#32 Add the example of asynchronous data loading into ViewFlow

viewflow-example/AndroidManifest.xml

@@ -17,6 +17,10 @@
 			android:configChanges="orientation">
 
 		</activity>
+
+		<activity android:label="@string/app_name"
+			android:configChanges="orientation" android:name=".AsyncDataFlowExample">
+		</activity>
 
 		<activity android:name="ViewFlowExample" android:label="@string/app_name">
 			<intent-filter>

viewflow-example/res/layout/day_view.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+	android:orientation="vertical" android:layout_width="match_parent"
+	android:layout_height="match_parent">
+
+	<ProgressBar android:id="@+id/progress"
+		android:layout_width="wrap_content" android:layout_height="wrap_content"></ProgressBar>
+
+	<LinearLayout android:layout_height="wrap_content"
+		android:id="@+id/content" android:layout_width="match_parent"
+		android:orientation="vertical">
+
+		<TextView android:id="@+id/text" android:text="Content loaded."
+			android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>
+
+		<TextView android:id="@+id/date" android:text="This is content."
+			android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>
+
+	</LinearLayout>
+
+</LinearLayout>

viewflow-example/res/values/strings.xml

@@ -5,4 +5,5 @@
     <string name="title_title">TitleFlowIndicator</string>
     <string name="circle_title">CircleFlowIndicator</string>
     <string name="diff_title">DifferentViewFlow</string>
+    <string name="async_title">AsyncDataLoading</string>
 </resources>

viewflow-example/src/org/taptwo/android/widget/viewflow/example/AsyncAdapter.java

@@ -0,0 +1,167 @@
+package org.taptwo.android.widget.viewflow.example;
+
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.Calendar;
+import java.util.Date;
+
+import org.taptwo.android.widget.TitleProvider;
+import org.taptwo.android.widget.viewflow.example.R;
+
+import android.content.Context;
+import android.os.AsyncTask;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.BaseAdapter;
+import android.widget.ProgressBar;
+import android.widget.TextView;
+
+
+public class AsyncAdapter extends BaseAdapter implements TitleProvider {
+
+	private LayoutInflater mInflater;
+
+	private static final DateFormat dfTitle = new SimpleDateFormat("E, dd MMM");
+
+	private static final int daysDepth = 10;
+	private static final int daysSize = daysDepth * 2 + 1;
+
+	private static Date[] dates = new Date[ daysSize ];
+	private static String[] content = new String[ daysSize ];
+
+
+	private class ViewHolder {
+		ProgressBar mProgressBar;
+		View mContent;
+		TextView mDate;
+	}
+
+
+	public AsyncAdapter(Context context) {
+		mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+		prepareDates();
+	}
+
+	@Override
+	public String getItem(int position) {
+		return content[position];
+	}
+
+	@Override
+	public long getItemId(int position) {
+		return position; 
+	}
+
+	@Override
+	public View getView(int position, View convertView, ViewGroup parent) {
+		return drawView(position, convertView);
+	}
+
+	private View drawView(int position, View view) {
+		ViewHolder holder = null;
+
+		if(view == null) {
+			view = mInflater.inflate(R.layout.day_view, null);
+
+			holder = new ViewHolder();
+
+			holder.mProgressBar = (ProgressBar) view.findViewById(R.id.progress);
+			holder.mDate = (TextView) view.findViewById(R.id.date);
+			holder.mContent = (View) view.findViewById(R.id.content);
+
+			view.setTag(holder);
+		} else {
+			holder = (ViewHolder) view.getTag();
+		}		
+
+
+		final String o = getItem(position);
+		if (o != null) {
+			holder.mProgressBar.setVisibility(View.GONE);
+			holder.mDate.setText(o);
+			holder.mContent.setVisibility(View.VISIBLE);
+		}
+		else {
+			new LoadContentTask().execute(position, view);
+
+			holder.mContent.setVisibility(View.GONE);
+			holder.mProgressBar.setVisibility(View.VISIBLE);
+		}
+
+		return view;
+	}
+
+	@Override
+	public String getTitle(int position) {
+		return dfTitle.format( dates[position] );
+	}
+
+	@Override
+	public int getCount() {
+		return dates.length;
+	}
+
+	public int getTodayId() {
+		return daysDepth;
+	}
+
+	public Date getTodayDate() {
+		return dates[daysDepth];
+	}
+
+	/**
+	 * Prepare dates for navigation, to past and to future
+	 */
+	private void prepareDates() {
+		Date today = new Date();
+
+		Calendar calPast = Calendar.getInstance();
+		Calendar calFuture = Calendar.getInstance();
+
+		calPast.setTime(today);
+		calFuture.setTime(today);
+
+		dates[ daysDepth ] = calPast.getTime();
+		for (int i = 1; i <= daysDepth; i++) {
+			calPast.add( Calendar.DATE, -1 );
+			dates[ daysDepth - i ] = calPast.getTime();
+
+			calFuture.add( Calendar.DATE, 1 );
+			dates[ daysDepth + i ] = calFuture.getTime();
+		}
+	}
+
+
+	private class LoadContentTask extends AsyncTask<Object, Object, Object> {
+
+		private Integer position;
+		private View view;
+
+		@Override
+		protected Object doInBackground(Object... arg) {
+			position = (Integer) arg[0];
+			view = (View) arg[1];
+
+// long-term task is here 			
+			try {
+				Thread.sleep(3000); // do nothing for 3000 miliseconds (3 second)
+			} catch (InterruptedException e) {
+				e.printStackTrace();
+			}
+
+			return getTitle(position);
+		}
+
+		protected void onPostExecute(Object result) {
+// process result    	 
+			content[position] = (String) result;
+
+	    	drawView(position, view);
+
+	    	view.postInvalidate();
+	     }
+
+	}	
+
+}

viewflow-example/src/org/taptwo/android/widget/viewflow/example/AsyncDataFlowExample.java

@@ -0,0 +1,29 @@
+package org.taptwo.android.widget.viewflow.example;
+
+import org.taptwo.android.widget.TitleFlowIndicator;
+import org.taptwo.android.widget.ViewFlow;
+
+import android.app.Activity;
+import android.os.Bundle;
+
+public class AsyncDataFlowExample extends Activity {
+
+	private ViewFlow viewFlow;
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+		super.onCreate(savedInstanceState);
+		setTitle(R.string.async_title);
+		setContentView(R.layout.title_layout);
+
+		viewFlow = (ViewFlow) findViewById(R.id.viewflow);
+		AsyncAdapter adapter = new AsyncAdapter(this);
+		viewFlow.setAdapter(adapter, adapter.getTodayId());
+
+		TitleFlowIndicator indicator = (TitleFlowIndicator) findViewById(R.id.viewflowindic);
+		indicator.setTitleProvider(adapter);
+
+		viewFlow.setFlowIndicator(indicator);
+    }
+
+}

viewflow-example/src/org/taptwo/android/widget/viewflow/example/ViewFlowExample.java

@@ -34,7 +34,7 @@ public void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 		setContentView(R.layout.main);
 		listView = (ListView) findViewById(R.id.menu);
-		String[] listeStrings = { "Circle indicator...", "Title indicator...", "Different Views..." };
+		String[] listeStrings = { "Circle indicator...", "Title indicator...", "Different Views...", "Async Data Loading..." };
 		listView.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, listeStrings));
 		listView.setOnItemClickListener(new OnItemClickListener() {
 			@Override
@@ -48,6 +48,10 @@ public void onItemClick(AdapterView<?> adapterView, View view, int position, lon
 					break;
 				case 2:
 					startActivity(new Intent(ViewFlowExample.this, DiffViewFlowExample.class));
+					break;
+				case 3:
+					startActivity(new Intent(ViewFlowExample.this, AsyncDataFlowExample.class));
+					break;
 				}
 			}
 		});