Improve styling and logging for UI font-size zoom

Refine zoom methods in `MainWindow` and font helpers
in `_style` to return `px_size` up the call chain and
log detailed zoom state on each change.

Deats,
- make `_set_qfont_px_size()` return `self.px_size`.
- make `configure_to_dpi()` and `_config_fonts_to_screen()`
  return the new `px_size` up through the call chain.
- add `font_size` to `log.info()` in `zoom_in()`,
  `zoom_out()`, and `reset_zoom()` alongside
  `zoom_step` and `zoom_level(%)`.
- reformat `has_ctrl`/`_has_shift` bitwise checks and
  key-match tuples to multiline style.
- comment out `Shift` modifier requirement for zoom
  hotkeys (now `Ctrl`-only).
- comment out unused `mn_dpi` and `dpi` locals.

Also,
- convert all single-line docstrings to `'''` multiline
  style across zoom and font methods.
- rewrap `configure_to_dpi()` docstring to 67 chars.
- move `from . import _style` to module-level import
  in `_window.py`.
- drop unused `screen` binding in `boundingRect()`.

(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code

piker/brokers/deribit/api.py

@@ -586,7 +586,7 @@ async def open_price_feed(
                 fh,
                 instrument
             )
-        ) as (chan, first):
+        ) as (first, chan):
             yield chan
 
 
@@ -653,7 +653,7 @@ async def open_order_feed(
                 fh,
                 instrument
             )
-        ) as (chan, first):
+        ) as (first, chan):
             yield chan
 
 

piker/brokers/deribit/feed.py

@@ -32,7 +32,7 @@ import tractor
 
 from piker.brokers import open_cached_client
 from piker.log import get_logger, get_console_log
-from tractor.ipc._shm import ShmArray
+from piker.data import ShmArray
 from piker.brokers._util import (
     BrokerError,
     DataUnavailable,

piker/brokers/ib/api.py

@@ -1529,7 +1529,7 @@ async def open_client_proxies() -> tuple[
             # TODO: maybe this should be the default in tractor?
             key=tractor.current_actor().uid,
 
-        ) as (cache_hit, (_, clients)),
+        ) as (cache_hit, (clients, _)),
 
         AsyncExitStack() as stack
     ):
@@ -1718,7 +1718,7 @@ async def open_client_proxy(
             open_aio_client_method_relay,
             client=client,
             event_consumers=event_table,
-        ) as (chan, first),
+        ) as (first, chan),
 
         trionics.collapse_eg(),  # loose-ify
         trio.open_nursery() as relay_tn,

piker/brokers/ib/broker.py

@@ -514,8 +514,8 @@ async def open_trade_event_stream(
         recv_trade_updates,
         client=client,
     ) as (
-        trade_event_stream,
         _,  # first pushed val
+        trade_event_stream,
     ):
         task_status.started(trade_event_stream)
         # block forever to keep session trio-asyncio session

piker/brokers/ib/feed.py

@@ -989,7 +989,7 @@ async def open_aio_quote_stream(
         symbol=symbol,
         contract=contract,
 
-    ) as (from_aio, contract):
+    ) as (contract, from_aio):
 
         assert contract
 

piker/data/__init__.py

@@ -23,13 +23,13 @@ sharing live streams over a network.
 
 """
 from .ticktools import iterticks
-from tractor.ipc._shm import (
-    ShmArray,
+from ._sharedmem import (
+    maybe_open_shm_array,
+    attach_shm_array,
+    open_shm_array,
     get_shm_token,
-    open_shm_ndarray as open_shm_array,
-    attach_shm_ndarray as attach_shm_array,
+    ShmArray,
 )
-from ._sharedmem import maybe_open_shm_array
 from ._source import (
     def_iohlcv_fields,
     def_ohlcv_fields,

piker/data/_formatters.py

@@ -28,7 +28,9 @@ from msgspec import field
 import numpy as np
 from numpy.lib import recfunctions as rfn
 
-from tractor.ipc._shm import ShmArray
+from ._sharedmem import (
+    ShmArray,
+)
 from ._pathops import (
     path_arrays_from_ohlc,
 )

piker/data/_sampling.py

@@ -55,7 +55,9 @@ from ._util import (
 from ..service import maybe_spawn_daemon
 
 if TYPE_CHECKING:
-    from tractor.ipc._shm import ShmArray
+    from ._sharedmem import (
+        ShmArray,
+    )
     from .feed import (
         _FeedsBus,
         Sub,
@@ -376,16 +378,16 @@ async def register_with_sampler(
                 # feed_is_live.is_set()
                 # ^TODO? pass it in instead?
             ):
-                from tractor.ipc._shm import (
-                    attach_shm_ndarray,
-                    NDToken,
+                from ._sharedmem import (
+                    attach_shm_array,
+                    _Token,
                 )
                 for period in shms_by_period:
 
                     # load and register shm handles
                     shm_token_msg = shms_by_period[period]
-                    shm = attach_shm_ndarray(
-                        NDToken.from_msg(shm_token_msg),
+                    shm = attach_shm_array(
+                        _Token.from_msg(shm_token_msg),
                         readonly=False,
                     )
                     shms_by_period[period] = shm

piker/data/_sharedmem.py

@@ -1,67 +1,622 @@
 # piker: trading gear for hackers
 # Copyright (C) Tyler Goodlet (in stewardship for pikers)
 
-# This program is free software: you can redistribute it
-# and/or modify it under the terms of the GNU Affero General
-# Public License as published by the Free Software
-# Foundation, either version 3 of the License, or (at your
-# option) any later version.
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
 
-# This program is distributed in the hope that it will be
-# useful, but WITHOUT ANY WARRANTY; without even the implied
-# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
-# PURPOSE.  See the GNU Affero General Public License for
-# more details.
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
 
-# You should have received a copy of the GNU Affero General
-# Public License along with this program.  If not, see
-# <https://www.gnu.org/licenses/>.
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-'''
-Piker-specific shared memory helpers.
+"""
+NumPy compatible shared memory buffers for real-time IPC streaming.
 
-Thin shim providing piker-only wrappers around
-``tractor.ipc._shm``; all core types and functions
-are now imported directly from tractor throughout
-the codebase.
+"""
+from __future__ import annotations
+from sys import byteorder
+import time
+from typing import Optional
+from multiprocessing.shared_memory import SharedMemory, _USE_POSIX
 
-'''
+if _USE_POSIX:
+    from _posixshmem import shm_unlink
+
+# import msgspec
 import numpy as np
-
-from tractor.ipc._shm import (
-    NDToken,
-    ShmArray,
-    _known_tokens,
-    _make_token as _tractor_make_token,
-    open_shm_ndarray,
-    attach_shm_ndarray,
-)
+from numpy.lib import recfunctions as rfn
+import tractor
 
 from ._util import log
+from ._source import def_iohlcv_fields
+from piker.types import Struct
+
+
+def cuckoff_mantracker():
+    '''
+    Disable all ``multiprocessing``` "resource tracking" machinery since
+    it's an absolute multi-threaded mess of non-SC madness.
+
+    '''
+    from multiprocessing import resource_tracker as mantracker
+
+    # Tell the "resource tracker" thing to fuck off.
+    class ManTracker(mantracker.ResourceTracker):
+        def register(self, name, rtype):
+            pass
+
+        def unregister(self, name, rtype):
+            pass
+
+        def ensure_running(self):
+            pass
+
+    # "know your land and know your prey"
+    # https://www.dailymotion.com/video/x6ozzco
+    mantracker._resource_tracker = ManTracker()
+    mantracker.register = mantracker._resource_tracker.register
+    mantracker.ensure_running = mantracker._resource_tracker.ensure_running
+    mantracker.unregister = mantracker._resource_tracker.unregister
+    mantracker.getfd = mantracker._resource_tracker.getfd
+
+
+cuckoff_mantracker()
+
+
+class SharedInt:
+    """Wrapper around a single entry shared memory array which
+    holds an ``int`` value used as an index counter.
+
+    """
+    def __init__(
+        self,
+        shm: SharedMemory,
+    ) -> None:
+        self._shm = shm
+
+    @property
+    def value(self) -> int:
+        return int.from_bytes(self._shm.buf, byteorder)
+
+    @value.setter
+    def value(self, value) -> None:
+        self._shm.buf[:] = value.to_bytes(self._shm.size, byteorder)
+
+    def destroy(self) -> None:
+        if _USE_POSIX:
+            # We manually unlink to bypass all the "resource tracker"
+            # nonsense meant for non-SC systems.
+            name = self._shm.name
+            try:
+                shm_unlink(name)
+            except FileNotFoundError:
+                # might be a teardown race here?
+                log.warning(f'Shm for {name} already unlinked?')
+
+
+class _Token(Struct, frozen=True):
+    '''
+    Internal represenation of a shared memory "token"
+    which can be used to key a system wide post shm entry.
+
+    '''
+    shm_name: str  # this servers as a "key" value
+    shm_first_index_name: str
+    shm_last_index_name: str
+    dtype_descr: tuple
+    size: int  # in struct-array index / row terms
+
+    @property
+    def dtype(self) -> np.dtype:
+        return np.dtype(list(map(tuple, self.dtype_descr))).descr
+
+    def as_msg(self):
+        return self.to_dict()
+
+    @classmethod
+    def from_msg(cls, msg: dict) -> _Token:
+        if isinstance(msg, _Token):
+            return msg
+
+        # TODO: native struct decoding
+        # return _token_dec.decode(msg)
+
+        msg['dtype_descr'] = tuple(map(tuple, msg['dtype_descr']))
+        return _Token(**msg)
+
+
+# _token_dec = msgspec.msgpack.Decoder(_Token)
+
+# TODO: this api?
+# _known_tokens = tractor.ActorVar('_shm_tokens', {})
+# _known_tokens = tractor.ContextStack('_known_tokens', )
+# _known_tokens = trio.RunVar('shms', {})
+
+# process-local store of keys to tokens
+_known_tokens = {}
+
+
+def get_shm_token(key: str) -> _Token:
+    """Convenience func to check if a token
+    for the provided key is known by this process.
+    """
+    return _known_tokens.get(key)
 
 
 def _make_token(
     key: str,
     size: int,
-    dtype: np.dtype|None = None,
-) -> NDToken:
+    dtype: Optional[np.dtype] = None,
+) -> _Token:
     '''
-    Wrap tractor's ``_make_token()`` with piker's
-    default dtype fallback to ``def_iohlcv_fields``.
+    Create a serializable token that can be used
+    to access a shared array.
 
     '''
-    from ._source import def_iohlcv_fields
-    dtype = (
-        def_iohlcv_fields
-        if dtype is None
-        else dtype
+    dtype = def_iohlcv_fields if dtype is None else dtype
+    return _Token(
+        shm_name=key,
+        shm_first_index_name=key + "_first",
+        shm_last_index_name=key + "_last",
+        dtype_descr=tuple(np.dtype(dtype).descr),
+        size=size,
     )
-    return _tractor_make_token(
+
+
+class ShmArray:
+    '''
+    A shared memory ``numpy`` (compatible) array API.
+
+    An underlying shared memory buffer is allocated based on
+    a user specified ``numpy.ndarray``. This fixed size array
+    can be read and written to by pushing data both onto the "front"
+    or "back" of a set index range. The indexes for the "first" and
+    "last" index are themselves stored in shared memory (accessed via
+    ``SharedInt`` interfaces) values such that multiple processes can
+    interact with the same array using a synchronized-index.
+
+    '''
+    def __init__(
+        self,
+        shmarr: np.ndarray,
+        first: SharedInt,
+        last: SharedInt,
+        shm: SharedMemory,
+        # readonly: bool = True,
+    ) -> None:
+        self._array = shmarr
+
+        # indexes for first and last indices corresponding
+        # to fille data
+        self._first = first
+        self._last = last
+
+        self._len = len(shmarr)
+        self._shm = shm
+        self._post_init: bool = False
+
+        # pushing data does not write the index (aka primary key)
+        dtype = shmarr.dtype
+        if dtype.fields:
+            self._write_fields = list(shmarr.dtype.fields.keys())[1:]
+        else:
+            self._write_fields = None
+
+    # TODO: ringbuf api?
+
+    @property
+    def _token(self) -> _Token:
+        return _Token(
+            shm_name=self._shm.name,
+            shm_first_index_name=self._first._shm.name,
+            shm_last_index_name=self._last._shm.name,
+            dtype_descr=tuple(self._array.dtype.descr),
+            size=self._len,
+        )
+
+    @property
+    def token(self) -> dict:
+        """Shared memory token that can be serialized and used by
+        another process to attach to this array.
+        """
+        return self._token.as_msg()
+
+    @property
+    def index(self) -> int:
+        return self._last.value % self._len
+
+    @property
+    def array(self) -> np.ndarray:
+        '''
+        Return an up-to-date ``np.ndarray`` view of the
+        so-far-written data to the underlying shm buffer.
+
+        '''
+        a = self._array[self._first.value:self._last.value]
+
+        # first, last = self._first.value, self._last.value
+        # a = self._array[first:last]
+
+        # TODO: eventually comment this once we've not seen it in the
+        # wild in a long time..
+        # XXX: race where first/last indexes cause a reader
+        # to load an empty array..
+        if len(a) == 0 and self._post_init:
+            raise RuntimeError('Empty array race condition hit!?')
+
+        return a
+
+    def ustruct(
+        self,
+        fields: Optional[list[str]] = None,
+
+        # type that all field values will be cast to
+        # in the returned view.
+        common_dtype: np.dtype = float,
+
+    ) -> np.ndarray:
+
+        array = self._array
+
+        if fields:
+            selection = array[fields]
+            # fcount = len(fields)
+        else:
+            selection = array
+            # fcount = len(array.dtype.fields)
+
+        # XXX: manual ``.view()`` attempt that also doesn't work.
+        # uview = selection.view(
+        #     dtype='<f16',
+        # ).reshape(-1, 4, order='A')
+
+        # assert len(selection) == len(uview)
+
+        u = rfn.structured_to_unstructured(
+            selection,
+            # dtype=float,
+            copy=True,
+        )
+
+        # unstruct = np.ndarray(u.shape, dtype=a.dtype, buffer=shm.buf)
+        # array[:] = a[:]
+        return u
+        # return ShmArray(
+        #     shmarr=u,
+        #     first=self._first,
+        #     last=self._last,
+        #     shm=self._shm
+        # )
+
+    def last(
+        self,
+        length: int = 1,
+
+    ) -> np.ndarray:
+        '''
+        Return the last ``length``'s worth of ("row") entries from the
+        array.
+
+        '''
+        return self.array[-length:]
+
+    def push(
+        self,
+        data: np.ndarray,
+
+        field_map: Optional[dict[str, str]] = None,
+        prepend: bool = False,
+        update_first: bool = True,
+        start: int | None = None,
+
+    ) -> int:
+        '''
+        Ring buffer like "push" to append data
+        into the buffer and return updated "last" index.
+
+        NB: no actual ring logic yet to give a "loop around" on overflow
+        condition, lel.
+
+        '''
+        length = len(data)
+
+        if prepend:
+            index = (start or self._first.value) - length
+
+            if index < 0:
+                raise ValueError(
+                    f'Array size of {self._len} was overrun during prepend.\n'
+                    f'You have passed {abs(index)} too many datums.'
+                )
+
+        else:
+            index = start if start is not None else self._last.value
+
+        end = index + length
+
+        if field_map:
+            src_names, dst_names = zip(*field_map.items())
+        else:
+            dst_names = src_names = self._write_fields
+
+        try:
+            self._array[
+                list(dst_names)
+            ][index:end] = data[list(src_names)][:]
+
+            # NOTE: there was a race here between updating
+            # the first and last indices and when the next reader
+            # tries to access ``.array`` (which due to the index
+            # overlap will be empty). Pretty sure we've fixed it now
+            # but leaving this here as a reminder.
+            if (
+                prepend
+                and update_first
+                and length
+            ):
+                assert index < self._first.value
+
+            if (
+                index < self._first.value
+                and update_first
+            ):
+                assert prepend, 'prepend=True not passed but index decreased?'
+                self._first.value = index
+
+            elif not prepend:
+                self._last.value = end
+
+            self._post_init = True
+            return end
+
+        except ValueError as err:
+            if field_map:
+                raise
+
+            # should raise if diff detected
+            self.diff_err_fields(data)
+            raise err
+
+    def diff_err_fields(
+        self,
+        data: np.ndarray,
+    ) -> None:
+        # reraise with any field discrepancy
+        our_fields, their_fields = (
+            set(self._array.dtype.fields),
+            set(data.dtype.fields),
+        )
+
+        only_in_ours = our_fields - their_fields
+        only_in_theirs = their_fields - our_fields
+
+        if only_in_ours:
+            raise TypeError(
+                f"Input array is missing field(s): {only_in_ours}"
+            )
+        elif only_in_theirs:
+            raise TypeError(
+                f"Input array has unknown field(s): {only_in_theirs}"
+            )
+
+    # TODO: support "silent" prepends that don't update ._first.value?
+    def prepend(
+        self,
+        data: np.ndarray,
+    ) -> int:
+        end = self.push(data, prepend=True)
+        assert end
+
+    def close(self) -> None:
+        self._first._shm.close()
+        self._last._shm.close()
+        self._shm.close()
+
+    def destroy(self) -> None:
+        if _USE_POSIX:
+            # We manually unlink to bypass all the "resource tracker"
+            # nonsense meant for non-SC systems.
+            shm_unlink(self._shm.name)
+
+        self._first.destroy()
+        self._last.destroy()
+
+    def flush(self) -> None:
+        # TODO: flush to storage backend like markestore?
+        ...
+
+
+def open_shm_array(
+    size: int,
+    key: str | None = None,
+    dtype: np.dtype | None = None,
+    append_start_index: int | None = None,
+    readonly: bool = False,
+
+) -> ShmArray:
+    '''Open a memory shared ``numpy`` using the standard library.
+
+    This call unlinks (aka permanently destroys) the buffer on teardown
+    and thus should be used from the parent-most accessor (process).
+
+    '''
+    # create new shared mem segment for which we
+    # have write permission
+    a = np.zeros(size, dtype=dtype)
+    a['index'] = np.arange(len(a))
+
+    shm = SharedMemory(
+        name=key,
+        create=True,
+        size=a.nbytes
+    )
+    array = np.ndarray(
+        a.shape,
+        dtype=a.dtype,
+        buffer=shm.buf
+    )
+    array[:] = a[:]
+    array.setflags(write=int(not readonly))
+
+    token = _make_token(
         key=key,
         size=size,
         dtype=dtype,
     )
 
+    # create single entry arrays for storing an first and last indices
+    first = SharedInt(
+        shm=SharedMemory(
+            name=token.shm_first_index_name,
+            create=True,
+            size=4,  # std int
+        )
+    )
+
+    last = SharedInt(
+        shm=SharedMemory(
+            name=token.shm_last_index_name,
+            create=True,
+            size=4,  # std int
+        )
+    )
+
+    # start the "real-time" updated section after 3-days worth of 1s
+    # sampled OHLC. this allows appending up to a days worth from
+    # tick/quote feeds before having to flush to a (tsdb) storage
+    # backend, and looks something like,
+    # -------------------------
+    # |              |        i
+    # _________________________
+    # <-------------> <------->
+    #  history         real-time
+    #
+    # Once fully "prepended", the history section will leave the
+    # ``ShmArray._start.value: int = 0`` and the yet-to-be written
+    # real-time section will start at ``ShmArray.index: int``.
+
+    # this sets the index to nearly 2/3rds into the the length of
+    # the buffer leaving at least a "days worth of second samples"
+    # for the real-time section.
+    if append_start_index is None:
+        append_start_index = round(size * 0.616)
+
+    last.value = first.value = append_start_index
+
+    shmarr = ShmArray(
+        array,
+        first,
+        last,
+        shm,
+    )
+
+    assert shmarr._token == token
+    _known_tokens[key] = shmarr.token
+
+    # "unlink" created shm on process teardown by
+    # pushing teardown calls onto actor context stack
+    stack = tractor.current_actor(
+        err_on_no_runtime=False,
+    ).lifetime_stack
+    if stack:
+        stack.callback(shmarr.close)
+        stack.callback(shmarr.destroy)
+
+    return shmarr
+
+
+def attach_shm_array(
+    token: tuple[str, str, tuple[str, str]],
+    readonly: bool = True,
+
+) -> ShmArray:
+    '''
+    Attach to an existing shared memory array previously
+    created by another process using ``open_shared_array``.
+
+    No new shared mem is allocated but wrapper types for read/write
+    access are constructed.
+
+    '''
+    token = _Token.from_msg(token)
+    key = token.shm_name
+
+    if key in _known_tokens:
+        assert _Token.from_msg(_known_tokens[key]) == token, "WTF"
+
+    # XXX: ugh, looks like due to the ``shm_open()`` C api we can't
+    # actually place files in a subdir, see discussion here:
+    # https://stackoverflow.com/a/11103289
+
+    # attach to array buffer and view as per dtype
+    _err: Optional[Exception] = None
+    for _ in range(3):
+        try:
+            shm = SharedMemory(
+                name=key,
+                create=False,
+            )
+            break
+        except OSError as oserr:
+            _err = oserr
+            time.sleep(0.1)
+    else:
+        if _err:
+            raise _err
+
+    shmarr = np.ndarray(
+        (token.size,),
+        dtype=token.dtype,
+        buffer=shm.buf
+    )
+    shmarr.setflags(write=int(not readonly))
+
+    first = SharedInt(
+        shm=SharedMemory(
+            name=token.shm_first_index_name,
+            create=False,
+            size=4,  # std int
+        ),
+    )
+    last = SharedInt(
+        shm=SharedMemory(
+            name=token.shm_last_index_name,
+            create=False,
+            size=4,  # std int
+        ),
+    )
+
+    # make sure we can read
+    first.value
+
+    sha = ShmArray(
+        shmarr,
+        first,
+        last,
+        shm,
+    )
+    # read test
+    sha.array
+
+    # Stash key -> token knowledge for future queries
+    # via `maybe_opepn_shm_array()` but only after we know
+    # we can attach.
+    if key not in _known_tokens:
+        _known_tokens[key] = token
+
+    # "close" attached shm on actor teardown
+    if (actor := tractor.current_actor(
+        err_on_no_runtime=False,
+    )):
+        actor.lifetime_stack.callback(sha.close)
+
+    return sha
+
 
 def maybe_open_shm_array(
     key: str,
@@ -70,37 +625,37 @@ def maybe_open_shm_array(
     append_start_index: int | None = None,
     readonly: bool = False,
     **kwargs,
+
 ) -> tuple[ShmArray, bool]:
     '''
-    Attempt to attach to a shared memory block
-    using a "key" lookup to registered blocks in
-    the user's overall "system" registry (presumes
-    you don't have the block's explicit token).
+    Attempt to attach to a shared memory block using a "key" lookup
+    to registered blocks in the users overall "system" registry
+    (presumes you don't have the block's explicit token).
 
-    This is a thin wrapper around tractor's
-    ``maybe_open_shm_ndarray()`` preserving piker's
-    historical defaults (``readonly=False``,
-    ``append_start_index=None``).
+    This function is meant to solve the problem of discovering whether
+    a shared array token has been allocated or discovered by the actor
+    running in **this** process. Systems where multiple actors may seek
+    to access a common block can use this function to attempt to acquire
+    a token as discovered by the actors who have previously stored
+    a "key" -> ``_Token`` map in an actor local (aka python global)
+    variable.
 
-    If you know the explicit ``NDToken`` for your
-    memory segment instead use
-    ``tractor.ipc._shm.attach_shm_ndarray()``.
+    If you know the explicit ``_Token`` for your memory segment instead
+    use ``attach_shm_array``.
 
     '''
     try:
         # see if we already know this key
         token = _known_tokens[key]
         return (
-            attach_shm_ndarray(
+            attach_shm_array(
                 token=token,
                 readonly=readonly,
             ),
             False,
         )
     except KeyError:
-        log.debug(
-            f'Could not find {key} in shms cache'
-        )
+        log.debug(f"Could not find {key} in shms cache")
         if dtype:
             token = _make_token(
                 key,
@@ -108,18 +663,9 @@ def maybe_open_shm_array(
                 dtype=dtype,
             )
             try:
-                return (
-                    attach_shm_ndarray(
-                        token=token,
-                        **kwargs,
-                    ),
-                    False,
-                )
+                return attach_shm_array(token=token, **kwargs), False
             except FileNotFoundError:
-                log.debug(
-                    f'Could not attach to shm'
-                    f' with token {token}'
-                )
+                log.debug(f"Could not attach to shm with token {token}")
 
         # This actor does not know about memory
         # associated with the provided "key".
@@ -127,7 +673,7 @@ def maybe_open_shm_array(
         # to fail if a block has been allocated
         # on the OS by someone else.
         return (
-            open_shm_ndarray(
+            open_shm_array(
                 key=key,
                 size=size,
                 dtype=dtype,
@@ -137,20 +683,18 @@ def maybe_open_shm_array(
             True,
         )
 
-
 def try_read(
-    array: np.ndarray,
-) -> np.ndarray|None:
-    '''
-    Try to read the last row from a shared mem
-    array or ``None`` if the array read returns
-    a zero-length array result.
+    array: np.ndarray
 
-    Can be used to check for backfilling race
-    conditions where an array is currently being
-    (re-)written by a writer actor but the reader
-    is unaware and reads during the window where
-    the first and last indexes are being updated.
+) -> Optional[np.ndarray]:
+    '''
+    Try to read the last row from a shared mem array or ``None``
+    if the array read returns a zero-length array result.
+
+    Can be used to check for backfilling race conditions where an array
+    is currently being (re-)written by a writer actor but the reader is
+    unaware and reads during the window where the first and last indexes
+    are being updated.
 
     '''
     try:
@@ -158,13 +702,14 @@ def try_read(
     except IndexError:
         # XXX: race condition with backfilling shm.
         #
-        # the underlying issue is that a backfill
-        # (aka prepend) and subsequent shm array
-        # first/last index update could result in an
-        # empty array read here since the indices may
-        # be updated in such a way that a read delivers
-        # an empty array (though it seems like we
-        # *should* be able to prevent that?).
+        # the underlying issue is that a backfill (aka prepend) and subsequent
+        # shm array first/last index update could result in an empty array
+        # read here since the indices may be updated in such a way that
+        # a read delivers an empty array (though it seems like we
+        # *should* be able to prevent that?). also, as and alt and
+        # something we need anyway, maybe there should be some kind of
+        # signal that a prepend is taking place and this consumer can
+        # respond (eg. redrawing graphics) accordingly.
 
-        # the array read was empty
+        # the array read was emtpy
         return None

piker/data/flows.py

@@ -31,10 +31,10 @@ import pendulum
 import numpy as np
 
 from piker.types import Struct
-from tractor.ipc._shm import (
+from ._sharedmem import (
+    attach_shm_array,
     ShmArray,
-    NDToken,
-    attach_shm_ndarray,
+    _Token,
 )
 from piker.accounting import MktPair
 
@@ -64,11 +64,11 @@ class Flume(Struct):
     '''
     mkt: MktPair
     first_quote: dict
-    _rt_shm_token: NDToken
+    _rt_shm_token: _Token
 
     # optional since some data flows won't have a "downsampled" history
     # buffer/stream (eg. FSPs).
-    _hist_shm_token: NDToken|None = None
+    _hist_shm_token: _Token | None = None
 
     # private shm refs loaded dynamically from tokens
     _hist_shm: ShmArray | None = None
@@ -88,7 +88,7 @@ class Flume(Struct):
     def rt_shm(self) -> ShmArray:
 
         if self._rt_shm is None:
-            self._rt_shm = attach_shm_ndarray(
+            self._rt_shm = attach_shm_array(
                 token=self._rt_shm_token,
                 readonly=self._readonly,
             )
@@ -104,7 +104,7 @@ class Flume(Struct):
             )
 
         if self._hist_shm is None:
-            self._hist_shm = attach_shm_ndarray(
+            self._hist_shm = attach_shm_array(
                 token=self._hist_shm_token,
                 readonly=self._readonly,
             )

piker/fsp/_api.py

@@ -37,12 +37,12 @@ import numpy as np
 import tractor
 from tractor.msg import NamespacePath
 
-from tractor.ipc._shm import (
+from ..data._sharedmem import (
     ShmArray,
-    NDToken,
-    attach_shm_ndarray,
+    maybe_open_shm_array,
+    attach_shm_array,
+    _Token,
 )
-from ..data._sharedmem import maybe_open_shm_array
 from ..log import get_logger
 
 log = get_logger(__name__)
@@ -78,8 +78,8 @@ class Fsp:
     # + the consuming fsp *to* the consumers output
     # shm flow.
     _flow_registry: dict[
-        tuple[NDToken, str],
-        tuple[NDToken, Optional[ShmArray]],
+        tuple[_Token, str],
+        tuple[_Token, Optional[ShmArray]],
     ] = {}
 
     def __init__(
@@ -148,7 +148,7 @@ class Fsp:
                 # times as possible as per:
                 # - https://github.com/pikers/piker/issues/359
                 # - https://github.com/pikers/piker/issues/332
-                maybe_array := attach_shm_ndarray(dst_token)
+                maybe_array := attach_shm_array(dst_token)
             )
 
         return maybe_array

piker/fsp/_engine.py

@@ -40,7 +40,7 @@ from ..log import (
 )
 from .. import data
 from ..data.flows import Flume
-from tractor.ipc._shm import ShmArray
+from ..data._sharedmem import ShmArray
 from ..data._sampling import (
     _default_delay_s,
     open_sample_stream,
@@ -49,7 +49,7 @@ from ..accounting import MktPair
 from ._api import (
     Fsp,
     _load_builtins,
-    NDToken,
+    _Token,
 )
 from ..toolz import Profiler
 
@@ -414,7 +414,7 @@ async def cascade(
     dst_flume_addr: dict,
     ns_path: NamespacePath,
 
-    shm_registry: dict[str, NDToken],
+    shm_registry: dict[str, _Token],
 
     zero_on_step: bool = False,
     loglevel: str|None = None,
@@ -465,9 +465,9 @@ async def cascade(
     # not sure how else to do it.
     for (token, fsp_name, dst_token) in shm_registry:
         Fsp._flow_registry[(
-            NDToken.from_msg(token),
+            _Token.from_msg(token),
             fsp_name,
-        )] = NDToken.from_msg(dst_token), None
+        )] = _Token.from_msg(dst_token), None
 
     fsp: Fsp = reg.get(
         NamespacePath(ns_path)

piker/fsp/_momo.py

@@ -25,7 +25,7 @@ from numba import jit, float64, optional, int64
 
 from ._api import fsp
 from ..data import iterticks
-from tractor.ipc._shm import ShmArray
+from ..data._sharedmem import ShmArray
 
 
 @jit(

piker/fsp/_volume.py

@@ -21,7 +21,7 @@ from tractor.trionics._broadcast import AsyncReceiver
 
 from ._api import fsp
 from ..data import iterticks
-from tractor.ipc._shm import ShmArray
+from ..data._sharedmem import ShmArray
 from ._momo import _wma
 from ..log import get_logger
 

piker/storage/cli.py

@@ -37,7 +37,9 @@ import typer
 
 from piker.service import open_piker_runtime
 from piker.cli import cli
-from tractor.ipc._shm import ShmArray
+from piker.data import (
+    ShmArray,
+)
 from piker import tsp
 from . import log
 from . import (

piker/storage/nativedb.py

@@ -64,8 +64,10 @@ from pendulum import (
 
 from piker import config
 from piker import tsp
-from tractor.ipc._shm import ShmArray
-from piker.data import def_iohlcv_fields
+from piker.data import (
+    def_iohlcv_fields,
+    ShmArray,
+)
 from piker.log import get_logger
 from . import TimeseriesNotFound
 

piker/tsp/_history.py

@@ -59,12 +59,11 @@ from piker.brokers import NoData
 from piker.accounting import (
     MktPair,
 )
-from piker.log import (
-    get_logger,
-    get_console_log,
+from piker.log import get_logger
+from ..data._sharedmem import (
+    maybe_open_shm_array,
+    ShmArray,
 )
-from tractor.ipc._shm import ShmArray
-from ..data._sharedmem import maybe_open_shm_array
 from piker.data._source import (
     def_iohlcv_fields,
 )
@@ -1387,10 +1386,6 @@ async def manage_history(
         engages.
 
     '''
-    get_console_log(
-        name=__name__,
-        level=loglevel,
-    )
     # TODO: is there a way to make each shm file key
     # actor-tree-discovery-addr unique so we avoid collisions
     # when doing tests which also allocate shms for certain instruments

piker/ui/_axes.py

@@ -75,6 +75,9 @@ class Axis(pg.AxisItem):
         self.pi = plotitem
         self._dpi_font = _font
 
+        # store for later recalculation on zoom
+        self._typical_max_str = typical_max_str
+
         self.setTickFont(_font.font)
         font_size = self._dpi_font.font.pixelSize()
 
@@ -156,6 +159,41 @@ class Axis(pg.AxisItem):
     def size_to_values(self) -> None:
         pass
 
+    def update_fonts(self, font: DpiAwareFont) -> None:
+        '''Update font and recalculate axis sizing after zoom change.'''
+        # IMPORTANT: tell Qt we're about to change geometry
+        self.prepareGeometryChange()
+
+        self._dpi_font = font
+        self.setTickFont(font.font)
+        font_size = font.font.pixelSize()
+
+        # recalculate text offset based on new font size
+        text_offset = None
+        if self.orientation in ('bottom',):
+            text_offset = floor(0.25 * font_size)
+        elif self.orientation in ('left', 'right'):
+            text_offset = floor(font_size / 2)
+
+        if text_offset:
+            self.setStyle(tickTextOffset=text_offset)
+
+        # recalculate bounding rect with new font
+        # Note: typical_max_str should be stored from init
+        if not hasattr(self, '_typical_max_str'):
+            self._typical_max_str = '100 000.000  '  # fallback default
+        self.typical_br = font._qfm.boundingRect(self._typical_max_str)
+
+        # Update PyQtGraph's internal text size tracking
+        # This is critical - PyQtGraph uses these internally for auto-expand
+        if self.orientation in ['left', 'right']:
+            self.textWidth = self.typical_br.width()
+        else:
+            self.textHeight = self.typical_br.height()
+
+        # resize axis to fit new font - this triggers PyQtGraph's auto-expand
+        self.size_to_values()
+
     def txt_offsets(self) -> tuple[int, int]:
         return tuple(self.style['tickTextOffset'])
 
@@ -256,7 +294,14 @@ class PriceAxis(Axis):
         self._min_tick = size
 
     def size_to_values(self) -> None:
-        self.setWidth(self.typical_br.width())
+        # Call PyQtGraph's internal width update mechanism
+        # This respects autoExpandTextSpace and updates min/max constraints
+        self._updateWidth()
+        # tell Qt our preferred size changed so layout recalculates
+        self.updateGeometry()
+        # force parent plot item to recalculate its layout
+        if self.pi and hasattr(self.pi, 'updateGeometry'):
+            self.pi.updateGeometry()
 
     # XXX: drop for now since it just eats up h space
 
@@ -300,7 +345,14 @@ class DynamicDateAxis(Axis):
     }
 
     def size_to_values(self) -> None:
-        self.setHeight(self.typical_br.height() + 1)
+        # Call PyQtGraph's internal height update mechanism
+        # This respects autoExpandTextSpace and updates min/max constraints
+        self._updateHeight()
+        # tell Qt our preferred size changed so layout recalculates
+        self.updateGeometry()
+        # force parent plot item to recalculate its layout
+        if self.pi and hasattr(self.pi, 'updateGeometry'):
+            self.pi.updateGeometry()
 
     def _indexes_to_timestrs(
         self,

piker/ui/_chart.py

@@ -49,7 +49,7 @@ from ._cursor import (
     Cursor,
     ContentsLabel,
 )
-from tractor.ipc._shm import ShmArray
+from ..data._sharedmem import ShmArray
 from ._ohlc import BarItems
 from ._curve import (
     Curve,

piker/ui/_dataviz.py

@@ -42,7 +42,9 @@ from numpy import (
 import pyqtgraph as pg
 
 from piker.ui.qt import QLineF
-from tractor.ipc._shm import ShmArray
+from ..data._sharedmem import (
+    ShmArray,
+)
 from ..data.flows import Flume
 from ..data._formatters import (
     IncrementalFormatter,

piker/ui/_exec.py

@@ -203,6 +203,9 @@ def run_qtractor(
     if is_windows:
         window.configure_to_desktop()
 
+    # install global keyboard shortcuts for UI zoom
+    window.install_global_zoom_filter()
+
     # actually render to screen
     window.show()
     app.exec_()

piker/ui/_forms.py

@@ -124,6 +124,13 @@ class Edit(QLineEdit):
         self.sizeHint()
         self.update()
 
+    def update_fonts(self, font: DpiAwareFont) -> None:
+        '''Update font and recalculate widget size.'''
+        self.dpi_font = font
+        self.setFont(font.font)
+        # tell Qt our size hint changed so it recalculates layout
+        self.updateGeometry()
+
     def focus(self) -> None:
         self.selectAll()
         self.show()
@@ -241,6 +248,14 @@ class Selection(QComboBox):
         icon_size = round(h * 0.75)
         self.setIconSize(QSize(icon_size, icon_size))
 
+    def update_fonts(self, font: DpiAwareFont) -> None:
+        '''Update font and recalculate widget size.'''
+        self.setFont(font.font)
+        # recalculate heights with new font
+        self.resize()
+        # tell Qt our size hint changed so it recalculates layout
+        self.updateGeometry()
+
     def set_items(
         self,
         keys: list[str],
@@ -431,6 +446,39 @@ class FieldsForm(QWidget):
         self.fields[key] = select
         return select
 
+    def update_fonts(self) -> None:
+        '''Update font sizes after zoom change.'''
+        from ._style import _font, _font_small
+
+        # update stored font size
+        self._font_size = _font_small.px_size - 2
+
+        # update all labels
+        for name, label in self.labels.items():
+            if hasattr(label, 'update_font'):
+                label.update_font(_font.font, self._font_size - 1)
+
+        # update all fields (edits, selects)
+        for key, field in self.fields.items():
+            # first check for our custom update_fonts method (Edit, Selection)
+            if hasattr(field, 'update_fonts'):
+                field.update_fonts(_font)
+            # then handle stylesheet updates for those without custom methods
+            elif hasattr(field, 'setStyleSheet'):
+                # regenerate stylesheet with new font size
+                field.setStyleSheet(
+                    f"""QLineEdit {{
+                        color : {hcolor('gunmetal')};
+                        font-size : {self._font_size}px;
+                    }}
+                    """
+                )
+                field.setFont(_font.font)
+
+            # for Selection widgets that need style updates
+            if hasattr(field, 'set_style'):
+                field.set_style(color='gunmetal', font_size=self._font_size)
+
 
 async def handle_field_input(
 
@@ -633,6 +681,37 @@ class FillStatusBar(QProgressBar):
         self.setRange(0, int(slots))
         self.setValue(value)
 
+    def update_fonts(self, font_size: int) -> None:
+        '''Update font size after zoom change.'''
+        from ._style import _font_small
+
+        self.font_size = font_size
+        # regenerate stylesheet with new font size
+        self.setStyleSheet(
+            f"""
+            QProgressBar {{
+
+                text-align: center;
+
+                font-size : {self.font_size - 2}px;
+
+                background-color: {hcolor('papas_special')};
+                color : {hcolor('papas_special')};
+
+                border: {self.border_px}px solid {hcolor('default_light')};
+                border-radius: 2px;
+            }}
+            QProgressBar::chunk {{
+
+                background-color: {hcolor('default_spotlight')};
+                color: {hcolor('bracket')};
+
+                border-radius: 2px;
+            }}
+            """
+        )
+        self.setFont(_font_small.font)
+
 
 def mk_fill_status_bar(
 

piker/ui/_fsp.py

@@ -44,12 +44,14 @@ from piker.fsp import (
     dolla_vlm,
     flow_rates,
 )
-from tractor.ipc._shm import (
+from piker.data import (
+    Flume,
     ShmArray,
-    NDToken,
 )
-from piker.data import Flume
-from piker.data._sharedmem import try_read
+from piker.data._sharedmem import (
+    _Token,
+    try_read,
+)
 from piker.log import get_logger
 from piker.toolz import Profiler
 from piker.types import Struct
@@ -380,7 +382,7 @@ class FspAdmin:
             tuple,
             tuple[tractor.MsgStream, ShmArray]
         ] = {}
-        self._flow_registry: dict[NDToken, str] = {}
+        self._flow_registry: dict[_Token, str] = {}
 
         # TODO: make this a `.src_flume` and add
         # a `dst_flume`?

piker/ui/_label.py

@@ -334,3 +334,19 @@ class FormatLabel(QLabel):
         out = self.fmt_str.format(**fields)
         self.setText(out)
         return out
+
+    def update_font(
+        self,
+        font: QtGui.QFont,
+        font_size: int,
+        font_color: str = 'default_lightest',
+    ) -> None:
+        '''Update font after zoom change.'''
+        self.setStyleSheet(
+            f"""QLabel {{
+                color : {hcolor(font_color)};
+                font-size : {font_size}px;
+            }}
+            """
+        )
+        self.setFont(font)

piker/ui/_position.py

@@ -178,6 +178,26 @@ class SettingsPane:
     # encompasing high level namespace
     order_mode: OrderMode | None = None  # typing: ignore # noqa
 
+    def update_fonts(self) -> None:
+        '''Update font sizes after zoom change.'''
+        from ._style import _font_small
+
+        # update form fields
+        if self.form and hasattr(self.form, 'update_fonts'):
+            self.form.update_fonts()
+
+        # update fill status bar
+        if self.fill_bar and hasattr(self.fill_bar, 'update_fonts'):
+            self.fill_bar.update_fonts(_font_small.px_size)
+
+        # update labels with new fonts
+        if self.step_label:
+            self.step_label.setFont(_font_small.font)
+        if self.pnl_label:
+            self.pnl_label.setFont(_font_small.font)
+        if self.limit_label:
+            self.limit_label.setFont(_font_small.font)
+
     def set_accounts(
         self,
         names: list[str],

piker/ui/_search.py

@@ -174,6 +174,13 @@ class CompleterView(QTreeView):
 
         self.setStyleSheet(f"font: {size}px")
 
+    def update_fonts(self) -> None:
+        '''Update font sizes after zoom change.'''
+        self.set_font_size(_font.px_size)
+        self.setIndentation(_font.px_size)
+        self.setFont(_font.font)
+        self.updateGeometry()
+
     def resize_to_results(
         self,
         w: float | None = 0,
@@ -630,6 +637,29 @@ class SearchWidget(QtWidgets.QWidget):
             | align_flag.AlignLeft,
         )
 
+    def update_fonts(self) -> None:
+        '''Update font sizes after zoom change.'''
+        # regenerate label stylesheet with new font size
+        self.label.setStyleSheet(
+            f"""QLabel {{
+                color : {hcolor('default_lightest')};
+                font-size : {_font.px_size - 2}px;
+            }}
+            """
+        )
+        self.label.setFont(_font.font)
+
+        # update search bar and view fonts
+        if hasattr(self.bar, 'update_fonts'):
+            self.bar.update_fonts(_font)
+        elif hasattr(self.bar, 'setFont'):
+            self.bar.setFont(_font.font)
+
+        if hasattr(self.view, 'update_fonts'):
+            self.view.update_fonts()
+
+        self.updateGeometry()
+
     def focus(self) -> None:
         self.show()
         self.bar.focus()

piker/ui/_style.py

@@ -79,9 +79,13 @@ class DpiAwareFont:
         self._font_inches: float = None
         self._screen = None
 
-    def _set_qfont_px_size(self, px_size: int) -> None:
-        self._qfont.setPixelSize(px_size)
+    def _set_qfont_px_size(
+        self,
+        px_size: int,
+    ) -> int:
+        self._qfont.setPixelSize(int(px_size))
         self._qfm = QtGui.QFontMetrics(self._qfont)
+        return self.px_size
 
     @property
     def screen(self) -> QtGui.QScreen:
@@ -124,17 +128,22 @@ class DpiAwareFont:
 
         return size
 
-    def configure_to_dpi(self, screen: QtGui.QScreen | None = None):
+    def configure_to_dpi(
+        self,
+        screen: QtGui.QScreen | None = None,
+        zoom_level: float = 1.0,
+    ) -> int:
         '''
-        Set an appropriately sized font size depending on the screen DPI.
+        Set an appropriately sized font size depending on the screen DPI
+        or scale the size according to `zoom_level`.
 
-        If we end up needing to generalize this more here there are resources
-        listed in the script in ``snippets/qt_screen_info.py``.
+        If we end up needing to generalize this more here there are
+        resources listed in the script in
+        ``snippets/qt_screen_info.py``.
 
         '''
         if self._font_size is not None:
-            self._set_qfont_px_size(self._font_size)
-            return
+            return self._set_qfont_px_size(self._font_size * zoom_level)
 
         # NOTE: if no font size set either in the [ui] section of the
         # config or not yet computed from our magic scaling calcs,
@@ -153,7 +162,7 @@ class DpiAwareFont:
             ldpi = pdpi
 
         mx_dpi = max(pdpi, ldpi)
-        mn_dpi = min(pdpi, ldpi)
+        # mn_dpi = min(pdpi, ldpi)
         scale = round(ldpi/pdpi, ndigits=2)
 
         if mx_dpi <= 97:  # for low dpi use larger font sizes
@@ -162,7 +171,7 @@ class DpiAwareFont:
         else:  # hidpi use smaller font sizes
             inches = _font_sizes['hi'][self._font_size_calc_key]
 
-        dpi = mn_dpi
+        # dpi = mn_dpi
 
         mult = 1.0
 
@@ -197,24 +206,25 @@ class DpiAwareFont:
         # always going to hit that error in range mapping from inches:
         # float to px size: int.
         self._font_inches = inches
-        font_size = math.floor(inches * dpi)
+        font_size = math.floor(inches * pdpi)
+
+        # apply zoom level multiplier
+        font_size = int(font_size * zoom_level)
 
         log.debug(
             f"screen:{screen.name()}\n"
             f"pDPI: {pdpi}, lDPI: {ldpi}, scale: {scale}\n"
+            f"zoom_level: {zoom_level}\n"
             f"\nOur best guess font size is {font_size}\n"
         )
         # apply the size
-        self._set_qfont_px_size(font_size)
+        return self._set_qfont_px_size(font_size)
 
     def boundingRect(self, value: str) -> QtCore.QRectF:
-
-        screen = self.screen
-        if screen is None:
+        if self.screen is None:
             raise RuntimeError("You must call .configure_to_dpi() first!")
 
-        unscaled_br = self._qfm.boundingRect(value)
-
+        unscaled_br: QtCore.QRectF = self._qfm.boundingRect(value)
         return QtCore.QRectF(
             0,
             0,
@@ -228,12 +238,22 @@ _font = DpiAwareFont()
 _font_small = DpiAwareFont(_font_size_key='small')
 
 
-def _config_fonts_to_screen() -> None:
-    'configure global DPI aware font sizes'
+def _config_fonts_to_screen(
+    zoom_level: float = 1.0
+) -> int:
+    '''
+    Configure global DPI aware font size(s).
 
+    If `zoom_level` is provided we apply it to auto-calculated
+    DPI-aware font.
+
+    Return the new `DpiAwareFont.px_size`.
+
+    '''
     global _font, _font_small
-    _font.configure_to_dpi()
-    _font_small.configure_to_dpi()
+    _font.configure_to_dpi(zoom_level=zoom_level)
+    _font_small.configure_to_dpi(zoom_level=zoom_level)
+    return _font.px_size
 
 
 def get_fonts() -> tuple[

piker/ui/_window.py

@@ -18,6 +18,7 @@
 Qt main window singletons and stuff.
 
 """
+from __future__ import annotations
 import os
 import signal
 import time
@@ -38,15 +39,107 @@ from piker.ui.qt import (
     QScreen,
     QCloseEvent,
     QSettings,
+    QEvent,
+    QObject,
 )
 from ..log import get_logger
-from ._style import _font_small, hcolor
+from . import _style
+from ._style import (
+    _font_small,
+    hcolor,
+)
 from ._widget import GodWidget
 
 
 log = get_logger(__name__)
 
 
+class GlobalZoomEventFilter(QObject):
+    '''
+    Application-level event filter for global UI zoom shortcuts.
+
+    This filter intercepts keyboard events BEFORE they reach widgets,
+    allowing us to implement global UI zoom shortcuts that take precedence
+    over widget-specific shortcuts.
+
+    Shortcuts:
+    - Ctrl+Shift+Plus/Equal: Zoom in
+    - Ctrl+Shift+Minus: Zoom out
+    - Ctrl+Shift+0: Reset zoom
+
+    '''
+    def __init__(self, main_window: MainWindow):
+        super().__init__()
+        self.main_window = main_window
+
+    def eventFilter(self, obj: QObject, event: QEvent) -> bool:
+        '''
+        Filter keyboard events for global zoom shortcuts.
+
+        Returns True to filter out (consume) the event, False to pass through.
+
+        '''
+        if event.type() == QEvent.Type.KeyPress:
+            key = event.key()
+            mods = event.modifiers()
+
+            # Mask out the KeypadModifier which Qt sometimes adds
+            mods = mods & ~Qt.KeyboardModifier.KeypadModifier
+
+            # Check if we have Ctrl+Shift (both required)
+            has_ctrl = bool(
+                mods
+                &
+                Qt.KeyboardModifier.ControlModifier
+            )
+            _has_shift = bool(
+                mods
+                &
+                Qt.KeyboardModifier.ShiftModifier
+            )
+
+            # Only handle UI zoom if BOTH Ctrl and Shift are pressed
+            # For Plus key: user presses Cmd+Shift+Equal (which makes Plus)
+            # For Minus key: user presses Cmd+Shift+Minus
+            if (
+                has_ctrl
+                # and
+                # has_shift
+            ):
+                # Zoom in: Ctrl+Shift+Plus
+                # Note: Plus key usually comes as Key_Equal with Shift modifier
+                if key in (
+                    Qt.Key.Key_Plus,
+                    Qt.Key.Key_Equal,
+                ):
+                    self.main_window.zoom_in()
+                    return True  # consume event
+
+                # Zoom out: Ctrl+Shift+Minus
+                # Note: On some keyboards Shift+Minus produces '_' (Underscore)
+                elif key in (
+                    Qt.Key.Key_Minus,
+                    Qt.Key.Key_Underscore,
+                ):
+                    self.main_window.zoom_out()
+                    return True  # consume event
+
+                # Reset zoom: Ctrl+Shift+0
+                # Note: On some keyboards Shift+0 produces ')' (ParenRight)
+                elif key in (
+                    Qt.Key.Key_0,
+                    Qt.Key.Key_ParenRight,
+                ):
+                    self.main_window.reset_zoom()
+                    return True  # consume event
+
+            # Pass through if only Ctrl (no Shift) - this goes to chart zoom
+            # Pass through all other events too
+            return False
+
+        return False
+
+
 class MultiStatus:
 
     bar: QStatusBar
@@ -189,6 +282,24 @@ class MainWindow(QMainWindow):
             self.restoreGeometry(geometry)
             log.debug('Restored window geometry from previous session')
 
+        # zoom level for UI scaling (1.0 = 100%, 1.5 = 150%, etc)
+        # Change this value to set the default startup zoom level
+        self._zoom_level: float = 1.0  # Start at 100% (normal)
+        self._min_zoom: float = 0.5
+        self._max_zoom: float = 3.0  # Reduced from 10.0 to prevent extreme cropping
+        self._zoom_step: float = 0.2  # 20% per keypress
+
+        # event filter for global zoom shortcuts
+        self._zoom_filter: GlobalZoomEventFilter | None = None
+
+    def install_global_zoom_filter(self) -> None:
+        '''Install application-level event filter for global UI zoom shortcuts.'''
+        if self._zoom_filter is None:
+            self._zoom_filter = GlobalZoomEventFilter(self)
+            app = QApplication.instance()
+            app.installEventFilter(self._zoom_filter)
+            log.info('Installed global zoom shortcuts: Ctrl+Shift+Plus/Minus/0')
+
     @property
     def mode_label(self) -> QLabel:
 
@@ -357,6 +468,201 @@ class MainWindow(QMainWindow):
         self.godwidget.on_win_resize(event)
         event.accept()
 
+    def zoom_in(self) -> None:
+        '''
+        Increase overall UI-widgets zoom level by scaling it the
+        global font sizes.
+
+        '''
+        new_zoom: float = min(
+            self._zoom_level + self._zoom_step,
+            self._max_zoom,
+        )
+        if new_zoom != self._zoom_level:
+            self._zoom_level = new_zoom
+            font_size: int = self._apply_zoom()
+            log.info(
+                f'Zoomed in UI\n'
+                f'zoom_step: {self._zoom_step!r}\n'
+                f'zoom_level(%): {self._zoom_level:.1%}\n'
+                f'font_size: {font_size!r}'
+            )
+
+    def zoom_out(self) -> float:
+        '''
+        Decrease UI zoom level.
+
+        '''
+        new_zoom: float = max(self._zoom_level - self._zoom_step, self._min_zoom)
+        if new_zoom != self._zoom_level:
+            self._zoom_level = new_zoom
+            font_size: int = self._apply_zoom()
+            log.info(
+                f'Zoomed out UI\n'
+                f'zoom_step: {self._zoom_step!r}\n'
+                f'zoom_level(%): {self._zoom_level:.1%}\n'
+                f'font_size: {font_size!r}'
+            )
+
+        return new_zoom
+
+    def reset_zoom(self) -> None:
+        '''
+        Reset UI zoom to 100%.
+
+        '''
+        if self._zoom_level != 1.0:
+            self._zoom_level = 1.0
+            font_size: int = self._apply_zoom()
+            log.info(
+                f'Reset zoom level\n'
+                f'zoom_step: {self._zoom_step!r}\n'
+                f'zoom_level(%): {self._zoom_level:.1%}\n'
+                f'font_size: {font_size!r}'
+            )
+
+        return self._zoom_level
+
+    def _apply_zoom(self) -> int:
+        '''
+        Apply current zoom level to all UI elements.
+
+        '''
+        # reconfigure fonts with zoom multiplier
+        font_size: int = _style._config_fonts_to_screen(
+            zoom_level=self._zoom_level
+        )
+
+        # update status bar styling with new font size
+        if self._status_bar:
+            sb = self.statusBar()
+            sb.setStyleSheet((
+                f"color : {hcolor('gunmetal')};"
+                f"background : {hcolor('default_dark')};"
+                f"font-size : {_style._font_small.px_size}px;"
+                "padding : 0px;"
+            ))
+
+        # force update of mode label if it exists
+        if self._status_label:
+            self._status_label.setFont(_style._font_small.font)
+
+        # update godwidget and its children
+        if self.godwidget:
+            # update search widget if it exists
+            if hasattr(self.godwidget, 'search') and self.godwidget.search:
+                self.godwidget.search.update_fonts()
+
+            # update order mode panes in all chart views
+            self._update_chart_order_panes()
+
+            # recursively update all other widgets with stylesheets
+            self._refresh_widget_fonts(self.godwidget)
+            self.godwidget.update()
+
+        return font_size
+
+    def _update_chart_order_panes(self) -> None:
+        '''
+        Update order entry panels in all charts.
+
+        '''
+        if not self.godwidget:
+            return
+
+        # iterate through all linked splits (hist and rt)
+        for splits_name in ['hist_linked', 'rt_linked']:
+            splits = getattr(self.godwidget, splits_name, None)
+            if not splits:
+                continue
+
+            # get main chart
+            chart = getattr(splits, 'chart', None)
+            if chart:
+                # update axes
+                self._update_chart_axes(chart)
+
+                # update order pane
+                if hasattr(chart, 'view'):
+                    view = chart.view
+                    if hasattr(view, 'order_mode') and view.order_mode:
+                        order_mode = view.order_mode
+                        if hasattr(order_mode, 'pane') and order_mode.pane:
+                            order_mode.pane.update_fonts()
+
+            # also check subplots
+            subplots = getattr(splits, 'subplots', {})
+            for name, subplot_chart in subplots.items():
+                # update subplot axes
+                self._update_chart_axes(subplot_chart)
+
+                # update subplot order pane
+                if hasattr(subplot_chart, 'view'):
+                    subplot_view = subplot_chart.view
+                    if hasattr(subplot_view, 'order_mode') and subplot_view.order_mode:
+                        subplot_order_mode = subplot_view.order_mode
+                        if hasattr(subplot_order_mode, 'pane') and subplot_order_mode.pane:
+                            subplot_order_mode.pane.update_fonts()
+
+            # resize all sidepanes to match main chart's sidepane width
+            # this ensures volume/subplot sidepanes match the main chart
+            if splits and hasattr(splits, 'resize_sidepanes'):
+                splits.resize_sidepanes()
+
+    def _update_chart_axes(self, chart) -> None:
+        '''Update axis fonts and sizing for a chart.'''
+        from . import _style
+
+        # update price axis (right side)
+        if hasattr(chart, 'pi') and chart.pi:
+            plot_item = chart.pi
+            # get all axes from plot item
+            for axis_name in ['left', 'right', 'bottom', 'top']:
+                axis = plot_item.getAxis(axis_name)
+                if axis and hasattr(axis, 'update_fonts'):
+                    axis.update_fonts(_style._font)
+
+            # force plot item to recalculate its entire layout
+            plot_item.updateGeometry()
+
+            # force chart widget to update
+            if hasattr(chart, 'updateGeometry'):
+                chart.updateGeometry()
+
+            # trigger a full scene update
+            if hasattr(chart, 'update'):
+                chart.update()
+
+    def _refresh_widget_fonts(self, widget: QWidget) -> None:
+        '''
+        Recursively update font sizes in all child widgets.
+
+        This handles widgets that have font-size hardcoded in their stylesheets.
+        '''
+        from . import _style
+
+        # recursively process all children
+        for child in widget.findChildren(QWidget):
+            # skip widgets that have their own update_fonts method (handled separately)
+            if hasattr(child, 'update_fonts'):
+                continue
+
+            # update child's stylesheet if it has font-size
+            child_stylesheet = child.styleSheet()
+            if child_stylesheet and 'font-size' in child_stylesheet:
+                # for labels and simple widgets, regenerate stylesheet
+                # this is a heuristic - may need refinement
+                try:
+                    child.setFont(_style._font.font)
+                except (AttributeError, RuntimeError):
+                    pass
+
+            # update child's font
+            try:
+                child.setFont(_style._font.font)
+            except (AttributeError, RuntimeError):
+                pass
+
 
 # singleton app per actor
 _qt_win: QMainWindow = None

piker/ui/qt.py

@@ -42,6 +42,7 @@ from PyQt6.QtCore import (
     QSize,
     QModelIndex,
     QItemSelectionModel,
+    QObject,
     pyqtBoundSignal,
     pyqtRemoveInputHook,
     QSettings,

pyproject.toml

@@ -203,8 +203,9 @@ pyvnc = { git = "https://github.com/regulad/pyvnc.git" }
 # xonsh = { git = 'https://github.com/xonsh/xonsh.git', branch = 'main' }
 
 # XXX since, we're like, always hacking new shite all-the-time. Bp
-tractor = { git = "https://github.com/goodboy/tractor.git", branch ="main" }
+tractor = { git = "https://github.com/goodboy/tractor.git", branch ="piker_pin" }
 # tractor = { git = "https://pikers.dev/goodboy/tractor", branch = "piker_pin" }
+# tractor = { git = "https://pikers.dev/goodboy/tractor", branch = "main" }
 # ------ goodboy ------
 # hackin dev-envs, usually there's something new he's hackin in..
 # tractor = { path = "../tractor", editable = true }

snippets/calc_ppi.xsh

@@ -0,0 +1,64 @@
+#!env xonsh
+'''
+Compute the pxs-per-inch (PPI) naively for the local DE.
+
+NOTE, currently this only supports the `sway`-TWM on wayland.
+
+!TODO!
+- [ ] support Xorg (and possibly other OSs as well?
+- [ ] conver this to pure py code, dropping the `.xsh` specifics
+     instead for `subprocess` API calls?
+- [ ] possibly unify all this with `./qt_screen_info.py` as part of
+     a "PPI config wizard" or something, but more then likely we'll
+     have lib-ified version inside modden/piker by then?
+
+'''
+
+import math
+import json
+
+# XXX, xonsh part using "subprocess mode"
+disp_infos: list[dict] = json.loads($(wlr-randr --json))
+lappy: dict = disp_infos[0]
+
+dims: dict[str, int] = lappy['physical_size']
+w_cm: int = dims['width']
+h_cm: int = dims['height']
+
+# cm per inch
+cpi: float = 25.4
+
+# compute "diagonal" size (aka hypot)
+diag_inches: float = math.sqrt((h_cm/cpi)**2 + (w_cm/cpi)**2)
+
+# compute reso-hypot / inches-hypot
+hi_res: dict[str, float|bool] = lappy['modes'][0]
+w_px: int = hi_res['width']
+h_px: int = hi_res['height']
+
+diag_pxs: float = math.sqrt(h_px**2 + w_px**2)
+unscaled_ppi: float = diag_pxs/diag_inches
+
+# retrieve TWM info on the display (including scaling info)
+sway_disp_info: dict = json.loads($(swaymsg -r -t get_outputs))[0]
+scale: float = sway_disp_info['scale']
+
+print(
+    f'output: {sway_disp_info["name"]!r}\n'
+    f'--- DIMENSIONS ---\n'
+    f'w_cm: {w_cm!r}\n'
+    f'h_cm: {h_cm!r}\n'
+    f'w_px: {w_px!r}\n'
+    f'h_cm: {h_px!r}\n'
+    f'\n'
+    f'--- DIAGONALS ---\n'
+    f'diag_inches: {diag_inches!r}\n'
+    f'diag_pxs: {diag_pxs!r}\n'
+    f'\n'
+    f'--- PPI-related-info ---\n'
+    f'(DE reported) scale: {scale!r}\n'
+    f'unscaled PPI: {unscaled_ppi!r}\n'
+    f'|_ =sqrt(h_px**2 + w_px**2) / sqrt(h_in**2 + w_in**2)\n'
+    f'scaled PPI: {unscaled_ppi/scale!r}\n'
+    f'|_ =unscaled_ppi/scale\n'
+)

snippets/qt_screen_info.py

@@ -31,8 +31,8 @@ Resource list for mucking with DPIs on multiple screens:
 - https://doc.qt.io/qt-5/qguiapplication.html#screenAt
 
 '''
+import os
 
-from pyqtgraph import QtGui
 from PyQt6 import (
     QtCore,
     QtWidgets,
@@ -43,6 +43,11 @@ from PyQt6.QtCore import (
     QSize,
     QRect,
 )
+from pyqtgraph import QtGui
+
+
+# https://doc.qt.io/qt-6/highdpi.html#environment-variable-reference
+os.environ['QT_USE_PHYSICAL_DPI'] = '1'
 
 # Proper high DPI scaling is available in Qt >= 5.6.0. This attibute
 # must be set before creating the application
@@ -58,13 +63,22 @@ if hasattr(Qt, 'AA_UseHighDpiPixmaps'):
         True,
     )
 
+# NOTE, inherits `QGuiApplication`
+# https://doc.qt.io/qt-6/qapplication.html
+# https://doc.qt.io/qt-6/qguiapplication.html
 app = QtWidgets.QApplication([])
+#
+# ^TODO? various global DPI settings?
+# [ ] DPI rounding policy,
+# - https://doc.qt.io/qt-6/qt.html#HighDpiScaleFactorRoundingPolicy-enum
+# - https://doc.qt.io/qt-6/qguiapplication.html#setHighDpiScaleFactorRoundingPolicy
+
 window = QtWidgets.QMainWindow()
 main_widget = QtWidgets.QWidget()
 window.setCentralWidget(main_widget)
 window.show()
 
-pxr: float = main_widget.devicePixelRatioF()
+_main_pxr: float = main_widget.devicePixelRatioF()
 
 # explicitly get main widget and primary displays
 current_screen: QtGui.QScreen = app.screenAt(
@@ -77,7 +91,13 @@ for screen in app.screens():
     name: str = screen.name()
     model: str = screen.model().rstrip()
     size: QSize = screen.size()
-    geo: QRect = screen.availableGeometry()
+    geo: QRect = screen.geometry()
+
+    # device-pixel-ratio
+    # https://doc.qt.io/qt-6/highdpi.html
+    pxr: float = screen.devicePixelRatio()
+
+    unscaled_size: QSize = pxr * size
     phydpi: float = screen.physicalDotsPerInch()
     logdpi: float = screen.logicalDotsPerInch()
     is_primary: bool = screen is primary_screen
@@ -88,11 +108,12 @@ for screen in app.screens():
         f'|_primary: {is_primary}\n'
         f' _current: {is_current}\n'
         f' _model: {model}\n'
-        f' _screen size: {size}\n'
-        f' _screen geometry: {geo}\n'
-        f' _devicePixelRationF(): {pxr}\n'
-        f' _physical dpi: {phydpi}\n'
-        f' _logical dpi: {logdpi}\n'
+        f' _size: {size}\n'
+        f' _geometry: {geo}\n'
+        f' _devicePixelRatio(): {pxr}\n'
+        f' _unscaled-size: {unscaled_size!r}\n'
+        f' _physical-dpi: {phydpi}\n'
+        f' _logical-dpi: {logdpi}\n'
     )
 
 # app-wide font info
@@ -110,8 +131,8 @@ str_w: int = str_br.width()
 
 print(
     f'------ global font settings ------\n'
-    f'font dpi: {fontdpi}\n'
-    f'font height: {font_h}\n'
-    f'string bounding rect: {str_br}\n'
-    f'string width : {str_w}\n'
+    f'font dpi: {fontdpi!r}\n'
+    f'font height: {font_h!r}\n'
+    f'string bounding rect: {str_br!r}\n'
+    f'string width : {str_w!r}\n'
 )

tests/test_dpi_font.py

@@ -0,0 +1,36 @@
+import pytest
+from piker.ui._style import DpiAwareFont
+
+
+class MockScreen:
+    def __init__(self, pdpi, ldpi, name="MockScreen"):
+        self._pdpi = pdpi
+        self._ldpi = ldpi
+        self._name = name
+
+    def physicalDotsPerInch(self):
+        return self._pdpi
+
+    def logicalDotsPerInch(self):
+        return self._ldpi
+
+    def name(self):
+        return self._name
+
+
+@pytest.mark.parametrize(
+    "pdpi, ldpi, expected_px",
+    [
+        (96, 96, 9),       # normal DPI
+        (169, 96, 15),     # HiDPI
+        (120, 96, 10),     # mid-DPI
+    ]
+)
+def test_font_px_size(pdpi, ldpi, expected_px):
+    font = DpiAwareFont()
+    font.configure_to_dpi(screen=MockScreen(pdpi, ldpi))
+
+    px = font.px_size
+    print(f"{pdpi}x{ldpi} DPI -> Computed pixel size: {px}")
+
+    assert px == expected_px

uv.lock

@@ -1034,7 +1034,7 @@ requires-dist = [
     { name = "tomli", specifier = ">=2.0.1,<3.0.0" },
     { name = "tomli-w", specifier = ">=1.0.0,<2.0.0" },
     { name = "tomlkit", git = "https://github.com/pikers/tomlkit.git?branch=piker_pin" },
-    { name = "tractor", git = "https://github.com/goodboy/tractor.git?branch=main" },
+    { name = "tractor", git = "https://github.com/goodboy/tractor.git?branch=piker_pin" },
     { name = "trio", specifier = ">=0.27" },
     { name = "trio-typing", specifier = ">=0.10.0" },
     { name = "trio-util", specifier = ">=0.7.0,<0.8.0" },
@@ -1676,7 +1676,7 @@ wheels = [
 [[package]]
 name = "tractor"
 version = "0.1.0a6.dev0"
-source = { git = "https://github.com/goodboy/tractor.git?branch=main#e77198bb64f0467a50e251ed140daee439752354" }
+source = { git = "https://github.com/goodboy/tractor.git?branch=piker_pin#566a17ba92469000a01fd18c709ea3e336e72796" }
 dependencies = [
     { name = "bidict" },
     { name = "cffi" },