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author | The Android Open Source Project <initial-contribution@android.com> | 2009-03-03 18:28:45 -0800 |
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committer | The Android Open Source Project <initial-contribution@android.com> | 2009-03-03 18:28:45 -0800 |
commit | d83a98f4ce9cfa908f5c54bbd70f03eec07e7553 (patch) | |
tree | 4b825dc642cb6eb9a060e54bf8d69288fbee4904 /docs/html/guide/tutorials/views/hello-mapview.jd | |
parent | 076357b8567458d4b6dfdcf839ef751634cd2bfb (diff) | |
download | frameworks_base-d83a98f4ce9cfa908f5c54bbd70f03eec07e7553.zip frameworks_base-d83a98f4ce9cfa908f5c54bbd70f03eec07e7553.tar.gz frameworks_base-d83a98f4ce9cfa908f5c54bbd70f03eec07e7553.tar.bz2 |
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diff --git a/docs/html/guide/tutorials/views/hello-mapview.jd b/docs/html/guide/tutorials/views/hello-mapview.jd deleted file mode 100644 index b0f59de..0000000 --- a/docs/html/guide/tutorials/views/hello-mapview.jd +++ /dev/null @@ -1,243 +0,0 @@ -page.title=Hello, MapView -parent.title=Hello, Views -parent.link=index.html -@jd:body - -<p>A MapView allows you to create your own map-viewing Activity. -First, we'll create a simple Activity that can view and navigate a map. Then we will add some overlay items.</p> - -<ol> - <li>Start a new project/Activity called HelloMapView. - - <li>Because we're using the Google Maps library, - which is not a part of the standard Android library, we need to - declare it in the Android Manifest. Open the AndroidManifest.xml - file and add the following as a child of the <code><application></code> element: - - <pre><uses-library android:name="com.google.android.maps" /></pre> - </li> - - <li>Open the layout file. Define the layout with a MapView inside a RelativeLayout: - -<pre> -<?xml version="1.0" encoding="utf-8"?> -<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" - android:id="@+id/mainlayout" - android:orientation="vertical" - android:layout_width="fill_parent" - android:layout_height="fill_parent" > - - <com.google.android.maps.MapView - android:id="@+id/mapview" - android:layout_width="fill_parent" - android:layout_height="fill_parent" - android:clickable="true" - android:apiKey="INSERT YOUR KEY HERE" - /> - -<RelativeLayout> -</pre> - <p>Setting <code>clickable</code> is important. Otherwise, the map does not allow any user interaction.</p> - - <p>The <code>android:apiKey</code> must contain an authentic Android Maps API key. - The API key is generated using the MD5 fingerprint of your application certificate. For the purposes of - this exercise, you should use the fingerprint of your debug certificate (which cannot be used to release - your application for Android devices, but will work while developing). See how to - <a href="{@docRoot}guide/topics/location/geo/mapkey.html#getdebugfingerprint">generate a fingerprint from your - debug certificate</a>, then <a href="http://code.google.com/android/maps-api-signup.html">register the - certificate</a> to retieve an API key. - Insert the API key as the value of the <code>apiKey</code> attribute. If you do not insert a valid - Maps API key, the application will still run, but no map tiles will load.</p></li> - - <li>Now open the HelloMapView.java file. For this Activity, we're going to extend the special sub-class of - Activity called MapActivity, so change the class declaration to extend - MapActicity, instead of Activity:</p> - - <pre>public class HelloMapView extends MapActivity {</pre> - - <li>The <code>isRouteDisplayed()</code> method is required, so add it inside the class: -<pre> -@Override -protected boolean isRouteDisplayed() { - return false; -} -</pre> -<p>You can actually run this now, but all it does is allow you to pan around the map.</p> -<p>Android provides a handy {@link android.widget.ZoomControls} widget for zooming in and out of a View. -MapView can automatically hook one for us by requesting it with the <code>getZoomControls()</code> -method. Let's do this.</p> - -<li>Go back to the layout file. We need a new ViewGroup element, in which we'll - place the ZoomControls. Just below the MapView element (but inside the RelativeLayout), add this element: -<pre> -<LinearLayout - android:id="@+id/zoomview" - android:layout_width="wrap_content" - android:layout_height="wrap_content" - android:layout_alignBottom="@id/mapview" - android:layout_centerHorizontal="true" -/></pre> - - <p>It doesn't really matter what kind of ViewGroup we use, because we just want a - container that we can position within our root RelativeLayout.</p> - - <p>The last two attributes are available only to an element that's a child of a - RelativeLayout. <code>layout_alignBottom</code> aligns the bottom of this element to the bottom of - the element identified with a resource tag (which must be a sibling to this element). - <code>layout_centerHorizontal</code> centers this on the horizontal plane.</p></li> - - <li>Now go back to the HelloMapView class. We'll now retrieve the ZoomControls object from - the MapView and add it to our new layout element. First, at the top of the HelloMapView, - instantiate handles for the MapView and LinearLayout, plus a ZoomControl object: -<pre> -LinearLayout linearLayout; -MapView mapView; -ZoomControls mZoom;</pre></li> - - <li>Then initialize each of these in <code>onCreate()</code>. We'll capture the LinearLayout and - MapView through their layout resources. Then get the ZoomControls from the MapView:: -<pre> -linearLayout = (LinearLayout) findViewById(R.id.zoomview); -mapView = (MapView) findViewById(R.id.mapview); -mZoom = (ZoomControls) mapView.getZoomControls();</pre> - - <p>By using the ZoomControls object provided by MapView, we don't have to do any of the work - required to actually perform the zoom operations. The ZoomControls widget that MapView - returns for us is already hooked into the MapView and works as soon as we add it to the - layout. The controls will appear whenever the user touches the map, then dissapear after - a few moments of inactivity.</p></li> - - <li>Now just plug our ZoomControls into the LinearLayout we added: - - <pre>linearLayout.addView(mZoom);</pre></li> - - <li>Run it.</li> -</ol> - -<hr/> - -<p>So, we now have full interaction controls. All well and good, but what we really want our map -for is custom markers and layovers. Let's add some Overlay -objects to our map. To do this, we're going to -implement the ItemizedOverlay -class, which can manage a whole set of Overlay items for us.</p> - -<ol> - <li>Create a new Java class named HelloItemizedOverlay that implements ItemizedOverlay. - - <p>When using Eclipse, right-click the package name in the Eclipse Package Explorer, and select New > Class. Fill-in - the Name field as <em>HelloItemizedOverlay</em>. For the Superclass, enter - <em>com.google.android.maps.ItemizedOverlay</em>. Click the checkbox for <em>Constructors from - superclass</em>. Click Finish.</p></li> - - <li> First thing, we need an OverlayItem ArrayList, in which we'll put each of the OverlayItem - objects we want on our map. Add this at the top of the HelloItemizedOverlay class: - - <pre>private ArrayList<OverlayItem> mOverlays = new ArrayList<OverlayItem>();</pre></li> - - <li>All the constructor does is define the default marker to be used on each of the OverlayItems. - In order for the Drawable to actually get drawn, it must have its bounds defined. And we want the - center-point at the bottom of the image to be the point at which it's attached to the map - coordinates. We handle all this with the boundCenterBottom() method. Wrap this around our - defaultMarker, so the super constructor call looks like this: - - <pre>super(boundCenterBottom(defaultMarker));</pre></li> - - <li>In order to add new OverlayItems to our ArrayList, we need a new public method. We'll handle - this with the following method: - -<pre> -public void addOverlay(OverlayItem overlay) { - mOverlays.add(overlay); - populate(); -}</pre> - - <p>Each time we add a new OverlayItem, we must call <code>populate()</code>, which will read each of out - OverlayItems and prepare them to be drawn.</p></li> - - <li>In order for the <code>populate()</code> method to read each OverlayItem, it will make a request to - <code>createItem(int)</code>. We must define this method to properly read from our ArrayList. Replace the - existing contents of the createItem method with a <code>get()</code> call to our ArrayList: - -<pre> -@Override -protected OverlayItem createItem(int i) { - return mOverlays.get(i); -} -</pre></li> - - <li>We're also required to override the <code>size()</code> method. Replace the existing contents of the - method with a size request to our ArrayList: - - <pre>return mOverlays.size();</pre></li> -</ol> - - -<p>That's it for the HelloItemizedOverlay class. We're now ready to use it.</p> - -<hr/> -<p>Go back to the HelloMapView -class. We'll start by creating one OverlayItem, adding to an instance of our HelloItemizedOverlay, -and then adding this to the MapView.</p> - -<img src="images/androidmarker.png" align="right" /> -<p>First, we need the image that we'll use for our map overlay. Here, we'll use the Android on the -right as our marker. Drag this image (or your own) to the res/drawable/ directory of your project workspace.</p> - -<p>Now we're ready to work in the HelloMapView:</p> - -<ol> - <li>First we need some more types. Add the following at the top of the HelloMapView class: - -<pre> -List<Overlay> mapOverlays; -Drawable drawable; -HelloItemizedOverlay itemizedOverlay;</pre></li> - - <li>Now pick up where we left off in the <code>onCreate()</code> method. Instantiate the - new fields: - -<pre> -mapOverlays = mapView.getOverlays(); -drawable = this.getResources().getDrawable(R.drawable.androidmarker); -itemizedoverlay = new HelloItemizedOverlay(drawable);</pre> - - <p>All overlay elements on a map are held by the MapView, so when we want to add some, we must - first retrieve the List with <code>getOverlays()</code> methods. We instantiate the Drawable, which will - be used as our map marker, by using our Context resources to get the Drawable we placed in - the res/drawable/ directory (androidmarker.png). Our HelloItemizedOverlay takes the Drawable in order to set the - default marker.</p></li> - - <li>Now let's make our first OverlayItem by creating a GeoPoint - that defines our map coordinates, then pass it to a new OverlayItem: - -<pre> -GeoPoint point = new GeoPoint(19240000,-99120000); -OverlayItem overlayitem = new OverlayItem(point, "", "");</pre> - - <p>GeoPoint coordinates are based in microdegrees (degrees * 1e6). The OverlayItem takes this - GeoPoint and two strings. Here, we won't concern ourselves with the strings, which can display - text when we click our marker, because we haven't yet written the click handler for the OverlayItem.</p></li> - - <li>All that's left is for us to add this OverlayItem to our collection in the HelloItemizedOverlay, - and add this to the List of Overlay objects retrieved from the MapView: - -<pre> -itemizedoverlay.addOverlay(overlayitem); -mapOverlays.add(itemizedoverlay);</pre></li> - - <li>Run it!</li> -</ol> - -<p>We've sent our droid to Mexico City. Hola, Mundo!</p> -<p>You should see the following:</p> -<img src="images/hello-mapview.png" width="150px" /> - -<p>Because we created our ItemizedOverlay class with an ArrayList, we can continue adding new -OverlayItems. Try adding another one. Before the <code>addOverlay()</code> method is called, add these lines:</p> -<pre> -GeoPoint point2 = new GeoPoint(35410000, 139460000); -OverlayItem overlayitem2 = new OverlayItem(point2, "", ""); -</pre> -<p>Run it again... We've sent a new droid to Tokyo. Sekai, konichiwa!</p> - |