ColorMap text color (#160)

* Add ability to specify text_color for ColorMap.

* Modify colormap example to include text color.

* Make text_color comment clearer.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Return executionCount to 1

* Use implied line contrinuation to shorten lines

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Apply black autoformatting.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* ENH: add ability to change color of legend's text

* Minor fixes for new text_color argument

* add default value to docstring

---------

Co-authored-by: ThomasBur <thomasbur@outlook>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Frank <33519926+Conengmo@users.noreply.github.com>

Author: 4 people

branca/colormap.py

@@ -72,19 +72,29 @@ class ColorMap(MacroElement):
         The right bound of the color scale.
     caption: str
         A caption to draw with the colormap.
+    text_color: str, default "black"
+        The color for the text.
     max_labels : int, default 10
         Maximum number of legend tick labels
     """
 
     _template = ENV.get_template("color_scale.js")
 
-    def __init__(self, vmin=0.0, vmax=1.0, caption="", max_labels=10):
+    def __init__(
+        self,
+        vmin=0.0,
+        vmax=1.0,
+        caption="",
+        text_color="black",
+        max_labels=10,
+    ):
         super().__init__()
         self._name = "ColorMap"
 
         self.vmin = vmin
         self.vmax = vmax
         self.caption = caption
+        self.text_color = text_color
         self.index = [vmin, vmax]
         self.max_labels = max_labels
         self.tick_labels = None
@@ -185,22 +195,32 @@ def _repr_html_(self):
                     for i in range(self.width)
                 ],
             )
-            + '<text x="0" y="38" style="text-anchor:start; font-size:11px; font:Arial">{}</text>'.format(  # noqa
+            + (
+                '<text x="0" y="38" style="text-anchor:start; font-size:11px;'
+                ' font:Arial; fill:{}">{}</text>'
+            ).format(
+                self.text_color,
                 self.vmin,
             )
             + "".join(
                 [
                     (
-                        '<text x="{}" y="38"; style="text-anchor:middle; font-size:11px; font:Arial">{}</text>'  # noqa
-                    ).format(x_ticks[i], val_ticks[i])
+                        '<text x="{}" y="38"; style="text-anchor:middle; font-size:11px;'
+                        ' font:Arial; fill:{}">{}</text>'
+                    ).format(x_ticks[i], self.text_color, val_ticks[i])
                     for i in range(1, nb_ticks - 1)
                 ],
             )
-            + '<text x="{}" y="38" style="text-anchor:end; font-size:11px; font:Arial">{}</text>'.format(
+            + (
+                '<text x="{}" y="38" style="text-anchor:end; font-size:11px;'
+                ' font:Arial; fill:{}">{}</text>'
+            ).format(
                 self.width,
+                self.text_color,
                 self.vmax,
             )
-            + '<text x="0" y="12" style="font-size:11px; font:Arial">{}</text>'.format(
+            + '<text x="0" y="12" style="font-size:11px; font:Arial; fill:{}">{}</text>'.format(
+                self.text_color,
                 self.caption,
             )
             + "</svg>"
@@ -233,6 +253,10 @@ class LinearColormap(ColorMap):
     vmax : float, default 1.
         The maximal value for the colormap.
         Values higher than `vmax` will be bound directly to `colors[-1]`.
+    caption: str
+        A caption to draw with the colormap.
+    text_color: str, default "black"
+        The color for the text.
     max_labels : int, default 10
         Maximum number of legend tick labels
     tick_labels: list of floats, default None
@@ -245,13 +269,15 @@ def __init__(
         vmin=0.0,
         vmax=1.0,
         caption="",
+        text_color="black",
         max_labels=10,
         tick_labels=None,
     ):
         super().__init__(
             vmin=vmin,
             vmax=vmax,
             caption=caption,
+            text_color=text_color,
             max_labels=max_labels,
         )
         self.tick_labels = tick_labels
@@ -415,13 +441,15 @@ def to_step(
         ]
 
         caption = self.caption
+        text_color = self.text_color
 
         return StepColormap(
             colors,
             index=index,
             vmin=index[0],
             vmax=index[-1],
             caption=caption,
+            text_color=text_color,
             max_labels=max_labels,
             tick_labels=self.tick_labels,
         )
@@ -439,6 +467,7 @@ def scale(self, vmin=0.0, vmax=1.0, max_labels=10):
             vmin=vmin,
             vmax=vmax,
             caption=self.caption,
+            text_color=self.text_color,
             max_labels=max_labels,
         )
 
@@ -469,6 +498,10 @@ class StepColormap(ColorMap):
     vmax : float, default 1.
         The maximal value for the colormap.
         Values higher than `vmax` will be bound directly to `colors[-1]`.
+    caption: str
+        A caption to draw with the colormap.
+    text_color: str, default "black"
+        The color for the text.
     max_labels : int, default 10
         Maximum number of legend tick labels
     tick_labels: list of floats, default None
@@ -482,13 +515,15 @@ def __init__(
         vmin=0.0,
         vmax=1.0,
         caption="",
+        text_color="black",
         max_labels=10,
         tick_labels=None,
     ):
         super().__init__(
             vmin=vmin,
             vmax=vmax,
             caption=caption,
+            text_color=text_color,
             max_labels=max_labels,
         )
         self.tick_labels = tick_labels
@@ -544,6 +579,8 @@ def to_linear(self, index=None, max_labels=10):
             index=index,
             vmin=self.vmin,
             vmax=self.vmax,
+            caption=self.caption,
+            text_color=self.text_color,
             max_labels=max_labels,
         )
 
@@ -560,6 +597,7 @@ def scale(self, vmin=0.0, vmax=1.0, max_labels=10):
             vmin=vmin,
             vmax=vmax,
             caption=self.caption,
+            text_color=self.text_color,
             max_labels=max_labels,
         )
 

branca/templates/color_scale.js

@@ -32,6 +32,7 @@
 
     {{this.get_name()}}.g = {{this.get_name()}}.svg.append("g")
         .attr("class", "key")
+        .attr("fill", {{ this.text_color | tojson }})
         .attr("transform", "translate(25,16)");
 
     {{this.get_name()}}.g.selectAll("rect")
@@ -51,5 +52,6 @@
     {{this.get_name()}}.g.call({{this.get_name()}}.xAxis).append("text")
         .attr("class", "caption")
         .attr("y", 21)
+        .attr("fill", {{ this.text_color | tojson }})
         .text({{ this.caption|tojson }});
 {% endmacro %}