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    <p>Yes, you just need to use <code>drawImage()</code> or <code>putImageData()</code>. The <code>drawImage()</code> function call can take a canvas as a data source parameter, so you can draw to your on-screen canvas using the off-screen one as the source. If you have transparency that you need to maintain, you will need to use <code>putImageData()</code> which does a complete overwrite of the existing canvas data. Conversely, <code>drawImage()</code> will apply a blending mode to the data using the <code>globalCompositeOperation</code> parameter of your context.</p> <pre><code>var offscreen_canvas = document.getElementById("offscreen_canvas"); var onscreen_canvas = document.getElementById("onscreen_canvas"); var onscreen_context = onscreen_canvas.getContext("2d"); // Don't care about transparency: onscreen_context.drawImage(offscreen_canvas, source_x, source_y, source_width, source_height, dest_x, dest_y, dest_width, dest_height); // Or, if we care about transparency preservation: var offscreen_context = offscreen_canvas.getContext("2d"); var offscreen_data = offscreen_context.getImageData(x, y, width, height); onscreen_context.putImageData(offscreen_data, dest_x, dest_y); </code></pre> <p>References: <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#dom-context-2d-drawimage">drawImage()</a> and <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#dom-context-2d-putimagedata">putImageData()</a>.</p>
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    1. COFor speed should I be getting a reference of the context each time, or should I store it somewhere?
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    2. COTheoretically you should receive better performance if you store the handle to the context after you have acquired it once. In practice, you likely will not notice a difference. The first time you call `getContext()` it will create an instance of the context in your preferred mode (either 2d or 3d). After that, if you call `getContext()`, it is just going to return a reference to the already-created object. So, there will be some minimal overhead for the function call.
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A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

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