Opaque lines are turning out to be a total pain, plus they ruin absolute
positioning on the lines div. The slight speed boost isn't seeming worth
it anymore.
Because lines are opaque and any area of a selection that overlaps a
line is actually rendered on the line itself, the screen-spanning
background of a multi-line selection can actually be rendered as a
single div spanning the entire screen from the first row to the
penultimate row of the selection.
Because lines are opaque on the GPU for sub pixel antialiasing, the
lines obscure the selections which were formerly rendered behind the
lines. This commit renders selection fragments *on* each opaque line
layer so the selections look correct again. Still needs cleanup and
optimization.
Now that everything is absolutely position, the editor no longer assumes
a "natural" height and width. This can be addressed later if we want to
allow editors to expand based on their content.
Since lines and line numbers are now on the GPU, their text won't be
properly anti-aliased on low-resolution displays unless their layers
have a solid background.
This is getting closer, but lines still need to be opaque. Multi-line
selections will still need to be rendered behind the line layers so they
can extend to the edge of the viewport, so this code still has value.
Previously, we were updating the scrollbars and relying on an async
scroll events to fire. But updating the scrollbars is expensive, so this
updates the model directly when the next animation frame fires instead.
Previously a menu for a keybinding with a .workspace selector would not
display the shortcut because the selector wasn't matching the test editor
element directly.
Now the parent elements of the test editor are checked as well.
Closes#2089
