Skip to main content

jQuery Plugin: ClipExpand


This is my son standing under the Flying Speghetti Monster. This is a nice photo, but maybe I want to zoom in on just my son. Further, maybe I want to do this on the client-side, not on the server-side.

There are a number of reasons I might want to do this. The most obvious is displaying a thumbnail that expands into the full photo. Rather than load two images, we can load a single one, crop the image to get the thumbnail, and expand it into the full image when the user wants to see it.


We might start by looking into the CSS clip property, but we'd run into an immediate problem: the result is just floating in dead-space! The image will be clipped as we specify, but this only hides the clipped areas and leaves the image otherwise in-place.

A better solution is to take the original layout of the image and reposition and resize it and adjust the clip, so that the region we specify by the clip property is expanded to fit the full size of the space we gave for the image.

This means we can define a simple thumbnail CSS class, and specify a height and width, then by specifying the portion of the image that makes up the thumbnail, they'll be generated and adjusted automatically. This is what the clipexpand() plugin does.

You can see an example usage below. You can grab a copy at the github downloads page for my phototagger app, which this grew out of.




Comments

Popular posts from this blog

Why I Switched From Git to Microsoft OneDrive

I made the unexpected move with a string of recent projects to drop Git to sync between my different computers in favor of OneDrive, the file sync offering from Microsoft. Its like Dropbox, but "enterprise."

Feeling a little ashamed at what I previously would have scoffed at should I hear of it from another developer, I felt a little write up of the why and the experience could be a good idea. Now, I should emphasize that I'm not dropping Git for all my projects, just specific kinds of projects. I've been making this change in habit for projects that are just for me, not shared with anyone else. It has been especially helpful in projects I work on sporadically. More on why a little later.

So, what drove me away from Git, exactly?

On the smallest projects, like game jam hacks, I just wanted to code. I didn't want to think about revisions and commit messages. I didn't need branching or merges. I didn't even need to rollback to another version, ever. I just …

Respect and Code Reviews

Code Reviews in a development team only function best, or possible at all, when everyone approaches them with respect. That’s something I’ve usually taken for granted because I’ve had the opportunity to work with amazing developers who shine not just in their technical skills but in their interpersonal skills on a team. That isn’t always the case, so I’m going to put into words something that often exists just in assumptions.
You have to respect your code. This is first only because the nature and intent of code reviews are to safeguard the quality of your code, so even having code reviews demonstrates a baseline of respect for that code. But, maybe not everyone on the team has the same level of respect or entered a team with existing review traditions that they aren’t acquainted with.
There can be culture shock when you enter a team that’s really heavy on code reviews, but also if you enter a team or interact with a colleague who doesn’t share that level of respect for the process or…

CARDIAC: The Cardboard Computer

I am just so excited about this.


CARDIAC. The Cardboard Computer. How cool is that? This piece of history is amazing and better than that: it is extremely accessible. This fantastic design was built in 1969 by David Hagelbarger at Bell Labs to explain what computers were to those who would otherwise have no exposure to them. Miraculously, the CARDIAC (CARDboard Interactive Aid to Computation) was able to actually function as a slow and rudimentary computer. 
One of the most fascinating aspects of this gem is that at the time of its publication the scope it was able to demonstrate was actually useful in explaining what a computer was. Could you imagine trying to explain computers today with anything close to the CARDIAC?

It had 100 memory locations and only ten instructions. The memory held signed 3-digit numbers (-999 through 999) and instructions could be encoded such that the first digit was the instruction and the second two digits were the address of memory to operate on. The only re…