code 0

发布于: 2020 年 06 月 23 日 阅读数: 26
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Kotlin实现组合模式-第三周作业二