Highlighting the current speech

Debate pages that have at least one timestamped speech (such as the previously mentioned last week’s Prime Minister’s Questions) have a video fixed to the bottom right hand corner (if your browser is recent enough) showing that debate. While playing the video, the currently playing speech is highlighted with a yellow background, and you can start watching from any timestamped speech by clicking the “Watch this” link by any such speech. So how does all that work?

I’m very proud of this feature, I wasn’t sure it would be possible, and it’s very exciting. 🙂

Flash has an ExternalInterface API, where JavaScript can call functions in the Flash, and vice-versa. When the video player loads, it requests an XML list from the server of all speech GIDs and timestamps for the current debate (here’s the file for the above debate). So when someone clicks a “Watch this”, it calls a moveVideo function in main.mxml with the GID of the speech, which loops through all the speeches and moves to the correct point if possible.

The highlighting works the other way – as the video is playing, it checks to see which speech we’re currently in, and if there’s been a change, it calls the updateSpeech function in TheyWorkForYou’s JavaScript, which finds the right row in the HTML and changes the class in order to highlight it. Quite straightforward, really, but it does make following the debate very simple and highlights the linking between the video and the text, all done by our excellent volunteers (join in! 🙂 ).

Talking of our busy timestampers, I’ve also been busy making improvements (and fixing bugs) to the timestamping interface to make things easier for them. As well as warnings when it looks like two people are timestamping the same debate at the same time, various invisible things have been changed, such as using other people’s timestamps to make the start point for future timestamps on the same day more accurate. I also added a totaliser, using the Google Chart API, for which you simply have to provide image size and percentage complete.

Approaching 45% of our entire archive of video timestamped, with the totaliser approaching the chartreuse 🙂

Previous articles

  1. The Flash player
  2. Seeking
  3. Highlighting the current speech