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<a href='#img-src-https-github-com-kaishin-gifu-raw-master-header-gif-alt-logo' class='anchor' aria-hidden=true><span class="header-anchor"></span></a><h1 id='img-src-https-github-com-kaishin-gifu-raw-master-header-gif-alt-logo'><img src="https://github.com/kaishin/Gifu/raw/master/header.gif" alt="Logo"></h1>
<p><a href="https://github.com/kaishin/Gifu/releases/latest"><img src="https://img.shields.io/github/release/kaishin/Gifu.svg?maxAge=2592000" alt="GitHub release"></a> <a href="https://travis-ci.org/kaishin/Gifu"><img src="https://travis-ci.org/kaishin/Gifu.svg?branch=master" alt="Travis"></a> <a href="https://github.com/Carthage/Carthage"><img src="https://img.shields.io/badge/Carthage-compatible-4BC51D.svg?style=flat" alt="Carthage compatible"></a> <a href="https://gitter.im/kaishin/gifu"><img src="https://badges.gitter.im/kaishin/gifu.svg" alt="Join the chat at https://gitter.im/kaishin/gifu"></a> <img src="https://img.shields.io/badge/Swift-3.0.x-orange.svg" alt="Swift 3.0.x"> <img src="https://img.shields.io/badge/platforms-iOS-lightgrey.svg" alt="platforms"></p>
<p>Gifu adds protocol-based, performance-aware animated GIF support to UIKit. (It&rsquo;s also a <a href="https://goo.gl/maps/CCeAc">prefecture in Japan</a>).</p>
<p><strong>Swift 2.3</strong> support is on the <a href="https://github.com/kaishin/Gifu/tree/swift2.3">swift2.3</a> branch. <strong>This branch will not be getting any future updates</strong>.</p>
<a href='#install' class='anchor' aria-hidden=true><span class="header-anchor"></span></a><h2 id='install'>Install</h2>
<a href='#a-href-https-github-com-carthage-carthage-carthage-a' class='anchor' aria-hidden=true><span class="header-anchor"></span></a><h3 id='a-href-https-github-com-carthage-carthage-carthage-a'><a href="https://github.com/Carthage/Carthage">Carthage</a></h3>
<ul>
<li>Add the following to your Cartfile: <code>github &quot;kaishin/Gifu&quot;</code></li>
<li>Then run <code>carthage update</code></li>
<li>Follow the current instructions in <a href="https://github.com/Carthage/Carthage#adding-frameworks-to-an-application">Carthage&rsquo;s README</a>
for up to date installation instructions.</li>
</ul>
<a href='#a-href-http-cocoapods-org-cocoapods-a' class='anchor' aria-hidden=true><span class="header-anchor"></span></a><h3 id='a-href-http-cocoapods-org-cocoapods-a'><a href="http://cocoapods.org">CocoaPods</a></h3>
<ul>
<li>Add the following to your <a href="http://guides.cocoapods.org/using/the-podfile.html">Podfile</a>: <code>pod &#39;Gifu&#39;</code></li>
<li>You will also need to make sure you&rsquo;re opting into using frameworks: <code>use_frameworks!</code></li>
<li>Then run <code>pod install</code> with CocoaPods 0.36 or newer.</li>
</ul>
<a href='#how-it-works' class='anchor' aria-hidden=true><span class="header-anchor"></span></a><h2 id='how-it-works'>How It Works</h2>
<p><code>Gifu</code> does not force you to use a specific subclass of <code>UIImageView</code>. The <code>Animator</code> class does the heavy-lifting, while the <code>GIFAnimatable</code> protocol exposes the functionality to the view classes that conform to it, using protocol extensions.</p>
<p>The <code>Animator</code> has a <code>FrameStore</code> that only keeps a limited number of frames in-memory, effectively creating a buffer for the animation without consuming all the available memory. This approach makes loading large GIFs a lot more resource-friendly.</p>
<p>The figure below summarizes how this works in practice. Given an image
containing 10 frames, Gifu will load the current frame (red), buffer the next two frames in this example (orange), and empty up all the other frames to free up memory (gray):</p>
<p><img src="https://db.tt/ZLfx23hg" width="300" /></p>
<a href='#usage' class='anchor' aria-hidden=true><span class="header-anchor"></span></a><h2 id='usage'>Usage</h2>
<p>There are two options that should cover any situation:</p>
<ul>
<li>Use the built-in <code>GIFImageView</code> subclass.</li>
<li>Make any class conform to <code>GIFAnimatable</code>. Subclassing <code>UIImageView</code> is the easiest since you get most of the required properties for free.</li>
</ul>
<a href='#gifimageview' class='anchor' aria-hidden=true><span class="header-anchor"></span></a><h3 id='gifimageview'>GIFImageView</h3>
<p>A subclass of <code>UIImageView</code> that conforms to <code>GIFAnimatable</code>. You can use this class as-is or subclass it for further customization (not recommended).</p>
<a href='#gifanimatable' class='anchor' aria-hidden=true><span class="header-anchor"></span></a><h3 id='gifanimatable'>GIFAnimatable</h3>
<p>The bread and butter of Gifu. Through protocol extensions, <code>GIFAnimatable</code> exposes all the APIs of the library, and with very little boilerplate, any <code>UIImageView</code> subclass can conform to it.</p>
<pre class="highlight swift"><code><span class="kd">class</span> <span class="kt">MyImageView</span><span class="p">:</span> <span class="kt">UIImageView</span><span class="p">,</span> <span class="kt">GIFAnimatable</span> <span class="p">{</span>
<span class="kd">public</span> <span class="kd">lazy</span> <span class="k">var</span> <span class="nv">animator</span><span class="p">:</span> <span class="kt">Animator</span><span class="p">?</span> <span class="o">=</span> <span class="p">{</span>
<span class="k">return</span> <span class="kt">Animator</span><span class="p">(</span><span class="nv">withDelegate</span><span class="p">:</span> <span class="k">self</span><span class="p">)</span>
<span class="p">}()</span>
<span class="k">override</span> <span class="kd">public</span> <span class="kd">func</span> <span class="nf">display</span><span class="p">(</span><span class="n">_</span> <span class="nv">layer</span><span class="p">:</span> <span class="kt">CALayer</span><span class="p">)</span> <span class="p">{</span>
<span class="nf">updateImageIfNeeded</span><span class="p">()</span>
<span class="p">}</span>
<span class="p">}</span>
</code></pre>
<p>That&rsquo;s it. Now <code>MyImageView</code> is fully GIF-compatible, and any of these methods can be called on it:</p>
<ul>
<li><code>prepareForAnimation(withGIFNamed:)</code> and <code>prepareForAnimation(withGIFData:)</code> to prepare the animator property for animation.</li>
<li><code>startAnimatingGIF()</code> and <code>stopAnimatingGIF()</code> to control the animation.</li>
<li><code>animate(withGIFNamed:)</code> and <code>animate(withGIFData:)</code> to prepare for animation and start animating immediately.</li>
<li><code>frameCount</code>, <code>isAnimatingGIF</code>, and <code>activeFrame</code> to inspect the GIF view.</li>
<li><code>prepareForReuse()</code> to free up resources.</li>
<li><code>updateImageIfNeeded()</code> to update the image property if necessary.</li>
</ul>
<p>This approach is especially powerful when you want to combine the functionality of different image libraries.</p>
<pre class="highlight swift"><code><span class="kd">class</span> <span class="kt">MyImageView</span><span class="p">:</span> <span class="kt">OtherImageClass</span><span class="p">,</span> <span class="kt">GIFAnimatable</span> <span class="p">{}</span>
</code></pre>
<p>Keep in mind that you need to have control over the class implementing <code>GIFAnimatable</code> since you cannot add the stored <code>Animator</code> property in an extension.</p>
<a href='#examples' class='anchor' aria-hidden=true><span class="header-anchor"></span></a><h3 id='examples'>Examples</h3>
<p>The simplest way to get started is initializing a <code>GIFAnimatable</code> class in code or in a storyboard, then calling <code>animate(:)</code> on it.</p>
<pre class="highlight swift"><code><span class="k">let</span> <span class="nv">imageView</span> <span class="o">=</span> <span class="kt">GIFImageView</span><span class="p">(</span><span class="nv">frame</span><span class="p">:</span> <span class="kt">CGRect</span><span class="p">(</span><span class="nv">x</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="nv">y</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="nv">width</span><span class="p">:</span> <span class="mi">200</span><span class="p">,</span> <span class="nv">height</span><span class="p">:</span> <span class="mi">100</span><span class="p">))</span>
<span class="n">imageView</span><span class="o">.</span><span class="nf">animate</span><span class="p">(</span><span class="nv">withGIFNamed</span><span class="p">:</span> <span class="s">"mugen"</span><span class="p">)</span>
</code></pre>
<p>You can also prepare for the animation when the view loads and only start animating after a user interaction.</p>
<pre class="highlight swift"><code><span class="c1">// In your view controller..</span>
<span class="k">override</span> <span class="kd">func</span> <span class="nf">viewDidLoad</span><span class="p">()</span> <span class="p">{</span>
<span class="k">super</span><span class="o">.</span><span class="nf">viewDidLoad</span><span class="p">()</span>
<span class="n">imageView</span><span class="o">.</span><span class="nf">prepareForAnimation</span><span class="p">(</span><span class="nv">withGIFNamed</span><span class="p">:</span> <span class="s">"mugen"</span><span class="p">)</span>
<span class="p">}</span>
<span class="kd">@IBAction</span> <span class="kd">func</span> <span class="nf">toggleAnimation</span><span class="p">(</span><span class="n">_</span> <span class="nv">sender</span><span class="p">:</span> <span class="kt">AnyObject</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="n">imageView</span><span class="o">.</span><span class="n">isAnimatingGIF</span> <span class="p">{</span>
<span class="n">imageView</span><span class="o">.</span><span class="nf">stopAnimatingGIF</span><span class="p">()</span>
<span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
<span class="n">imageView</span><span class="o">.</span><span class="nf">startAnimatingGIF</span><span class="p">()</span>
<span class="p">}</span>
<span class="p">}</span>
</code></pre>
<p>If you are using a <code>GIFAnimatable</code> class in a table or collection view, you can call the <code>prepareForReuse()</code> method in your cell subclass:</p>
<pre class="highlight swift"><code><span class="k">override</span> <span class="kd">func</span> <span class="nf">prepareForReuse</span><span class="p">()</span> <span class="p">{</span>
<span class="k">super</span><span class="o">.</span><span class="nf">prepareForReuse</span><span class="p">()</span>
<span class="n">imageView</span><span class="o">.</span><span class="nf">prepareForReuse</span><span class="p">()</span>
<span class="p">}</span>
</code></pre>
<a href='#demo-app' class='anchor' aria-hidden=true><span class="header-anchor"></span></a><h3 id='demo-app'>Demo App</h3>
<p>Clone or download the repository and open <code>Gifu.xcworkspace</code> to check out the demo app.</p>
<a href='#documentation' class='anchor' aria-hidden=true><span class="header-anchor"></span></a><h2 id='documentation'>Documentation</h2>
<p>See the <a href="http://kaishin.github.io/Gifu/">full API documentation</a>.</p>
<a href='#compatibility' class='anchor' aria-hidden=true><span class="header-anchor"></span></a><h2 id='compatibility'>Compatibility</h2>
<ul>
<li>iOS 9.0+</li>
<li>Swift 3.0</li>
<li>Xcode 8.0</li>
</ul>
<a href='#license' class='anchor' aria-hidden=true><span class="header-anchor"></span></a><h2 id='license'>License</h2>
<p>See LICENSE.</p>
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