This isn't ideal, but it is better than previously: we would
close the window and before the Drop impl had updated the
list of known windows, we'd try to re-assign that window
to another mux window in a different workspace, but it would
never appear because the window was closed.
refs: https://github.com/wez/wezterm/issues/1531
Originally I had this the other way around but it was problematic
when considering things like maximized, font scaling and full screen
states.
refs: https://github.com/wez/wezterm/issues/1531
Rather than just quitting the app and potentially silently killing off
a number of panes that might be running in other workspaces, we now
will pick one of those workspaces and activate it.
refs: #1531
This action causes the active workspace for the gui to change.
If the name is omitted a random name will be generated.
If the workspace doesn't exist, it will be be created.
The optional spawn parameter can be used to launch a specific
program into the new workspace; if omitted, the default prog
will be used.
The gui only supports a single active workspace. Switching workspaces
will repurpose existing gui windows and re-assign them to windows
in the new workspace, adjusting their size to fit those windows,
spawning new windows or closing unused windows as required.
The gui now exits when there are no panes in the active workspace,
rather than no panes at all.
refs: #1531
The mux now has a notion of which client is actively doing things.
This allows, for example, newly spawned windows to take on the
active workspace for a given client.
The gui now assigns a client id on startup, and sets the active
workspace to `default`.
The mux server temporarily overrides the active id to that of
the currently dispatching client when processing PDUs.
refs: https://github.com/wez/wezterm/issues/1531
Tidies up some code duplication within the mux protocol handler.
Move some of the logic into Mux, remove legacy Spawn Pdu to reduce
more duplication.
I want to dedup some of the similar logic that exists in the gui
spawn implementation as well in a follow up.
`ScrollByPage` can accept non-integer values in the configuration.
This allows fractional page scrolling, such as by half a page.
The default remains the same, at 1 page.
This is not exposed through any UX; the mux api allows setting
the workspace and propagating information about windows whose
workspace has changed.
Windows start with a blank workspace name.
This is just plumbing; nothing uses it yet.
refs: #1531
This is a similar race condition to one we had before with the
multiplexer, where the connection UI made us think that we didn't
need to start a new process.
Additionally, the attach method would unconditionally create a
new client without checking whether we already had one.
In the case that the published symlink is stale, our default
client connection logic was to retry connecting with backoff
to give a newly spawned server a chance to startup.
In the context of a newly launched gui process checking to see
if an existing gui process can serve the same request, we don't
need to give it any grace: it will either answer immediately
or be deemed not useful.
This commit limits us to a single connection attempt in the case
where we're not automatically starting the server, which in turn
constrains the overhead to something in the order of microseconds
rather than nearly 0.5 seconds.
While we're in here, I noticed that if we thought we had a socket
to try and that failed, we'd always try to publish a new symlink.
However, if we failed due to mismatched version info, we shouldn't
publish over the top of the already running instance.
refs: #1529
user vars were stubbed out. This commit adds storage for them
in the mux client and adds a new notification that publishes each
var as it is changed. That differential stream is applied to the
storage in the mux client when it is received.
```lua
local wezterm = require 'wezterm'
wezterm.on("update-right-status", function(window, pane)
local woot = pane:get_user_vars().woot
window:set_right_status(tostring(woot))
end);
return {
unix_domains = {
{name="unix"},
},
}
```
then running:
* `wezterm connect unix`
* in that session: `printf "\033]1337;SetUserVar=%s=%s\007" woot `echo -n nice | base64``
causes `nice` to show in the status area.
refs: #1528
This puts us in a better position for the future to be able
to configure whether we use wezterm, tmux or no multiplexing.
Today we allow wezterm or no multiplexing.
Add docs on this new setting.
refs: https://github.com/wez/wezterm/issues/1456
If an ssh domain is set to use_multiplexer=false, it is now
possible to `wezterm connect` to it.
Previously, it was only possible to connect to domains that
used the mux client.
refs: https://github.com/wez/wezterm/issues/1456
If we decide we want re-use and existing gui due to config differences
we shouldn't then publish the new, differently configured, gui as
the canonical path for that display/class.
Clarify the message that we print when re-using an existing gui
in case someone doesn't want that behavior.
When set, changes the default domain to the domain with the specified
name, which potentially affects the default program.
eg: default_domain = "WSL:Ubuntu-18.04" will cause the initial tab
to be spawned via WSL.
The idea is that we want to be able to spawn into wsl with the
convenience of a local domain, but without the awkwardness of
it having a different filesystem namespace.
It would also be great to be able to spawn a new tab or pane
in the same domain and pick up the cwd of the existing one.
The WslDomain allows the user to explicitly list WslDomains
and control eg: default shell, username and so on, but wezterm
will pre-fill a default list of domains based on the `wsl -l`
output that we were already using in the launcher menu.
The existing LocalDomain has been augmented to understand that
it may need to fixup a command invocation and that gives it
the opportunity to rewrite the command so that we can launch
it via `wsl.exe` and pass down the cwd and so on.
This same technique might be extensible to eg: docker instances
in the future.
This commit:
* Introduces `wsl_domains` config and its default list of wsl
distributions
* Creates LocalDomain instances from that list
* The launcher menu allows spawning a new tab via one of those domains
The client machinery would try to spawn an async attempt at
detaching the unixdomain from the mux on shutdown, but since
we're in the middle of tearing down the scoped executor,
we could sometimes panic.
The client we have in this situation isn't actually associated
with a domain, so we don't need to detach in that situation.
Formalize that by making it an Option, and address the
fanout.
Using the new publish/discovery stuff from the past couple of commits,
if we can find a matching socket path for a running gui, and the
configuration is likely a match, then use the mux protocol to talk
to the already running gui and ask it to spawn the equivalent program
into the same process.
refs: https://github.com/wez/wezterm/discussions/1486
We need 100% of the info for it to work correctly, so this commit:
* Exposes the keyboard encoding mode via the Pane trait
* Adds the scan code to the RawKeyEvent
* Has the GUI perform the encoding if the keyboard is set that way
* Removes the basic encoder from termwiz in favor of the gui level one
The net result is that we bypass the Pane::key_up/Pane::key_down methods
in almost all cases when the encoding mode is set to win32-input-mode.
There is now a config option: allow_win32_input_mode that can be
used to prevent using this mode.
refs: #1509
When spawned with no WEZTERM_UNIX_SOCKET environment set,
we now prefer to resolve the gui instance, falling back to
the mux if it doesn't look like the gui is running.
`wezterm cli --prefer-mux` will use the original behavior of
trying to resolve the path from the unix domain in the config.
Nothing generates them right now, and the mux client has no
way to represent them on the wire.
I'm considering constraining them to just win32 for now.
refs: https://github.com/wez/wezterm/issues/1509
It was showing the whole text for the cluster for each shaped
glyph.
Fix it up to map back to the corresponding cell range and
extract the text from the line.
Include the x_advance metric in the output while we're in
there.
refs: https://github.com/wez/wezterm/issues/1333
When rendering the IME composing text, I noticed that for the Korean
input sequence: shift+'ㅅ' followed by 'ㅏ' we'd render the 'ㅆ' (the
shifted first character) in black and the composing 'ㅏ' in white
against the cursor color, and that was very difficult to read,
especially at the default font size.
To resolve this, this commit:
* Forces clustering to break around the cursor boundary, so that
we treat the cursor position as its own separately styled cluster
* Adjusts cursor/bg rendering so that we always consider the start of
the cluster for the colors of that run. We are guaranteed that a
ligatured sequence will fit in the background area anyway.
This has the effect of "breaking" programming ligatures such as '->'
when cursoring through them, and decomposing them into their individual
'-' and '>' glyphs, which is a reasonable price to pay for being able
to see things better on screen.
refs: https://github.com/wez/wezterm/issues/1504
refs: https://github.com/wez/wezterm/issues/478
When we translate a dead key, send the composed event immediately
and don't try to route the current key press via the IME.
Improve rendering when in the composing state: overlay the composing
text at the cursor position to show what the composing text would
look like, even though it hasn't been committed to the input stream
yet.
refs: https://github.com/wez/wezterm/issues/1504
For Korean text input, pressing SHIFT and then typing in certain
keys begins a composition sequence. Our logic for when to route
via the IME got so distracted by ALT that it didn't consider SHIFT
and didn't send this sequence to the IME, so we'd fail to compose
those sequences.
While poking at this, I realized that we should treat this composition
similarly to dead keys, in that we can signal the term window to
highlight the cursor color and report that status.
There's some further work to do: the composing text should be rendered
by us. So far our IME integration assumes that the IME itself will
render over the top of our window, but for this particular input
it doesn't do that.
refs: https://github.com/wez/wezterm/issues/1504
The same core code is used to render both the tab navigator
and the launcher. The context is specified using some flags
so that you don't get an unholy mess in both places.
The net result of this is that the tab navigator now supports
fuzzy matching.
refs: #664
refs: 1485
* Allow selecting the first few rows by number
* Allow scrolling through long lists of items
* Add actions from key assignments to list
refs: #1485
refs: #1413
Since we now have RawKeyEvent and a sane way to indicate handling,
we don't need these any more, and it simplifies key dispatch to
remove them.
refs: #1483
Pass down whether we are in a live resize to the gui layer, so that
we don't incorrectly assume that the scale has changed, and fight
with the window manager.
Built this on my mac: will need to fixup for windows and linux.
refs: https://github.com/wez/wezterm/issues/1491
This commit adds a couple of helper methods that provide insight into
the state of the keyboard layer.
The intent is for users to add status information about the keyboard
state.
This commit also ensures that we schedule an update when the leader
key duration expires, and ensures that we close out the leader state
for an invalid key press.
refs: #686closes: #688
```lua
local wezterm = require 'wezterm';
wezterm.on("update-right-status", function(window, pane)
local leader = ""
if window:leader_is_active() then
leader = "LEADER"
end
local dead = ""
if window:dead_key_active() then
dead = "DEAD"
end
window:set_right_status(leader .. " " .. dead)
end);
return {
leader = { key="a", mods="CTRL" },
colors = {
dead_key_cursor = "orange",
},
}
```
When set, the cursor will change to this color during dead key
or leader key processing.
```lua
return {
colors = {
dead_key_cursor = "orange",
},
}
```
refs: #686
refs: #688
on macos only (for now), we generate a RawKeyEvent prior to
dead key or IME composition and route it to the window to give it
a chance to handle the event.
RawKeyEvent handling is scoped only to key assignments, not generating
input for the terminal.
A raw key event can be marked as handled to prevent moving on to
performing composition and generating cooked key input.
refs: https://github.com/wez/wezterm/issues/877
```lua
local wezterm = require 'wezterm'
return {
debug_key_events = true,
keys = {
{key="phys:Q", action=wezterm.action{SendString="woot"}},
},
}
```
The above will send "woot" to the pane whenever the key in same
physical position as Q on an ANSI standard US keyboard is pressed.
refs: https://github.com/wez/wezterm/issues/1483
This comes from a time where our quads were always locked to grid
positions. We don't need it any more: we can simply add the adjustments
to the quad positions that we set.
Removing it makes the vertex a bit smaller and reduces the amount
of GPU accessible memory we need to use.
I'm running down a weird thing where the main font renders weirdly
when the title font is 12 pt vs the main font 10 pt.
I thought there might have been a cache invalidation issue and
realized that we could have an A-B-A style issue with the font_ptr
stuff, so I replaced it with an incrementing id.
That didn't fix the thing I was looking at, but does feel a bit
nicer overall.
The default we use on macOS looks decent. Roboto is a similar
looking font that we can use for the other platforms.
I may make it the same on all three once I've had a chance
to compare it on a mac.
Previously, we would implicitly set it to the special SEQ_ZERO
value, but since that value always flags the row as changed,
it causes some over-invalidation issues downstream in wezterm.
This commit makes that parameter required, so that the code that
is creating a new Line always passes down the seqno from that event.
refs: #1472
We only need to recompute when the tab content changes, or when
the window is resized, plus invalidations of the shape cache
of texture atlas filling up.
Hover events don't need to re-shape.
We can now also place the tab bar at the bottom of the screen again.
The main tab area now takes the background color from the first
cell in a formatted tab bar item as the full background color
for the whole tab area, which looks a lot nicer than just the
using that color for the minimal bounding box of the tab text.
This commit adds a CSS box model inspired element / layout
facility, and replaces the hand implemented fancy tab bar
element render.
This makes the code for fancy tab bar much easier to read
and update.
The right status area now expands to the full height of the
tab bar area, and uses a line height of 2.0, which makes
it line up nicely in the tab bar.
Switch to the slightly more structured verbose output of `wsl -l -v`
in the hope that we are less prone to localization issues and
are more robust in the face of future changes.
refs: #1462
Rather than hardcode a fixed default value in the config crate, define
the default as optional and leave it to the font crate to compute
the value.
This is a step towards allow introducing system dependent GUI related
code to resolve/understand the title font: we can't put that directly
in the config crate.
Add `get_foreground_process_name` to both Pane and the lua wrapper.
Add `foreground_process_name` and `current_working_dir` fields to
`PaneInformation`. In order for those to be dynamically fetched,
switch the lua conversion for `PaneInformation` to be a UserData
with field access methods. It's a little more verbose but allows
us to lazily compute these two new fields.
refs: https://github.com/wez/wezterm/discussions/1421
refs: https://github.com/wez/wezterm/issues/915
refs: https://github.com/wez/wezterm/issues/876
This commit expands quick select mode so that you can trigger it
with distinct sets of patterns (eg: urls on one key assignment,
hashes on a different key assignment), different alphabets,
and lastly, the option to perform a different action from
the default copy action.
You can pair this with `action_callback` to run lua code to
do something with the selected text.
This commit also adds `wezterm.open_with`, a helper function
for opening documents/URLs.
refs: #846
refs: #1362
The label dedup code has panicked on me a couple of times.
I managed to capture the line number, so this commit aims to
capture some state to try to understand what's going on,
and importantly, to avoid the actual panic part.
refs: #1271
permits iTerm2 images to be drawn anywhere on screen without
scrolling the cursor, including the bottom row.
Also included is a check in fcwrap.rs to_range_set(), without which
was causing a panic at runtime due to subtraction from unsigned
leading to overflow.
This helps us correctly set the size of the image cell
for the case where we have a partial cell at the right/bottom
edge of an image being mapped across cells.
refs: #1270
Move away from the imprecise simple pow version and over to a
version that properly respects the linear and non-linear portions
of the curve.
refs: #1025
On Windows, both EGL and MESA render modes were too dark.
After a bit of hunting around what I found made EGL and MESA
consistent with my default nVidia GPL rendering was:
* Tell glium that our shader outputs srgb
* Add explicit gamma conversion from linear to srgb in the shader
AFAICT, that shouldn't be required, but it seems as though something
deep in glium really wants to apply some kind of gamma conversion,
and it seems to select the wrong kind unless we set things explicitly
to SRGB.
There are some people complaining about this in
https://github.com/glium/glium/issues/1615.
I actually tried to move entirely aware from the glium srgbtexture2d
type in the hope of having explicit control over the gamma, but the
issue is in what happens to the outputs rather than the inputs.
It appears to me as though the text now looks slightly less
intense, so I think this may be what we need for the gamma issue
in https://github.com/wez/wezterm/issues/544 and potentially
also https://github.com/wez/wezterm/issues/1025
refs: https://github.com/wez/wezterm/issues/1373
Adds some plumbing to allow the GUI to implement a download handler
and connect that up for iterm2 image/file transfers that have their
inline property set to false.
Previously we'd just log an error.
Now we will by default download the file to the user's download
directory.
This behavior can be turned off via the new `allow_download_protocols`
configuration setting.
File transfers can be initiated on a remote host via the
https://iterm2.com/utilities/it2dl script.
When the download completes, a toast notification is shown that will
open the file when clicked.
refs: https://github.com/wez/wezterm/discussions/1450
Remove special case for blocks where we switched it out for a blank
sprite and instead varied the cell background.
We now always render a matching cursor sprite as a separate layer
over the top of the text background color, but below the text
foreground layer.
This is preparing for https://github.com/wez/wezterm/issues/1432
Make bar/line cursors use the text foreground color when reverse
video cursors are enabled, per @VKondakoff:
https://github.com/wez/wezterm/issues/1076#issuecomment-978214136
Finally getting around to fixing this usability wart: this commit
changes the behavior of Window closing so that you can close a window
containing multiplexer panes without prompting and without killing
off those panes.
This is achieved through some plumbing:
* The mux can now advise Domains about an impending window closure,
giving them the opportunity to "do things" in readiness.
* The mux client domain informs the container ClientPane instances
to ignore the next Pane::kill call, which would otherwise inform
the mux server to kill the remote pane
* Pane:can_close_without_prompting now requires a CloseReason.
* ClientPane's can_close_without_prompting impl allows Window closing
without prompting on the assumption that the ignore-next-kill hack
above is working
refs: #848
refs: #917
refs: #1224
The mux client just returns a dummy reader, and some overlays
have panicking stubs: just allow for them to return None
instead of potentially spawning a useless thread.
Previously, we would only look at the `check_for_updates` config
on startup.
This commit adjusts the update checker logic so that we always
start it, and that we respect config reloads.
Only show the update window and/or generate a toast notification
is the current wezterm-gui process is the eldest of the set of
running wezterm-guis.
This avoids spamming the user with update information.
refs: https://github.com/wez/wezterm/issues/1402
This code was partially replicating the initial window setup
where we didn't necessarily know the dpi, but in the context
where this is run, we do know the dpi for the window, so
let's consistently use that number throughout.
refs: #1039
The intent is to workaround what appears to be an i3 bug.
Not totally sure this is a good change, but let's try it!
Might also help with an issue on macos.
refs: #1140
refs: #1310
This moves away from using special block glyphs for the lines and
just draws lines directly.
In addition, since these lines are no longer constrained to available
glyphs or glyph boundaries, we can now render lines that cross when
there are a mix of horizontal and vertical splits, which looks a
bit nicer.
refs: #1256
Assuming that the window config reloaded hook doesn't actually change
anything, this will avoid a cycle where we keep triggering the hook
over and over.
This is a fairly far-reaching commit. The idea is:
* Introduce a unicode_version config that specifies the default level
of unicode conformance for each newly created Terminal (each Pane)
* The unicode_version is passed down to the `grapheme_column_width`
function which interprets the width based on the version
* `Cell` records the width so that later calculations don't need to
know the unicode version
In a subsequent diff, I will introduce an escape sequence that allows
setting/pushing/popping the unicode version so that it can be overridden
via eg: a shell alias prior to launching an application that uses a
different version of unicode from the default.
This approach allows output from multiple applications with differing
understanding of unicode to coexist on the same screen a little more
sanely.
Note that the default `unicode_version` is set to 9, which means that
emoji presentation selectors are now by-default ignored. This was
selected to better match the level of support in widely deployed
applications.
I expect to raise that default version in the future.
Also worth noting: there are a number of callers of
`unicode_column_width` in things like overlays and lua helper functions
that pass `None` for the unicode version: these will assume the latest
known-to-wezterm/termwiz version of unicode to be desired. If those
overlays do things with emoji presentation selectors, then there may be
some alignment artifacts. That can be tackled in a follow up commit.
refs: #1231
refs: #997
It appears as though Menlo is the only font on macos to contain the
heavy ballot cross symbol, which is commonly used on macos (eg: in
`brew` output).
Our fallback list, despite starting with Menlo, didn't include menlo
itself in the candidates.
Furthermore, `ls-fonts` wouldn never see the result of the system
fallback resolution because it didn't know to try again, and was
using the list of handles from before the fallback.
This commit resolves all of these concerns.
refs: #849
Since we may have two different sizes/namespaces of fonts between
the title font and the main terminal font, we need to be a bit more
careful to pass down distinguishing font information when caching
glyphs.
In addition, I noticed that the advance for custom block glyphs
(eg: powerline!) weren't right in the tab bar. To resolve this,
when shaping, we skip using the glyph from the font and synthesize
a placeholder with the appropriate advance.
We were truncating the right-status text because we were passing
the padded number of cols for the tab bar, but since the tab bar
now exists outside the padding, that value was too small.
This commit introduces the `Dimension` type which allows specifying
a value in a variety of units; pixels, points, cells, percent.
`Dimension` needs contextual information to be evaluated as pixel
values, which makes resolving the value from the config slightly
more of a chore.
However, this type allows more flexible configurations that scale
with the font size and display dpi.
refs: #1124, #291, #195
The previous commit was partially OK, but the main cause of
emoji being wonky was this bit of macos specific code that I
added ages ago.
Remove that hack and the portion of the code from the previous
commit that was working to undo it.
This should make the baselines consistent across all platforms.
refs: #1203
Avoid accidentally scaling the tab bar when using IncreaseFontSize.
Use a "better" default title font based on the platform.
Avoid a gap between bottom of tab button and dividing line at
certain font sizes.
When split horizontally, selecting multiple lines at the top of the left
pane could paint a horizontal selection line all the way across the rest
of the terminal to the right hand edge.
Removes the dependency on knowing where the pane top/left position
is so that the line render routine could be used in more places.
Adjusts the tab bar and scroll bar positioning so that the tab bar
ignores window padding and is always flush with the top/bottom window
edge (full width as well), and that the scroll bar top/bottom respects
the tab bar position and height.
More of a "fix"; we use some heuristics based on the bearing
and glyph width to figure out if a sequence looks like a funky
ligature that moves left to render the glyph.
This may be prone to false positives, but the consequences are low:
when we think a glyph is part of a ligature, then rather than using
the cursor_fg color (which is typically black, or close to invisible),
we retain the normal text fg color.
This way the portion of the glyph outside of the cursor retains its
foreground color, and just the cell containing the cursor may have
a slightly funky fg color in the case where the heuristic was bad.
closes: #478
`use_fancy_tab_bar` switches to an alternate rendering of the tab
bar that uses the window_frame config to get a proportional
title font to use to render tabs, as well as rendering a few
additional elements to space out and make the tabs feel more
like tabs.
Computing the number of tabs doesn't respect the alternate font
at this time.
Formatted tab item foreground and background colors are also
not respected at this time.
refs: #1180
We now compute the cap-height from the rasterized glyph data.
Moved the scaling action of use_cap_height_to_scale_fallback_fonts from
glyphcache into the font resolver: when enabled, and we have data
about the baseline font and the font being resolved, then the resolving
font will be scaled such that the cap-height of both fonts has the same
pixel size.
The effect of this is that `I` glyphs from both fonts should appear to
have the same height.
Added a row of `I`'s in differing styles at the bottom of styles.txt
to make this easier to visualize.
refs: #1189
This is to handle situations such as some versions of the Terminus
bitmap font, where the individual bitmap strike sizes are broken
out across multiple individual files.
Font matching now passes down the nominal pixel height based on
the current DPI and font scale factor, and will use that to select
the font file that has the closest pixel size.
Previously, it would be potentially undefined which of the Terminus
font files would be selected.
refs: https://github.com/wez/wezterm/issues/1189
This commit adjusts the the window event routing/queuing so that
a queued event can capture a pane_id other than the focused pane.
Since we only allow one queued instance of a given named event in a
window, a consequence of this is that multiple bell events coming
from different panes at the same time may race and the loser's
event will be dropped. We log a warning in that case.
refs: #3
This commit introduces a mechanism for specifying resize increments
for a window, and then arranges for the termwindow to set those
to match the current font cell metrics.
This should help to avoid cases where there is excess padding pixels
resulting from the window being slightly larger than computed number
of cells and the font metrics.
Fast-clicking users generally expect to be able to rapidly do regular selections
or otherwise cancel double/triple/quad clicks, so significant mouse movement should end the streak.
Allowing tiny pixel movements to account for touchpads is necessary.
Fortunately, the position here is already in character grid cells, which provides enough margin for this.
Other code editors like gedit also seem to do this based on the character grid.
It appears as though kakoune hides the terminal cursor and renders
its own version of the cursor.
The hidden state was being picked up by the copymode overlay,
making it awkward to use.
This commit forces the cursor to be visible (and a block) when
copy mode is active.
closes: #1113
I think this is a hangover from the older logic to figure out
the initial sizing, and I suspect that it is what is causing
refs: 1074
So this is a speculative change to see if it helps!
This splits rendering into 3 passes:
* background pass for z-index < 0. This is for solid background colors,
background images, and image attachments with z-index < 0.
Rendered with regular alpha blending.
* glyph pass: for glyphs at z-index==0. This is rendered with dual
source blending enabled to facilitate subpixel aa appearance.
* top layer pass for z-index >= 0 graphics. This is rendered with
regular alpha blending.
This avoids weird effects, like images with alpha shining through
the back of the window when the window itself isn't transparent.
refs: #544
transparent images weren't always blending correctly, and were
instead shining through.
This might also have affected cursors.
It may also be a factor in a couple of recent reports of excessive
boldness which looked like funky over-alpha multiplication.
Let's see what people say about this.
This makes the comparison in https://github.com/wez/wezterm/issues/544
work for me on mac, linux (x11, wayland) and also on Windows but
only using WGL.
It looks like we can use the proper colorspace on all targets
except for ANGLE EGL. For whatever reason, the combination of
glium and ANGLE EGL on windows over-gamma corrects.
AFAICT, the framebuffer and perhaps the surfaces it creates
don't indicate srgb support, and whatever combination of status
they return tickles glium's srgb stuff the wrong way.
I think the "solution" is just to directly use WGL by default.
EGL was on by default because it tended to be more survivable
when graphics card drivers were updated, but the last couple
of times I updated mine it still killed wezterm anyway.
refs: #544
Add a more general dragging thingy and use that to know when we
are dragging splits or the scroll thumb.
Fixup scrollbar math, which didn't account for whether the tabbar
was shown and which might cause the scroll thumb to jump around
on first drag (resolves#568)
The idea here is to make it a bit easier to do hit detection for UI
elements; today we've been duplicating position math between the render
and the mouse movement handlers, with both pieces of code knowing the
location of the UI element.
UIItem allows the render phase to record the position, which allows
the mouse phase to be a more independent lookup against the registered
elements.
This makes it easier to add more UI elements in the future.
