Add examples for cancellation

Author: LukasLechnerDev

app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/playground/cancellation/1_cancellation.kt

@@ -0,0 +1,25 @@
+package com.lukaslechner.coroutineusecasesonandroid.playground.cancellation
+
+import kotlinx.coroutines.CancellationException
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.runBlocking
+
+fun main() = runBlocking {
+
+    val job = launch {
+        repeat(10) { index ->
+            println("operation number $index")
+            try {
+                delay(100)
+            } catch (exception: CancellationException) {
+                println("CancellationException was thrown")
+                throw CancellationException()
+            }
+        }
+    }
+
+    delay(250)
+    println("Cancelling Coroutine")
+    job.cancel()
+}

app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/playground/cancellation/2_cooperative_cancellation.kt

@@ -0,0 +1,36 @@
+package com.lukaslechner.coroutineusecasesonandroid.playground.cancellation
+
+import kotlinx.coroutines.*
+
+fun main() = runBlocking<Unit> {
+
+    val job = launch(Dispatchers.Default) {
+        repeat(10) { index ->
+            if (isActive) {
+                println("operation number $index")
+                Thread.sleep(100)
+            } else {
+                // perform some cleanup on cancellation
+                withContext(NonCancellable) {
+                    delay(100)
+                    println("Clean up done!")
+                }
+                throw CancellationException()
+            }
+        }
+    }
+
+    delay(250)
+    println("Cancelling Coroutine")
+    job.cancel()
+
+    val globalCoroutineJob = GlobalScope.launch {
+        repeat(10) {
+            println("$it")
+            delay(100)
+        }
+    }
+    delay(250)
+    globalCoroutineJob.cancel()
+    delay(1000)
+}