Redesign plot tab: per-plot add/remove traces, persist settings, readable axes

- Replace static combo grid with a control bar above each plot:
  add-trace dropdown + "+" button; active traces shown as colored chips with
  "×" to remove (max 4 per plot)
- Save trace selection to ~/.config/we_monitor/plot_settings.json on every
  change; restore automatically once matching signals arrive from the server
- Remove tiny tick-font overrides so axis labels are readable at default size
- Show received record count in the status bar

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

gui_client.py

@@ -17,6 +17,7 @@ import sys
 import threading
 from collections import deque
 from datetime import datetime
+from pathlib import Path
 
 from PyQt5.QtCore import QObject, Qt, pyqtSignal
 from PyQt5.QtGui import QColor, QFont
@@ -32,7 +33,8 @@ import pyqtgraph as pg
 pg.setConfigOption("background", "w")
 pg.setConfigOption("foreground", "k")
 
-MAX_PLOT_POINTS = 200
+MAX_PLOT_POINTS  = 200
+_SETTINGS_PATH   = Path.home() / ".config" / "we_monitor" / "plot_settings.json"
 
 
 # ── TCP reader ────────────────────────────────────────────────────────────────
@@ -269,41 +271,17 @@ class DashboardTab(QWidget):
 # ── Plot tab ──────────────────────────────────────────────────────────────────
 
 class PlotTab(QWidget):
-    NUM_PLOTS = 4
+    NUM_PLOTS  = 4
-    TRACES    = 4
+    MAX_TRACES = 4
-    COLORS    = ["#1f77b4", "#ff7f0e", "#2ca02c", "#d62728"]
+    COLORS     = ["#1f77b4", "#ff7f0e", "#2ca02c", "#d62728"]
 
     def __init__(self):
         super().__init__()
-        layout = QVBoxLayout(self)
+        main_layout = QVBoxLayout(self)
-        layout.setContentsMargins(4, 4, 4, 4)
+        main_layout.setContentsMargins(4, 4, 4, 4)
-        layout.setSpacing(4)
+        main_layout.setSpacing(4)
 
-        # ── trace selectors ───────────────────────────────────────────────────
+        # ── toolbar ───────────────────────────────────────────────────────────
-        sel = QWidget()
-        sel.setMaximumHeight(120)
-        sel_grid = QGridLayout(sel)
-        sel_grid.setContentsMargins(0, 0, 0, 0)
-        sel_grid.setSpacing(3)
-
-        self._combos: list[list[QComboBox]] = []
-        for i in range(self.NUM_PLOTS):
-            lbl = QLabel(f"<b>Plot {i + 1}</b>")
-            lbl.setAlignment(Qt.AlignRight | Qt.AlignVCenter)
-            sel_grid.addWidget(lbl, i, 0)
-            row: list[QComboBox] = []
-            for j in range(self.TRACES):
-                cb = QComboBox()
-                cb.setMinimumWidth(160)
-                cb.addItem("—")
-                cb.currentIndexChanged.connect(self._on_selection_changed)
-                sel_grid.addWidget(cb, i, j + 1)
-                row.append(cb)
-            self._combos.append(row)
-
-        layout.addWidget(sel)
-
-        # ── toolbar row ───────────────────────────────────────────────────────
         tb = QWidget()
         tb_layout = QHBoxLayout(tb)
         tb_layout.setContentsMargins(0, 0, 0, 0)
@@ -316,27 +294,68 @@ class PlotTab(QWidget):
         self._cursor_label.setStyleSheet("font-size: 11px; color: #333;")
         tb_layout.addWidget(self._cursor_label)
         tb_layout.addStretch()
-        layout.addWidget(tb)
+        main_layout.addWidget(tb)
 
-        # ── 2×2 pyqtgraph plot grid ───────────────────────────────────────────
+        # ── data ──────────────────────────────────────────────────────────────
+        self._traces:       list[list[str]] = [[] for _ in range(self.NUM_PLOTS)]
+        self._saved_traces: list[list[str]] = self._load_settings()
+        self._series: dict[str, deque] = {}
+        self._units:  dict[str, str]   = {}
+
+        # ── 2×2 plot grid (each cell: control bar + plot) ─────────────────────
         plot_container = QWidget()
         plot_grid = QGridLayout(plot_container)
         plot_grid.setContentsMargins(0, 0, 0, 0)
         plot_grid.setSpacing(4)
 
-        self._plot_widgets: list[pg.PlotWidget] = []
+        self._plot_widgets: list[pg.PlotWidget]  = []
         self._vlines:       list[pg.InfiniteLine] = []
-        self._proxies:      list = []   # keep SignalProxy refs alive
+        self._proxies:      list = []
+        self._add_combos:   list[QComboBox]       = []
+        self._chip_bars:    list[QHBoxLayout]     = []
 
         for i in range(self.NUM_PLOTS):
+            cell = QWidget()
+            cell_vbox = QVBoxLayout(cell)
+            cell_vbox.setContentsMargins(0, 0, 0, 0)
+            cell_vbox.setSpacing(2)
+
+            # control bar
+            ctrl = QWidget()
+            ctrl.setMaximumHeight(30)
+            ctrl_row = QHBoxLayout(ctrl)
+            ctrl_row.setContentsMargins(0, 0, 0, 0)
+            ctrl_row.setSpacing(4)
+
+            add_combo = QComboBox()
+            add_combo.setMinimumWidth(180)
+            add_combo.addItem("— add trace —")
+            add_combo.setSizePolicy(QSizePolicy.Preferred, QSizePolicy.Fixed)
+            self._add_combos.append(add_combo)
+            ctrl_row.addWidget(add_combo)
+
+            add_btn = QPushButton("+")
+            add_btn.setFixedSize(26, 22)
+            add_btn.clicked.connect(lambda checked, idx=i: self._add_trace(idx))
+            ctrl_row.addWidget(add_btn)
+
+            ctrl_row.addSpacing(8)
+            chip_bar = QHBoxLayout()
+            chip_bar.setSpacing(4)
+            chip_bar.setContentsMargins(0, 0, 0, 0)
+            self._chip_bars.append(chip_bar)
+            ctrl_row.addLayout(chip_bar)
+            ctrl_row.addStretch()
+
+            cell_vbox.addWidget(ctrl)
+
+            # plot
             pw = pg.PlotWidget(
                 background="white",
                 axisItems={"bottom": pg.DateAxisItem(orientation="bottom")},
             )
             pw.showGrid(x=True, y=True, alpha=0.3)
-            pw.getAxis("bottom").setStyle(tickFont=QFont("", 7))
+            pw.addLegend(offset=(0, 0), labelTextSize="8pt")
-            pw.getAxis("left").setStyle(tickFont=QFont("", 7))
-            pw.addLegend(offset=(0, 0), labelTextSize="7pt")
             pw.setSizePolicy(QSizePolicy.Expanding, QSizePolicy.Expanding)
 
             vl = pg.InfiniteLine(
@@ -354,14 +373,55 @@ class PlotTab(QWidget):
             )
             self._proxies.append(proxy)
 
-            plot_grid.addWidget(pw, i // 2, i % 2)
+            cell_vbox.addWidget(pw)
             self._plot_widgets.append(pw)
+            plot_grid.addWidget(cell, i // 2, i % 2)
 
-        layout.addWidget(plot_container)
+        main_layout.addWidget(plot_container)
 
-        # ── data ──────────────────────────────────────────────────────────────
+    # ── trace management ──────────────────────────────────────────────────────
-        self._series: dict[str, deque] = {}
+
-        self._units:  dict[str, str]   = {}
+    def _add_trace(self, plot_idx: int):
+        key    = self._add_combos[plot_idx].currentText()
+        traces = self._traces[plot_idx]
+        if key.startswith("—") or key not in self._series:
+            return
+        if key in traces or len(traces) >= self.MAX_TRACES:
+            return
+        traces.append(key)
+        self._add_chip(plot_idx, key, len(traces) - 1)
+        self._save_settings()
+        self._redraw()
+
+    def _add_chip(self, plot_idx: int, key: str, color_idx: int):
+        short = key.split(".")[-1]
+        color = self.COLORS[color_idx]
+        btn = QPushButton(f"{short}  ×")
+        btn.setFixedHeight(22)
+        btn.setStyleSheet(
+            f"QPushButton {{ background:{color}; color:white; border-radius:3px;"
+            f" padding:1px 6px; font-size:11px; }}"
+            f"QPushButton:hover {{ background:#888; }}"
+        )
+        btn.clicked.connect(lambda: self._remove_trace(plot_idx, key))
+        self._chip_bars[plot_idx].addWidget(btn)
+
+    def _remove_trace(self, plot_idx: int, key: str):
+        if key not in self._traces[plot_idx]:
+            return
+        self._traces[plot_idx].remove(key)
+        self._rebuild_chips(plot_idx)
+        self._save_settings()
+        self._redraw()
+
+    def _rebuild_chips(self, plot_idx: int):
+        bar = self._chip_bars[plot_idx]
+        while bar.count():
+            item = bar.takeAt(0)
+            if item.widget():
+                item.widget().deleteLater()
+        for j, key in enumerate(self._traces[plot_idx]):
+            self._add_chip(plot_idx, key, j)
 
     # ── public update called on every new snapshot ────────────────────────────
 
@@ -392,24 +452,51 @@ class PlotTab(QWidget):
 
         self._redraw()
 
-    # ── combo management ──────────────────────────────────────────────────────
+    # ── combo refresh + saved-trace restore ──────────────────────────────────
 
     def _refresh_combos(self):
         signals = sorted(self._series.keys())
-        for row in self._combos:
+        for combo in self._add_combos:
-            for cb in row:
+            current = combo.currentText()
-                current = cb.currentText()
+            combo.blockSignals(True)
-                cb.blockSignals(True)
+            combo.clear()
-                cb.clear()
+            combo.addItem("— add trace —")
-                cb.addItem("—")
+            for s in signals:
-                for s in signals:
+                combo.addItem(s)
-                    cb.addItem(s)
+            idx = combo.findText(current)
-                idx = cb.findText(current)
+            combo.setCurrentIndex(idx if idx >= 0 else 0)
-                cb.setCurrentIndex(idx if idx >= 0 else 0)
+            combo.blockSignals(False)
-                cb.blockSignals(False)
 
-    def _on_selection_changed(self):
+        for i, saved in enumerate(self._saved_traces):
-        self._redraw()
+            for key in list(saved):
+                if key not in self._series:
+                    continue
+                traces = self._traces[i]
+                if key not in traces and len(traces) < self.MAX_TRACES:
+                    traces.append(key)
+                    self._add_chip(i, key, len(traces) - 1)
+                saved.remove(key)
+
+    # ── settings persistence ──────────────────────────────────────────────────
+
+    def _save_settings(self):
+        try:
+            _SETTINGS_PATH.parent.mkdir(parents=True, exist_ok=True)
+            _SETTINGS_PATH.write_text(
+                json.dumps({"traces": [list(t) for t in self._traces]}, indent=2)
+            )
+        except OSError:
+            pass
+
+    def _load_settings(self) -> list[list[str]]:
+        try:
+            data   = json.loads(_SETTINGS_PATH.read_text())
+            saved  = data.get("traces", [])
+            while len(saved) < self.NUM_PLOTS:
+                saved.append([])
+            return [list(t) for t in saved[: self.NUM_PLOTS]]
+        except (OSError, json.JSONDecodeError, KeyError):
+            return [[] for _ in range(self.NUM_PLOTS)]
 
     # ── drawing ───────────────────────────────────────────────────────────────
 
@@ -421,9 +508,8 @@ class PlotTab(QWidget):
             if pi.legend:
                 pi.legend.clear()
 
-            for j, cb in enumerate(self._combos[i]):
+            for j, key in enumerate(self._traces[i]):
-                key = cb.currentText()
+                if key not in self._series:
-                if key == "—" or key not in self._series:
                     continue
                 series = self._series[key]
                 if not series:
@@ -459,9 +545,8 @@ class PlotTab(QWidget):
         vl.setVisible(True)
 
         parts = []
-        for j, cb in enumerate(self._combos[plot_idx]):
+        for j, key in enumerate(self._traces[plot_idx]):
-            key = cb.currentText()
+            if key not in self._series:
-            if key == "—" or key not in self._series:
                 continue
             series = list(self._series[key])
             if not series:
@@ -506,6 +591,7 @@ class MainWindow(QMainWindow):
 
         self._connector.connect_requested.connect(self._connect)
         self._connector.disconnect_requested.connect(self._disconnect)
+        self._record_count = 0
 
     def _connect(self, host: str, port: int):
         err = self._reader.connect_to(host, port)
@@ -513,8 +599,9 @@ class MainWindow(QMainWindow):
             self._connector.set_disconnected(err)
             self._statusbar.showMessage(f"Connection failed: {err}")
         else:
+            self._record_count = 0
             self._connector.set_connected(host, port)
-            self._statusbar.showMessage(f"Connected to {host}:{port}")
+            self._statusbar.showMessage(f"Connected to {host}:{port}  |  Records: 0")
 
     def _disconnect(self):
         self._reader.disconnect()
@@ -524,8 +611,9 @@ class MainWindow(QMainWindow):
     def _on_message(self, data: dict):
         self._dashboard.update(data)
         self._plot.update(data)
+        self._record_count += 1
         self._statusbar.showMessage(
-            f"Last snapshot: {data.get('ts', '?')}"
+            f"Last snapshot: {data.get('ts', '?')}  |  Records: {self._record_count}"
         )
 
     def _on_connection_lost(self, reason: str):