Many programs (eg Kate, Decibel Audio Player) have their own embedded file browsers.

I wonder if it would be possible to get a file browser like dolphin to act as if it were the embedded file browser for another program (I'm imagining Dolphin in tree-view mode here).
For instance, if connected to a Kate instance, double-clicking could open an unopened file in Kate, and single-clicking could switch to an already open one.
On the Dolphin side, Kate would be able to signal to Dolphin which files are open and have unsaved edits, and these could be given more prominent icons. Eg: unopened files could be half transparent.

A two-way protocol would need to be designed to implement this.

The advantages to this would be:

• Far easier for applications to implement than creating their own embedded browser.
• Dolphin will probably have far more features and customization than an embedded browser.
• Dolphin can also manipulate files itself (unless the user & application would prefer to disable that in the tied/connected dolphin window).
• Additional ease-of-use (eg: creating a new file in dolphin could automatically open the new document in Kate).
• More standardization and modularity. Also, other browsers could also implement this protocol.
• Separate windows.

This could be used with many different apps, eg:

• Image viewers / editors.
• Music/media players (where clicking adds to a playlist).
• Debuggers (the active function's file could be highlighted one way, and the other stack functions' files could use a weaker highlight).

Programs could create their own instances of dolphin, or, alternately, people could possibly link them by clicking on a button on dolphin then clicking on the application.

As different programs would likely want to process dolphin events differently, the protocol should probably allow the application to use:

• Single-click, right-click, double-click etc.
• Right-click context-menu items.
• Modifier-key + click (eg: add to playlist vs play immediately).

The user should be allowed to configure these, for each application.

In the other direction, dolphin should handle events such as:

• File opened, edited, saved, closed.
• Active file changed (eg: when a playlist moves to the next track).
• Program closed.

I guess a small subset of this functionality can be achieved by just creating a separate dolphin install and tweaking the shortcuts, but that's nowhere near as useful as this could be.

Does this sound like a good concept?