Re: [scintilla] Pango support on GTK+ 2.x

["Neil Hodgson" <nhodgson bigpond net au>]

Owen Taylor:

> What I was saying is that, more or less, if you layout an entire
> file in a couple of seconds (or 0.5 seconds) then you'll be
> able to lay out a screen of text quite fast enough to render
> it, so there is no point in caching more than the minimum you
> need for scrollbar maintenance.

   Users expect selection and the display of associated highlighting of
braces and indentation to be very smooth. You mentioned Pango caches the
last paragraph. This sounds like an optimisation that works well when caret
movement is within a multi-line paragraph. With source code, there are more
and shorter paragraphs and more likelihood of caret movement between them.
There is a perceptible difference here between caching different ranges of
layout information. Scintilla supports caching nothing, a line, a page, or
the whole file.

   Paragraph reflow during window resize may be a bit of a gimmick but some
people do like this to be fast. I find myself resizing wrapped logging
windows quite often.

> How do you have an _inaccurate_ horizontal scrollbar? Just make
> the horizontal scrolling area very big?

   An accurate horizontal scrollbar is one where the thumb exactly
represents the window width as a proportion of the widest line. An
inaccurate version may use an approximation and allow extension when a long
line is rendered or when the user uses the right scroll arrow to go past the
end.

   Neil