Random Thoughts of a Programmer

I needed a way to animate any property of an object in JavaScript (not necessarily even an element on the page). I did not find anything satisfactory (to me) online, so I decided to write my own. This is the result. It's a simple animation class, loosely modeled on the Android animations API (in fact, the built-in animation interpolators are simple translations from the Android source code). It is very flexible, and supports animating any  numeric property of any object. Animations run at 60 Hz to be fluid if UI elements are being animated. Features: Animate any numeric value Start/stop, pause/resume/restart Repeat - for a specified count or infinitely Reverse animation on repeat. Callbacks for start, stop, resume, end, repeat Custom interpolators NO dependencies Download the code here (includes documentation for all methods). A demo of the code is  available here . It simply animates a box moving to the right, but demonstrates how the class is used. Proto...

Here's a handy little function to force-create directories in PHP. If the directory does not exist, it will create it. If there is a file with such a name, it will delete that file and create the directory in its place. Params: same as  http://us.php.net/manual/en/function.mkdir.php Returns: true on success (the given path is now a directory), false on error function super_mkdir($file, $mode = 0777, $recursive = false) { if (!file_exists($file)) return mkdir($file, $mode, $recursive); if (is_dir($file)) return true; if (!unlink($file)) return false; if (!mkdir($file, $mode, $recursive)) return false; return true; } I will possibly have a better version later which would return error codes instead of just false...

My primary computer at the moment is an HP dv6 laptop (with Broadcom 2070 Bluetooth chip). Upon getting my laptop, I immediately wiped the hard drive and slapped on a fresh copy of Windows 7. Installed the drivers from HP, and everything was rolling along nicely... Fast-forward 4 months... Now I'm having some issues with Bluetooth communication between my phone (Android) and my laptop. So I reinstall the Bluetooth driver... The installation took a long  time, but eventually errored-out, and quit. Of course, I had left the computer unattended during this, and came back to an almost-empty hard drive (!!!!). Restored for backup, some minor data loss, no problem... I thought I had snagged a virus in the download (even though it was direct from HP's site). Redownload, scan with multiple scanners, run it ....... SAME RESULT!!! Giving up on the official installer, I just took the drivers that the installer unpacked, and manually installed them... That didn't solve my original pr...

Recently, I was working on a project in Java and needed to have a combo box, but with certain items in the list disabled (e.g. gray and non-selectable). At first, I simply set a custom renderer for the combo box which checked if the item was disabled. That, however, did not prevent the items from being selected. Thus, I set about to find a viable solution. There are plenty of solutions out there, but none seemed to work exactly the way I wanted. In the end, I ended up subclassing JComboBox to provide the functionality of disabling individual items. Here is my result, in under 100 lines: import java.awt.Component; import java.util.ArrayList; import javax.swing.JComboBox; import javax.swing.JList; import javax.swing.plaf.basic.BasicComboBoxRenderer; public class PartialDisableComboBox extends JComboBox { private static final long serialVersionUID = -1690671707274328126L; private ArrayList<boolean> itemsState = new ArrayList<boolean>(); public PartialDisableComboBox...

Recently, I came across an issue I had with full-screen (more specifically, full-viewport) canvas drawing. It all worked fine, except that the canvas dimensions must be specified in pixels, as opposed to percentages. This means you can't just set the canvas' width and height to "100%" and be done with it... The dimensions were automatically set when the page loaded, but if the user resized the browser window after that, the canvas would stay the same size, and would be either too big or too small. Thus, the canvas must be resized every time the browser window is resized. Prototype makes all of this easy. All that's necessary is to attach a listener to the onresize event of the window object, and then use document.viewport.getDimensions() to determine the new width and height. Here's some sample code: Event.observe(window, "resize", function() { var width = document.viewport.getWidth(); var height = document.viewport.getHeight(); ...

Many times, there are various interactions that take place in a web app based on mouse movement, clicking, dragging, etc. With a mouse, this is fairly simple, as there is a single point, and events like mousedown, mouseup, and mousemove can be used to discover the state of the mouse at any given time. On mobile browsers, however, it's a different story. Most phones support at least some kind of multi-touch, and the mousedown and mouseup events are not fired (there is, after all, no button). In addition, mousemove will only be applicable when dragging. Instead, mobile browsers dispatch touchstart, touchmove, and touchend events. Moreover, these events keep track of all touch points, not just the first or last one, and as such make handling them a bit more difficult. For the purposes of an application that only requires tracking clicks and drags, it is more convenient to translate these touch events into mouse events without having code duplication. This can be accomplished quick...