iwmlib/lib/frames.html

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<!DOCTYPE html>
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<head>
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<h1><a href="index.html">lib.</a>Frames</h1>
<p>
Frames are a major way to modularize the design of complex applications. Since pages presented in frames are
independent of each other they can fail without impact on other pages. In addition preparing content in
individual HTML files largely simplfies the workflow of content production.
</p>
<p>This approach, however, has limitations:</p>
<script>
function appleError() {
alert(
"Refused to display 'http://www.apple.com/de/' in a frame because it set 'X-Frame-Options' to 'SAMEORIGIN'."
)
}
</script>
<ul>
<li>
Some pages may prevent embedding them by 'X-Frame-Options', e.g.
<a href="javascript:appleError()">www.apple.com</a>
</li>
<li>
Sites with responsive design might not be able to detect the available space, e.g.
<a href="https:///de.wikipedia.org">de.wikipedia.org</a>
</li>
<li>
Touch events are not dispatched correctly to multiple frames on platforms with <b>TouchEvents</b>, e.g.
if frame one receives touch1, all related touch points touch2, ... touchN, are send to frame1 although
they might occur over frame two.
</li>
</ul>
<p>To solve the last mentioned problem, we prevent frames form touch events by assigning a</p>
<pre>pointer-events: none;</pre>
style. A wrapping div is used to capture the events instead. Captured events are collected by an
InteractionMapper and distributed as synthesized mouse or touch events to the wrapped iframes.
<p>Let's look at an example of two HTML IFrames embedded in this Doctest.</p>
<pre><code class="html">
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&lt;div id="frameWrapper1"&gt;
&lt;iframe style="pointer-events: none;" src="examples/multitouch.html"&gt;&lt;/iframe&gt;
&lt;/div&gt;
&lt;div id="frameWrapper2" style="padding: 4px"&gt;
&lt;iframe style="pointer-events: none;" src="examples/multitouch.html"&gt;&lt;/iframe&gt;
&lt;/div&gt;
</code></pre>
<div class="grayBorder" id="container" style="display: flex; justify-content: space-around">
<div id="frameWrapper1" style="padding: 4px">
<iframe
style="width: 400px; height: 360px; border: 0; pointer-events: none"
src="examples/multitouch.html"
allowfullscreen
></iframe>
</div>
<div id="frameWrapper2" style="padding: 4px">
<iframe
style="width: 400px; height: 360px; border: 0; pointer-events: none"
src="examples/multitouch.html"
allowfullscreen
></iframe>
</div>
</div>
<p>
The distribution of events is handled by the enclosing container. The container registers a
InteractionMapper and provides adapter for iframes, that implement IInteractionTarget by sending
programmatically generated events. If you test these frames on a multitouch device you will notice that the
scatters within the frames can be manipulated independently of each other:
</p>
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<p />
<script class="doctest">
let frameContainer = new FrameContainer(container)
</script>
<h2>References</h2>
<ul>
<li>
<a href="http://stackoverflow.com/questions/8068578/how-do-i-use-multiple-iframes-in-my-html-page"
>Multiple iFrames</a
>
</li>
<li><a href="https://benmarshall.me/responsive-iframes/">Responsive iFrames</a></li>
</ul>
</body>
</html>