Add support for labels on-hover for bar plots

Author: eqbech

src/ert/gui/tools/plot/plottery/plot_context.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from enum import StrEnum
 from typing import TYPE_CHECKING, ClassVar
 
 if TYPE_CHECKING:
@@ -10,6 +11,12 @@
     from .plot_config import PlotConfig
 
 
+class PlotType(StrEnum):
+    LINE = "LINE"
+    BAR = "BAR"
+    SCATTER = "SCATTER"
+
+
 class PlotContext:
     UNKNOWN_AXIS = None
     VALUE_AXIS = "VALUE"
@@ -25,9 +32,6 @@ class PlotContext:
         INDEX_AXIS,
         VALUE_AXIS,
     ]
-    PLOT_TYPES: ClassVar[list[str]] = [
-        "BAR",
-    ]
 
     def __init__(
         self,
@@ -51,7 +55,7 @@ def __init__(
         self._log_scale = False
         self._extended_plot_information = False
 
-        self._plot_type: str | None = None
+        self._plot_type: PlotType | None = None
 
     @property
     def flip_response_axis(self) -> bool:
@@ -116,15 +120,11 @@ def y_axis(self, value: str) -> None:
         self._y_axis = value
 
     @property
-    def plot_type(self) -> str | None:
+    def plot_type(self) -> PlotType | None:
         return self._plot_type
 
     @plot_type.setter
-    def plot_type(self, value: str) -> None:
-        if value not in PlotContext.PLOT_TYPES:
-            raise UserWarning(
-                f"Plot type: '{value}' is not one of: {PlotContext.PLOT_TYPES}"
-            )
+    def plot_type(self, value: PlotType) -> None:
         self._plot_type = value
 
     def setXLabel(self, value: str) -> None:

src/ert/gui/tools/plot/plottery/plots/everest_gradients_plot.py

@@ -5,6 +5,8 @@
 import numpy as np
 import pandas as pd
 
+from ert.gui.tools.plot.plottery.plot_context import PlotType
+
 from .plot_tools import ConditionalAxisFormatter, PlotTools
 
 if TYPE_CHECKING:
@@ -50,7 +52,7 @@ def plot(
 
         plot_context.y_axis = plot_context.VALUE_AXIS
         plot_context.x_axis = plot_context.INDEX_AXIS
-        plot_context.plot_type = "BAR"
+        plot_context.plot_type = PlotType.BAR
         plot_context.deactivateDateSupport()
 
         response_key = key_def.key if key_def else "Response"
@@ -85,6 +87,8 @@ def plot(
         n_controls = len(self.selected_controls)
         bar_width = 0.8 / n_controls
 
+        bar_containers = []
+
         for i, control in enumerate(self.selected_controls):
             color = colors[i % len(colors)][0]
             values = []
@@ -105,6 +109,8 @@ def plot(
                 alpha=0.7,
             )
             config.addLegendItem(control, bars[0])
+            bar_containers.append(bars)
+
         axes.axhline(0, color="black", linewidth=1.0, alpha=0.3)
         axes.set_xticks(pos)
         axes.set_xticklabels([f"Batch {b}" for b in batch_ids], rotation=0)
@@ -113,6 +119,16 @@ def plot(
         axes.spines["left"].set_visible(False)
         axes.spines["top"].set_visible(False)
 
+        bar_labels = [
+            f"batch {batch}\n{control}"
+            for batch in batch_ids
+            for control in self.selected_controls
+        ]
+
+        PlotTools.labels_on_hover(
+            axes, plot_context, figure, (bar_containers, bar_labels)
+        )
+
         PlotTools.finalizePlot(
             plot_context,
             figure,

src/ert/gui/tools/plot/plottery/plots/plot_tools.py

@@ -1,9 +1,13 @@
 from __future__ import annotations
 
 import math
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Any
 
 import matplotlib.ticker as mticker
+from matplotlib.backend_bases import Event
+from matplotlib.text import Annotation
+
+from ert.gui.tools.plot.plottery.plot_context import PlotType
 
 if TYPE_CHECKING:
     from datetime import date
@@ -33,7 +37,7 @@ def __init__(
         self,
         low: float = 1e-3,
         high: float = 1e4,
-        precision: float = 0,
+        precision: int = 0,
     ) -> None:
         self.low = low
         self.high = high
@@ -61,7 +65,7 @@ class PlotTools:
     def showGrid(axes: Axes, plot_context: PlotContext) -> None:
         config = plot_context.plotConfig()
         if config.isGridEnabled():
-            if plot_context.plot_type == "BAR":
+            if plot_context.plot_type == PlotType.BAR:
                 axes.grid(axis="y", color="black", alpha=0.1)
             else:
                 axes.grid(visible=True, color="black", alpha=0.4)
@@ -163,3 +167,56 @@ def __setupLabels(
 
         if config.yLabel() is None:
             config.setYLabel(default_y_label)
+
+    @staticmethod
+    def labels_on_hover(
+        axes: Axes,
+        plot_context: PlotContext,
+        figure: Figure,
+        data: tuple[list[Any], list[str]],
+    ) -> None:
+        annot = axes.annotate(
+            "",
+            xy=(0, 0),
+            xytext=(-40, 10),
+            textcoords="offset points",
+            bbox={"boxstyle": "round,pad=0.5", "fc": "pink", "alpha": 0.7},
+            arrowprops={"arrowstyle": "->", "connectionstyle": "arc3,rad=0"},
+        )
+        annot.set_visible(False)
+
+        if plot_context.plot_type == PlotType.BAR:
+            figure.canvas.mpl_connect(
+                "motion_notify_event",
+                lambda event: PlotTools.__on_hover_bar_group(
+                    event, axes, annot, figure, data
+                ),
+            )
+        else:
+            raise NotImplementedError(
+                f"Hover labels not implemented for: {plot_context.plot_type}"
+            )
+
+    @staticmethod
+    def __on_hover_bar_group(
+        event: Event,
+        axes: Axes,
+        annot: Annotation,
+        figure: Figure,
+        data: tuple[list[Any], list[str]],
+    ) -> None:
+        if event.inaxes == axes:  # type: ignore
+            for bar_container_idx, bars in enumerate(data[0]):
+                for bar_idx, bar in enumerate(bars):
+                    if bar.contains(event)[0]:
+                        value = bar.get_height()
+
+                        annot.xy = (bar.get_x() + bar.get_width() / 2, value)
+                        idx = bar_idx * len(data[0]) + bar_container_idx
+                        annot.set_text(f"{data[1][idx]}\nValue: {value:.3g}")
+                        annot.set_visible(True)
+                        figure.canvas.draw_idle()
+                        return
+
+        annot.set_visible(False)
+        figure.canvas.draw_idle()