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react-native/docs/panresponder.html
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<!DOCTYPE html><html><head><meta charset="utf-8"><meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"><title>React Native | A framework for building native apps using React</title><meta name="viewport" content="width=device-width"><meta property="og:title" content="React Native | A framework for building native apps using React"><meta property="og:type" content="website"><meta property="og:url" content="http://facebook.github.io/react-native/index.html"><meta property="og:image" content="http://facebook.github.io/react-native/img/opengraph.png?2"><meta property="og:description" content="A framework for building native apps using React"><link rel="shortcut icon" href="/react-native/img/favicon.png?2"><link rel="stylesheet" href="/react-native/css/react-native.css"><script type="text/javascript" src="//use.typekit.net/vqa1hcx.js"></script><script type="text/javascript">try{Typekit.load();}catch(e){}</script></head><body><div class="container"><div class="nav-main"><div class="wrap"><a class="nav-home" href="/react-native/"><img src="/react-native/img/header_logo.png">React Native</a><div class="nav-site-wrapper"><ul class="nav-site nav-site-internal"><li><a href="/react-native/docs/getting-started.html" class="active">Docs</a></li><li><a href="/react-native/support.html" class="">Support</a></li></ul><ul class="nav-site nav-site-external"><li><a href="http://github.com/facebook/react-native" class="">GitHub</a></li><li><a href="http://facebook.github.io/react" class="">React</a></li></ul></div></div></div><section class="content wrap documentationContent"><div class="nav-docs"><div class="nav-docs-section"><h3>Quick Start</h3><ul><li><a style="margin-left:0;" class="" href="/react-native/docs/getting-started.html#content">Getting Started</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/tutorial.html#content">Tutorial</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/videos.html#content">Videos</a></li></ul></div><div class="nav-docs-section"><h3>Guides</h3><ul><li><a style="margin-left:0;" class="" href="/react-native/docs/style.html#content">Style</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/gesture-responder-system.html#content">Gesture Responder System</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/nativemodulesios.html#content">Native Modules (iOS)</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/nativecomponentsios.html#content">Native UI Components (iOS)</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/linking-libraries.html#content">Linking Libraries</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/debugging.html#content">Debugging</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/testing.html#content">Testing</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/runningondevice.html#content">Running On Device</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/embedded-app.html#content">Integration with Existing App</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/javascript-environment.html#content">JavaScript Environment</a></li></ul></div><div class="nav-docs-section"><h3>components</h3><ul><li><a style="margin-left:0;" class="" href="/react-native/docs/activityindicatorios.html#content">ActivityIndicatorIOS</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/datepickerios.html#content">DatePickerIOS</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/image.html#content">Image</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/listview.html#content">ListView</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/mapview.html#content">MapView</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/navigator.html#content">Navigator</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/navigatorios.html#content">NavigatorIOS</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/pickerios.html#content">PickerIOS</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/scrollview.html#content">ScrollView</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/sliderios.html#content">SliderIOS</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/switchios.html#content">SwitchIOS</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/tabbarios.html#content">TabBarIOS</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/tabbarios-item.html#content">TabBarIOS.Item</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/text.html#content">Text</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/textinput.html#content">TextInput</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/touchablehighlight.html#content">TouchableHighlight</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/touchableopacity.html#content">TouchableOpacity</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/touchablewithoutfeedback.html#content">TouchableWithoutFeedback</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/view.html#content">View</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/webview.html#content">WebView</a></li></ul></div><div class="nav-docs-section"><h3>apis</h3><ul><li><a style="margin-left:0;" class="" href="/react-native/docs/alertios.html#content">AlertIOS</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/appregistry.html#content">AppRegistry</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/appstateios.html#content">AppStateIOS</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/asyncstorage.html#content">AsyncStorage</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/cameraroll.html#content">CameraRoll</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/interactionmanager.html#content">InteractionManager</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/layoutanimation.html#content">LayoutAnimation</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/linkingios.html#content">LinkingIOS</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/netinfo.html#content">NetInfo</a></li><li><a style="margin-left:0;" class="active" href="/react-native/docs/panresponder.html#content">PanResponder</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/pixelratio.html#content">PixelRatio</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/pushnotificationios.html#content">PushNotificationIOS</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/statusbarios.html#content">StatusBarIOS</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/stylesheet.html#content">StyleSheet</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/vibrationios.html#content">VibrationIOS</a></li></ul></div><div class="nav-docs-section"><h3>Polyfills</h3><ul><li><a style="margin-left:0;" class="" href="/react-native/docs/flexbox.html#content">Flexbox</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/geolocation.html#content">Geolocation</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/network.html#content">Network</a></li><li><a style="margin-left:0;" class="" href="/react-native/docs/timers.html#content">Timers</a></li></ul></div></div><div class="inner-content"><a id="content"></a><h1>PanResponder</h1><div><div><p><code>PanResponder</code> reconciles several touches into a single gesture. It makes
single-touch gestures resilient to extra touches, and can be used to
recognize simple multi-touch gestures.</p><p>It provides a predictable wrapper of the responder handlers provided by the
<a href="/react-native/docs/gesture-responder-system.html" target="">gesture responder system</a>.
For each handler, it provides a new <code>gestureState</code> object alongside the
normal event.</p><p>A <code>gestureState</code> object has the following:</p><ul><li><code>stateID</code> - ID of the gestureState- persisted as long as there at least
one touch on screen</li><li><code>moveX</code> - the latest screen coordinates of the recently-moved touch</li><li><code>moveY</code> - the latest screen coordinates of the recently-moved touch</li><li><code>x0</code> - the screen coordinates of the responder grant</li><li><code>y0</code> - the screen coordinates of the responder grant</li><li><code>dx</code> - accumulated distance of the gesture since the touch started</li><li><code>dy</code> - accumulated distance of the gesture since the touch started</li><li><code>vx</code> - current velocity of the gesture</li><li><code>vy</code> - current velocity of the gesture</li><li><code>numberActiveTouches</code> - Number of touches currently on screeen</li></ul><h3><a class="anchor" name="basic-usage"></a>Basic Usage <a class="hash-link" href="#basic-usage">#</a></h3><div class="prism language-javascript"> componentWillMount<span class="token punctuation">:</span> <span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">this</span><span class="token punctuation">.</span>_panGesture <span class="token operator">=</span> PanResponder<span class="token punctuation">.</span><span class="token function">create<span class="token punctuation">(</span></span><span class="token punctuation">{</span>
<span class="token comment" spellcheck="true"> // Ask to be the responder:
</span> onStartShouldSetPanResponder<span class="token punctuation">:</span> <span class="token punctuation">(</span>evt<span class="token punctuation">,</span> gestureState<span class="token punctuation">)</span> <span class="token operator">=</span><span class="token operator">&gt;</span> <span class="token boolean">true</span><span class="token punctuation">,</span>
onStartShouldSetPanResponderCapture<span class="token punctuation">:</span> <span class="token punctuation">(</span>evt<span class="token punctuation">,</span> gestureState<span class="token punctuation">)</span> <span class="token operator">=</span><span class="token operator">&gt;</span> <span class="token boolean">true</span><span class="token punctuation">,</span>
onMoveShouldSetPanResponder<span class="token punctuation">:</span> <span class="token punctuation">(</span>evt<span class="token punctuation">,</span> gestureState<span class="token punctuation">)</span> <span class="token operator">=</span><span class="token operator">&gt;</span> <span class="token boolean">true</span><span class="token punctuation">,</span>
onMoveShouldSetPanResponderCapture<span class="token punctuation">:</span> <span class="token punctuation">(</span>evt<span class="token punctuation">,</span> gestureState<span class="token punctuation">)</span> <span class="token operator">=</span><span class="token operator">&gt;</span> <span class="token boolean">true</span><span class="token punctuation">,</span>
onPanResponderGrant<span class="token punctuation">:</span> <span class="token punctuation">(</span>evt<span class="token punctuation">,</span> gestureState<span class="token punctuation">)</span> <span class="token operator">=</span><span class="token operator">&gt;</span> <span class="token punctuation">{</span>
<span class="token comment" spellcheck="true"> // The guesture has started. Show visual feedback so the user knows
</span> <span class="token comment" spellcheck="true"> // what is happening!
</span>
<span class="token comment" spellcheck="true"> // gestureState.{x,y}0 will be set to zero now
</span> <span class="token punctuation">}</span><span class="token punctuation">,</span>
onPanResponderMove<span class="token punctuation">:</span> <span class="token punctuation">(</span>evt<span class="token punctuation">,</span> gestureState<span class="token punctuation">)</span> <span class="token operator">=</span><span class="token operator">&gt;</span> <span class="token punctuation">{</span>
<span class="token comment" spellcheck="true"> // The most recent move distance is gestureState.move{X,Y}
</span>
<span class="token comment" spellcheck="true"> // The accumulated gesture distance since becoming responder is
</span> <span class="token comment" spellcheck="true"> // gestureState.d{x,y}
</span> <span class="token punctuation">}</span><span class="token punctuation">,</span>
onPanResponderTerminationRequest<span class="token punctuation">:</span> <span class="token punctuation">(</span>evt<span class="token punctuation">,</span> gestureState<span class="token punctuation">)</span> <span class="token operator">=</span><span class="token operator">&gt;</span> <span class="token boolean">true</span><span class="token punctuation">,</span>
onPanResponderRelease<span class="token punctuation">:</span> <span class="token punctuation">(</span>evt<span class="token punctuation">,</span> gestureState<span class="token punctuation">)</span> <span class="token operator">=</span><span class="token operator">&gt;</span> <span class="token punctuation">{</span>
<span class="token comment" spellcheck="true"> // The user has released all touches while this view is the
</span> <span class="token comment" spellcheck="true"> // responder. This typically means a gesture has succeeded
</span> <span class="token punctuation">}</span><span class="token punctuation">,</span>
onPanResponderTerminate<span class="token punctuation">:</span> <span class="token punctuation">(</span>evt<span class="token punctuation">,</span> gestureState<span class="token punctuation">)</span> <span class="token operator">=</span><span class="token operator">&gt;</span> <span class="token punctuation">{</span>
<span class="token comment" spellcheck="true"> // Another component has become the responder, so this gesture
</span> <span class="token comment" spellcheck="true"> // should be cancelled
</span> <span class="token punctuation">}</span><span class="token punctuation">,</span>
<span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span>
render<span class="token punctuation">:</span> <span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">return</span> <span class="token punctuation">(</span>
&lt;View <span class="token punctuation">{</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token keyword">this</span><span class="token punctuation">.</span>_panResponder<span class="token punctuation">.</span>panHandlers<span class="token punctuation">}</span> <span class="token operator">/</span><span class="token operator">&gt;</span>
<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span></div><h3><a class="anchor" name="working-example"></a>Working Example <a class="hash-link" href="#working-example">#</a></h3><p>To see it in action, try the
<a href="https://github.com/facebook/react-native/blob/master/Examples/UIExplorer/ResponderExample.js" target="_blank">PanResponder example in UIExplorer</a></p></div><span><h3><a class="anchor" name="methods"></a>Methods <a class="hash-link" href="#methods">#</a></h3><div class="props"><div class="prop"><h4 class="propTitle"><a class="anchor" name="create"></a><span class="propType">static </span>create<span class="propType">(config: object)</span> <a class="hash-link" href="#create">#</a></h4><div><p>@param {object} config Enhanced versions of all of the responder callbacks
that provide not only the typical <code>ResponderSyntheticEvent</code>, but also the
<code>PanResponder</code> gesture state. Simply replace the word <code>Responder</code> with
<code>PanResponder</code> in each of the typical <code>onResponder*</code> callbacks. For
example, the <code>config</code> object would look like:</p><ul><li><code>onMoveShouldSetPanResponder: (e, gestureState) =&gt; {...}</code></li><li><code>onMoveShouldSetPanResponderCapture: (e, gestureState) =&gt; {...}</code></li><li><code>onStartShouldSetPanResponder: (e, gestureState) =&gt; {...}</code></li><li><code>onStartShouldSetPanResponderCapture: (e, gestureState) =&gt; {...}</code></li><li><code>onPanResponderReject: (e, gestureState) =&gt; {...}</code></li><li><code>onPanResponderGrant: (e, gestureState) =&gt; {...}</code></li><li><code>onPanResponderStart: (e, gestureState) =&gt; {...}</code></li><li><code>onPanResponderEnd: (e, gestureState) =&gt; {...}</code></li><li><code>onPanResponderRelease: (e, gestureState) =&gt; {...}</code></li><li><code>onPanResponderMove: (e, gestureState) =&gt; {...}</code></li><li><code>onPanResponderTerminate: (e, gestureState) =&gt; {...}</code></li><li><p><code>onPanResponderTerminationRequest: (e, gestureState) =&gt; {...}</code></p><p>In general, for events that have capture equivalents, we update the
gestureState once in the capture phase and can use it in the bubble phase
as well.</p><p>Be careful with onStartShould* callbacks. They only reflect updated
<code>gestureState</code> for start/end events that bubble/capture to the Node.
Once the node is the responder, you can rely on every start/end event
being processed by the gesture and <code>gestureState</code> being updated
accordingly. (numberActiveTouches) may not be totally accurate unless you
are the responder.</p></li></ul></div></div></div></span></div><div><h3><a class="anchor" name="examples"></a><a class="edit-github" href="https://github.com/facebook/react-native/blob/master/Examples/UIExplorer/PanResponderExample.js">Edit on GitHub</a>Examples <a class="hash-link" href="#examples">#</a></h3><div class="prism language-javascript"><span class="token string">&#x27;use strict&#x27;</span><span class="token punctuation">;</span>
<span class="token keyword">var</span> React <span class="token operator">=</span> <span class="token function">require<span class="token punctuation">(</span></span><span class="token string">&#x27;react-native&#x27;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">var</span> <span class="token punctuation">{</span>
StyleSheet<span class="token punctuation">,</span>
PanResponder<span class="token punctuation">,</span>
View<span class="token punctuation">,</span>
<span class="token punctuation">}</span> <span class="token operator">=</span> React<span class="token punctuation">;</span>
<span class="token keyword">var</span> CIRCLE_SIZE <span class="token operator">=</span> <span class="token number">80</span><span class="token punctuation">;</span>
<span class="token keyword">var</span> CIRCLE_COLOR <span class="token operator">=</span> <span class="token string">&#x27;blue&#x27;</span><span class="token punctuation">;</span>
<span class="token keyword">var</span> CIRCLE_HIGHLIGHT_COLOR <span class="token operator">=</span> <span class="token string">&#x27;green&#x27;</span><span class="token punctuation">;</span>
<span class="token keyword">var</span> NavigatorIOSExample <span class="token operator">=</span> React<span class="token punctuation">.</span><span class="token function">createClass<span class="token punctuation">(</span></span><span class="token punctuation">{</span>
statics<span class="token punctuation">:</span> <span class="token punctuation">{</span>
title<span class="token punctuation">:</span> <span class="token string">&#x27;PanResponder Sample&#x27;</span><span class="token punctuation">,</span>
description<span class="token punctuation">:</span> <span class="token string">&#x27;Basic gesture handling example&#x27;</span><span class="token punctuation">,</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span>
_panResponder<span class="token punctuation">:</span> <span class="token punctuation">{</span><span class="token punctuation">}</span><span class="token punctuation">,</span>
_previousLeft<span class="token punctuation">:</span> <span class="token number">0</span><span class="token punctuation">,</span>
_previousTop<span class="token punctuation">:</span> <span class="token number">0</span><span class="token punctuation">,</span>
_circleStyles<span class="token punctuation">:</span> <span class="token punctuation">{</span><span class="token punctuation">}</span><span class="token punctuation">,</span>
circle<span class="token punctuation">:</span> <span class="token punctuation">(</span><span class="token keyword">null</span> <span class="token punctuation">:</span> <span class="token operator">?</span><span class="token punctuation">{</span> <span class="token function">setNativeProps<span class="token punctuation">(</span></span>props<span class="token punctuation">:</span> Object<span class="token punctuation">)</span><span class="token punctuation">:</span> void <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">,</span>
componentWillMount<span class="token punctuation">:</span> <span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">this</span><span class="token punctuation">.</span>_panResponder <span class="token operator">=</span> PanResponder<span class="token punctuation">.</span><span class="token function">create<span class="token punctuation">(</span></span><span class="token punctuation">{</span>
onStartShouldSetPanResponder<span class="token punctuation">:</span> <span class="token keyword">this</span><span class="token punctuation">.</span>_handleStartShouldSetPanResponder<span class="token punctuation">,</span>
onMoveShouldSetPanResponder<span class="token punctuation">:</span> <span class="token keyword">this</span><span class="token punctuation">.</span>_handleMoveShouldSetPanResponder<span class="token punctuation">,</span>
onPanResponderGrant<span class="token punctuation">:</span> <span class="token keyword">this</span><span class="token punctuation">.</span>_handlePanResponderGrant<span class="token punctuation">,</span>
onPanResponderMove<span class="token punctuation">:</span> <span class="token keyword">this</span><span class="token punctuation">.</span>_handlePanResponderMove<span class="token punctuation">,</span>
onPanResponderRelease<span class="token punctuation">:</span> <span class="token keyword">this</span><span class="token punctuation">.</span>_handlePanResponderEnd<span class="token punctuation">,</span>
onPanResponderTerminate<span class="token punctuation">:</span> <span class="token keyword">this</span><span class="token punctuation">.</span>_handlePanResponderEnd<span class="token punctuation">,</span>
<span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">this</span><span class="token punctuation">.</span>_previousLeft <span class="token operator">=</span> <span class="token number">20</span><span class="token punctuation">;</span>
<span class="token keyword">this</span><span class="token punctuation">.</span>_previousTop <span class="token operator">=</span> <span class="token number">84</span><span class="token punctuation">;</span>
<span class="token keyword">this</span><span class="token punctuation">.</span>_circleStyles <span class="token operator">=</span> <span class="token punctuation">{</span>
left<span class="token punctuation">:</span> <span class="token keyword">this</span><span class="token punctuation">.</span>_previousLeft<span class="token punctuation">,</span>
top<span class="token punctuation">:</span> <span class="token keyword">this</span><span class="token punctuation">.</span>_previousTop<span class="token punctuation">,</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span>
componentDidMount<span class="token punctuation">:</span> <span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">this</span><span class="token punctuation">.</span><span class="token function">_updatePosition<span class="token punctuation">(</span></span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span>
render<span class="token punctuation">:</span> <span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">return</span> <span class="token punctuation">(</span>
&lt;View
style<span class="token operator">=</span><span class="token punctuation">{</span>styles<span class="token punctuation">.</span>container<span class="token punctuation">}</span><span class="token operator">&gt;</span>
&lt;View
ref<span class="token operator">=</span><span class="token punctuation">{</span><span class="token punctuation">(</span>circle<span class="token punctuation">)</span> <span class="token operator">=</span><span class="token operator">&gt;</span> <span class="token punctuation">{</span>
<span class="token keyword">this</span><span class="token punctuation">.</span>circle <span class="token operator">=</span> circle<span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">}</span>
style<span class="token operator">=</span><span class="token punctuation">{</span>styles<span class="token punctuation">.</span>circle<span class="token punctuation">}</span>
<span class="token punctuation">{</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token keyword">this</span><span class="token punctuation">.</span>_panResponder<span class="token punctuation">.</span>panHandlers<span class="token punctuation">}</span>
<span class="token operator">/</span><span class="token operator">&gt;</span>
&lt;<span class="token operator">/</span>View<span class="token operator">&gt;</span>
<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span>
_highlight<span class="token punctuation">:</span> <span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">this</span><span class="token punctuation">.</span>circle &amp;&amp; <span class="token keyword">this</span><span class="token punctuation">.</span>circle<span class="token punctuation">.</span><span class="token function">setNativeProps<span class="token punctuation">(</span></span><span class="token punctuation">{</span>
backgroundColor<span class="token punctuation">:</span> CIRCLE_HIGHLIGHT_COLOR
<span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span>
_unHighlight<span class="token punctuation">:</span> <span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">this</span><span class="token punctuation">.</span>circle &amp;&amp; <span class="token keyword">this</span><span class="token punctuation">.</span>circle<span class="token punctuation">.</span><span class="token function">setNativeProps<span class="token punctuation">(</span></span><span class="token punctuation">{</span>
backgroundColor<span class="token punctuation">:</span> CIRCLE_COLOR
<span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span>
_updatePosition<span class="token punctuation">:</span> <span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">this</span><span class="token punctuation">.</span>circle &amp;&amp; <span class="token keyword">this</span><span class="token punctuation">.</span>circle<span class="token punctuation">.</span><span class="token function">setNativeProps<span class="token punctuation">(</span></span><span class="token keyword">this</span><span class="token punctuation">.</span>_circleStyles<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span>
_handleStartShouldSetPanResponder<span class="token punctuation">:</span> <span class="token keyword">function</span><span class="token punctuation">(</span>e<span class="token punctuation">:</span> Object<span class="token punctuation">,</span> gestureState<span class="token punctuation">:</span> Object<span class="token punctuation">)</span><span class="token punctuation">:</span> boolean <span class="token punctuation">{</span>
<span class="token comment" spellcheck="true"> // Should we become active when the user presses down on the circle?
</span> <span class="token keyword">return</span> <span class="token boolean">true</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span>
_handleMoveShouldSetPanResponder<span class="token punctuation">:</span> <span class="token keyword">function</span><span class="token punctuation">(</span>e<span class="token punctuation">:</span> Object<span class="token punctuation">,</span> gestureState<span class="token punctuation">:</span> Object<span class="token punctuation">)</span><span class="token punctuation">:</span> boolean <span class="token punctuation">{</span>
<span class="token comment" spellcheck="true"> // Should we become active when the user moves a touch over the circle?
</span> <span class="token keyword">return</span> <span class="token boolean">true</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span>
_handlePanResponderGrant<span class="token punctuation">:</span> <span class="token keyword">function</span><span class="token punctuation">(</span>e<span class="token punctuation">:</span> Object<span class="token punctuation">,</span> gestureState<span class="token punctuation">:</span> Object<span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">this</span><span class="token punctuation">.</span><span class="token function">_highlight<span class="token punctuation">(</span></span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span>
_handlePanResponderMove<span class="token punctuation">:</span> <span class="token keyword">function</span><span class="token punctuation">(</span>e<span class="token punctuation">:</span> Object<span class="token punctuation">,</span> gestureState<span class="token punctuation">:</span> Object<span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">this</span><span class="token punctuation">.</span>_circleStyles<span class="token punctuation">.</span>left <span class="token operator">=</span> <span class="token keyword">this</span><span class="token punctuation">.</span>_previousLeft <span class="token operator">+</span> gestureState<span class="token punctuation">.</span>dx<span class="token punctuation">;</span>
<span class="token keyword">this</span><span class="token punctuation">.</span>_circleStyles<span class="token punctuation">.</span>top <span class="token operator">=</span> <span class="token keyword">this</span><span class="token punctuation">.</span>_previousTop <span class="token operator">+</span> gestureState<span class="token punctuation">.</span>dy<span class="token punctuation">;</span>
<span class="token keyword">this</span><span class="token punctuation">.</span><span class="token function">_updatePosition<span class="token punctuation">(</span></span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span>
_handlePanResponderEnd<span class="token punctuation">:</span> <span class="token keyword">function</span><span class="token punctuation">(</span>e<span class="token punctuation">:</span> Object<span class="token punctuation">,</span> gestureState<span class="token punctuation">:</span> Object<span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">this</span><span class="token punctuation">.</span><span class="token function">_unHighlight<span class="token punctuation">(</span></span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">this</span><span class="token punctuation">.</span>_previousLeft <span class="token operator">+</span><span class="token operator">=</span> gestureState<span class="token punctuation">.</span>dx<span class="token punctuation">;</span>
<span class="token keyword">this</span><span class="token punctuation">.</span>_previousTop <span class="token operator">+</span><span class="token operator">=</span> gestureState<span class="token punctuation">.</span>dy<span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span>
<span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">var</span> styles <span class="token operator">=</span> StyleSheet<span class="token punctuation">.</span><span class="token function">create<span class="token punctuation">(</span></span><span class="token punctuation">{</span>
circle<span class="token punctuation">:</span> <span class="token punctuation">{</span>
width<span class="token punctuation">:</span> CIRCLE_SIZE<span class="token punctuation">,</span>
height<span class="token punctuation">:</span> CIRCLE_SIZE<span class="token punctuation">,</span>
borderRadius<span class="token punctuation">:</span> CIRCLE_SIZE <span class="token operator">/</span> <span class="token number">2</span><span class="token punctuation">,</span>
backgroundColor<span class="token punctuation">:</span> CIRCLE_COLOR<span class="token punctuation">,</span>
position<span class="token punctuation">:</span> <span class="token string">&#x27;absolute&#x27;</span><span class="token punctuation">,</span>
left<span class="token punctuation">:</span> <span class="token number">0</span><span class="token punctuation">,</span>
top<span class="token punctuation">:</span> <span class="token number">0</span><span class="token punctuation">,</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span>
container<span class="token punctuation">:</span> <span class="token punctuation">{</span>
flex<span class="token punctuation">:</span> <span class="token number">1</span><span class="token punctuation">,</span>
paddingTop<span class="token punctuation">:</span> <span class="token number">64</span><span class="token punctuation">,</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span>
<span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
module<span class="token punctuation">.</span>exports <span class="token operator">=</span> NavigatorIOSExample<span class="token punctuation">;</span></div></div><div class="docs-prevnext"><a class="docs-next" href="pixelratio.html#content">Next →</a></div></div></section><footer class="wrap"><div class="right">© 2015 Facebook Inc.</div></footer></div><div id="fb-root"></div><script>
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