feat(waveform): new type of curve - history curve

bec_widgets/cli/client.py

@@ -4726,6 +4726,8 @@ class Waveform(RPCBase):
         color: "str | None" = None,
         label: "str | None" = None,
         dap: "str | None" = None,
+        scan_id: "str | None" = None,
+        scan_number: "int | None" = None,
         **kwargs,
     ) -> "Curve":
         """
@@ -4748,6 +4750,10 @@ class Waveform(RPCBase):
             dap(str): The dap model to use for the curve, only available for sync devices.
             If not specified, none will be added.
             Use the same string as is the name of the LMFit model.
+            scan_id(str):  Optional scan ID. When provided, the curve is treated as a **history** curve and
+                the y‑data (and optional x‑data) are fetched from that historical scan. Such curves are
+                never cleared by live‑scan resets.
+            scan_number(int): Optional scan index. When provided, the curve is treated as a **history** curve and
 
         Returns:
             Curve: The curve object.

bec_widgets/examples/jupyter_console/jupyter_console_window.py

@@ -55,7 +55,7 @@ class JupyterConsoleWindow(QWidget):  # pragma: no cover:
                     # "btn6": self.btn6,
                     # "pb": self.pb,
                     # "pi": self.pi,
-                    # "wf": self.wf,
+                    "wf": self.wf,
                     # "scatter": self.scatter,
                     # "scatter_mi": self.scatter,
                     # "mwf": self.mwf,
@@ -105,12 +105,11 @@ class JupyterConsoleWindow(QWidget):  # pragma: no cover:
         # self.btn5 = QPushButton("Button 5")
         # self.btn6 = QPushButton("Button 6")
         #
-        # fifth_tab = QWidget()
-        # fifth_tab_layout = QVBoxLayout(fifth_tab)
-        # self.wf = Waveform()
-        # fifth_tab_layout.addWidget(self.wf)
-        # tab_widget.addTab(fifth_tab, "Waveform Next Gen")
-        # tab_widget.setCurrentIndex(4)
+        fifth_tab = QWidget()
+        fifth_tab_layout = QVBoxLayout(fifth_tab)
+        self.wf = Waveform()
+        fifth_tab_layout.addWidget(self.wf)
+        tab_widget.addTab(fifth_tab, "Waveform Next Gen")
         #
         sixth_tab = QWidget()
         sixth_tab_layout = QVBoxLayout(sixth_tab)

bec_widgets/widgets/plots/waveform/curve.py

@@ -42,10 +42,16 @@ class CurveConfig(ConnectionConfig):
     pen_style: Literal["solid", "dash", "dot", "dashdot"] | None = Field(
         "solid", description="The style of the pen of the curve."
     )
-    source: Literal["device", "dap", "custom"] = Field(
+    source: Literal["device", "dap", "custom", "history"] = Field(
         "custom", description="The source of the curve."
     )
     signal: DeviceSignal | None = Field(None, description="The signal of the curve.")
+    scan_id: str | None = Field(None, description="Scan ID to be used when `source` is 'history'.")
+    scan_number: int | None = Field(
+        None, description="Scan index to be used when `source` is 'history'."
+    )
+    # TODO have to decide if make sense
+    current_x_mode: str | None = Field(None, description="The current x mode of the history curve.")
     parent_label: str | None = Field(
         None, description="The label of the parent plot, only relevant for dap curves."
     )
@@ -199,7 +205,7 @@ class Curve(BECConnector, pg.PlotDataItem):
         Raises:
             ValueError: If the source is not custom.
         """
-        if self.config.source == "custom":
+        if self.config.source in ["custom", "history"]:
             self.setData(x, y)
         else:
             raise ValueError(f"Source {self.config.source} do not allow custom data setting.")

bec_widgets/widgets/plots/waveform/settings/curve_settings/curve_tree.py

@@ -5,7 +5,31 @@ from typing import TYPE_CHECKING
 
 from bec_lib.logger import bec_logger
 from bec_qthemes._icon.material_icons import material_icon
-from qtpy.QtCore import Qt
+from qtpy.QtGui import QValidator
+
+
+class ScanIndexValidator(QValidator):
+    """Validator to allow only 'live' or integer scan numbers within range."""
+
+    def __init__(self, max_scan: int, parent=None):
+        super().__init__(parent)
+        self.max_scan = max_scan
+
+    def validate(self, input_str: str, pos: int):
+        # Accept empty or 'live'
+        if input_str == "" or input_str == "live":
+            return QValidator.Acceptable, input_str, pos
+        # Allow partial editing of "live"
+        if "live".startswith(input_str):
+            return QValidator.Intermediate, input_str, pos
+        # Accept integer within [1, max_scan]
+        if input_str.isdigit():
+            num = int(input_str)
+            if 1 <= num <= self.max_scan:
+                return QValidator.Acceptable, input_str, pos
+        return QValidator.Invalid, input_str, pos
+
+
 from qtpy.QtWidgets import (
     QComboBox,
     QHBoxLayout,
@@ -91,8 +115,32 @@ class CurveRow(QTreeWidgetItem):
         # Create columns 1..2, depending on source
         self._init_source_ui()
         # Create columns 3..6 (color, style, width, symbol)
+        self._init_scan_index_ui()
         self._init_style_controls()
 
+    def _init_scan_index_ui(self):
+        """Create the Scan # editable combobox in column 3."""
+        if self.source not in ("device", "history"):
+            return
+        self.scan_index_combo = QComboBox()
+        self.scan_index_combo.setEditable(True)
+        # Populate 'live' and all available history scan indices
+        self.scan_index_combo.addItem("live")
+        history = getattr(self.curve_tree.client, "history", None)
+        num_scans = len(history) if history is not None else 0
+        # Restrict input to 'live' or valid scan numbers
+        validator = ScanIndexValidator(num_scans, self.scan_index_combo)
+        self.scan_index_combo.lineEdit().setValidator(validator)
+        for idx in range(num_scans):
+            # Display scan numbers starting at 1
+            self.scan_index_combo.addItem(str(idx + 1))
+        # Select current scan number if set, otherwise default to 'live'
+        if getattr(self.config, "scan_number", None) is not None:
+            self.scan_index_combo.setCurrentText(str(self.config.scan_number))
+        else:
+            self.scan_index_combo.setCurrentText("live")
+        self.tree.setItemWidget(self, 3, self.scan_index_combo)
+
     def _init_actions(self):
         """Create the actions widget in column 0, including a delete button and maybe 'Add DAP'."""
         self.actions_widget = QWidget()
@@ -114,7 +162,7 @@ class CurveRow(QTreeWidgetItem):
         actions_layout.addWidget(self.delete_button)
 
         # If device row, add "Add DAP" button
-        if self.source == "device":
+        if self.source in ("device", "history"):
             self.add_dap_button = QPushButton("DAP")
             self.add_dap_button.clicked.connect(lambda: self.add_dap_row())
             actions_layout.addWidget(self.add_dap_button)
@@ -123,7 +171,7 @@ class CurveRow(QTreeWidgetItem):
 
     def _init_source_ui(self):
         """Create columns 1 and 2. For device rows, we have device/entry edits; for dap rows, label/model combo."""
-        if self.source == "device":
+        if self.source in ("device", "history"):
             # Device row: columns 1..2 are device line edits
             self.device_edit = DeviceComboBox(parent=self.tree)
             self.device_edit.insertItem(0, "")
@@ -152,7 +200,6 @@ class CurveRow(QTreeWidgetItem):
 
             self.tree.setItemWidget(self, 1, self.device_edit)
             self.tree.setItemWidget(self, 2, self.entry_edit)
-
         else:
             # DAP row: column1= "Model" label, column2= DapComboBox
             self.label_widget = QLabel("Model")
@@ -171,31 +218,31 @@ class CurveRow(QTreeWidgetItem):
             self.tree.setItemWidget(self, 2, self.dap_combo)
 
     def _init_style_controls(self):
-        """Create columns 3..6: color button, style combo, width spin, symbol spin."""
-        # Color in col 3
+        """Create columns 4..7: color button, style combo, width spin, symbol spin."""
+        # Color in col 4
         self.color_button = ColorButtonNative(color=self.config.color)
         self.color_button.color_changed.connect(self._on_color_changed)
-        self.tree.setItemWidget(self, 3, self.color_button)
+        self.tree.setItemWidget(self, 4, self.color_button)
 
-        # Style in col 4
+        # Style in col 5
         self.style_combo = QComboBox()
         self.style_combo.addItems(["solid", "dash", "dot", "dashdot"])
         idx = self.style_combo.findText(self.config.pen_style)
         if idx >= 0:
             self.style_combo.setCurrentIndex(idx)
-        self.tree.setItemWidget(self, 4, self.style_combo)
+        self.tree.setItemWidget(self, 5, self.style_combo)
 
-        # Pen width in col 5
+        # Pen width in col 6
         self.width_spin = QSpinBox()
         self.width_spin.setRange(1, 20)
         self.width_spin.setValue(self.config.pen_width)
-        self.tree.setItemWidget(self, 5, self.width_spin)
+        self.tree.setItemWidget(self, 6, self.width_spin)
 
-        # Symbol size in col 6
+        # Symbol size in col 7
         self.symbol_spin = QSpinBox()
         self.symbol_spin.setRange(1, 20)
         self.symbol_spin.setValue(self.config.symbol_size)
-        self.tree.setItemWidget(self, 6, self.symbol_spin)
+        self.tree.setItemWidget(self, 7, self.symbol_spin)
 
     @SafeSlot(str, verify_sender=True)
     def _on_color_changed(self, new_color: str):
@@ -209,8 +256,8 @@ class CurveRow(QTreeWidgetItem):
         self.config.symbol_color = new_color
 
     def add_dap_row(self):
-        """Create a new DAP row as a child. Only valid if source='device'."""
-        if self.source != "device":
+        """Create a new DAP row as a child. Only valid if source is 'device' or 'history'."""
+        if self.source not in ("device", "history"):
             return
         curve_tree = self.tree.parent()
         parent_label = self.config.label
@@ -288,7 +335,7 @@ class CurveRow(QTreeWidgetItem):
         Returns:
             dict: The serialized config based on the GUI state.
         """
-        if self.source == "device":
+        if self.source in ("device", "history"):
             # Gather device name/entry
             device_name = ""
             device_entry = ""
@@ -309,8 +356,22 @@ class CurveRow(QTreeWidgetItem):
                     )
 
             self.config.signal = DeviceSignal(name=device_name, entry=device_entry)
-            self.config.source = "device"
-            self.config.label = f"{device_name}-{device_entry}"
+            scan_combo_text = self.scan_index_combo.currentText()
+            if scan_combo_text == "live" or scan_combo_text == "":
+                self.config.scan_number = None
+                self.config.scan_id = None
+                self.config.source = "device"
+                self.config.label = f"{device_name}-{device_entry}"
+            if scan_combo_text.isdigit():
+                try:
+                    scan_num = int(scan_combo_text)
+                except ValueError:
+                    scan_num = None
+                self.config.scan_number = scan_num
+                self.config.source = "history"
+                # Label history curves with scan number suffix
+                if scan_num is not None:
+                    self.config.label = f"{device_name}-{device_entry}-scan-{scan_num}"
         else:
             # DAP logic
             parent_conf_dict = {}
@@ -443,10 +504,12 @@ class CurveTree(BECWidget, QWidget):
         self.toolbar.show_bundles(["curve_tree"])
 
     def _init_tree(self):
-        """Initialize the QTreeWidget with 7 columns and compact widths."""
+        """Initialize the QTreeWidget with 8 columns and compact widths."""
         self.tree = QTreeWidget()
-        self.tree.setColumnCount(7)
-        self.tree.setHeaderLabels(["Actions", "Name", "Entry", "Color", "Style", "Width", "Symbol"])
+        self.tree.setColumnCount(8)
+        self.tree.setHeaderLabels(
+            ["Actions", "Name", "Entry", "Scan #", "Color", "Style", "Width", "Symbol"]
+        )
 
         header = self.tree.header()
         for idx in range(self.tree.columnCount()):
@@ -456,10 +519,10 @@ class CurveTree(BECWidget, QWidget):
                 header.setSectionResizeMode(idx, QHeaderView.Fixed)
         header.setStretchLastSection(False)
         self.tree.setColumnWidth(0, 90)
-        self.tree.setColumnWidth(3, 70)
-        self.tree.setColumnWidth(4, 80)
-        self.tree.setColumnWidth(5, 50)
+        self.tree.setColumnWidth(4, 70)
+        self.tree.setColumnWidth(5, 80)
         self.tree.setColumnWidth(6, 50)
+        self.tree.setColumnWidth(7, 50)
 
         self.layout.addWidget(self.tree)
 
@@ -583,9 +646,9 @@ class CurveTree(BECWidget, QWidget):
         self.tree.clear()
         self.all_items = []
 
-        device_curves = [c for c in self.waveform.curves if c.config.source == "device"]
+        top_curves = [c for c in self.waveform.curves if c.config.source in ("device", "history")]
         dap_curves = [c for c in self.waveform.curves if c.config.source == "dap"]
-        for dev in device_curves:
+        for dev in top_curves:
             dr = CurveRow(self.tree, parent_item=None, config=dev.config, device_manager=self.dev)
             for dap in dap_curves:
                 if dap.config.parent_label == dev.config.label:

bec_widgets/widgets/plots/waveform/waveform.py

@@ -8,6 +8,7 @@ import numpy as np
 import pyqtgraph as pg
 from bec_lib import bec_logger, messages
 from bec_lib.endpoints import MessageEndpoints
+from bec_lib.scan_data_container import ScanDataContainer
 from pydantic import Field, ValidationError, field_validator
 from qtpy.QtCore import Qt, QTimer, Signal
 from qtpy.QtWidgets import (
@@ -23,7 +24,6 @@ from qtpy.QtWidgets import (
     QWidget,
 )
 
-from bec_lib.scan_data_container import ScanDataContainer
 from bec_widgets.utils import ConnectionConfig
 from bec_widgets.utils.bec_signal_proxy import BECSignalProxy
 from bec_widgets.utils.colors import Colors, set_theme
@@ -163,6 +163,7 @@ class Waveform(PlotBase):
         # Curve data
         self._sync_curves = []
         self._async_curves = []
+        self._history_curves = []
         self._slice_index = None
         self._dap_curves = []
         self._mode = None
@@ -179,6 +180,7 @@ class Waveform(PlotBase):
             "readout_priority": None,
             "label_suffix": "",
         }
+        self._current_x_device: tuple[str, str] | None = None
 
         # Specific GUI elements
         self._init_roi_manager()
@@ -503,8 +505,11 @@ class Waveform(PlotBase):
         self.x_axis_mode["name"] = value
         if value not in ["timestamp", "index", "auto"]:
             self.x_axis_mode["entry"] = self.entry_validator.validate_signal(value, None)
+            self._current_x_device = (value, self.x_axis_mode["entry"])
         self._switch_x_axis_item(mode=value)
-        self._refresh_x_label_suffix()
+        self._current_x_device = None
+        self._refresh_history_curves()
+        self._update_curve_visibility()
         self.async_signal_update.emit()
         self.sync_signal_update.emit()
         self.plot_item.enableAutoRange(x=True)
@@ -532,7 +537,8 @@ class Waveform(PlotBase):
             return
         self.x_axis_mode["entry"] = self.entry_validator.validate_signal(self.x_mode, value)
         self._switch_x_axis_item(mode="device")
-        self._refresh_x_label_suffix()
+        self._refresh_history_curves()
+        self._update_curve_visibility()
         self.async_signal_update.emit()
         self.sync_signal_update.emit()
         self.plot_item.enableAutoRange(x=True)
@@ -673,6 +679,8 @@ class Waveform(PlotBase):
         color: str | None = None,
         label: str | None = None,
         dap: str | None = None,
+        scan_id: str | None = None,
+        scan_number: int | None = None,
         **kwargs,
     ) -> Curve:
         """
@@ -695,6 +703,10 @@ class Waveform(PlotBase):
             dap(str): The dap model to use for the curve, only available for sync devices.
             If not specified, none will be added.
             Use the same string as is the name of the LMFit model.
+            scan_id(str):  Optional scan ID. When provided, the curve is treated as a **history** curve and
+                the y‑data (and optional x‑data) are fetched from that historical scan. Such curves are
+                never cleared by live‑scan resets.
+            scan_number(int): Optional scan index. When provided, the curve is treated as a **history** curve and
 
         Returns:
             Curve: The curve object.
@@ -764,6 +776,8 @@ class Waveform(PlotBase):
             label=label,
             color=color,
             source=source,
+            scan_id=scan_id,
+            scan_number=scan_number,
             **kwargs,
         )
 
@@ -771,6 +785,9 @@ class Waveform(PlotBase):
         if source == "device":
             config.signal = DeviceSignal(name=y_name, entry=y_entry)
 
+        if scan_id is not None or scan_number is not None:
+            config.source = "history"
+
         # CREATE THE CURVE
         curve = self._add_curve(config=config, x_data=x_data, y_data=y_data)
 
@@ -809,7 +826,7 @@ class Waveform(PlotBase):
         device_curve = self._find_curve_by_label(device_label)
         if not device_curve:
             raise ValueError(f"No existing curve found with label '{device_label}'.")
-        if device_curve.config.source != "device":
+        if device_curve.config.source not in ("device", "history"):
             raise ValueError(
                 f"Curve '{device_label}' is not a device curve. Only device curves can have DAP."
             )
@@ -818,7 +835,7 @@ class Waveform(PlotBase):
         dev_entry = device_curve.config.signal.entry
 
         # 2) Build a label for the new DAP curve
-        dap_label = f"{dev_name}-{dev_entry}-{dap_name}"
+        dap_label = f"{device_label}-{dap_name}"
 
         # 3) Possibly raise if the DAP curve already exists
         if self._check_curve_id(dap_label):
@@ -871,7 +888,19 @@ class Waveform(PlotBase):
             ValueError: If a duplicate curve label/config is found, or if
                         custom data is missing for `source='custom'`.
         """
+        scan_item: ScanDataContainer | None = None
+        if config.source == "history":
+            # Convert 1-based scan_number (from user/API) to 0-based list index
+            list_index = config.scan_number - 1 if config.scan_number is not None else None
+            scan_item = self.get_history_scan_item(scan_id=config.scan_id, scan_index=list_index)
+            config.scan_id = scan_item.metadata["bec"]["scan_id"]
+            # Preserve the 1-based scan_number for external labeling
+            config.scan_number = scan_item.metadata["bec"]["scan_number"]
+
         label = config.label
+        if config.source == "history":
+            label = f"{config.signal.name}-{config.signal.entry}-scan-{config.scan_number}"
+            config.label = label
         if not label:
             # Fallback label
             label = WidgetContainerUtils.generate_unique_name(
@@ -893,7 +922,7 @@ class Waveform(PlotBase):
                 raise ValueError("For 'custom' curves, x_data and y_data must be provided.")
 
         # Actually create the Curve item
-        curve = self._add_curve_object(name=label, config=config)
+        curve = self._add_curve_object(name=label, config=config, scan_item=scan_item)
 
         # If custom => set initial data
         if config.source == "custom" and x_data is not None and y_data is not None:
@@ -910,25 +939,126 @@ class Waveform(PlotBase):
             self.setup_dap_for_scan()
             self.roi_enable.emit(True)  # Enable the ROI toolbar action
             self.request_dap()  # Request DAP update directly without blocking proxy
+        if config.source == "history":
+            self._history_curves.append(curve)
 
         return curve
 
-    def _add_curve_object(self, name: str, config: CurveConfig) -> Curve:
+    def _add_curve_object(
+        self, name: str, config: CurveConfig, scan_item: ScanDataContainer | None = None
+    ) -> Curve:
         """
         Low-level creation of the PlotDataItem (Curve) from a `CurveConfig`.
 
         Args:
             name (str): The name/label of the curve.
             config (CurveConfig): Configuration model describing the curve.
+            scan_item (ScanDataContainer | None): Optional scan item for history curves.
 
         Returns:
             Curve: The newly created curve object, added to the plot.
         """
         curve = Curve(config=config, name=name, parent_item=self)
         self.plot_item.addItem(curve)
+        if scan_item is not None:
+            self._fetch_history_data_for_curve(curve, scan_item)
         self._categorise_device_curves()
         return curve
 
+    def _fetch_history_data_for_curve(
+        self, curve: Curve, scan_item: ScanDataContainer
+    ) -> Curve | None:
+        # Check if the data are already set
+        device = curve.config.signal.name
+        entry = curve.config.signal.entry
+        y_device = None
+        # 1. get y data
+        x_data, y_data = curve.get_data()
+        if y_data is None:  # fetch only if not set, y device data are never chagne later
+            y_device = scan_item.devices.get(device)
+            if y_device is None:
+                raise ValueError(f"Device '{device}' not found in scan item.")
+
+            y_data = y_device.get(entry).read().get("value")
+
+        # 2. get x data
+        readout_priority = scan_item.metadata.get("bec", {}).get("readout_priority", [])
+        all_devices_used = self._devices_from_readout_priority(readout_priority)
+
+        # Determine X-axis data
+        if self.x_axis_mode["name"] == "index":
+            x_data = np.arange(len(y_data))
+            curve.config.current_x_mode = "index"
+        elif self.x_axis_mode["name"] == "timestamp":
+            if y_device is None:
+                y_device = scan_item.devices.get(device)
+            x_data = y_device.get(entry).read().get("timestamp")
+            curve.config.current_x_mode = "timestamp"
+        elif self.x_axis_mode["name"] not in ("index", "timestamp", "auto"):
+            # Custom device mode
+            if self.x_axis_mode["name"] not in all_devices_used:
+                logger.warning(
+                    f"Custom device '{self.x_axis_mode['name']}' not found in scan item of history curve '{curve.name()}'."
+                )
+                curve.setVisible(False)
+                return
+            x_entry_custom = self.x_axis_mode.get("entry")
+            if x_entry_custom is None:
+                x_entry_custom = self.entry_validator.validate_signal(
+                    self.x_axis_mode["name"], None
+                )
+            x_device = scan_item.devices.get(self.x_axis_mode["name"])
+            x_data = x_device.get(x_entry_custom).read().get("value")
+            curve.config.current_x_mode = self.x_axis_mode["name"]
+        elif self.x_axis_mode["name"] == "auto":
+            if (
+                self._current_x_device is None
+            ):  # Scenario where no x device is set yet, because there was no live scan done in this widget yet
+                # If no current x device, use the first motor from scan item
+                scan_motors = self._ensure_str_list(
+                    scan_item.metadata.get("bec").get("scan_report_devices")
+                )
+                if not scan_motors:  # scan was done without reported motor from whatever reason
+                    x_data = np.arange(len(y_data))  # Fallback to index
+                    curve.set_data(x=x_data, y=y_data)
+                    return curve
+                x_entry = self.entry_validator.validate_signal(scan_motors[0], None)
+                x_data = scan_item.devices.get(scan_motors[0]).get(x_entry).read().get("value")
+                self._current_x_device = (scan_motors[0], x_entry)
+                self._update_x_label_suffix(f" (auto: {scan_motors[0]}-{x_entry})")
+                curve.config.current_x_mode = "auto"
+            else:  # Scan in auto mode was done and live scan already set the current x device
+                if self._current_x_device[0] not in all_devices_used:
+                    logger.warning(
+                        f"Auto x data for device '{self._current_x_device[0]}' "
+                        f"and entry '{self._current_x_device[1]}'"
+                        f" not found in scan item of the history curve {curve.name()}."
+                    )
+                    curve.setVisible(False)
+                    return
+                x_device = scan_item.devices.get(self._current_x_device[0])
+                x_data = x_device.get(self._current_x_device[1]).read().get("value")
+                curve.config.current_x_mode = "auto"
+        if x_data is None:
+            logger.warning(
+                f"X data for curve '{curve.name()}' could not be determined. "
+                f"Check if the x_mode '{self.x_axis_mode['name']}' is valid for the scan item."
+            )
+            curve.setVisible(False)
+            return
+        curve.set_data(x=x_data, y=y_data)
+        return curve
+
+    def _refresh_history_curves(self):
+        for curve in self._history_curves:
+            scan_item = self.get_history_scan_item(
+                scan_id=curve.config.scan_id, scan_index=curve.config.scan_number
+            )
+            if scan_item is not None:
+                self._fetch_history_data_for_curve(curve, scan_item)
+            else:
+                logger.warning(f"Scan item for curve {curve.name()} not found.")
+
     def _generate_color_from_palette(self) -> str:
         """
         Generate a color for the next new curve, based on the current number of curves.
@@ -956,7 +1086,42 @@ class Waveform(PlotBase):
         Clear all data from the plot widget, but keep the curve references.
         """
         for c in self.curves:
-            c.clear_data()
+            if c.config.source != "history":
+                c.clear_data()
+
+    # X-axis compatibility helpers
+    def _is_curve_compatible(self, curve: Curve) -> bool:
+        """
+        Return True when *curve* can be shown with the current x-axis mode.
+
+        • ‘index’, ‘timestamp’ and ‘auto’ are always compatible.
+        • For history curves we check whether the requested motor
+          (self.x_axis_mode["name"]) exists in the cached
+          history_data_buffer["x"] dictionary.
+        • Device / DAP / custom curves are treated as compatible because
+          their x-data are re-evaluated on every update.
+        """
+        mode = self.x_axis_mode.get("name", "index")
+        if mode in ("index", "timestamp"):  # always compatible - wild west mode
+            return True
+        if curve.config.source == "history":
+            scan_item = self.get_history_scan_item(
+                scan_id=curve.config.scan_id, scan_index=curve.config.scan_number
+            )
+            # TODO double check this logic!!!
+            curve = self._fetch_history_data_for_curve(curve, scan_item)
+            if curve is None:
+                return False
+        if curve.config.source == "device":
+            # TODO do some check for live curve, not yet implemented, check should be done from self.scan_item
+            return True
+        # TODO figure out how to handle DAP curves
+        return True
+
+    def _update_curve_visibility(self) -> None:
+        """Show or hide curves according to `_is_curve_compatible`."""
+        for c in self.curves:
+            c.setVisible(self._is_curve_compatible(c))
 
     def clear_all(self):
         """
@@ -1118,7 +1283,7 @@ class Waveform(PlotBase):
             self.scan_id = current_scan_id
             self.scan_item = self.queue.scan_storage.find_scan_by_ID(self.scan_id)  # live scan
             self._slice_index = None  # Reset the slice index
-
+            self._update_curve_visibility()
             self._mode = self._categorise_device_curves()
 
             # First trigger to sync and async data
@@ -1604,6 +1769,7 @@ class Waveform(PlotBase):
                 entry_obj = data.get(x_name, {}).get(x_entry)
                 x_data = entry_obj.read()["value"] if entry_obj else [0]
             new_suffix = f" (custom: {x_name}-{x_entry})"
+            self._current_x_device = (x_name, x_entry)
 
         # 2 User wants timestamp
         if self.x_axis_mode["name"] == "timestamp":
@@ -1618,11 +1784,13 @@ class Waveform(PlotBase):
                 timestamps = entry_obj.read()["timestamp"] if entry_obj else [0]
             x_data = timestamps
             new_suffix = " (timestamp)"
+            self._current_x_device = None
 
         # 3 User wants index
         if self.x_axis_mode["name"] == "index":
             x_data = None
             new_suffix = " (index)"
+            self._current_x_device = None
 
         # 4 Best effort automatic mode
         if self.x_axis_mode["name"] is None or self.x_axis_mode["name"] == "auto":
@@ -1630,6 +1798,7 @@ class Waveform(PlotBase):
             if len(self._async_curves) > 0:
                 x_data = None
                 new_suffix = " (auto: index)"
+                self._current_x_device = None
             # 4.2 If there are sync curves, use the first device from the scan report
             else:
                 try:
@@ -1645,6 +1814,7 @@ class Waveform(PlotBase):
                     entry_obj = data.get(x_name, {}).get(x_entry)
                     x_data = entry_obj.read()["value"] if entry_obj else None
                 new_suffix = f" (auto: {x_name}-{x_entry})"
+                self._current_x_device = (x_name, x_entry)
         self._update_x_label_suffix(new_suffix)
         return x_data
 
@@ -1661,30 +1831,6 @@ class Waveform(PlotBase):
         self.x_axis_mode["label_suffix"] = new_suffix
         self.set_x_label_suffix(new_suffix)
 
-    def _refresh_x_label_suffix(self):
-        """
-        Update the x‑axis label suffix immediately based on the current
-        ``x_axis_mode`` dictionary, without waiting for the next data
-        update cycle.
-        """
-        mode = self.x_axis_mode.get("name", "auto")
-
-        if mode == "timestamp":
-            suffix = " (timestamp)"
-        elif mode == "index":
-            suffix = " (index)"
-        elif mode == "auto":
-            suffix = " (auto)"
-        else:
-            x_name = mode
-            x_entry = self.x_axis_mode.get("entry", None)
-            if x_entry:
-                suffix = f" (custom: {x_name}-{x_entry})"
-            else:
-                suffix = f" (custom: {x_name})"
-
-        self._update_x_label_suffix(suffix)
-
     def _switch_x_axis_item(self, mode: str):
         """
         Switch the x-axis mode between timestamp, index, the best effort and custom signal.
@@ -1786,7 +1932,7 @@ class Waveform(PlotBase):
             ScanDataContainer | None: The fetched scan item or None if no item was found.
         """
         if scan_index is not None and scan_id is not None:
-            raise ValueError("Only one of scan_id or scan_index can be provided.")
+            scan_index = None  # Only one of scan_id or scan_index can be provided -> scan id is more reliable
 
         if scan_index is None and scan_id is None:
             logger.warning("Neither scan_id or scan_number was provided, fetching the latest scan")
@@ -1821,9 +1967,6 @@ class Waveform(PlotBase):
             scan_id(str, optional): ScanID of the scan to be updated. Defaults to None.
             scan_index(int, optional): Index of the scan to be updated. Defaults to None.
         """
-        if scan_index is not None and scan_id is not None:
-            raise ValueError("Only one of scan_id or scan_index can be provided.")
-
         self.scan_item = self.get_history_scan_item(scan_index=scan_index, scan_id=scan_id)
 
         if self.scan_item is None:
@@ -1832,7 +1975,7 @@ class Waveform(PlotBase):
         if scan_id is not None:
             self.scan_id = scan_id
         else:
-            # If scan_index was used, set the scan_id from the fetched item
+            # If scan_number was used, set the scan_id from the fetched item
             if hasattr(self.scan_item, "metadata"):
                 self.scan_id = self.scan_item.metadata["bec"]["scan_id"]
             else:
@@ -1950,6 +2093,35 @@ class Waveform(PlotBase):
             return True
         return False
 
+    def _devices_from_readout_priority(
+        self, rp: dict | None, *, exclude_keys: set[str] | None = None  # keyword-only
+    ) -> list[str]:
+        """
+        Flatten a BEC *readout_priority* mapping into a list[str] of device names.
+
+        Args:
+            rp(dict | None): The readout priority mapping from the scan report.
+
+        Returns:
+            list[str]: A list of unique device names from the readout priority mapping.
+        """
+        if not rp:
+            return []
+
+        if exclude_keys is None:  # baseline readings are excluded by default
+            exclude_keys = {"baseline"}
+
+        seen: set[str] = set()
+        devices: list[str] = []
+        for key, value in rp.items():
+            if key in exclude_keys:
+                continue
+            for dev in self._ensure_str_list(value):
+                if dev not in seen:
+                    seen.add(dev)
+                    devices.append(dev)
+        return devices
+
     def _ensure_str_list(self, entries: list | tuple | np.ndarray):
         """
         Convert a variety of possible inputs (string, bytes, list/tuple/ndarray of either)
@@ -2081,6 +2253,7 @@ class DemoApp(QMainWindow):  # pragma: no cover
 
         self.waveform_popup = Waveform(popups=True)
         self.waveform_popup.plot(y_name="waveform")
+        self.waveform_popup.plot("bpm4i", scan_number=0)
 
         self.waveform_side = Waveform(popups=False)
         self.waveform_side.plot(y_name="bpm4i", y_entry="bpm4i", dap="GaussianModel")