Add event.location property.

notebooks/using_show_and_widgets.ipynb

@@ -493,7 +493,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "d58975ba",
+   "id": "0e1adc74",
    "metadata": {},
    "source": [
     "## Handling PlotWidget clicks\n",
@@ -504,14 +504,14 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "ba3cbe25",
+   "id": "439c2809",
    "metadata": {},
    "outputs": [],
    "source": [
     "from baukit import Textbox\n",
     "coord_b = Textbox()\n",
     "def handle_click(e):\n",
-    "    loc = pw.event_location(e)\n",
+    "    loc = e.target.event_location(e)\n",
     "    coord_b.value = f'x,y=({loc.x:.2f}, {loc.y:.2f}) inside={loc.inside}'\n",
     "pw.on('click', handle_click)\n",
     "show(show.TIGHT, [['Click the previous plot to see coordinates here:', coord_b]])"