EmacsWiki: Semantic Idle Breadcrumbs Mode (original) (raw)
Introduction
The semantic idle breadcrumbs mode displays information about the structural context of point in the header line or mode line. The display update is performed using Semantic’s idle scheduler. This means the update happens after a short period of inactivity.
The screenshot below illustrates one of the display styles in the header line for the C++, Python and Emacs Lisp programming languages:
Usage
In recent versions of CEDET, the mode can be enabled for individual buffers using the ‘semantic-idle-breadcrumbs-mode’ command. The command is executed by typing
M-x semantic-idle-breadcrumbs-mode RET
In addition, the mode can be enabled globally (meaning that the mode will automatically be enabled in all buffers) using ‘global-semantic-idle-breadcrumbs-mode’. To make the activation of this global mode permanent, the following code can be added to the Emacs startup file (usually `.emacs`)
(global-semantic-idle-breadcrumbs-mode 1)
The display style can be customized in the ‘semantic’ customization group.
Display Styles
- The context can be displayed in a traditional "breadcrumbs" manner such that elements are displayed from left to right using an outermost to innermost order. Example:
outer_namespace::inner_namespace::class::member_function
- A variant of this style uses a configurable language-independent separator string. Example:
outer_namespace > inner_namespace > class > member_function
- It is also possible to display the innermost element with more detail followed by a “breadcrumbs” path. This style is shown in the screenshot above. Example:
void member_function (int a, int b) | outer_namespace::inner_namespace::class
Q: Could you specify how you achieved the format in the screenshot?
A: That is done by setting ‘semantic-idle-breadcrumbs-format-tag-list-function’ to ‘semantic-idle-breadcrumbs--format-innermost-first’.
Alternatives
An alternative mode that offers similar functionality for several programming languages is WhichFuncMode.