Set image cmap from figure options.

This patch allows the user to interactively set an image's colormap from the axes and lines (and now images) parameters editor (in the Qt backend). Colormaps are listed from those registered with matplotlib.cm. Colorbars seem to be handled properly.
matplotlib · anntzer · Jul 2, 2016 · Jul 9, 2016 · Jul 9, 2016 · Jul 10, 2016
commit 240d24b15e29e1ec4f9689e51725fb01d4ba124d
diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -1732,6 +1732,8 @@ def add_image(self, image):
         Returns the image.
         """
         self._set_artist_props(image)
+        if not image.get_label():
+            image.set_label('_image%d' % len(self.images))
         self.images.append(image)
         image._remove_method = lambda h: self.images.remove(h)
         self.stale = True

diff --git a/lib/matplotlib/backends/qt_editor/figureoptions.py b/lib/matplotlib/backends/qt_editor/figureoptions.py
@@ -16,7 +16,7 @@
 
 import matplotlib.backends.qt_editor.formlayout as formlayout
 from matplotlib.backends.qt_compat import QtGui
-from matplotlib import markers
+from matplotlib import cm, markers
 from matplotlib.colors import colorConverter, rgb2hex
 
 
@@ -43,8 +43,6 @@ def figure_edit(axes, parent=None):
     """Edit matplotlib figure options"""
     sep = (None, None)  # separator
 
-    has_curve = len(axes.get_lines()) > 0
-
     # Get / General
     xmin, xmax = axes.get_xlim()
     ymin, ymax = axes.get_ylim()
@@ -69,79 +67,103 @@ def figure_edit(axes, parent=None):
     xunits = axes.xaxis.get_units()
     yunits = axes.yaxis.get_units()
 
-    if has_curve:
-        # Get / Curves
-        linedict = {}
-        for line in axes.get_lines():
-            label = line.get_label()
-            if label == '_nolegend_':
-                continue
-            linedict[label] = line
-        curves = []
-
-        def prepare_data(d, init):
-            """Prepare entry for FormLayout.
-
-            `d` is a mapping of shorthands to style names (a single style may
-            have multiple shorthands, in particular the shorthands `None`,
-            `"None"`, `"none"` and `""` are synonyms); `init` is one shorthand
-            of the initial style.
-
-            This function returns an list suitable for initializing a
-            FormLayout combobox, namely `[initial_name, (shorthand,
-            style_name), (shorthand, style_name), ...]`.
-            """
-            # Drop duplicate shorthands from dict (by overwriting them during
-            # the dict comprehension).
-            name2short = {name: short for short, name in d.items()}
-            # Convert back to {shorthand: name}.
-            short2name = {short: name for name, short in name2short.items()}
-            # Find the kept shorthand for the style specified by init.
-            canonical_init = name2short[d[init]]
-            # Sort by representation and prepend the initial value.
-            return ([canonical_init] +
-                    sorted(short2name.items(),
-                           key=lambda short_and_name: short_and_name[1]))
-
-        curvelabels = sorted(linedict.keys())
-        for label in curvelabels:
-            line = linedict[label]
-            color = rgb2hex(colorConverter.to_rgb(line.get_color()))
-            ec = rgb2hex(colorConverter.to_rgb(line.get_markeredgecolor()))
-            fc = rgb2hex(colorConverter.to_rgb(line.get_markerfacecolor()))
-            curvedata = [
-                ('Label', label),
-                sep,
-                (None, '<b>Line</b>'),
-                ('Line Style', prepare_data(LINESTYLES, line.get_linestyle())),
-                ('Draw Style', prepare_data(DRAWSTYLES, line.get_drawstyle())),
-                ('Width', line.get_linewidth()),
-                ('Color', color),
-                sep,
-                (None, '<b>Marker</b>'),
-                ('Style', prepare_data(MARKERS, line.get_marker())),
-                ('Size', line.get_markersize()),
-                ('Facecolor', fc),
-                ('Edgecolor', ec)]
-            curves.append([curvedata, label, ""])
-
-        # make sure that there is at least one displayed curve
-        has_curve = bool(curves)
+    # Get / Curves
+    linedict = {}
+    for line in axes.get_lines():
+        label = line.get_label()
+        if label == '_nolegend_':
+            continue
+        linedict[label] = line
+    curves = []
+
+    def prepare_data(d, init):
+        """Prepare entry for FormLayout.
+
+        `d` is a mapping of shorthands to style names (a single style may
+        have multiple shorthands, in particular the shorthands `None`,
+        `"None"`, `"none"` and `""` are synonyms); `init` is one shorthand
+        of the initial style.
+
+        This function returns an list suitable for initializing a
+        FormLayout combobox, namely `[initial_name, (shorthand,
+        style_name), (shorthand, style_name), ...]`.
+        """
+        # Drop duplicate shorthands from dict (by overwriting them during
+        # the dict comprehension).
+        name2short = {name: short for short, name in d.items()}
+        # Convert back to {shorthand: name}.
+        short2name = {short: name for name, short in name2short.items()}
+        # Find the kept shorthand for the style specified by init.
+        canonical_init = name2short[d[init]]
+        # Sort by representation and prepend the initial value.
+        return ([canonical_init] +
+                sorted(short2name.items(),
+                       key=lambda short_and_name: short_and_name[1]))
+
+    curvelabels = sorted(linedict.keys())
+    for label in curvelabels:
+        line = linedict[label]
+        color = rgb2hex(colorConverter.to_rgb(line.get_color()))
+        ec = rgb2hex(colorConverter.to_rgb(line.get_markeredgecolor()))
+        fc = rgb2hex(colorConverter.to_rgb(line.get_markerfacecolor()))
+        curvedata = [
+            ('Label', label),
+            sep,
+            (None, '<b>Line</b>'),
+            ('Line Style', prepare_data(LINESTYLES, line.get_linestyle())),
+            ('Draw Style', prepare_data(DRAWSTYLES, line.get_drawstyle())),
+            ('Width', line.get_linewidth()),
+            ('Color', color),
+            sep,
+            (None, '<b>Marker</b>'),
+            ('Style', prepare_data(MARKERS, line.get_marker())),
+            ('Size', line.get_markersize()),
+            ('Facecolor', fc),
+            ('Edgecolor', ec)]
+        curves.append([curvedata, label, ""])
+    # Is there a curve displayed?
+    has_curve = bool(curves)
+
+    # Get / Images
+    imagedict = {}
+    for image in axes.get_images():
+        label = image.get_label()
+        if label == '_nolegend_':
+            continue
+        imagedict[label] = image
+    imagelabels = sorted(imagedict)
+    images = []
+    cmaps = [(cmap, name) for name, cmap in sorted(cm.cmap_d.items())]
+    for label in imagelabels:
+        image = imagedict[label]
+        cmap = image.get_cmap()
+        if cmap not in cm.cmap_d:
+            cmaps = [(cmap, cmap.name)] + cmaps
+        imagedata = [
+            ('Label', label),
+            ('Colormap', [cmap.name] + cmaps)
+        ]
+        images.append([imagedata, label, ""])
+    # Is there an image displayed?
+    has_image = bool(images)
 
     datalist = [(general, "Axes", "")]
-    if has_curve:
+    if curves:
         datalist.append((curves, "Curves", ""))
+    if images:
+        datalist.append((images, "Images", ""))
 
     def apply_callback(data):
         """This function will be called to apply changes"""
-        if has_curve:
-            general, curves = data
-        else:
-            general, = data
+        general = data.pop(0)
+        curves = data.pop(0) if has_curve else []
+        images = data.pop(0) if has_image else []
+        if data:
+            raise ValueError("Unexpected field")
 
         # Set / General
-        title, xmin, xmax, xlabel, xscale, ymin, ymax, ylabel, yscale, \
-            generate_legend = general
+        (title, xmin, xmax, xlabel, xscale, ymin, ymax, ylabel, yscale,
+         generate_legend) = general
 
         if axes.get_xscale() != xscale:
             axes.set_xscale(xscale)
@@ -162,26 +184,30 @@ def apply_callback(data):
         axes.xaxis._update_axisinfo()
         axes.yaxis._update_axisinfo()
 
-        if has_curve:
-            # Set / Curves
-            for index, curve in enumerate(curves):
-                line = linedict[curvelabels[index]]
-                label, linestyle, drawstyle, linewidth, color, \
-                    marker, markersize, markerfacecolor, markeredgecolor \
-                    = curve
-                line.set_label(label)
-                line.set_linestyle(linestyle)
-                line.set_drawstyle(drawstyle)
-                line.set_linewidth(linewidth)
-                line.set_color(color)
-                if marker is not 'none':
-                    line.set_marker(marker)
-                    line.set_markersize(markersize)
-                    line.set_markerfacecolor(markerfacecolor)
-                    line.set_markeredgecolor(markeredgecolor)
+        # Set / Curves
+        for index, curve in enumerate(curves):
+            line = linedict[curvelabels[index]]
+            (label, linestyle, drawstyle, linewidth, color, marker, markersize,
+             markerfacecolor, markeredgecolor) = curve
+            line.set_label(label)
+            line.set_linestyle(linestyle)
+            line.set_drawstyle(drawstyle)
+            line.set_linewidth(linewidth)
+            line.set_color(color)
+            if marker is not 'none':
+                line.set_marker(marker)
+                line.set_markersize(markersize)
+                line.set_markerfacecolor(markerfacecolor)
+                line.set_markeredgecolor(markeredgecolor)
+
+        # Set / Images
+        for index, image_settings in enumerate(images):
+            image = imagedict[imagelabels[index]]
+            label, cmap = image_settings
+            image.set_label(label)
+            image.set_cmap(cm.get_cmap(cmap))
 
         # re-generate legend, if checkbox is checked
-
         if generate_legend:
             draggable = None
             ncol = 1