In KDE file associations allow you to specify what actions occur when you click on various file types. They also offer alternate actions and embedding preferences. KDE provides an extensive list of media types to configure, all with default settings, although you can easily add more when necessary. In addition, KDE also has a separate settings component for certain default application types.
Default Applications
Some users only need to configure a few default applications and are really not concerned with specific file types. To access these settings, do the following:
Click the K-menu
Start System Settings (or press Alt-F2 and type System Settings)
In the “Personal” section, click “Default Applications”
Choose the application type you want to configure. For example: Web Browser.
The first setting will essentially open all web content in Konqueror. If you use another browser, such as Firefox, click on “in the following browser:”..
Click on the “…” next to the text box.
Find your application, and click on it.
Click Apply. You can repeat the same steps for any application type listed. Some of them, like File Manager, have a list of file managers you can choose, or you can pick another not in the list. You can even select a different window manager, if you prefer something with more desktop effects like Compiz, or something slimmer like Openbox.
File Associations
You can find the File Associations configuration in System Settings in the Advanced tab. It displays a tree view of known file types, listed under several categories, such as audio, image, video, and text. It also has a search box if you know exactly what you want to configure. Before you begin making changes, make sure you test the file types you want to use in your application. Nothing is worse than having to go back and reconfigure numerous file types. For the purposes of this example, we will set the default video player that we want to use for most video types. By default, KDE 4 ships with a video player called Dragon Player. It uses the Phonon backend, which relies on either Xine or Gstreamer, and is easy to use. Dragon Player, however, is nowhere nearly as robust as Kaffeine from KDE 3, and it is like a child’s toy compared to more advanced players like KMplayer, SMplayer, or VLC. Therefore, one of the first things I would do on a new install is change the default video player by taking the following steps:
Click the plus next to “video” to expand its contents.
Starting scrolling through the list for video types you want to change.
Select a type, such as “quicktime”. It will show you the file patterns that it uses (such as *.mov and *.qt).
Under “Application Preference Order”, find your favorite video player. If you cannot find yours in the list, click “Add…” and find yours from the menu provided.
Select your video player and click “Move Up” repeatedly until it is at the top. The order of other players will be the order they appear when you right click on that video type. You can change that order however you like.
If you are also configuring Konquerer, click the “Embedding” tab and select the embedded player you want to play the file. This will apply to sites such as Apple Trailers, which requires an embedded Quicktime player. When you are satisfied, click “Apply”. Look through the list of files and find any other types you want to configure. You might want to also click “Add…” at the bottom to add a new file type. Once you have all the file associations configured, be sure to test them to make sure they work as expected. With those tasks completed, you will be a few steps closer to complete customization heaven.