As some of you who monitor the KDE news sphere may have noticed, there has been a recent addition to the kdebase module. The Dolphin File Manager has been added to complement Konqueror's browsing capabilities. Read on for more information about this new File Manager and its relationship to Konqueror and the rest of KDE.
A brief history lesson so you can get an overview of how file management has evolved with KDE: In KDE 1.x, KFM (the KDE File Manager) was born. It was a very rudimentary, very basic file manager with limited web browsing capabilities. Below is a shot of KFM browsing files (from the kde.org screenshot archive) so you get an idea of how it operated.
While it's obvious that KDE has come a long way since KDE 1.x, it is still easy to see which parts of KFM have inspired Konqueror's contemporary design, which was introduced as part of KDE 2.0. KParts technology revolutionized the way we used our File Manager application, turning Konqueror into a full fledged web-browser, and more. Here's a shot of Konqueror from KDE 3.5.6, and you can see that while the user interface is much improved, the same basic concepts remain visible from the KFM days.
Konqueror really shines as a beacon of KDE technologies in the KDE 2.x and 3.x series, showcasing the best parts of KDE technologies. Konqueror showcased the power of KDE's IO slaves, allowing true network transparency when managing your files over FTP, fish (SSH), HTTP, and much more. Konqueror is so advanced that you can enter an FTP URL into a HTML upload form and it just works as you would logically expect it to (as far as I know, it is the only browser which allows this). It also featured KParts, which allowed it to embed just about any sort of viewer required, directly into the interface, embedding things like KPDF, KWord, image viewers, and most importantly, the ever-improving KHTML page renderer. This is important, since even Konqueror's icon views were implemented as pluggable parts, making just about any kind of icon view possible.
So, Konqueror is a really powerful tool that can do just about everything you and your system can possibly want, and with this power comes unlimited configurability and extensibility through control modules and plugins. However, what often happens in Konqueror when you are browsing the internet is that Konqueror still wants to behave as a file manager and not a web browser. This split behavior is easily noticed through elements such as toolbar buttons. For example: the "Up" arrow is still available on the toolbar even when browsing Google Maps, but it is totally irrelevant in this context; another is having a web bookmarks toolbar visible while sorting icons in your /home folder.
Introducing Dolphin: Dolphin is a new File Manager for KDE 4 which is dedicated 100% to file management, and is not intended to be a one-size-fits-all tool as Konqueror currently attempts. It is intended to optimize your file management related tasks, and present an easy to use file manager for casual KDE use. That doesn't mean it won't be powerful or configurable, only that Dolphin is being built for a single purpose.
Dolphin isn't a total rewrite however, and is not intended to compete with Konqueror, rather the two applications will be complimentary. Dolphin uses the already existing IO slave facilities of the KDE platform to perform remote or local file management, meaning that it will be capable of doing all of the 'remote management' type activities that Konqueror has already matured. Dolphin just won't show web pages or PDF files embedded as Konqueror does.
And Konqueror will benefit from Dolphin as well. Konqueror is not going to disappear for KDE 4, although its user interface may yet see some adjustments as its primary utility will not as the default file manager. Of course, Konqueror will still be available for file management tasks as it has been in the past - there will be no changes in this regard. Changes made to KDE's icon view parts through the development of Dolphin will also help to improve Konqueror's icon views, as they both share these libraries. As stated before, Konqueror loads all of these icon views as pluggable libraries called KParts - improvements to the underlying KParts automatically benefit all users.
So lets take a look at Dolphin and Konqueror as they currently exist in KDE's Subversion repository. Please keep in mind that these snapshots represent developer work-in-progress builds and, while publicly available, are not representative of the final appearance or intended functionality of either applications, nor are they recommended for everyday use.
Konqueror currently looks something like this, and the icon views only half work. The problem is that these file views are simply direct ports of the KDE 3 codebase. Konqueror will eventually receive the same fileviews that Dolphin is currently using.
You can tell from Konqueror's default configuration of using tabs, and various other related interface choices that Konqueror is now mostly a web browser that also happens to do file management. While Konqueror's roots are truly derive from file management, it is more frequently operated as a browser these days by many KDE users. Konqueror does a great job as a web browser, underpinned by the fact it now implements CSS 3, including the highly-anticipated 'opacity' tags.
So while Konqueror continues to improve as a browser, it will continue to maintain KDE 3.x file management standards, providing a baseline functionality, and will be improved as code is shared between itself and Dolphin.
Dolphin is a whole different animal. It is a 'real' file manager - it's interface has a lot of elements which are specific to a file manager and cannot really be justified in a browser. This is best demonstrated with a screenshot.
Notice the implemention of a 'breadcrumb'-style directory selector, which works well for file management in a lot of cases, but is totally useless if you need to enter a URL when using a browser, and so becomes the sort of widget which is only useful when dealing with file hierarchies. Breadcrumb widgets may be familiar to anyone who has used OS X's Finder or GNOME's Nautilus. Another comment about the above screenshot: clicking and holding a breadcrumb item displays a list of directories that are at the same level as the one clicked, allowing for more efficient navigation.
However, using the breadcrumb widget is not essential, and if you are more comfortable with a Konqueror-style location bar, this mode of operation is easily configurable, as seen above. In fact, much of Dolphin is configurable, illustrated below.
This screenshot evidences the amount of effort KDE is spending trying to make configuration layouts sane while still providing as many options as reason allows. Also note the improved appearance of the configuration dialogs in KDE 4. Of course, this is going to be revisited somewhat as the dialog is too tall for some screens at the moment. After the Oxygen visual components go live, this dialog will be even easier on the eyes.
So, Dolphin's functionality is not entirely new, other than it presents itself in a new way. It can be seen as a hybrid between the power of Konqueror and the structure of Nautilus. Dolphin still builds on a strong KDE base, reusing existing technologies like KIO slaves and so forth. Right-click actions that were available in Konqueror will still be mostly present (except that Dolphin will necessarily load files externally instead of using embedding viewers). And Konqueror can now improve its web browsing experience even more, doing so without losing the file browsing support that has been there since KDE 2.0.
When KDE 4 is released, Dolphin will be configured as the default application for the local file:/ protocol, as well as the default file manager listed in the applications menu. Konqueror will ship as the default web browser, and will still be usable as a file manager to those that prefer the historical lifestyle. Users of KDE will have the ability to set the default file browser, much like how KDE 3.x can use third-party applications such as Krusader as the default file manager. Stay tuned for more information as Dolphin and KDE evolve towards 4.0.