picture-module - OSL Monitor

Slide-Show

The Slide show ( as seen on http://bigscreen.osuosl.org/oslmon/dev/ ) is a dynamic slide-show of pictures, which refreshes after a certain amount of time.

The Animation:
A made two "Post-Apps" to calculate the position of the slide/to get the Trigonometrie of an Ellipse running. The process can be seen here:
http://bigscreen.osuosl.org/oslmon/slideshow/way/

The number of images on the Slide-Show can by set, anyway it must be clear that less then 4 pictures it makes no sense (and more then 30/40 also). Therefore i'll included another small app "The Imagebrowser". I'll add that Component later on.

Using PHP as Proxy-Layer / Image-Cache for Image loading

Cause Flash can only load JPG out of the Box in Solo-Application (in a Laszlo-Server-Modus all image-processing is proxied by OpenLaszlo-Server) PHP does now the Job for us so that we can load JPGs/GIFs and PNG Files (and create Thumbs of all). This feature is using the GD-lib of PHP. GD-lib is enabled @ default configuration in PHP (and normally all ISPs/Providers-/WebHoster-) enable it cause its quite common to use it.

Its all in the class class.thumbnail.php:

1.It loads the Image via tcp-fsockopen from another Server (see RSS-Component) and investigates the Content/Type
2.If Content-Type is image/png or image/gif or image/jpg it create a temp file of that Image (there is an attribute forcereload, that forces PHP to overwrite the file if it already exists, otherwise temp file will not be created once again ->thats the caching )
3. Based on that temp-file a thumb of that image will be created in the requested-size ( again same thing with attribute forcereload )
4. It returns an array of the name of the created thumbpath/status/tempfilepath

cause there will be files written on the disk the directory "thumbs" needs to be writeable (at least for the user who is running PHP)