* Simplify scrollbar refresh and measurement by using imperative DOM
manipulation instead of React to hide/show scrollbars.
* Rename `::performInitialMeasurement` to `::becameVisible`
* Break `::checkForVisibilityChange` out of `::pollDOM` and use it in
to check for the element becoming visible in `componentWillUpdate`.
* Don't rely on stored visibility state anywhere. Always check again.
This could potentially be cached for an update cycle but being wrong
about this is disastrous so I'm being conservative.
This ensures lines have an opaque background that matches whatever the
editor is styled as, but avoids the need to apply the .editor-colors
class to the .lines div. That approach fell down when people were
setting the background color via means other than .editor-colors, such
as styling mini editors via the .editor.mini selector in the settings
view.
Having the editor-colors class on these elements was causing the theme
to be applied to lines in mini editors in the settings view, which
caused a black inset box to appear with dark syntax themes.
This was added to give the lines an opaque background which was supposed
to enable sub pixel anti-aliasing despite being on the GPU, but it
didn't seem to be working. Perhaps we can revisit this issue after the
Chrome 35 upgrade to see if sub pixel antialiasing works with opaque
backgrounds afterward.
Previously, these measurements were always performed when the editor
component was mounted. This didn't work in situations where the
component was mounted in a non-visible state. This commit includes a
visibility check in the resize polling we were already doing, kicking
off the measurement process as soon as the editor is visible.
Previously the indent guide was always showing on the whitespace only
lines in the React editor. This is the same behavior as in the old
editor and had the same fix, just ported to `LinesComponent`.
See: 314833bbacFixes#2274
Fixes#2367
* The indent level of empty lines is the *max* of the nearest non empty
line, rather than favoring the level of the line below.
* An extra wrap guide is no longer rendered for empty lines
I didn't port the specs over because we already had good coverage at the
model level. It just needed to be updated for the preferred behavior.
Previously, when the last highlight div was removed from the lines
layer, chunks of the lines would sometimes disappear. Since we've
discovered that giving the lines an opaque background doesn't help with
subpixel anti-aliasing anyway, I've found that rendering highlights on
their own layer behind the lines and making the lines layer transparent
avoids the arficacts.
