Function

Summary

Caches the display of an output pane, ready for later drawing.

Package

capi

Signature

output-pane-cache-display output-pane &optional from-display-p

Arguments

output-pane

An output-pane.

from-display-p

A generalized boolean.

Description

The function output-pane-cache-display caches the display of the output-pane output-pane , that is what it currently shows. The result can be used later by output-pane-draw-from-cached-display.

When from-display-p is false the cached display is created by a "dummy" call to the display-callback of output-pane . If from-display-p is true the cached display is created by copying whatever is currently showing on the screen. Note that any obscured part of the pane will not be copied in this case. The default value of from-display-p is false.

Before caching the display, output-pane-cache-display performs an implicit call to output-pane-free-cached-display, which undoes the effect of all previous Cached Display interface calls.

Notes

1. Caching the display is useful when you want to avoid calls to the display-callback during some period, which may be because it is slow or perhaps some other reason.
2. The Cached Display interface functions do not affect the display-callback and it is your responsibility to prevent the display-callback being called. See output-pane-draw-from-cached-display for more information.

See also

output-pane
output-pane-draw-from-cached-display
output-pane-free-cached-display
start-drawing-with-cached-display
Transient display on output-pane and subclasses