45 lines
1.0 KiB
Kotlin
45 lines
1.0 KiB
Kotlin
package design_patterns
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/**
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* pattern: Adapter
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*
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* using: used when we cannot directly use the functionality of an object
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*
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* description: to use the functionality of an object, a special class is created, which is called an adapter
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*/
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interface Adapter<T> {
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fun getItem(position: Int) : T
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fun getItemCount() : Int
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}
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/**
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* here is a simplified imitation of RecyclerView component from android
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*/
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class RecyclerView<T> {
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private var adapter: Adapter<T>? = null
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fun changeAdapter(adapter: Adapter<T>) {
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this.adapter = adapter
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}
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/**
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* renders elements from the adapter
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*
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* @return returns a list of elements to test
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*/
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fun draw() : List<T> {
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val items = mutableListOf<T>()
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val myAdapter = adapter
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if (myAdapter != null) {
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val count = myAdapter.getItemCount()
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for (i in 0 until count) {
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items.add(myAdapter.getItem(i))
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// draw item
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}
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}
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return items
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}
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} |