This commit adds a static property, EditorComponent.performSyncUpdates,
which can be used to control the update behavior of all editor
components. In addition, an instance property called performSyncUpdates
be assigned to control the update behavior of a specific instance.
The .line-numbers div has to have an opaque background because it's
sent as a texture to the GPU, and otherwise it will have isuses with
subpixel antialiasing.
However, themes style the background of the .gutter div, which was
getting obscured by the opaque background of the line numbers. This
commit adds the .gutter class to the .line-numbers div as well and
ensures it always fills the entire height of the editor.
Using the marker's id plus the decoration class can cause an error in
the event we apply a decoration with the same class twice to the same
marker. This is admittedly unlikely, but I think it's cleaner to just
allocate unique id's for decoration objects.
We always measure the scroll view in the ::componentWillUpdate hook, so
performing *another* update in response to the measurement causes an
invariant violation in react. Whenever we are measuring, we are always
already updating.
This commit also changes input handling to be more like it was in the
previous editor. We're using textInput rather than input events because
they are emitted *before* characters are inserted, enabling much simpler
detection of characters inserted via the accented-character menu on
OS X.
Previously I avoided this because something about it was causing reflows
in the old editor, but in this editor that doesn't seem to be a problem,
and it's actually faster.
When the cursor is positioned before a character, we always make it the
width of that character. But at the end of a line, there is no character
to use to set the width, so we just use the defaultCharWidth.
This makes the block cursor visible on empty lines in vim-mode.
