Merge "docs: add 101 class about intents, Interacting with Other Apps" into ics-mr1

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diff --git a/docs/html/training/basics/intents/filters.jd b/docs/html/training/basics/intents/filters.jd
new file mode 100644
index 0000000..0090c98
--- /dev/null
+++ b/docs/html/training/basics/intents/filters.jd
@@ -0,0 +1,244 @@
+page.title=Allowing Other Apps to Start Your Activity
+parent.title=Interacting with Other Apps
+parent.link=index.html
+
+trainingnavtop=true
+previous.title=Getting a Result from an Activity
+previous.link=result.html
+
+@jd:body
+
+<div id="tb-wrapper">
+  <div id="tb">
+
+<h2>This lesson teaches you to</h2>
+<ol>
+  <li><a href="#AddIntentFilter">Add an Intent Filter</a></li>
+  <li><a href="#HandleIntent">Handle the Intent in Your Activity</a></li>
+  <li><a href="#ReturnResult">Return a Result</a></li>
+</ol>
+
+<h2>You should also read</h2>
+<ul>
+  <li><a href="{@docRoot}training/sharing/index.html">Sharing Content</a></li>
+</ul>
+  </div>
+</div>
+
+<p>The previous two lessons focused on one side of the story: starting another app's activity from
+your app. But if your app can perform an action that might be useful to another app,
+your app should be prepared to respond to action requests from other apps. For instance, if you
+build a social app that can share messages or photos with the user's friends, it's in your best
+interest to support the {@link android.content.Intent#ACTION_SEND} intent so users can initiate a
+"share" action from another app and launch your app to perform the action.</p>
+
+<p>To allow other apps to start your activity, you need to add an <a
+href="{@docRoot}guide/topics/manifest/intent-filter-element.html">{@code &lt;intent-filter>}</a>
+element in your manifest file for the corresponding <a
+href="{@docRoot}guide/topics/manifest/activity-element.html">{@code &lt;activity>}</a> element.</p>
+
+<p>When your app is installed on a device, the system identifies your intent
+filters and adds the information to an internal catalog of intents supported by all installed apps.
+When an app calls {@link android.app.Activity#startActivity
+startActivity()} or {@link android.app.Activity#startActivityForResult startActivityForResult()},
+with an implicit intent, the system finds which activity (or activities) can respond to the
+intent.</p>
+
+
+
+<h2 id="AddIntentFilter">Add an Intent Filter</h2>
+
+<p>In order to properly define which intents your activity can handle, each intent filter you add
+should be as specific as possible in terms of the type of action and data the activity
+accepts.</p>
+
+<p>The system may send a given {@link android.content.Intent} to an activity if that activity has
+an intent filter fulfills the following criteria of the {@link android.content.Intent} object:</p>
+
+<dl>
+  <dt>Action</dt>
+    <dd>A string naming the action to perform. Usually one of the platform-defined values such
+as {@link android.content.Intent#ACTION_SEND} or {@link android.content.Intent#ACTION_VIEW}.
+    <p>Specify this in your intent filter with the <a
+href="{@docRoot}guide/topics/manifest/action-element.html">{@code &lt;action>}</a> element.
+The value you specify in this element must be the full string name for the action, instead of the
+API constant (see the examples below).</p></dd>
+
+  <dt>Data</dt>
+    <dd>A description of the data associated with the intent.
+    <p>Specify this in your intent filter with the <a
+href="{@docRoot}guide/topics/manifest/data-element.html">{@code &lt;data>}</a> element. Using one
+or more attributes in this element, you can specify just the MIME type, just a URI prefix,
+just a URI scheme, or a combination of these and others that indicate the data type
+accepted.</p>
+    <p class="note"><strong>Note:</strong> If you don't need to declare specifics about the data
+{@link android.net.Uri} (such as when your activity handles to other kind of "extra" data, instead
+of a URI), you should specify only the {@code android:mimeType} attribute to declare the type of
+data your activity handles, such as {@code text/plain} or {@code image/jpeg}.</p>
+</dd>
+  <dt>Category</dt>
+    <dd>Provides an additional way to characterize the activity handling the intent, usually related
+to the user gesture or location from which it's started. There are several different categories
+supported by the system, but most are rarely used. However, all implicit intents are defined with
+{@link android.content.Intent#CATEGORY_DEFAULT} by default.
+    <p>Specify this in your intent filter with the <a
+href="{@docRoot}guide/topics/manifest/category-element.html">{@code &lt;category>}</a>
+element.</p></dd>
+</dl>
+
+<p>In your intent filter, you can declare which criteria your activity accepts
+by declaring each of them with corresponding XML elements nested in the <a
+href="{@docRoot}guide/topics/manifest/intent-filter-element.html">{@code &lt;intent-filter>}</a>
+element.</p>
+
+<p>For example, here's an activity with an intent filter that handles the {@link
+android.content.Intent#ACTION_SEND} intent when the data type is either text or an image:</p>
+
+<pre>
+&lt;activity android:name="ShareActivity">
+    &lt;intent-filter>
+        &lt;action android:name="android.intent.action.SEND"/>
+        &lt;category android:name="android.intent.category.DEFAULT"/>
+        &lt;data android:mimeType="text/plain"/>
+        &lt;data android:mimeType="image/*"/>
+    &lt;/intent-filter>
+&lt;/activity>
+</pre>
+
+<p>Each incoming intent specifies only one action and one data type, but it's OK to declare multiple
+instances of the <a href="{@docRoot}guide/topics/manifest/action-element.html">{@code
+&lt;action>}</a>, <a href="{@docRoot}guide/topics/manifest/category-element.html">{@code
+&lt;category>}</a>, and <a href="{@docRoot}guide/topics/manifest/data-element.html">{@code
+&lt;data>}</a> elements in each
+<a href="{@docRoot}guide/topics/manifest/intent-filter-element.html">{@code
+&lt;intent-filter>}</a>.</p>
+
+<p>If any two pairs of action and data are mutually exclusive in
+their behaviors, you should create separate intent filters to specify which actions are acceptable
+when paired with which data types.</p>
+
+<p>For example, suppose your activity handles both text and images for both the {@link
+android.content.Intent#ACTION_SEND} and {@link
+android.content.Intent#ACTION_SENDTO} intents. In this case, you must define two separate
+intent filters for the two actions because a {@link
+android.content.Intent#ACTION_SENDTO} intent must use the data {@link android.net.Uri} to specify
+the recipient's address using the {@code send} or {@code sendto} URI scheme. For example:</p>
+
+<pre>
+&lt;activity android:name="ShareActivity">
+    &lt;!-- filter for sending text; accepts SENDTO action with sms URI schemes -->
+    &lt;intent-filter>
+        &lt;action android:name="android.intent.action.SENDTO"/>
+        &lt;category android:name="android.intent.category.DEFAULT"/>
+        &lt;data android:scheme="sms" />
+        &lt;data android:scheme="smsto" />
+    &lt;/intent-filter>
+    &lt;!-- filter for sending text or images; accepts SEND action and text or image data -->
+    &lt;intent-filter>
+        &lt;action android:name="android.intent.action.SEND"/>
+        &lt;category android:name="android.intent.category.DEFAULT"/>
+        &lt;data android:mimeType="image/*"/>
+        &lt;data android:mimeType="text/plain"/>
+    &lt;/intent-filter>
+&lt;/activity>
+</pre>
+
+<p class="note"><strong>Note:</strong> In order to receive implicit intents, you must include the
+{@link android.content.Intent#CATEGORY_DEFAULT} category in the intent filter. The methods {@link
+android.app.Activity#startActivity startActivity()} and {@link
+android.app.Activity#startActivityForResult startActivityForResult()} treat all intents as if they
+contained the {@link android.content.Intent#CATEGORY_DEFAULT} category. If you do not declare it, no
+implicit intents will resolve to your activity.</p>
+
+<p>For more information about sending and receiving {@link android.content.Intent#ACTION_SEND}
+intents that perform social sharing behaviors, see the lesson about <a
+href="{@docRoot}training/sharing/receive.html">Receiving Content from Other Apps</a>.</p>
+
+
+<h2 id="HandleIntent">Handle the Intent in Your Activity</h2>
+
+<p>In order to decide what action to take in your activity, you can read the {@link
+android.content.Intent} that was used to start it.</p>
+
+<p>As your activity starts, call {@link android.app.Activity#getIntent()} to retrieve the
+{@link android.content.Intent} that started the activity. You can do so at any time during the
+lifecycle of the activity, but you should generally do so during early callbacks such as
+{@link android.app.Activity#onCreate onCreate()} or {@link android.app.Activity#onStart()}.</p>
+
+<p>For example:</p>
+
+<pre>
+&#64;Override
+protected void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+
+    setContentView(R.layout.main);
+
+    // Get the intent that started this activity
+    Intent intent = getIntent();
+    Uri data = intent.getData();
+
+    // Figure out what to do based on the intent type
+    if (intent.getType().indexOf("image/") != -1) {
+        // Handle intents with image data ...
+    } else if (intent.getType().equals("text/plain")) {
+        // Handle intents with text ...
+    }
+}
+</pre>
+
+
+<h2 id="ReturnResult">Return a Result</h2>
+
+<p>If you want to return a result to the activity that invoked yours, simply call {@link
+android.app.Activity#setResult(int,Intent) setResult()} to specify the result code and result {@link
+android.content.Intent}. When your operation is done and the user should return to the original
+activity, call {@link android.app.Activity#finish()} to close (and destroy) your activity. For
+example:</p>
+
+<pre>
+// Create intent to deliver some kind of result data
+Intent result = new Intent("com.example.RESULT_ACTION", Uri.parse("content://result_uri");
+setResult(Activity.RESULT_OK, result);
+finish();
+</pre>
+
+<p>You must always specify a result code with the result. Generally, it's either {@link
+android.app.Activity#RESULT_OK} or {@link android.app.Activity#RESULT_CANCELED}. You can then
+provide additional data with an {@link android.content.Intent}, as necessary.</p>
+
+<p class="note"><strong>Note:</strong> The result is set to {@link
+android.app.Activity#RESULT_CANCELED} by default. So, if the user presses the <em>Back</em>
+button before completing the action and before you set the result, the original activity receives
+the "canceled" result.</p>
+
+<p>If you simply need to return an integer that indicates one of several result options, you can set
+the result code to any value higher than 0. If you use the result code to deliver an integer and you
+have no need to include the {@link android.content.Intent}, you can call {@link
+android.app.Activity#setResult(int) setResult()} and pass only a result code. For example:</p>
+
+<pre>
+setResult(RESULT_COLOR_RED);
+finish();
+</pre>
+
+<p>In this case, there might be only a handful of possible results, so the result code is a locally
+defined integer (greater than 0). This works well when you're returning a result to an activity
+in your own app, because the activity that receives the result can reference the public
+constant to determine the value of the result code.</p>
+
+<p class="note"><strong>Note:</strong> There's no need to check whether your activity was started
+with {@link
+android.app.Activity#startActivity startActivity()} or {@link
+android.app.Activity#startActivityForResult startActivityForResult()}. Simply call {@link
+android.app.Activity#setResult(int,Intent) setResult()} if the intent that started your activity
+might expect a result. If the originating activity had called {@link
+android.app.Activity#startActivityForResult startActivityForResult()}, then the system delivers it
+the result you supply to {@link android.app.Activity#setResult(int,Intent) setResult()}; otherwise,
+the result is ignored.</p>
+
+
+
+
+
+
diff --git a/docs/html/training/basics/intents/index.jd b/docs/html/training/basics/intents/index.jd
new file mode 100644
index 0000000..c661d98
--- /dev/null
+++ b/docs/html/training/basics/intents/index.jd
@@ -0,0 +1,64 @@
+page.title=Interacting with Other Apps
+
+trainingnavtop=true
+startpage=true
+next.title=Sending the User to Another App
+next.link=sending.html
+
+@jd:body
+
+<div id="tb-wrapper">
+<div id="tb">
+
+<h2>Dependencies and prerequisites</h2>
+<ul>
+  <li>Basic understanding of the Activity lifecycle (see <a
+href="{@docRoot}training/basics/activity-lifecycle/index.html">Managing the Activity
+Lifecycle</a>)</li>
+</ul>
+
+
+<h2>You should also read</h2>
+<ul>
+  <li><a href="{@docRoot}training/sharing/index.html">Sharing Content</a></li>
+  <li><a
+href="http://android-developers.blogspot.com/2009/11/integrating-application-with-intents.html">
+Integrating Application with Intents (blog post)</a></li>
+  <li><a href="{@docRoot}guide/topics/intents/intents-filters.html">Intents and Intent
+Filters</a></li>
+</ul>
+
+</div>
+</div>
+
+<p>An Android app typically has several <a
+href="{@docRoot}guide/topics/fundamentals/activities.html">activities</a>. Each activity displays a
+user interface that allows the user to perform a specific task (such as view a map or take a photo).
+To take the user from one activity to another, your app must use an {@link
+android.content.Intent} to define your app's "intent" to do something. When you pass an
+{@link android.content.Intent} to the system with a method such as {@link
+android.app.Activity#startActivity startActivity()}, the system uses the {@link
+android.content.Intent} to identify and start the appropriate app component. Using intents even
+allows your app to start an activity that is contained in a separate app.</p>
+
+<p>An {@link android.content.Intent} can be <em>explicit</em> in order to start a specific component
+(a specific {@link android.app.Activity} instance) or <em>implicit</em> in order to start any
+component that can handle the intended action (such as "capture a photo").</p>
+
+<p>This class shows you how to use an {@link android.content.Intent} to perform some basic
+interactions with other apps, such as start another app, receive a result from that app, and
+make your app able to respond to intents from other apps.</p>
+
+<h2>Lessons</h2>
+ 
+<dl>
+  <dt><b><a href="sending.html">Sending the User to Another App</a></b></dt>
+  <dd>Shows how you can create implicit intents to launch other apps that can perform an
+action.</dd>
+  <dt><b><a href="result.html">Getting a Result from an Activity</a></b></dt>
+  <dd>Shows how to start another activity and receive a result from the activity.</dd>
+  <dt><b><a href="filters.html">Allowing Other Apps to Start Your Activity</a></b></dt>
+  <dd>Shows how to make activities in your app open for use by other apps by defining
+intent filters that declare the implicit intents your app accepts.</dd>
+</dl> 
+
diff --git a/docs/html/training/basics/intents/result.jd b/docs/html/training/basics/intents/result.jd
new file mode 100644
index 0000000..0086913
--- /dev/null
+++ b/docs/html/training/basics/intents/result.jd
@@ -0,0 +1,182 @@
+page.title=Getting a Result from an Activity
+parent.title=Interacting with Other Apps
+parent.link=index.html
+
+trainingnavtop=true
+previous.title=Sending the User to Another App
+previous.link=sending.html
+next.title=Allowing Other Apps to Start Your Activity
+next.link=filters.html
+
+@jd:body
+
+<div id="tb-wrapper">
+  <div id="tb">
+
+<h2>This lesson teaches you to</h2>
+<ol>
+  <li><a href="#StartActivity">Start the Activity</a></li>
+  <li><a href="#ReceiveResult">Receive the Result</a></li>
+</ol>
+
+<h2>You should also read</h2>
+<ul>
+  <li><a href="{@docRoot}training/sharing/index.html">Sharing Content</a></li>
+</ul>
+
+  </div>
+</div>
+
+<p>Starting another activity doesn't have to be one-way. You can also start another activity and
+receive a result back. To receive a result, call {@link android.app.Activity#startActivityForResult
+startActivityForResult()} (instead of {@link android.app.Activity#startActivity
+startActivity()}).</p>
+
+<p>For example, your app can start a camera app and receive the captured photo as a result. Or, you
+might start the People app in order for the user to select a
+contact and you'll receive the contact details as a result.</p>
+
+<p>Of course, the activity that responds must be designed to return a result. When it does, it
+sends the result as another {@link android.content.Intent} object. Your activity receives it in
+the {@link android.app.Activity#onActivityResult onActivityResult()} callback.</p>
+
+<p class="note"><strong>Note:</strong> You can use explicit or implicit intents when you call
+{@link android.app.Activity#startActivityForResult startActivityForResult()}. When starting one of
+your own activities to receive a result, you should use an explicit intent to ensure that you
+receive the expected result.</p>
+
+
+<h2 id="StartActivity">Start the Activity</h2>
+
+<p>There's nothing special about the {@link android.content.Intent} object you use when starting
+an activity for a result, but you do need to pass an additional integer argument to the {@link
+android.app.Activity#startActivityForResult startActivityForResult()} method.</p>
+
+<p>The integer argument is a "request code" that identifies your request. When you receive the
+result {@link android.content.Intent}, the callback provides the same request code so that your
+app can properly identify the result and determine how to handle it.</p>
+
+<p>For example, here's how to start an activity that allows the user to pick a contact:</p>
+
+<pre>
+static final int PICK_CONTACT_REQUEST = 1;  // The request code
+...
+private void pickContact() {
+    Intent pickContactIntent = new Intent(Intent.ACTION_PICK, new Uri("content://contacts"));
+    pickContactIntent.setType(Phone.CONTENT_TYPE); // Show user only contacts w/ phone numbers
+    startActivityForResult(pickContactIntent, PICK_CONTACT_REQUEST);
+}
+</pre>
+
+
+<h2 id="ReceiveResult">Receive the Result</h2>
+
+<p>When the user is done with the subsequent activity and returns, the system calls your activity's 
+{@link android.app.Activity#onActivityResult onActivityResult()} method. This method includes three
+arguments:</p>
+
+<ul>
+  <li>The request code you passed to {@link
+android.app.Activity#startActivityForResult startActivityForResult()}.</li>
+  <li>A result code specified by the second activity. This is either {@link
+android.app.Activity#RESULT_OK} if the operation was successful or {@link
+android.app.Activity#RESULT_CANCELED} if the user backed out or the operation failed for some
+reason.</li>
+  <li>An {@link android.content.Intent} that carries the result data.</li>
+</ul>
+
+<p>For example, here's how you can handle the result for the "pick a contact" intent:</p>
+
+<pre>
+&#64;Override
+protected void onActivityResult(int requestCode, int resultCode, Intent data) {
+    // Check which request we're responding to
+    if (requestCode == PICK_CONTACT_REQUEST) {
+        // Make sure the request was successful
+        if (resultCode == RESULT_OK) {
+            // The user picked a contact.
+            // The Intent's data Uri identifies which contact was selected.
+
+            // Do something with the contact here (bigger example below)
+        }
+    }
+}
+</pre>
+
+<p>In this example, the result {@link android.content.Intent} returned by
+Android's Contacts or People app provides a content {@link android.net.Uri} that identifies the
+contact the user selected.</p>
+
+<p>In order to successfully handle the result, you must understand what the format of the result
+{@link android.content.Intent} will be. Doing so is easy when the activity returning a result is
+one of your own activities. Apps included with the Android platform offer their own APIs that
+you can count on for specific result data. For instance, the People app (Contacts app on some older
+versions) always returns a result with the content URI that identifies the selected contact, and the
+Camera app returns a {@link android.graphics.Bitmap} in the {@code "data"} extra (see the class
+about <a href="{@docRoot}training/camera/index.html">Capturing Photos</a>).</p>
+
+
+<h4>Bonus: Read the contact data</h4>
+
+<p>The code above showing how to get a result from the People app doesn't go into
+details about how to actually read the data from the result, because it requires more advanced
+discussion about <a href="{@docRoot}guide/topics/providers/content-providers.html">content
+providers</a>. However, if you're curious, here's some more code that shows how to query the
+result data to get the phone number from the selected contact:</p>
+
+<pre>
+&#64;Override
+protected void onActivityResult(int requestCode, int resultCode, Intent data) {
+    // Check which request it is that we're responding to
+    if (requestCode == PICK_CONTACT_REQUEST) {
+        // Make sure the request was successful
+        if (resultCode == RESULT_OK) {
+            // Get the URI that points to the selected contact
+            Uri contactUri = data.getData();
+            // We only need the NUMBER column, because there will be only one row in the result
+            String[] projection = {Phone.NUMBER};
+
+            // Perform the query on the contact to get the NUMBER column
+            // We don't need a selection or sort order (there's only one result for the given URI)
+            // CAUTION: The query() method should be called from a separate thread to avoid blocking
+            // your app's UI thread. (For simplicity of the sample, this code doesn't do that.)
+            // Consider using {@link android.content.CursorLoader} to perform the query.
+            Cursor cursor = getContentResolver()
+                    .query(contactUri, projection, null, null, null);
+            cursor.moveToFirst();
+
+            // Retrieve the phone number from the NUMBER column
+            int column = cursor.getColumnIndex(Phone.NUMBER);
+            String number = cursor.getString(column);
+
+            // Do something with the phone number...
+        }
+    }
+}
+</pre>
+
+<p class="note"><strong>Note:</strong> Before Android 2.3 (API level 9), performing a query
+on the {@link android.provider.ContactsContract.Contacts Contacts Provider} (like the one shown
+above) requires that your app declare the {@link
+android.Manifest.permission#READ_CONTACTS} permission (see <a
+href="{@docRoot}guide/topics/security/security.html">Security and Permissions</a>). However,
+beginning with Android 2.3, the Contacts/People app grants your app a temporary
+permission to read from the Contacts Provider when it returns you a result. The temporary permission
+applies only to the specific contact requested, so you cannot query a contact other than the one
+specified by the intent's {@link android.net.Uri}, unless you do declare the {@link
+android.Manifest.permission#READ_CONTACTS} permission.</p>
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/docs/html/training/basics/intents/sending.jd b/docs/html/training/basics/intents/sending.jd
new file mode 100644
index 0000000..a71c8f9
--- /dev/null
+++ b/docs/html/training/basics/intents/sending.jd
@@ -0,0 +1,211 @@
+page.title=Sending the User to Another App
+parent.title=Interacting with Other Apps
+parent.link=index.html
+
+trainingnavtop=true
+next.title=Getting a Result from an Activity
+next.link=result.html
+
+@jd:body
+
+
+<div id="tb-wrapper">
+  <div id="tb">
+
+<h2>This lesson teaches you to</h2>
+<ol>
+  <li><a href="#Build">Build an Implicit Intent</a></li>
+  <li><a href="#Verify">Verify There is an App to Receive the Intent</a></li>
+  <li><a href="#StartActivity">Start an Activity with the Intent</a></li>
+</ol>
+
+<h2>You should also read</h2>
+<ul>
+  <li><a href="{@docRoot}training/sharing/index.html">Sharing Content</a></li>
+</ul>
+
+  </div>
+</div>
+
+<p>One of Android's most important features is an app's ability to send the user to another app
+based on an "action" it would like to perform. For example, if
+your app has the address of a business that you'd like to show on a map, you don't have to build
+an activity in your app that shows a map. Instead, you can send a out a request to view the address
+using an {@link android.content.Intent}. The Android system then starts an app that's able to view
+the address on a map.</p>
+
+<p>As shown in the first class, <a href="{@docRoot}training/basics/firstapp/index.html">Building
+Your First App</a>, you must use intents to navigate between activities in your own app. You
+generally do so with an <em>explicit intent</em>, which defines the exact class name of the
+component you want to start. However, when you want to have a separate app perform an action, such
+as "view a map," you must use an <em>implicit intent</em>.</p>
+
+<p>This lesson shows you how to create an implicit intent for a particular action, and how to use it
+to start an activity that performs the action in another app.</p>
+
+
+
+<h2 id="Build">Build an Implicit Intent</h2>
+
+<p>Implicit intents do not declare the class name of the component to start, but instead declare an
+action to perform. The action specifies the thing you want to do, such as <em>view</em>,
+<em>edit</em>, <em>send</em>, or <em>get</em> something. Intents often also include data associated
+with the action, such as the address you want to view, or the email message you want to send.
+Depending on the intent you want to create, the data might be a {@link android.net.Uri},
+one of several other data types, or the intent might not need data at all.</p>
+
+<p>If your data is a {@link android.net.Uri}, there's a simple {@link
+android.content.Intent#Intent(String,Uri) Intent()} constructor you can use define the action and
+data.</p>
+
+<p>For example, here's how to create an intent to initiate a phone call using the {@link
+android.net.Uri} data to specify the telephone number:</p>
+
+<pre>
+Uri number = Uri.parse("tel:5551234");
+Intent callIntent = new Intent(Intent.ACTION_DIAL, number);
+</pre>
+
+<p>When your app invokes this intent by calling {@link android.app.Activity#startActivity
+startActivity()}, the Phone app initiates a call to the given phone number.</p>
+
+<p>Here are a couple other intents and their action and {@link android.net.Uri} data
+pairs:</p>
+
+<ul>
+  <li>View a map:
+<pre>
+// Map point based on address
+Uri location = Uri.parse("geo:0,0?q=1600+Amphitheatre+Parkway,+Mountain+View,+California");
+// Or map point based on latitude/longitude
+// Uri location = Uri.parse("geo:37.422219,-122.08364?z=14"); // z param is zoom level
+Intent mapIntent = new Intent(Intent.ACTION_VIEW, location);
+</pre>
+  </li>
+  <li>View a web page:
+<pre>
+Uri webpage = Uri.parse("http://www.android.com");
+Intent webIntent = new Intent(Intent.ACTION_VIEW, webpage);
+</pre>
+  </li>
+</ul>
+
+<p>Other kinds of implicit intents require "extra" data that provide different data types,
+such as a string. You can add one or more pieces of extra data using the various {@link
+android.content.Intent#putExtra(String,String) putExtra()} methods.</p>
+
+<p>By default, the system determines the appropriate MIME type required by an intent based on the
+{@link android.net.Uri} data that's included. If you don't include a {@link android.net.Uri} in the
+intent, you should usually use {@link android.content.Intent#setType setType()} to specify the type
+of data associated with the intent. Setting the MIME type further specifies which kinds of
+activities should receive the intent.</p>
+
+<p>Here are some more intents that add extra data to specify the desired action:</p>
+
+<ul>
+  <li>Send an email with an attachment:
+<pre>
+Intent emailIntent = new Intent(Intent.ACTION_SEND);
+// The intent does not have a URI, so declare the "text/plain" MIME type
+emailIntent.setType(HTTP.PLAIN_TEXT_TYPE);
+emailIntent.putExtra(Intent.EXTRA_EMAIL, new String[] {"jon@example.com"}); // recipients
+emailIntent.putExtra(Intent.EXTRA_SUBJECT, "Email subject");
+emailIntent.putExtra(Intent.EXTRA_TEXT, "Email message text");
+emailIntent.putExtra(Intent.EXTRA_STREAM, Uri.parse("content://path/to/email/attachment");
+// You can also attach multiple items by passing an ArrayList of Uris
+</pre>
+  </li>
+  <li>Create a calendar event:
+<pre>
+Intent calendarIntent = new Intent(Intent.ACTION_INSERT, Events.CONTENT_URI);
+Calendar beginTime = Calendar.getInstance().set(2012, 0, 19, 7, 30);
+Calendar endTime = Calendar.getInstance().set(2012, 0, 19, 10, 30);
+calendarIntent.putExtra(CalendarContract.EXTRA_EVENT_BEGIN_TIME, beginTime.getTimeInMillis());
+calendarIntent.putExtra(CalendarContract.EXTRA_EVENT_END_TIME, endTime.getTimeInMillis());
+calendarIntent.putExtra(Events.TITLE, "Ninja class");
+calendarIntent.putExtra(Events.EVENT_LOCATION, "Secret dojo");
+</pre>
+<p class="note"><strong>Note:</strong> This intent for a calendar event is supported only with API
+level 14 and higher.</p>
+  </li>
+</ul>
+
+<p class="note"><strong>Note:</strong> It's important that you define your {@link
+android.content.Intent} to be as specific as possible. For example, if you want to display an image
+using the {@link android.content.Intent#ACTION_VIEW} intent, you should specify a MIME type of
+{@code image/*}. This prevents apps that can "view" other types of data (like a map app) from being
+triggered by the intent.</p>
+
+
+
+<h2 id="Verify">Verify There is an App to Receive the Intent</h2>
+
+<p>Although the Android platform guarantees that certain intents will resolve to one of the
+built-in apps (such as the Phone, Email, or Calendar app), you should always include a
+verification step before invoking an intent.</p>
+
+<p class="caution"><strong>Caution:</strong> If you invoke an intent and there is no app
+available on the device that can handle the intent, your app will crash.</p>
+
+<p>To verify there is an activity available that can respond to the intent, call {@link
+android.content.pm.PackageManager#queryIntentActivities queryIntentActivities()} to get a list
+of activities capable of handling your {@link android.content.Intent}. If the returned {@link
+java.util.List} is not empty, you can safely use the intent. For example:</p>
+
+<pre>
+PackageManager packageManager = {@link android.content.Context#getPackageManager()};
+List&lt;ResolveInfo> activities = packageManager.queryIntentActivities(intent, 0);
+boolean isIntentSafe = activities.size() > 0;
+</pre>
+
+<p>If <code>isIntentSafe</code> is <code>true</code>, then at least one app will respond to
+the intent. If it is <code>false</code>, then there aren't any apps to handle the intent.</p>
+
+<p class="note"><strong>Note:</strong> You should perform this check when your activity first
+starts in case you need to disable the feature that uses the intent before the user attempts to use
+it. If you know of a specific app that can handle the intent, you can also provide a link for the
+user to download the app (see how to <a
+href="{@docRoot}guide/publishing/publishing.html#marketintent">link to an app on Google
+Play</a>).</p>
+
+
+<h2 id="StartActivity">Start an Activity with the Intent</h2>
+
+<div class="figure" style="width:200px">
+  <img src="{@docRoot}images/training/basics/intents-choice.png" alt="" />
+  <p class="img-caption"><strong>Figure 1.</strong> Example of the selection dialog that appears
+when more than one app can handle an intent.</p>
+</div>
+
+<p>Once you have created your {@link android.content.Intent} and set the extra info, call {@link
+android.app.Activity#startActivity startActivity()} to send it to the system. If the system
+identifies more than one activity that can handle the intent, it displays a dialog for the user to
+select which app to use, as shown in figure 1. If there is only one activity that handles the
+intent, the system immediately starts it.</p>
+
+<pre>
+startActivity(intent);
+</pre>
+
+<p>Here's a complete example that shows how to create an intent to view a map, verify that an
+app exists to handle the intent, then start it:</p>
+
+<pre>
+// Build the intent
+Uri location = Uri.parse("geo:0,0?q=1600+Amphitheatre+Parkway,+Mountain+View,+California");
+Intent mapIntent = new Intent(Intent.ACTION_VIEW, location);
+
+// Verify it resolves
+PackageManager packageManager = {@link android.content.Context#getPackageManager()};
+List&lt;ResolveInfo> activities = packageManager.queryIntentActivities(mapIntent, 0);
+boolean isIntentSafe = activities.size() > 0;
+  
+// Start an activity if it's safe
+if (isIntentSafe) {
+    startActivity(mapIntent);
+}
+</pre>
+
+
+
+