ECB offers a ECB-windows for displaying source-file-names of a certain directory: The sources-window. It displays all source-file names of the currently selected directory of the directories-ECB-window (see ECB Directories-window).
The history-tree-buffer is a “flat” tree-buffers means all nodes are direct children of the invisible root-node and can not be expanded.
IMPORTANT: If you use the POWER-click (i.e. hold down the SHIFT-key while clicking with the primary mouse button (see Using the mouse) or RETURN (see Using the keyboard)) on a source row in the ECB-Sources-windows then the source will not be displayed in an edit-window but it will be scanned in the background and all its contents (e.g. methods and variables) are listed in the ECB Methods-window (see ECB Methods-window. So you can get an overlook over the source without changing the buffer in the edit-window.
Either use one of the predefined layouts which contain the sources ECB-window
(see Changing the ECB-layout) (e.g. via C-c . l c) or create a new
ecb-layout via the command
ecb-create-new-layout and add a buffer of
type “sources” into this new layout (see Creating a new ECB-layout).
See ecb-sources for a list of all options currently available for customizing this ECB-window to your needs.