To install this package, run in Emacs:
M-x package-install RET on-screen RET
Scrolling can be distracting because your eyes may lose orientation. This library implements a minor mode that highlights the previously visible buffer part after each scroll. Installation: Put this library somewhere in your load-path, or install via M-x package-list-packages. Then add to your init-file: (require 'on-screen) To invoke on-screen globally for all buffers, also add (on-screen-global-mode +1) Alternatively you can use the buffer local version `on-screen-mode'. For example, add this line to your init file: (add-hook 'Info-mode-hook 'on-screen-mode) to enable it in all Info buffers. By default, fringe markers are used for highlighting - see `on-screen-highlight-method' to change that. Type M-x customize-group RET on-screen RET to see what else can be configured. If you use a configuration file (.emacs), you may also want to define mode specific settings by using buffer local variables. For example, to use non intrusive fringe markers by default, but transparent overlays in w3m, you would add (add-hook 'w3m-mode-hook (defun my-w3m-setup-on-screen () (setq-local on-screen-highlight-method 'shadow))) to your .emacs. If you use transparent overlays for highlighting and there is the library "hexrgb.el" in your `load-path', it will be used to compute highlighting colors dynamically instead of using constant faces. I.e. if you use non-default background colors (e.g. from custom themes), on-screen will try to perform highlighting with a suitable, slightly different color. See `on-screen-highlighting-to-background-delta' to control this. Implementation notes (mainly for myself): Implementing this functionality is not as straightforward as one might think. There are commands that scroll other windows than the current one. Not only scrolling commands can scroll text - also editing or even redisplay can cause windows to scroll. There is weird stuff such as folding and narrowing, influencing the visible buffer part. And although highlighting is realized in the displayed buffers (with overlays), it must be organized on a per-window basis, because different buffer parts may be displayed in different windows, and their highlightings must not interfere. That all makes it necessary to observe windows via hacks in different hooks, and to manage information about buffers, visible parts and timers in a data structure (`on-screen-data'). It is realized as an association list whose keys are windows. There are some pitfalls - e.g. the data can be out of date if the window configuration has changed and windows display different buffers now. The data must be updated, but not simply be thrown away, because the highlightings in the old buffers must be removed nonetheless. Acknowledgments: This library was inspired by a similar feature of the "Conqueror" web browser. Thanks for Drew Adams for testing and contributions.