V8

1 files changed, 629 insertions, 0 deletions

diff --git a/ui/plot_config.py b/ui/plot_config.py
new file mode 100644
index 0000000..058915f
--- /dev/null
+++ b/ui/plot_config.py
@@ -0,0 +1,629 @@
+"""
+ui/plot_config.py
+
+Plot Configuration Builder — floating window.
+
+Lets the user define:
+  • How many subplot rows to show
+  • Which channels go in each row (any mix of devices/channels)
+  • Per-channel: label override, color, line width, visibility
+  • Per-plot:    Y-axis label, Y min/max (or auto), grid on/off
+  • Global:      time window, sample decimation, background color
+
+The resulting config is stored as a list of PlotConfig dataclasses
+and emitted via the `config_applied` signal so StripChartWidget can
+rebuild itself on demand.
+"""
+
+from __future__ import annotations
+import json
+from copy import deepcopy
+from dataclasses import dataclass, field, asdict
+from typing import List, Optional
+
+from PyQt6.QtWidgets import (
+    QWidget, QVBoxLayout, QHBoxLayout, QLabel, QPushButton,
+    QScrollArea, QFrame, QLineEdit, QDoubleSpinBox, QSpinBox,
+    QCheckBox, QComboBox, QColorDialog, QGroupBox, QFormLayout,
+    QSizePolicy, QSplitter, QListWidget, QListWidgetItem,
+    QAbstractItemView, QToolButton, QSlider,
+)
+from PyQt6.QtCore import Qt, pyqtSignal, QSize
+from PyQt6.QtGui import QColor, QIcon, QCloseEvent
+
+from devices.device_registry import DeviceRegistry
+
+
+# ══════════════════════════════════════════════════════════════════════════════
+#  Data model
+# ══════════════════════════════════════════════════════════════════════════════
+
+@dataclass
+class ChannelTrace:
+    device_id:  str
+    channel_id: str
+    label:      str         = ""      # "" → use channel name
+    color:      str         = "#00d4ff"
+    width:      float       = 1.8
+    visible:    bool        = True
+    style:      str         = "solid" # "solid" | "dash" | "dot"
+
+
+@dataclass
+class PlotConfig:
+    title:      str                      = "Plot"
+    y_label:    str                      = ""
+    y_auto:     bool                     = True
+    y_min:      float                    = -10.0
+    y_max:      float                    =  10.0
+    grid:       bool                     = True
+    traces:     List[ChannelTrace]       = field(default_factory=list)
+
+
+@dataclass
+class ChartConfig:
+    plots:          List[PlotConfig]     = field(default_factory=list)
+    time_window_s:  float                = 30.0
+    bg_color:       str                  = "#0b0e13"
+    link_x:         bool                 = True
+    show_legend:    bool                 = True
+
+    def to_json(self) -> str:
+        return json.dumps(asdict(self), indent=2)
+
+    @staticmethod
+    def from_json(s: str) -> "ChartConfig":
+        d = json.loads(s)
+        plots = []
+        for p in d.get("plots", []):
+            traces = [ChannelTrace(**t) for t in p.pop("traces", [])]
+            plots.append(PlotConfig(**p, traces=traces))
+        d["plots"] = plots
+        return ChartConfig(**{k: v for k, v in d.items() if k != "plots"},
+                           plots=plots)
+
+
+def default_config(registry: DeviceRegistry) -> ChartConfig:
+    """Build a sensible default config from whatever devices are registered."""
+    cfg = ChartConfig()
+    for dev in registry.all_instances():
+        if not dev.info.channels:
+            continue
+        p = PlotConfig(
+            title=dev.info.name,
+            y_label=dev.info.channels[0].unit if dev.info.channels else "",
+        )
+        for ch in dev.info.channels:
+            if ch.enabled:
+                p.traces.append(ChannelTrace(
+                    device_id=dev.info.device_id,
+                    channel_id=ch.channel_id,
+                    label=ch.name,
+                    color=ch.color,
+                ))
+        if p.traces:
+            cfg.plots.append(p)
+    return cfg
+
+
+# ══════════════════════════════════════════════════════════════════════════════
+#  Colour swatch button
+# ══════════════════════════════════════════════════════════════════════════════
+
+class ColorButton(QPushButton):
+    color_changed = pyqtSignal(str)
+
+    def __init__(self, color: str = "#00d4ff"):
+        super().__init__()
+        self._color = color
+        self.setFixedSize(28, 22)
+        self._apply()
+        self.clicked.connect(self._pick)
+
+    def _apply(self):
+        self.setStyleSheet(
+            f"QPushButton {{ background:{self._color}; border:1px solid #2a3558;"
+            f" border-radius:3px; }} "
+            f"QPushButton:hover {{ border-color:#3b82f6; }}"
+        )
+
+    def _pick(self):
+        c = QColorDialog.getColor(QColor(self._color), self, "Pick colour")
+        if c.isValid():
+            self._color = c.name()
+            self._apply()
+            self.color_changed.emit(self._color)
+
+    @property
+    def color(self): return self._color
+
+    @color.setter
+    def color(self, v: str):
+        self._color = v
+        self._apply()
+
+
+# ══════════════════════════════════════════════════════════════════════════════
+#  Trace row widget  (one row per ChannelTrace inside a plot)
+# ══════════════════════════════════════════════════════════════════════════════
+
+class TraceRow(QFrame):
+    removed   = pyqtSignal(object)   # self
+    changed   = pyqtSignal()
+
+    def __init__(self, trace: ChannelTrace, registry: DeviceRegistry):
+        super().__init__()
+        self.trace    = trace
+        self.registry = registry
+        self.setObjectName("traceRow")
+        self._build()
+
+    def _build(self):
+        lay = QHBoxLayout(self)
+        lay.setContentsMargins(6, 4, 6, 4)
+        lay.setSpacing(6)
+
+        # Visibility checkbox
+        self._vis = QCheckBox()
+        self._vis.setChecked(self.trace.visible)
+        self._vis.setToolTip("Show/hide trace")
+        self._vis.toggled.connect(self._on_vis)
+        lay.addWidget(self._vis)
+
+        # Color swatch
+        self._color_btn = ColorButton(self.trace.color)
+        self._color_btn.color_changed.connect(self._on_color)
+        lay.addWidget(self._color_btn)
+
+        # Source label  dev_id / ch_id
+        src = QLabel(f"{self.trace.device_id} / {self.trace.channel_id}")
+        src.setObjectName("traceSource")
+        src.setMinimumWidth(120)
+        lay.addWidget(src)
+
+        # Label override
+        self._label_edit = QLineEdit(self.trace.label)
+        self._label_edit.setPlaceholderText("Label…")
+        self._label_edit.setObjectName("traceLabel")
+        self._label_edit.textChanged.connect(self._on_label)
+        lay.addWidget(self._label_edit, 1)
+
+        # Line style
+        self._style_cb = QComboBox()
+        self._style_cb.addItems(["solid", "dash", "dot"])
+        self._style_cb.setCurrentText(self.trace.style)
+        self._style_cb.setObjectName("traceStyleCb")
+        self._style_cb.setFixedWidth(64)
+        self._style_cb.currentTextChanged.connect(self._on_style)
+        lay.addWidget(self._style_cb)
+
+        # Width
+        self._width_spin = QDoubleSpinBox()
+        self._width_spin.setRange(0.5, 6.0)
+        self._width_spin.setSingleStep(0.5)
+        self._width_spin.setValue(self.trace.width)
+        self._width_spin.setFixedWidth(56)
+        self._width_spin.setObjectName("traceWidthSpin")
+        self._width_spin.valueChanged.connect(self._on_width)
+        lay.addWidget(self._width_spin)
+
+        # Remove button
+        rm = QToolButton()
+        rm.setText("✕")
+        rm.setObjectName("traceRemoveBtn")
+        rm.setFixedSize(22, 22)
+        rm.clicked.connect(lambda: self.removed.emit(self))
+        lay.addWidget(rm)
+
+    def _on_vis(self, v):   self.trace.visible = v;         self.changed.emit()
+    def _on_color(self, c): self.trace.color   = c;         self.changed.emit()
+    def _on_label(self, t): self.trace.label   = t;         self.changed.emit()
+    def _on_style(self, s): self.trace.style   = s;         self.changed.emit()
+    def _on_width(self, w): self.trace.width   = w;         self.changed.emit()
+
+
+# ══════════════════════════════════════════════════════════════════════════════
+#  Plot block widget  (one collapsible section per PlotConfig)
+# ══════════════════════════════════════════════════════════════════════════════
+
+class PlotBlock(QFrame):
+    removed  = pyqtSignal(object)   # self
+    changed  = pyqtSignal()
+    move_up  = pyqtSignal(object)
+    move_dn  = pyqtSignal(object)
+
+    def __init__(self, plot_cfg: PlotConfig, registry: DeviceRegistry, index: int):
+        super().__init__()
+        self.plot_cfg = plot_cfg
+        self.registry = registry
+        self.index    = index
+        self.setObjectName("plotBlock")
+        self._trace_rows: list[TraceRow] = []
+        self._build()
+
+    def _build(self):
+        outer = QVBoxLayout(self)
+        outer.setContentsMargins(0, 0, 0, 0)
+        outer.setSpacing(0)
+
+        # ── Header bar ──────────────────────────────────────────────
+        hdr = QWidget(); hdr.setObjectName("plotBlockHeader"); hdr.setFixedHeight(32)
+        hdr_lay = QHBoxLayout(hdr); hdr_lay.setContentsMargins(8, 0, 6, 0)
+
+        self._title_edit = QLineEdit(self.plot_cfg.title)
+        self._title_edit.setObjectName("plotBlockTitle")
+        self._title_edit.textChanged.connect(self._on_title)
+        hdr_lay.addWidget(self._title_edit, 1)
+
+        up_btn = QToolButton(); up_btn.setText("▲"); up_btn.setObjectName("plotMoveBtn")
+        up_btn.setFixedSize(22, 22); up_btn.clicked.connect(lambda: self.move_up.emit(self))
+        dn_btn = QToolButton(); dn_btn.setText("▼"); dn_btn.setObjectName("plotMoveBtn")
+        dn_btn.setFixedSize(22, 22); dn_btn.clicked.connect(lambda: self.move_dn.emit(self))
+        rm_btn = QToolButton(); rm_btn.setText("✕"); rm_btn.setObjectName("plotRemoveBtn")
+        rm_btn.setFixedSize(22, 22); rm_btn.clicked.connect(lambda: self.removed.emit(self))
+
+        for b in (up_btn, dn_btn, rm_btn): hdr_lay.addWidget(b)
+        outer.addWidget(hdr)
+
+        # ── Settings row ────────────────────────────────────────────
+        settings = QWidget(); settings.setObjectName("plotBlockSettings")
+        s_lay = QHBoxLayout(settings); s_lay.setContentsMargins(8, 6, 8, 6)
+
+        s_lay.addWidget(QLabel("Y Label:"))
+        self._ylabel_edit = QLineEdit(self.plot_cfg.y_label)
+        self._ylabel_edit.setPlaceholderText("e.g. Voltage (V)")
+        self._ylabel_edit.setObjectName("plotYLabelEdit")
+        self._ylabel_edit.textChanged.connect(self._on_ylabel)
+        s_lay.addWidget(self._ylabel_edit)
+
+        self._auto_chk = QCheckBox("Auto Y")
+        self._auto_chk.setChecked(self.plot_cfg.y_auto)
+        self._auto_chk.toggled.connect(self._on_auto)
+        s_lay.addWidget(self._auto_chk)
+
+        s_lay.addWidget(QLabel("Min:"))
+        self._ymin = QDoubleSpinBox()
+        self._ymin.setRange(-1e9, 1e9); self._ymin.setValue(self.plot_cfg.y_min)
+        self._ymin.setFixedWidth(72); self._ymin.setEnabled(not self.plot_cfg.y_auto)
+        self._ymin.valueChanged.connect(self._on_ymin)
+        s_lay.addWidget(self._ymin)
+
+        s_lay.addWidget(QLabel("Max:"))
+        self._ymax = QDoubleSpinBox()
+        self._ymax.setRange(-1e9, 1e9); self._ymax.setValue(self.plot_cfg.y_max)
+        self._ymax.setFixedWidth(72); self._ymax.setEnabled(not self.plot_cfg.y_auto)
+        self._ymax.valueChanged.connect(self._on_ymax)
+        s_lay.addWidget(self._ymax)
+
+        self._grid_chk = QCheckBox("Grid")
+        self._grid_chk.setChecked(self.plot_cfg.grid)
+        self._grid_chk.toggled.connect(self._on_grid)
+        s_lay.addWidget(self._grid_chk)
+
+        s_lay.addStretch()
+        outer.addWidget(settings)
+
+        # ── Traces container ─────────────────────────────────────────
+        self._traces_widget = QWidget()
+        self._traces_widget.setObjectName("plotBlockTraces")
+        self._traces_layout = QVBoxLayout(self._traces_widget)
+        self._traces_layout.setContentsMargins(4, 2, 4, 4)
+        self._traces_layout.setSpacing(2)
+
+        for tr in self.plot_cfg.traces:
+            self._add_trace_row(tr)
+
+        # ── Add trace button ─────────────────────────────────────────
+        add_row = QHBoxLayout()
+        self._ch_picker = self._build_channel_picker()
+        add_row.addWidget(self._ch_picker, 1)
+        add_tr_btn = QPushButton("＋ Add Trace")
+        add_tr_btn.setObjectName("addTraceBtn")
+        add_tr_btn.clicked.connect(self._on_add_trace)
+        add_row.addWidget(add_tr_btn)
+        self._traces_layout.addLayout(add_row)
+
+        outer.addWidget(self._traces_widget)
+
+    # ── Helpers ──────────────────────────────────────────────────────────
+
+    def _build_channel_picker(self) -> QComboBox:
+        cb = QComboBox()
+        cb.setObjectName("channelPickerCb")
+        cb.setPlaceholderText("Select channel…")
+        for dev in self.registry.all_instances():
+            for ch in dev.info.channels:
+                label = f"{dev.info.device_id}  /  {ch.channel_id}  ({ch.name})"
+                cb.addItem(label, userData=(dev.info.device_id, ch.channel_id,
+                                            ch.name, ch.color))
+        return cb
+
+    def _add_trace_row(self, trace: ChannelTrace):
+        row = TraceRow(trace, self.registry)
+        row.removed.connect(self._remove_trace_row)
+        row.changed.connect(self.changed)
+        self._trace_rows.append(row)
+        # Insert before the add-row (last item)
+        idx = self._traces_layout.count() - 1
+        self._traces_layout.insertWidget(idx, row)
+
+    def _remove_trace_row(self, row: TraceRow):
+        self.plot_cfg.traces.remove(row.trace)
+        self._trace_rows.remove(row)
+        self._traces_layout.removeWidget(row)
+        row.deleteLater()
+        self.changed.emit()
+
+    def _on_add_trace(self):
+        data = self._ch_picker.currentData()
+        if data is None:
+            return
+        dev_id, ch_id, ch_name, ch_color = data
+        tr = ChannelTrace(device_id=dev_id, channel_id=ch_id,
+                          label=ch_name, color=ch_color)
+        self.plot_cfg.traces.append(tr)
+        self._add_trace_row(tr)
+        self.changed.emit()
+
+    # ── Config slots ─────────────────────────────────────────────────────
+
+    def _on_title(self, t):  self.plot_cfg.title   = t;     self.changed.emit()
+    def _on_ylabel(self, t): self.plot_cfg.y_label  = t;    self.changed.emit()
+    def _on_auto(self, v):
+        self.plot_cfg.y_auto = v
+        self._ymin.setEnabled(not v); self._ymax.setEnabled(not v)
+        self.changed.emit()
+    def _on_ymin(self, v):   self.plot_cfg.y_min   = v;     self.changed.emit()
+    def _on_ymax(self, v):   self.plot_cfg.y_max   = v;     self.changed.emit()
+    def _on_grid(self, v):   self.plot_cfg.grid     = v;    self.changed.emit()
+
+
+# ══════════════════════════════════════════════════════════════════════════════
+#  PlotConfigWindow  — the main floating builder
+# ══════════════════════════════════════════════════════════════════════════════
+
+class PlotConfigWindow(QWidget):
+    """
+    Floating plot configuration builder.
+
+    Emits `config_applied(ChartConfig)` when the user clicks Apply or
+    when live-preview is enabled and any setting changes.
+    """
+
+    config_applied = pyqtSignal(object)   # ChartConfig
+    closed         = pyqtSignal()
+
+    def __init__(self, registry: DeviceRegistry,
+                 current_config: Optional[ChartConfig] = None,
+                 parent=None):
+        super().__init__(
+            parent,
+            Qt.WindowType.Window | Qt.WindowType.Tool,
+        )
+        self.registry = registry
+        self.cfg      = deepcopy(current_config) if current_config \
+                        else default_config(registry)
+
+        self.setWindowTitle("Plot Configuration")
+        self.setMinimumSize(680, 560)
+        self.resize(760, 640)
+        self._blocks: list[PlotBlock] = []
+        self._build()
+        self._populate()
+
+    # ── Build shell ───────────────────────────────────────────────────────
+
+    def _build(self):
+        root = QVBoxLayout(self)
+        root.setContentsMargins(0, 0, 0, 0)
+        root.setSpacing(0)
+
+        # ── Top bar ──────────────────────────────────────────────────
+        topbar = QWidget(); topbar.setObjectName("cfgTopBar"); topbar.setFixedHeight(44)
+        tb_lay = QHBoxLayout(topbar); tb_lay.setContentsMargins(12, 0, 12, 0)
+
+        title = QLabel("📈  PLOT CONFIGURATION")
+        title.setObjectName("cfgTopBarTitle")
+        tb_lay.addWidget(title, 1)
+
+        self._live_chk = QCheckBox("Live preview")
+        self._live_chk.setChecked(False)
+        self._live_chk.setObjectName("cfgLiveChk")
+        tb_lay.addWidget(self._live_chk)
+
+        root.addWidget(topbar)
+
+        # ── Global settings strip ────────────────────────────────────
+        glob = QWidget(); glob.setObjectName("cfgGlobalBar")
+        g_lay = QHBoxLayout(glob); g_lay.setContentsMargins(12, 6, 12, 6)
+
+        g_lay.addWidget(QLabel("Time window:"))
+        self._win_spin = QDoubleSpinBox()
+        self._win_spin.setRange(1, 3600); self._win_spin.setSuffix(" s")
+        self._win_spin.setValue(self.cfg.time_window_s)
+        self._win_spin.setObjectName("cfgGlobalSpin")
+        self._win_spin.valueChanged.connect(self._on_global_change)
+        g_lay.addWidget(self._win_spin)
+        g_lay.addSpacing(16)
+
+        self._linkx_chk = QCheckBox("Link X axes")
+        self._linkx_chk.setChecked(self.cfg.link_x)
+        self._linkx_chk.setObjectName("cfgLiveChk")
+        self._linkx_chk.toggled.connect(self._on_global_change)
+        g_lay.addWidget(self._linkx_chk)
+
+        self._legend_chk = QCheckBox("Show legend")
+        self._legend_chk.setChecked(self.cfg.show_legend)
+        self._legend_chk.setObjectName("cfgLiveChk")
+        self._legend_chk.toggled.connect(self._on_global_change)
+        g_lay.addWidget(self._legend_chk)
+
+        g_lay.addStretch()
+
+        add_plot_btn = QPushButton("＋  Add Plot Row")
+        add_plot_btn.setObjectName("addDeviceButton")
+        add_plot_btn.clicked.connect(self._add_plot)
+        g_lay.addWidget(add_plot_btn)
+
+        root.addWidget(glob)
+
+        # divider
+        div = QFrame(); div.setFrameShape(QFrame.Shape.HLine)
+        div.setObjectName("devWindowDivider"); root.addWidget(div)
+
+        # ── Scrollable plot blocks ───────────────────────────────────
+        scroll = QScrollArea()
+        scroll.setWidgetResizable(True)
+        scroll.setHorizontalScrollBarPolicy(Qt.ScrollBarPolicy.ScrollBarAlwaysOff)
+        scroll.setObjectName("deviceScroll")
+
+        self._container  = QWidget()
+        self._blocks_lay = QVBoxLayout(self._container)
+        self._blocks_lay.setContentsMargins(10, 10, 10, 10)
+        self._blocks_lay.setSpacing(12)
+        self._blocks_lay.addStretch()
+
+        scroll.setWidget(self._container)
+        root.addWidget(scroll, 1)
+
+        # ── Bottom action bar ────────────────────────────────────────
+        btm = QWidget(); btm.setObjectName("cfgBottomBar")
+        b_lay = QHBoxLayout(btm); b_lay.setContentsMargins(12, 8, 12, 8)
+
+        self._reset_btn = QPushButton("⟳  Reset to Default")
+        self._reset_btn.setObjectName("configButton")
+        self._reset_btn.clicked.connect(self._reset_defaults)
+        b_lay.addWidget(self._reset_btn)
+
+        self._export_btn = QPushButton("↓  Export JSON")
+        self._export_btn.setObjectName("configButton")
+        self._export_btn.clicked.connect(self._export_json)
+        b_lay.addWidget(self._export_btn)
+
+        self._import_btn = QPushButton("↑  Import JSON")
+        self._import_btn.setObjectName("configButton")
+        self._import_btn.clicked.connect(self._import_json)
+        b_lay.addWidget(self._import_btn)
+
+        b_lay.addStretch()
+
+        self._apply_btn = QPushButton("✓  Apply")
+        self._apply_btn.setObjectName("applyButton")
+        self._apply_btn.clicked.connect(self._apply)
+        b_lay.addWidget(self._apply_btn)
+
+        root.addWidget(btm)
+
+    # ── Populate from config ───────────────────────────────────────────────
+
+    def _populate(self):
+        for blk in self._blocks:
+            self._blocks_lay.removeWidget(blk)
+            blk.deleteLater()
+        self._blocks.clear()
+
+        for i, p in enumerate(self.cfg.plots):
+            self._insert_block(p, i)
+
+    def _insert_block(self, plot_cfg: PlotConfig, index: int):
+        blk = PlotBlock(plot_cfg, self.registry, index)
+        blk.removed.connect(self._remove_block)
+        blk.changed.connect(self._on_block_changed)
+        blk.move_up.connect(self._move_block_up)
+        blk.move_dn.connect(self._move_block_dn)
+        self._blocks.append(blk)
+        self._blocks_lay.insertWidget(self._blocks_lay.count() - 1, blk)
+
+    # ── Block management ──────────────────────────────────────────────────
+
+    def _add_plot(self):
+        p = PlotConfig(title=f"Plot {len(self.cfg.plots) + 1}")
+        self.cfg.plots.append(p)
+        self._insert_block(p, len(self._blocks))
+        self._maybe_live()
+
+    def _remove_block(self, blk: PlotBlock):
+        if blk.plot_cfg in self.cfg.plots:
+            self.cfg.plots.remove(blk.plot_cfg)
+        self._blocks.remove(blk)
+        self._blocks_lay.removeWidget(blk)
+        blk.deleteLater()
+        self._maybe_live()
+
+    def _move_block_up(self, blk: PlotBlock):
+        i = self._blocks.index(blk)
+        if i == 0: return
+        self.cfg.plots.insert(i - 1, self.cfg.plots.pop(i))
+        self._blocks.insert(i - 1, self._blocks.pop(i))
+        self._blocks_lay.removeWidget(blk)
+        self._blocks_lay.insertWidget(i - 1, blk)
+        self._maybe_live()
+
+    def _move_block_dn(self, blk: PlotBlock):
+        i = self._blocks.index(blk)
+        if i >= len(self._blocks) - 1: return
+        self.cfg.plots.insert(i + 1, self.cfg.plots.pop(i))
+        self._blocks.insert(i + 1, self._blocks.pop(i))
+        self._blocks_lay.removeWidget(blk)
+        self._blocks_lay.insertWidget(i + 1, blk)
+        self._maybe_live()
+
+    # ── Global settings ───────────────────────────────────────────────────
+
+    def _on_global_change(self):
+        self.cfg.time_window_s = self._win_spin.value()
+        self.cfg.link_x        = self._linkx_chk.isChecked()
+        self.cfg.show_legend   = self._legend_chk.isChecked()
+        self._maybe_live()
+
+    def _on_block_changed(self):
+        self._maybe_live()
+
+    def _maybe_live(self):
+        if self._live_chk.isChecked():
+            self.config_applied.emit(deepcopy(self.cfg))
+
+    # ── Actions ───────────────────────────────────────────────────────────
+
+    def _apply(self):
+        self.config_applied.emit(deepcopy(self.cfg))
+
+    def _reset_defaults(self):
+        self.cfg = default_config(self.registry)
+        self._win_spin.setValue(self.cfg.time_window_s)
+        self._populate()
+        self._maybe_live()
+
+    def _export_json(self):
+        from PyQt6.QtWidgets import QFileDialog
+        path, _ = QFileDialog.getSaveFileName(
+            self, "Export Plot Config", "plot_config.json",
+            "JSON Files (*.json)"
+        )
+        if path:
+            with open(path, "w") as f:
+                f.write(self.cfg.to_json())
+
+    def _import_json(self):
+        from PyQt6.QtWidgets import QFileDialog
+        path, _ = QFileDialog.getOpenFileName(
+            self, "Import Plot Config", "", "JSON Files (*.json)"
+        )
+        if path:
+            try:
+                with open(path) as f:
+                    self.cfg = ChartConfig.from_json(f.read())
+                self._win_spin.setValue(self.cfg.time_window_s)
+                self._populate()
+                self._maybe_live()
+            except Exception as e:
+                from PyQt6.QtWidgets import QMessageBox
+                QMessageBox.critical(self, "Import failed", str(e))
+
+    def closeEvent(self, event: QCloseEvent):
+        self.closed.emit()
+        event.accept()
+
+    def update_registry(self):
+        """Call after devices are added/removed to refresh channel pickers."""
+        self._populate()