1 files changed, 79 insertions, 0 deletions
diff --git a/platform/android/src/com/artifex/mupdfdemo/CancellableAsyncTask.java b/platform/android/src/com/artifex/mupdfdemo/CancellableAsyncTask.java
new file mode 100644
index 00000000..fcb1b744
--- /dev/null
+++ b/platform/android/src/com/artifex/mupdfdemo/CancellableAsyncTask.java
@@ -0,0 +1,79 @@
+package com.artifex.mupdfdemo;
+
+import java.util.concurrent.CancellationException;
+import java.util.concurrent.ExecutionException;
+
+// Ideally this would be a subclass of AsyncTask, however the cancel() method is final, and cannot
+// be overridden. I felt that having two different, but similar cancel methods was a bad idea.
+public class CancellableAsyncTask<Params, Result>
+{
+	private final AsyncTask<Params, Void, Result> asyncTask;
+	private final CancellableTaskDefinition<Params, Result> ourTask;
+
+	public void onPreExecute()
+	{
+
+	}
+
+	public void onPostExecute(Result result)
+	{
+
+	}
+
+	public CancellableAsyncTask(final CancellableTaskDefinition<Params, Result> task)
+	{
+		if (task == null)
+				throw new IllegalArgumentException();
+
+		this.ourTask = task;
+		asyncTask = new AsyncTask<Params, Void, Result>()
+				{
+					@Override
+					protected Result doInBackground(Params... params)
+					{
+						return task.doInBackground(params);
+					}
+
+					@Override
+					protected void onPreExecute()
+					{
+						CancellableAsyncTask.this.onPreExecute();
+					}
+
+					@Override
+					protected void onPostExecute(Result result)
+					{
+						CancellableAsyncTask.this.onPostExecute(result);
+						task.doCleanup();
+					}
+				};
+	}
+
+	public void cancelAndWait()
+	{
+		this.asyncTask.cancel(true);
+		ourTask.doCancel();
+
+		try
+		{
+			this.asyncTask.get();
+		}
+		catch (InterruptedException e)
+		{
+		}
+		catch (ExecutionException e)
+		{
+		}
+		catch (CancellationException e)
+		{
+		}
+
+		ourTask.doCleanup();
+	}
+
+	public void execute(Params ... params)
+	{
+		asyncTask.execute(params);
+	}
+
+}