First working version of lasso select in plot_evoked_topo

mne/viz/evoked_field.py

@@ -67,6 +67,10 @@ class EvokedField:
         The number of contours.
 
         .. versionadded:: 0.21
+    contour_line_width : float
+        The line_width of the contour lines.
+
+        .. versionadded:: 1.6
     show_density : bool
         Whether to draw the field density as an overlay on top of the helmet/head
         surface. Defaults to ``True``.
@@ -111,6 +115,7 @@ def __init__(
         fig=None,
         vmax=None,
         n_contours=21,
+        contour_line_width=1.0,
         show_density=True,
         alpha=None,
         interpolation="nearest",
@@ -132,6 +137,7 @@ def __init__(
 
         self._vmax = _validate_type(vmax, (None, "numeric", dict), "vmax")
         self._n_contours = _ensure_int(n_contours, "n_contours")
+        self._contour_line_width = contour_line_width
         self._time_interpolation = _check_option(
             "interpolation",
             interpolation,
@@ -354,6 +360,7 @@ def _update(self):
                         vmin=-surf_map["map_vmax"],
                         vmax=surf_map["map_vmax"],
                         colormap=self._colormap_lines,
+                        width=self._contour_line_width,
                     )
         if self._time_label is not None:
             if hasattr(self, "_time_label_actor"):
@@ -442,6 +449,16 @@ def _callback(vmax, type, scaling):
             callback=self.set_contours,
             layout=layout,
         )
+
+        self._widgets["contours_line_width"] = r._dock_add_slider(
+            name="Thickness",
+            value=1,
+            rng=[0, 10],
+            callback=self.set_contour_line_width,
+            double=True,
+            layout=layout,
+        )
+
         r._dock_finalize()
 
     def _on_time_change(self, event):
@@ -503,9 +520,13 @@ def _on_contours(self, event):
                 break
         surf_map["contours"] = event.contours
         self._n_contours = len(event.contours)
+        if event.line_width is not None:
+            self._contour_line_width = event.line_width
         with disable_ui_events(self):
             if "contours" in self._widgets:
                 self._widgets["contours"].set_value(len(event.contours))
+            if "contour_line_width" in self._widgets and event.line_width is not None:
+                self._widgets["contour_line_width"].set_value(event.line_width)
         self._update()
 
     def set_time(self, time):
@@ -540,6 +561,7 @@ def set_contours(self, n_contours):
                     contours=np.linspace(
                         -surf_map["map_vmax"], surf_map["map_vmax"], n_contours
                     ).tolist(),
+                    line_width=self._contour_line_width,
                 ),
             )
 
@@ -574,3 +596,14 @@ def _rescale(self):
             current_data = surf_map["data_interp"](self._current_time)
             vmax = float(np.max(current_data))
             self.set_vmax(vmax, type=surf_map["map_kind"])
+
+    def set_contour_line_width(self, line_width):
+        """Set the line_width of the contour lines.
+
+        Parameters
+        ----------
+        line_width : float
+            The desired line_width of the contour lines.
+        """
+        self._contour_line_width = line_width
+        self.set_contours(self._n_contours)

mne/viz/topo.py

@@ -26,6 +26,7 @@
     _setup_ax_spines,
     _check_cov,
     _plot_masked_image,
+    SelectFromCollection,
 )
 
 
@@ -195,8 +196,11 @@ def format_coord_multiaxis(x, y, ch_name=None):
         under_ax.set(xlim=[0, 1], ylim=[0, 1])
 
         axs = list()
+
+    shown_ch_names = []
     for idx, name in iter_ch:
         ch_idx = ch_names.index(name)
+        shown_ch_names.append(name)
         if not unified:  # old, slow way
             ax = plt.axes(pos[idx])
             ax.patch.set_facecolor(axis_facecolor)
@@ -237,15 +241,22 @@ def format_coord_multiaxis(x, y, ch_name=None):
             ],
             [1, 0, 2],
         )
-        if not img:
-            under_ax.add_collection(
-                collections.PolyCollection(
-                    verts,
-                    facecolor=axis_facecolor,
-                    edgecolor=axis_spinecolor,
-                    linewidth=1.0,
-                )
-            )  # Not needed for image plots.
+        if not img:  # Not needed for image plots.
+            collection = collections.PolyCollection(
+                verts,
+                facecolor=axis_facecolor,
+                edgecolor=axis_spinecolor,
+            )
+            under_ax.add_collection(collection)
+            fig.lasso = SelectFromCollection(
+                ax=under_ax,
+                collection=collection,
+                names=shown_ch_names,
+                alpha_nonselected=0,
+                alpha_selected=1,
+                linewidth_nonselected=0,
+                linewidth_selected=0.7,
+            )
         for ax in axs:
             yield ax, ax._mne_ch_idx
 
@@ -344,6 +355,9 @@ def _plot_topo_onpick(event, show_func):
     """Onpick callback that shows a single channel in a new figure."""
     # make sure that the swipe gesture in OS-X doesn't open many figures
     orig_ax = event.inaxes
+    if orig_ax.figure.canvas._key in ["shift", "alt"]:
+        return
+
     import matplotlib.pyplot as plt
 
     try:

mne/viz/ui_events.py

@@ -176,6 +176,9 @@ class Contours(UIEvent):
         kinds.
     contours : list of float
         The new values at which contour lines need to be drawn.
+    line_width : float | None
+        The line_width with which to draw the contour lines. Can be ``None`` to
+        indicate to keep using the current line_width.
 
     Attributes
     ----------
@@ -186,10 +189,34 @@ class Contours(UIEvent):
         kinds.
     contours : list of float
         The new values at which contour lines need to be drawn.
+    line_width : float | None
+        The line_width with which to draw the contour lines. Can be ``None`` to
+        indicate to keep using the current line_width.
     """
 
     kind: str
     contours: List[str]
+    line_width: Optional[float]
+
+
+@dataclass
+@fill_doc
+class ChannelsSelect(UIEvent):
+    """Indicates that the user has selected one or more channels.
+
+    Parameters
+    ----------
+    ch_names : list of str
+        The names of the channels that were selected.
+
+    Attributes
+    ----------
+    %(ui_event_name_source)s
+    ch_names : list of str
+        The names of the channels that were selected.
+    """
+
+    ch_names: List[str]
 
 
 def _get_event_channel(fig):