This is a continuation of #15266. In that pull-request we managed to
prevent IME previews from being displayed in the editor when the
originating `keydown` event was default-prevented. However, it was still
possible for IME input to make it through the previous workarounds, thus
triggering the `textInput` event and showing unwanted text.
Pressing another key that would complete the in-progress IME input
would, in fact, first replace `this.lastKeydown` and then trigger the
`textInput` event. In the handling of that event we would detect
`this.lastKeydown` as "non-default-prevented" and therefore mistakenly
insert the IME text.
With this commit we are adopting a different strategy to mitigate the
issue. When receiving the wrong `compositionupdate` event we will first
disable the hidden input and then re-enable it on the next tick.
Disabling the input causes the in-progress IME input to be aborted and
the browser to never fire `textInput` nor `compositionupdate` events
anymore after that.
The only downside of this approach is that the hidden input also loses
focus, but we transfer it back to it as soon as the next tick of the
event loop is served and the input has been re-enabled.
When changing the editor styles, we force the component to remeasure
character dimensions. If they change, each line's height could change
too, causing the current scroll top position to not match the viewport
the user was observing. Thus, when detecting a line height change, we
try to show users the area of the screen they were looking prior to
tweaking the font size.
In trying to maintain the aforementioned logical position, however, we
were mistakenly scheduling a new update before actually finishing the
current one. This was problematic because if the first update detected
that the longest screen line changed and such line was off-screen, it
would try to render it. Before having the chance to measure it, though,
the new update would kick in and delete the new longest screen line
node, because it assumed it had already been measured. Finally, when
`measureContentDuringUpdateSync` fired, it would notice that the longest
screen line node did not exist and throw an exception as a result.
This commit changes the `updateSync` method to set the `updateScheduled`
flag only before returning control to the caller, as opposed to doing so
at the beginning. This prevents calls to `scheduleUpdate` made in
`updateSync` from scheduling new unwanted updates.
This avoids mysterious timing issues in which the editor gets a 'focus'
event in a state where `isVisible` returns false. If we always render
the hidden input, we can always focus it.
Signed-off-by: Antonio Scandurra <as-cii@github.com>
Previously, clicking on a block decoration to interact with it would
cause the editor to scroll to the line next to it. This is inconvenient,
especially if the decoration was designed to be interactive and
contained buttons or links. If the decoration was close to the bottom of
the screen, clicking on a button inside of it would make the editor
scroll down and abort the click.
This behavior regressed during the editor rendering layer rewrite and
with this commit we are restoring the original behavior by simply
ignoring clicks that land on block decorations.
I think this slipped through during the refactoring performed in
dc32018. With this commit we are fixing the regression and adding a new
main process regression test to exercise this behavior.
Electron allows us to pass an "accelerator" property for each menu item, which
is renders to the right of the menu item. We were already adding these for the
application level menus.
This pull request adds the accelerator property to regular context menu items,
which should make it easier for people to discover/recall key mappings for
actions which they usually take via a context menu.
Instead, if the measured line height equals 0, default it to 1 so that
the editor component doesn't start computing `NaN` or `Infinity` values
due to e.g. dividing by 0.
We should probably consider sanitizing line heights smaller than a
certain threshold, but that's non trivial because line height is
expressed as a multiplier of the font size. Also, users may style the
`line-height` property via CSS, which may still throw errors when using
small values.
Calling `pixelPositionForScreenPosition` was sometimes throwing an error
indicating that the requested position was not rendered and that, as
such, could not be measured.
This was caused by trying to measure a line that was visible at the
moment of the call while also having a pending autoscroll request that
would cause that line to go off-screen. Due to how the code was
structured, we would mistakenly detect that line as visible, autoscroll
to a different location, re-render a different region of the buffer and
then try to measure the now invisible line.
This commit fixes this issue by restructuring and simplifying the logic
for rendering extra lines in order to measure them. Now, every line for
which a measurement has been requested is stored in a `linesToMeasure`
map. During the first phase of the update process (after honoring
autoscroll requests), we detect which of these lines are currently
visible and if they're not, store them into the
`extraRenderedScreenLines` map, which is then used to render lines that
are invisible but need to be measured.
We use the value of the hidden input to display a preview of the
composition, but it might already contain spaces from previous
keystrokes, since we don't call preventDefault when spaces are inserted.
Etch's reconciliation routine causes elements to be sometimes
re-ordered. In order to move an element, however, Etch needs to first
detach it from the DOM and then re-append it at the right location.
This behavior is unacceptable for highlight decorations because it could
re-start CSS animations on a certain highlight decoration when a
completely different one is added or removed.
Even though we are still interested in restructuring etch's
reconciliation logic to prevent unwanted re-orderings, with this commit
we are switching to a custom routine to create/update/remove highlight
decorations that prevents unnecessary moves and, as a result, fixes the
undesired behavior described above.
