NonGNU ELPA - better-jumper

better-jumper

A configurable jump list implementation for Emacs that can be used to easily jump back to previous locations.

Usage

Install

Better-jumper is available on MELPA.

M-x package-install better-jumper

emacs-lisp (require 'better-jumper)

better-jumper comes with a global mode: better-jumper-mode and a local mode: better-jumper-local-mode.

You can either a) enable globally:

```elisp (better-jumper-mode +1)

;; and disable in specific modes (push 'python-mode better-jumper-disabled-modes)

;; or disable it manually (add-hook 'python-mode-hook #'turn-off-better-jumper-mode) ```

Or b) enable locally, where you need it:

elisp (add-hook 'python-mode-hook #'turn-on-better-jumper-mode)

Getting started

Once better-jumper has been loaded it is ready to start tracking jump history. Anytime better-jumper-set-jump is invoked the current location is added to either the window or buffer specific jump list (depending on the better-jumper-context setting). At any time the jump backward/forward functions can be used to navigate through the jump history.

If you are an evil user then better-jumper can piggy back off of the built in jumplist implementation to track when jumps occur. The setting better-jumper-use-evil-jump-advice dictates this behavior and defaults to t. Note that better-jumper does not interact with or alter evil's jump list in any way.

Summary of interactive commands

Command	Description
better-jumper-set-jump	Add a new jump location to jump list using current buffer/position
better-jumper-jump-backward	Jump to back to previous location in jump list
better-jumper-jump-forward	Jump forward to next location in jump list
better-jumper-get-jumps	Get jump state for window or buffer
better-jumper-set-jumps	Set jump state for window or buffer

Example keybinding

Configure the standard jump list navigation keybindings for evil/vim:

lisp (with-eval-after-load 'evil-maps (define-key evil-motion-state-map (kbd "C-o") 'better-jumper-jump-backward) (define-key evil-motion-state-map (kbd "<C-i>") 'better-jumper-jump-forward))

Configuration Options

Jump Context (better-jumper-context)

This setting specifies the context in which jump lists are tracked. This can either be set to 'buffer or 'window. If the value is 'buffer then a jump list is maintained for each individual buffer. Conversly, if the value is 'window then the jump list is maintained per window and will operate across buffers in that window.

While in the 'window context, jump lists are stored as persistent window parameters and can be saved and restored along with the window configuration using something like desktop or persp-mode. This is the default context.

While in the 'buffer context, jump lists are maintained using buffer-local variables and can optionally by saved using savehist.

New Window Behavior (better-jumper-new-window-behavior)

This setting specifies the behavior that will take place when a new window is created AND the current context is set to 'window. This can be either set to 'copy or 'empty. If the value is 'copy then the last selected window's jump list will be copied to the new window. If the value is 'empty then the new window's jump list will start empty.

Add Jump Behavior (better-jumper-add-jump-behavior)

This setting specifies how the jump list is affected when a new jump is added. If the value is set to 'append then new items are always added to the end of the jump list regardless of the current position. If the value is set to replace, then if the any jumps newer than the current position in the jump list will be replaced. I.e. If a user jumps back three times then adds a new jump, those three jumps will be replaced by the new jump in the list.

Max Length (better-jumper-max-length)

This is a numeric value that dictate the maximum length that a jump list can grow to. If the length of a jump list exceeds this size then the oldest items in the list will be dropped.

Use Evil Jump Advice (better-jumper-use-evil-jump-advice)

If non-nil better jumper will attach a piece of advice to the evil-jump function that will ensure that anytime a jump is added using evil-jump a corresponding jump will be added using better-jumper.

better-jumper-use-savehist (better-jumper-use-savehist)

If non-nil better jumper will use savehist to save jump history. This is currently only implemented for the 'buffer context. Persistent window parameters are used to save and restore jump history for windows.

better-jumper-buffer-savehist-size (better-jumper-buffer-savehist-size)

This number dictates how many of the most recent buffers should have their jump state saved to the savehist file when savehist is enabled the the context is set to 'buffer.

Hooks

Pre-jump Hook (better-jumper-pre-jump-hook)

A hook that is invoked before a jump occurs.

Post-jump Hook (better-jumper-post-jump-hook)

A hook that is invoked after a jump occurs.

Comparison with evil-jump

This package was heavily inspired by evil-jump and initially was planned as a modification of or pull request to evil. It was primarily born out of the desire to isolate jumps across persp-mode perspectives, however the changes proved to be to large to be a simple modification. Additionally, this package provides more customization options as well as a few other core improvements.

A few advantages of better-jumper are:

• Uses window persistent parameters to store jump lists. As a result better-jumper properly works with persp-mode and any other feature that manages window configurations.

• True buffer specific jump lists. When instructed to not cross buffer boundaries evil-jumper still tracks jumps per window only limits the jumps available to ones located in the current buffer.

• Configurable new window behavior. evil-jumper ALWAYS copies the jump list from the previously selected window to any newly created window.

Caveats

• Jump locations are stored as markers so they will maintain a more accurate location in the buffer. However, due to the fact that markers can't be serialized they are down converted to simple buffer positions when saved either via window configuration or savehist.

• Currently savehist support is only limited to the 'buffer context. When running in the 'window context, the jump list is stored as a persistent window parameter and is intended to be saved using alongside the window configuration using somethinig like desktop or persp-mode.