Re: Putting auto-image-file-mode in Options menu

[David Kastrup <dak@gnu.org>]

Richard Stallman <rms@gnu.org> writes:

>     If you used an overlay instead of text properties, there would be no
>     necessity to modify the buffer.
>
> That is true.  However, copying the image to another buffer would only
> get you text.

Which is what would be appropriate when copying an XPM icon into a C
source file.  And since the C source file would not be in
auto-image-mode to start with, I could not remove the imagery by
turning auto-image-mode off.  Other buffers are unlikely to retain the
image when being saved and reloaded, unless their file name would also
imply auto-image-mode.  But I think it reasonable that you have to
reload in that case.

> That's why I decided to make it a text property.

Funny.  That's exactly the reason why I would have made the decision
the other way round (and in fact, the preview-latex project uses
overlays instead of text properties for this reason).

I think that without special yank properties that would, say, cause
the image to be included as an image in a HTML buffer and other
locations, it is pointless to have this as a text property since the
image will not usually survive saving and reloading in a different
buffer.  And since the image actually is the outcome of a _mode_, it
would appear that the "is-an-image" state, being coupled with the
mode, belongs to the buffer instead of the text.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum