diff options
Diffstat (limited to 'docs/html/training')
| -rw-r--r-- | docs/html/training/app-indexing/index.jd | 8 | ||||
| -rw-r--r-- | docs/html/training/articles/perf-tips.jd | 1 | ||||
| -rw-r--r-- | docs/html/training/cloudsync/backupapi.jd | 2 | ||||
| -rw-r--r-- | docs/html/training/cloudsync/index.jd | 10 | ||||
| -rw-r--r-- | docs/html/training/tv/index.jd | 59 | ||||
| -rw-r--r-- | docs/html/training/tv/optimizing-layouts-tv.jd | 246 | ||||
| -rw-r--r-- | docs/html/training/tv/optimizing-navigation-tv.jd | 206 | ||||
| -rw-r--r-- | docs/html/training/tv/unsupported-features-tv.jd | 157 |
8 files changed, 11 insertions, 678 deletions
diff --git a/docs/html/training/app-indexing/index.jd b/docs/html/training/app-indexing/index.jd index cb4135f..7e7241b 100644 --- a/docs/html/training/app-indexing/index.jd +++ b/docs/html/training/app-indexing/index.jd @@ -59,14 +59,6 @@ in your app by adding intent filters in your app manifest.</li> </li> </ol> -<p class="note"><strong>Note: </strong> -Currently, the Google Search app indexing capability is restricted to -English-only Android apps from developers participating in the early adopter -program. You can sign up to be a participant by submitting the <a -href="https://docs.google.com/a/google.com/forms/d/1itcqPAQqggJ6e4m8aejWLM8Dc5O8P6qybgGbKCNxGV0/viewform" -class="external-link" target="_blank">App Indexing Expression of Interest</a> form. -</p> - <p>This class shows how to enable deep linking and indexing of your application content so that users can open this content directly from mobile search results.</p> diff --git a/docs/html/training/articles/perf-tips.jd b/docs/html/training/articles/perf-tips.jd index 7ff6c5c..1660b7f 100644 --- a/docs/html/training/articles/perf-tips.jd +++ b/docs/html/training/articles/perf-tips.jd @@ -16,7 +16,6 @@ page.article=true <li><a href="#AvoidFloat">Avoid Using Floating-Point</a></li> <li><a href="#UseLibraries">Know and Use the Libraries</a></li> <li><a href="#NativeMethods">Use Native Methods Carefully</a></li> - <li><a href="#library">Know And Use The Libraries</a></li> <li><a href="#native_methods">Use Native Methods Judiciously</a></li> <li><a href="#closing_notes">Closing Notes</a></li> </ol> diff --git a/docs/html/training/cloudsync/backupapi.jd b/docs/html/training/cloudsync/backupapi.jd index a5436c6..fd35ada 100644 --- a/docs/html/training/cloudsync/backupapi.jd +++ b/docs/html/training/cloudsync/backupapi.jd @@ -41,7 +41,7 @@ new devices using the Backup API.</p> <h2 id="register">Register for the Android Backup Service</h2> <p>This lesson requires the use of the <a - href="http://code.google.com/android/backup/index.html">Android Backup + href="{@docRoot}google/backup/index.html">Android Backup Service</a>, which requires registration. Go ahead and <a href="http://code.google.com/android/backup/signup.html">register here</a>. Once that's done, the service pre-populates an XML tag for insertion in your Android diff --git a/docs/html/training/cloudsync/index.jd b/docs/html/training/cloudsync/index.jd index 55b275b..8679009 100644 --- a/docs/html/training/cloudsync/index.jd +++ b/docs/html/training/cloudsync/index.jd @@ -6,6 +6,16 @@ startpage=true @jd:body +<div id="tb-wrapper"> +<div id="tb"> + +<h2>Dependencies and prerequisites</h2> +<ul> + <li>Android 2.2 (API level 8) and higher</li> +</ul> +</div> +</div> + <p>By providing powerful APIs for internet connectivity, the Android framework helps you build rich cloud-enabled apps that sync their data to a remote web service, making sure all your devices always stay in sync, and your valuable diff --git a/docs/html/training/tv/index.jd b/docs/html/training/tv/index.jd deleted file mode 100644 index 54f7016..0000000 --- a/docs/html/training/tv/index.jd +++ /dev/null @@ -1,59 +0,0 @@ -page.title=Designing for TV -page.tags="input","screens" - -trainingnavtop=true -startpage=true - -@jd:body - -<div id="tb-wrapper"> -<div id="tb"> - -<!-- Required platform, tools, add-ons, devices, knowledge, etc. --> -<h2>Dependencies and prerequisites</h2> -<ul> - <li>Android 2.0 (API Level 5) or higher</li> -</ul> - -</div> -</div> - -<a class="notice-developers-video wide" href="http://www.youtube.com/watch?v=zsRnRLh-O34"> -<div> - <h3>Video</h3> - <p>DevBytes: Design for Large Displays - Part 1</p> -</div> -</a> - -<p> - Smart TVs powered by Android bring your favorite Android apps to the best screen in your house. - Thousands of apps in the Google Play Store are already optimized for TVs. This class shows how - you can optimize your Android app for TVs, including how to build a layout that - works great when the user is ten feet away and navigating with a remote control. -</p> - -<h2>Lessons</h2> - -<dl> - <dt><b><a href="optimizing-layouts-tv.html">Optimizing Layouts for TV</a></b></dt> - <dd>Shows you how to optimize app layouts for TV screens, which have some unique characteristics such as: - <ul> - <li>permanent "landscape" mode</li> - <li>high-resolution displays</li> - <li>"10 foot UI" environment.</li> - </ul> - </dd> - - <dt><b><a href="optimizing-navigation-tv.html">Optimizing Navigation for TV</a></b></dt> - <dd>Shows you how to design navigation for TVs, including: - <ul> - <li>handling D-pad navigation</li> - <li>providing navigational feedback</li> - <li>providing easily-accessible controls on the screen.</li> - </ul> - </dd> - - <dt><b><a href="unsupported-features-tv.html">Handling features not supported on TV</a></b></dt> - <dd>Lists the hardware features that are usually not available on TVs. This lesson also shows you how to - provide alternatives for missing features or check for missing features and disable code at run time.</dd> -</dl> diff --git a/docs/html/training/tv/optimizing-layouts-tv.jd b/docs/html/training/tv/optimizing-layouts-tv.jd deleted file mode 100644 index a6db052..0000000 --- a/docs/html/training/tv/optimizing-layouts-tv.jd +++ /dev/null @@ -1,246 +0,0 @@ -page.title=Optimizing Layouts for TV -parent.title=Designing for TV -parent.link=index.html - -trainingnavtop=true -next.title=Optimizing Navigation for TV -next.link=optimizing-navigation-tv.html - -@jd:body - -<div id="tb-wrapper"> -<div id="tb"> - -<h2>This lesson teaches you to</h2> -<ol> - <li><a href="#DesignLandscapeLayouts">Design Landscape Layouts</a></li> - <li><a href="#MakeTextControlsEasyToSee">Make Text and Controls Easy to See</a></li> - <li><a href="#DesignForLargeScreens">Design for High-Density Large Screens</a></li> - <li><a href="#HandleLargeBitmaps">Design to Handle Large Bitmaps</a></li> -</ol> - -<h2>You should also read</h2> -<ul> - <li><a href="{@docRoot}guide/practices/screens_support.html">Supporting Multiple Screens</a></li> -</ul> - -</div> -</div> - -<p> -When your application is running on a television set, you should assume that the user is sitting about -ten feet away from the screen. This user environment is referred to as the -<a href="http://en.wikipedia.org/wiki/10-foot_user_interface">10-foot UI</a>. To provide your -users with a usable and enjoyable experience, you should style and lay out your UI accordingly.. -</p> -<p> -This lesson shows you how to optimize layouts for TV by: -</p> -<ul> - <li>Providing appropriate layout resources for landscape mode.</li> - <li>Ensuring that text and controls are large enough to be visible from a distance.</li> - <li>Providing high resolution bitmaps and icons for HD TV screens.</li> -</ul> - -<h2 id="DesignLandscapeLayouts">Design Landscape Layouts</h2> - -<p> -TV screens are always in landscape orientation. Follow these tips to build landscape layouts optimized for TV screens: -</p> -<ul> - <li>Put on-screen navigational controls on the left or right side of the screen and save the - vertical space for content.</li> - <li>Create UIs that are divided into sections, by using <a href="{@docRoot}guide/components/fragments.html">Fragments</a> - and use view groups like {@link android.widget.GridView} instead - of {@link android.widget.ListView} to make better use of the - horizontal screen space.</li> - <li>Use view groups such as {@link android.widget.RelativeLayout} - or {@link android.widget.LinearLayout} to arrange views. - This allows the Android system to adjust the position of the views to the size, alignment, - aspect ratio, and pixel density of the TV screen.</li> - <li>Add sufficient margins between layout controls to avoid a cluttered UI.</li> -</ul> - -<p> -For example, the following layout is optimized for TV: -</p> - -<img src="{@docRoot}images/training/panoramio-grid.png" /> - -<p> -In this layout, the controls are on the lefthand side. The UI is displayed within a -{@link android.widget.GridView}, which is well-suited to landscape orientation. -In this layout both GridView and Fragment have the width and height set -dynamically, so they can adjust to the screen resolution. Controls are added to the left side Fragment programatically at runtime. -The layout file for this UI is {@code res/layout-land-large/photogrid_tv.xml}. -(This layout file is placed in {@code layout-land-large} because TVs have large screens with landscape orientation. For details refer to -<a href="{@docRoot}guide/practices/screens_support.html">Supporting Multiple Screens</a>.)</p> - -res/layout-land-large/photogrid_tv.xml -<pre> -<RelativeLayout - android:layout_width="fill_parent" - android:layout_height="fill_parent" > - - <fragment - android:id="@+id/leftsidecontrols" - android:layout_width="0dip" - android:layout_marginLeft="5dip" - android:layout_height="match_parent" /> - - <GridView - android:id="@+id/gridview" - android:layout_width="wrap_content" - android:layout_height="wrap_content" /> - -</RelativeLayout> -</pre> - -<p> -To set up action bar items on the left side of the screen, you can also include the <a -href="http://code.google.com/p/googletv-android-samples/source/browse/#git%2FLeftNavBarLibrary"> -Left navigation bar library</a> in your application to set up action items on the left side -of the screen, instead of creating a custom Fragment to add controls: -</p> - -<pre> -LeftNavBar bar = (LeftNavBarService.instance()).getLeftNavBar(this); -</pre> - -<p> -When you have an activity in which the content scrolls vertically, always use a left navigation bar; -otherwise, your users have to scroll to the top of the content to switch between the content view and -the ActionBar. Look at the -<a href="http://code.google.com/p/googletv-android-samples/source/browse/#git%2FLeftNavBarDemo"> -Left navigation bar sample app</a> to see how to simple it is to include the left navigation bar in your app. -</p> - -<h2 id="MakeTextControlsEasyToSee">Make Text and Controls Easy to See</h2> -<p> -The text and controls in a TV application's UI should be easily visible and navigable from a distance. -Follow these tips to make them easier to see from a distance : -</p> - -<ul> - <li>Break text into small chunks that users can quickly scan.</li> - <li>Use light text on a dark background. This style is easier to read on a TV.</li> - <li>Avoid lightweight fonts or fonts that have both very narrow and very broad strokes. Use simple sans-serif - fonts and use anti-aliasing to increase readability.</li> - <li>Use Android's standard font sizes: - <pre> - <TextView - android:id="@+id/atext" - android:layout_width="wrap_content" - android:layout_height="wrap_content" - android:gravity="center_vertical" - android:singleLine="true" - android:textAppearance="?android:attr/textAppearanceMedium"/> - </pre></li> - <li>Ensure that all your view widgets are large enough to be clearly visible to someone sitting 10 feet away - from the screen (this distance is greater for very large screens). The best way to do this is to use - layout-relative sizing rather than absolute sizing, and density-independent pixel units instead of absolute - pixel units. For example, to set the width of a widget, use wrap_content instead of a pixel measurement, - and to set the margin for a widget, use dip instead of px values. - </li> -</ul> -<p> - -</p> - -<h2 id="DesignForLargeScreens">Design for High-Density Large Screens</h2> - -<p> -The common HDTV display resolutions are 720p, 1080i, and 1080p. Design your UI for 1080p, and then -allow the Android system to downscale your UI to 720p if necessary. In general, downscaling (removing pixels) -does not degrade the UI (Notice that the converse is not true; you should avoid upscaling because it degrades -UI quality). -</p> - -<p> -To get the best scaling results for images, provide them as <a href="{@docRoot}tools/help/draw9patch.html"> -9-patch image</a> elements if possible. -If you provide low quality or small images in your layouts, they will appear pixelated, fuzzy, or grainy. This -is not a good experience for the user. Instead, use high-quality images. -</p> - -<p> -For more information on optimizing apps for large screens see <a href="{@docRoot}training/multiscreen/index.html"> -Designing for multiple screens</a>. -</p> - -<h2 id="HandleLargeBitmaps">Design to Handle Large Bitmaps</h2> - -<p> -The Android system has a limited amount of memory, so downloading and storing high-resolution images can often -cause out-of-memory errors in your app. To avoid this, follow these tips: -</p> - -<ul> - <li>Load images only when they're displayed on the screen. For example, when displaying multiple images in - a {@link android.widget.GridView} or - {@link android.widget.Gallery}, only load an image when - {@link android.widget.Adapter#getView(int, View, ViewGroup) getView()} - is called on the View's {@link android.widget.Adapter}. - </li> - <li>Call {@link android.graphics.Bitmap#recycle()} on - {@link android.graphics.Bitmap} views that are no longer needed. - </li> - <li>Use {@link java.lang.ref.WeakReference} for storing references - to {@link android.graphics.Bitmap} objects in an in-memory - {@link java.util.Collection}.</li> - <li>If you fetch images from the network, use {@link android.os.AsyncTask} - to fetch them and store them on the SD card for faster access. - Never do network transactions on the application's UI thread. - </li> - <li>Scale down really large images to a more appropriate size as you download them; otherwise, downloading the image - itself may cause an "Out of Memory" exception. Here is sample code that scales down images while downloading: - - <pre> - // Get the source image's dimensions - BitmapFactory.Options options = new BitmapFactory.Options(); - // This does not download the actual image, just downloads headers. - options.inJustDecodeBounds = true; - BitmapFactory.decodeFile(IMAGE_FILE_URL, options); - // The actual width of the image. - int srcWidth = options.outWidth; - // The actual height of the image. - int srcHeight = options.outHeight; - - // Only scale if the source is bigger than the width of the destination view. - if(desiredWidth > srcWidth) - desiredWidth = srcWidth; - - // Calculate the correct inSampleSize/scale value. This helps reduce memory use. It should be a power of 2. - int inSampleSize = 1; - while(srcWidth / 2 > desiredWidth){ - srcWidth /= 2; - srcHeight /= 2; - inSampleSize *= 2; - } - - float desiredScale = (float) desiredWidth / srcWidth; - - // Decode with inSampleSize - options.inJustDecodeBounds = false; - options.inDither = false; - options.inSampleSize = inSampleSize; - options.inScaled = false; - // Ensures the image stays as a 32-bit ARGB_8888 image. - // This preserves image quality. - options.inPreferredConfig = Bitmap.Config.ARGB_8888; - - Bitmap sampledSrcBitmap = BitmapFactory.decodeFile(IMAGE_FILE_URL, options); - - // Resize - Matrix matrix = new Matrix(); - matrix.postScale(desiredScale, desiredScale); - Bitmap scaledBitmap = Bitmap.createBitmap(sampledSrcBitmap, 0, 0, - sampledSrcBitmap.getWidth(), sampledSrcBitmap.getHeight(), matrix, true); - sampledSrcBitmap = null; - - // Save - FileOutputStream out = new FileOutputStream(LOCAL_PATH_TO_STORE_IMAGE); - scaledBitmap.compress(Bitmap.CompressFormat.JPEG, 100, out); - scaledBitmap = null; - </pre> - </li> </ul>
\ No newline at end of file diff --git a/docs/html/training/tv/optimizing-navigation-tv.jd b/docs/html/training/tv/optimizing-navigation-tv.jd deleted file mode 100644 index bb78258..0000000 --- a/docs/html/training/tv/optimizing-navigation-tv.jd +++ /dev/null @@ -1,206 +0,0 @@ -page.title=Optimizing Navigation for TV -parent.title=Designing for TV -parent.link=index.html - -trainingnavtop=true -previous.title=Optimizing Layouts for TV -previous.link=optimizing-layouts-tv.html -next.title=Handling Features Not Supported on TV -next.link=unsupported-features-tv.html - -@jd:body - -<div id="tb-wrapper"> -<div id="tb"> - -<h2>This lesson teaches you to</h2> -<ol> - <li><a href="#HandleDpadNavigation">Handle D-pad Navigation</a></li> - <li><a href="#HandleFocusSelection">Provide Clear Visual Indication for Focus and Selection</a></li> - <li><a href="#DesignForEasyNavigation">Design for Easy Navigation</a></li> -</ol> - -<h2>You should also read</h2> -<ul> - <li><a href="{@docRoot}training/design-navigation/index.html">Designing Effective Navigation</a></li> -</ul> - -</div> -</div> - -<p> -An important aspect of the user experience when operating a TV is the direct human interface: a remote control. -As you optimize your Android application for TVs, you should pay special attention to how the user actually navigates -around your application when using a remote control instead of a touchscreen. -</p> -<p> -This lesson shows you how to optimize navigation for TV by: -</p> - -<ul> - <li>Ensuring all layout controls are D-pad navigable.</li> - <li>Providing highly obvious feedback for UI navigation.</li> - <li>Placing layout controls for easy access.</li> -</ul> - -<h2 id="HandleDpadNavigation">Handle D-pad Navigation</h2> - -<p> -On a TV, users navigate with controls on a TV remote, using either a D-pad or arrow keys. -This limits movement to up, down, left, and right. -To build a great TV-optimized app, you must provide a navigation scheme in which the user can -quickly learn how to navigate your app using the remote. -</p> - -<p> -When you design navigation for D-pad, follow these guidelines: -</p> - -<ul> - <li>Ensure that the D-pad can navigate to all the visible controls on the screen.</li> - <li>For scrolling lists with focus, D-pad up/down keys scroll the list and Enter key selects an item in the list. Ensure that users can - select an element in the list and that the list still scrolls when an element is selected.</li> - <li>Ensure that movement between controls is straightforward and predictable.</li> -</ul> - -<p> -Android usually handles navigation order between layout elements automatically, so you don't need to do anything extra. If the screen layout -makes navigation difficult, or if you want users to move through the layout in a specific way, you can set up explicit navigation for your -controls. -For example, for an {@code android.widget.EditText}, to define the next control to receive focus, use: -<pre> -<EditText android:id="@+id/LastNameField" android:nextFocusDown="@+id/FirstNameField"\> -</pre> -The following table lists all of the available navigation attributes: -</p> - -<table> -<tr> -<th>Attribute</th> -<th>Function</th> -</tr> -<tr> -<td>{@link android.R.attr#nextFocusDown}</td> -<td>Defines the next view to receive focus when the user navigates down.</td> -</tr> -<tr> -<td>{@link android.R.attr#nextFocusLeft}</td> -<td>Defines the next view to receive focus when the user navigates left.</td> -</tr> -<tr> -<td>{@link android.R.attr#nextFocusRight}</td> -<td>Defines the next view to receive focus when the user navigates right.</td> -</tr> -<tr> -<td>{@link android.R.attr#nextFocusUp}</td> -<td>Defines the next view to receive focus when the user navigates up.</td> -</tr> -</table> - -<p> -To use one of these explicit navigation attributes, set the value to the ID (android:id value) of another widget in the layout. You should set -up the navigation order as a loop, so that the last control directs focus back to the first one. -</p> - -<p> -Note: You should only use these attributes to modify the navigation order if the default order that the system applies does not work well. -</p> - -<h2 id="HandleFocusSelection">Provide Clear Visual Indication for Focus and Selection</h2> - -<p> -Use appropriate color highlights for all navigable and selectable elements in the UI. This makes it easy for users to know whether the control -is currently focused or selected when they navigate with a D-pad. Also, use uniform highlight scheme across your application. -</p> - -<p> -Android provides <a href="{@docRoot}guide/topics/resources/drawable-resource.html#StateList">Drawable State List Resources</a> to implement highlights -for selected and focused controls. For example: -</p> - -res/drawable/button.xml: -<pre> -<?xml version="1.0" encoding="utf-8"?> -<selector xmlns:android="http://schemas.android.com/apk/res/android"> - <item android:state_pressed="true" - android:drawable="@drawable/button_pressed" /> <!-- pressed --> - <item android:state_focused="true" - android:drawable="@drawable/button_focused" /> <!-- focused --> - <item android:state_hovered="true" - android:drawable="@drawable/button_focused" /> <!-- hovered --> - <item android:drawable="@drawable/button_normal" /> <!-- default --> -</selector> -</pre> - -<p> -This layout XML applies the above state list drawable to a {@link android.widget.Button}: -</p> -<pre> -<Button - android:layout_height="wrap_content" - android:layout_width="wrap_content" - android:background="@drawable/button" /> -</pre> - -<p> -Provide sufficient padding within the focusable and selectable controls so that the highlights around them are clearly visible. -</p> - -<h2 id="DesignForEasyNavigation">Design for Easy Navigation</h2> - -<p> -Users should be able to navigate to any UI control with a couple of D-pad clicks. Navigation should be easy and intuitive to -understand. For any non-intuitive actions, provide users with written help, using a dialog triggered by a help button or action bar icon. -</p> - -<p> -Predict the next screen that the user will want to navigate to and provide one click navigation to it. If the current screen UI is very sparse, -consider making it a multi pane screen. Use fragments for making multi-pane screens. For example, consider the multi-pane UI below with continent names -on the left and list of cool places in each continent on the right. -</p> - -<img src="{@docRoot}images/training/cool-places.png" alt="" /> - -<p> -The above UI consists of three Fragments - <code>left_side_action_controls</code>, <code>continents</code> and -<code>places</code> - as shown in its layout -xml file below. Such multi-pane UIs make D-pad navigation easier and make good use of the horizontal screen space for -TVs. -</p> -res/layout/cool_places.xml -<pre> -<LinearLayout - android:layout_width="match_parent" - android:layout_height="match_parent" - android:orientation="horizontal" - > - <fragment - android:id="@+id/left_side_action_controls" - android:layout_width="0px" - android:layout_height="match_parent" - android:layout_marginLeft="10dip" - android:layout_weight="0.2"/> - <fragment - android:id="@+id/continents" - android:layout_width="0px" - android:layout_height="match_parent" - android:layout_marginLeft="10dip" - android:layout_weight="0.2"/> - - <fragment - android:id="@+id/places" - android:layout_width="0px" - android:layout_height="match_parent" - android:layout_marginLeft="10dip" - android:layout_weight="0.6"/> - -</LinearLayout> -</pre> - -<p> -Also, notice in the UI layout above action controls are on the left hand side of a vertically scrolling list to make -them easily accessible using D-pad. -In general, for layouts with horizontally scrolling components, place action controls on left or right hand side and -vice versa for vertically scrolling components. -</p> - diff --git a/docs/html/training/tv/unsupported-features-tv.jd b/docs/html/training/tv/unsupported-features-tv.jd deleted file mode 100644 index a9f090b..0000000 --- a/docs/html/training/tv/unsupported-features-tv.jd +++ /dev/null @@ -1,157 +0,0 @@ -page.title=Handling Features Not Supported on TV -parent.title=Designing for TV -parent.link=index.html - -trainingnavtop=true -previous.title=Optimizing Navigation for TV -previous.link=optimizing-navigation-tv.html - -@jd:body - -<div id="tb-wrapper"> -<div id="tb"> - -<h2>This lesson teaches you to</h2> -<ol> - <li><a href="#WorkaroundUnsupportedFeatures">Work Around Features Not Supported on TV</a></li> - <li><a href="#CheckAvailableFeatures">Check for Available Features at Runtime</a></li> -</ol> - -</div> -</div> - -<p> -TVs are much different from other Android-powered devices: -</p> -<ul> - <li>They're not mobile.</li> - <li>Out of habit, people use them for watching media with little or no interaction.</li> - <li>People interact with them from a distance.</li> -</ul> - -<p> -Because TVs have a different purpose from other devices, they usually don't have hardware features -that other Android-powered devices often have. For this reason, the Android system does not -support the following features for a TV device: -<table> -<tr> -<th>Hardware</th> -<th>Android feature descriptor</th> -</tr> -<tr> -<td>Camera</td> -<td>android.hardware.camera</td> -</tr> -<tr> -<td>GPS</td> -<td>android.hardware.location.gps</td> -</tr> -<tr> -<td>Microphone</td> -<td>android.hardware.microphone</td> -</tr> -<tr> -<td>Near Field Communications (NFC)</td> -<td>android.hardware.nfc</td> -</tr> -<tr> -<td>Telephony</td> -<td>android.hardware.telephony</td> -</tr> -<tr> -<td>Touchscreen</td> -<td>android.hardware.touchscreen</td> -</tr> -</table> -</p> - -<p> -This lesson shows you how to work around features that are not available on TV by: -<ul> - <li>Providing work arounds for some non-supported features.</li> - <li>Checking for available features at runtime and conditionally activating/deactivating certain code - paths based on availability of those features.</li> -</ul> -</p> - - -<h2 id="WorkaroundUnsupportedFeatures">Work Around Features Not Supported on TV</h2> - -<p> -Android doesn't support touchscreen interaction for TV devices, most TVs don't have touch screens, -and interacting with a TV using a touchscreen is not consistent with the 10 foot environment. For -these reasons, users interact with Android-powered TVs using a remote. In consideration of this, -ensure that every control in your app can be accessed with the D-pad. Refer back to the previous two lessons -<a href="{@docRoot}training/tv/optimizing-layouts-tv.html">Optimizing Layouts for TV</a> and -<a href="{@docRoot}training/tv/optimizing-navigation-tv.html">Optimize Navigation for TV</a> for -more details -on this topic. The Android system assumes that a device has a touchscreen, so if you want your application -to run on a TV, you must <strong>explicitly</strong> disable the touchscreen requirement in your manifest file: -<pre> -<uses-feature android:name="android.hardware.touchscreen" android:required="false"/> -</pre> -</p> - -<p> -Although a TV doesn't have a camera, you can still provide a photography-related application on a TV. -For example, if you have an app that takes, views and edits photos, you can disable its picture-taking -functionality for TVs and still allow users to view and even edit photos. The next section talks about how to -deactivate or activate specific functions in the application based on runtime device type detection. -</p> - -<p> -Because TVs are stationary, indoor devices, they don't have built-in GPS. If your application uses location -information, allow users to search for a location or use a "static" location provider to get -a location from the zip code configured during the TV setup. -<pre> -LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE); -Location location = locationManager.getLastKnownLocation("static"); -Geocoder geocoder = new Geocoder(this); -Address address = null; - -try { - address = geocoder.getFromLocation(location.getLatitude(), location.getLongitude(), 1).get(0); - Log.d("Zip code", address.getPostalCode()); - -} catch (IOException e) { - Log.e(TAG, "Geocoder error", e); -} -</pre> -</p> - -<p> -TVs usually don't support microphones, but if you have an application that uses voice control, -you can create a mobile device app that takes voice input and then acts as a remote control for a TV. -</p> - -<h2 id="CheckAvailableFeatures">Check for Available Features at Runtime</h2> - -<p> -To check if a feature is available at runtime, call -{@link android.content.pm.PackageManager#hasSystemFeature(String)}. - This method takes a single argument : a string corresponding to the -feature you want to check. For example, to check for touchscreen, use -{@link android.content.pm.PackageManager#hasSystemFeature(String)} with the argument -{@link android.content.pm.PackageManager#FEATURE_TOUCHSCREEN}. -</p> - -<p> -The following code snippet demonstrates how to detect device type at runtime based on supported features: - -<pre> -// Check if android.hardware.telephony feature is available. -if (getPackageManager().hasSystemFeature("android.hardware.telephony")) { - Log.d("Mobile Test", "Running on phone"); -// Check if android.hardware.touchscreen feature is available. -} else if (getPackageManager().hasSystemFeature("android.hardware.touchscreen")) { - Log.d("Tablet Test", "Running on devices that don't support telphony but have a touchscreen."); -} else { - Log.d("TV Test", "Running on a TV!"); -} -</pre> -</p> - -<p> -This is just one example of using runtime checks to deactivate app functionality that depends on features -that aren't available on TVs. -</p>
\ No newline at end of file |