docs/html/training/wearables/watch-faces/designing.jd

page.title=Designing Watch Faces

@jd:body

<div id="tb-wrapper">
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<h2>This lesson teaches you to</h2>
<ol>
  <li><a href="#DesignGuidelines">Conform to the Design Guidelines</a></li>
  <li><a href="#ImplementationStrategy">Create an Implementation Strategy</a></li>
</ol>
<h2>You should also read</h2>
<ul>
  <li><a href="{@docRoot}design/wear/watchfaces.html">Watch Faces for Android Wear</a></li>
</ul>
</div>
</div>

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<a class="notice-designers wide" href="{@docRoot}design/wear/watchfaces.html">
  <div>
    <h3>Design Guide</h3>
    <p>Watch Faces</p>
  </div>
</a>

<p>Similar to the process of designing a traditional watch face, creating one for
Android Wear is an exercise in visualizing time clearly. Android Wear devices
provide advanced capabilities for watch faces that you can leverage in your designs, such as
vibrant colors, dynamic backgrounds, animations, and data integration. However, there are
also many design considerations that you must take into account.</p>

<p>This lesson provides a summary of the design considerations for watch faces and general
guidelines to get started implementing a design. For more information, read the <a
href="{@docRoot}design/wear/watchfaces.html">Watch Faces for Android Wear</a> design guide.</p>



<h2 id="DesignGuidelines">Conform to the Design Guidelines</h2>

<p>As you plan the look of your watch face and what kind of information it should present
to users, consider these design guidelines:</p>

<div style="float:right;margin-top:-5px;margin-left:20px">
  <img src="{@docRoot}training/wearables/watch-faces/images/Render_Next.png"
       width="200" height="195" alt="" style="margin-right:5px"/><br>
  <img src="{@docRoot}training/wearables/watch-faces/images/Render_Interactive.png"
       width="200" height="195" alt="" style="margin-right:5px"/>
  <p class="img-caption" style="margin-top:0px;margin-left:10px">
  <strong>Figure 1.</strong> Example watch faces.</p>
</div>

<dl>
<dt><em>Plan for square and round devices</em></dt>
<dd>Your design should work for both square and round Android Wear devices, including devices with
<a href="{@docRoot}training/wearables/ui/layouts.html#same-layout">insets on the bottom of the
screen</a>.</dd>

<dt><em>Support all display modes</em></dt>
<dd>Your watch face should support ambient mode with limited color and interactive mode with
full color and animations.</dd>

<dt><em>Optimize for special screen technologies</em></dt>
<dd>In ambient mode, your watch face should keep most pixels black. Depending on the screen
technology, you may need to avoid large blocks of white pixels, use only black and white, and
disable anti-aliasing.</dd>

<dt><em>Accomodate system UI elements</em></dt>
<dd>Your design should ensure that system indicators remain visible and that users can still
read the time when notification cards appear on the screen.</dd>

<dt><em>Integrate data</em></dt>
<dd>Your watch face can leverage sensors and cellular connectivity on the companion mobile
device to show user data relevant to the context, such as the weather for the day or their next
calendar event.</dd>

<dt><em>Provide configuration options</em></dt>
<dd>You can let users configure some aspects of your design (like colors and sizes) on the
wearable or on the Android Wear companion app.</dd>
</dl>

<p>For more information about designing watch faces for Android Wear, see the <a
href="{@docRoot}design/wear/watchfaces.html">Watch Faces for Android Wear</a> design guide.</p>



<h2 id="ImplementationStrategy">Create an Implementation Strategy</h2>

<p>After you finalize the design for your watch face, you need to determine how to obtain any
necessary data and draw the watch face on the wearable device. Most implementations
consist of the following components:</p>

<ul>
<li>One or more background images</li>
<li>Application code to retrieve the required data</li>
<li>Application code to draw text and shapes over the background images</li>
</ul>

<p>You typically use one background image in interactive mode and a different background image
in ambient mode. The background in ambient mode is often completely black. Background images for
Android Wear devices with a screen density of hdpi should be 320 by 320 pixels in size to fit
both square and round devices. The corners of the background image are not visible on round
devices. In your code, you can detect the size of the device screen and scale down the background
image if the device has a lower resolution than your image. To improve performance, you should
scale the background image only once and store the resulting bitmap.</p>

<p>You should run the application code to retrieve contextual data only as often as required
and store the results to reuse the data every time you draw the watch face. For example, you
don't need to fetch weather updates every minute.</p>

<p>To increase battery life, the application code that draws your watch face in ambient mode
should be relatively simple. You usually draw outlines of shapes using a limited set of colors
in this mode. In interactive mode, you can use full color, complex shapes, gradients, and
animations to draw your watch face.</p>

<p>The remaining lessons in this class show you how to implement watch faces in detail.</p>