Feature: allow user control over axis title angle

chaco/axis.py

@@ -52,6 +52,9 @@ class PlotAxis(AbstractOverlay):
     # The color of the title.
     title_color = ColorTrait("black")
 
+    # The angle of the title, in degrees, from horizontal line
+    title_angle = Float(0.)
+
     # The thickness (in pixels) of each tick.
     tick_weight = Float(1.0)
 
@@ -535,7 +538,6 @@ def _calculate_geometry(self):
             self._minor_axis_size = self.bounds[1]
             self._major_axis = array([1., 0.])
             self._title_orientation = array([0.,1.])
-            self.title_angle = 0.0
             if self.orientation == 'top':
                 self._origin_point = array(self.position)
                 self._inside_vector = array([0.,-1.])
@@ -553,11 +555,9 @@ def _calculate_geometry(self):
             if self.orientation == 'left':
                 self._origin_point = array(self.position) + array([self.bounds[0], 0.])
                 self._inside_vector = array([1., 0.])
-                self.title_angle = 90.0
             else: #self.orientation == 'right'
                 self._origin_point = array(self.position)
                 self._inside_vector = array([-1., 0.])
-                self.title_angle = 270.0
             if "top" in origin:
                 screenlow, screenhigh = screenhigh, screenlow
 
@@ -584,7 +584,6 @@ def _calculate_geometry_overlay(self, overlay_component=None):
             self._minor_axis_size = overlay_component.bounds[1]
             self._major_axis = array([1., 0.])
             self._title_orientation = array([0.,1.])
-            self.title_angle = 0.0
             if self.orientation == 'top':
                 self._origin_point = array([overlay_component.x, overlay_component.y2])
                 self._inside_vector = array([0.0, -1.0])
@@ -602,11 +601,9 @@ def _calculate_geometry_overlay(self, overlay_component=None):
             if self.orientation == 'left':
                 self._origin_point = array([overlay_component.x, overlay_component.y])
                 self._inside_vector = array([1.0, 0.0])
-                self.title_angle = 90.0
             else:
                 self._origin_point = array([overlay_component.x2, overlay_component.y])
                 self._inside_vector = array([-1.0, 0.0])
-                self.title_angle = 270.0
             if "top" in component_origin:
                 screenlow, screenhigh = screenhigh, screenlow
 
@@ -728,6 +725,7 @@ def _anytrait_changed(self, name, old, new):
             'title_font',
             'title_spacing',
             'title_color',
+            'title_angle',
             'tick_weight',
             'tick_color',
             'tick_label_font',
@@ -756,6 +754,18 @@ def _anytrait_changed(self, name, old, new):
         if name in invalidate_traits:
             self._invalidate()
 
+    # ------------------------------------------------------------------------
+    # Initialization-related methods
+    # ------------------------------------------------------------------------
+
+    def _title_angle_default(self):
+        if self.orientation == 'left':
+            return 90.0
+        if self.orientation == 'right':
+            return 270.0
+        # Then self.orientation in {'top', 'bottom'}
+        return 0.0
+
     #------------------------------------------------------------------------
     # Persistence-related methods
     #------------------------------------------------------------------------
@@ -795,6 +805,7 @@ def __setstate__(self, state):
         self._cache_valid = False
         return
 
+
 class MinorPlotAxis(PlotAxis):
     """
     The MinorPlotAxis is a PlotAxis which draws ticks with a smaller interval,

docs/source/user_manual/basic_elements/overlays.rst

@@ -88,14 +88,17 @@ These attributes control the appearance of the axis:
 :attr:`~chaco.axis.PlotAxis.title_font`,
 :attr:`~chaco.axis.PlotAxis.title_color`,
 :attr:`~chaco.axis.PlotAxis.title_spacing`
+:attr:`~chaco.axis.PlotAxis.title_angle`
 
   Define the axis label. :attr:`title` is a string or unicode object
   that is rendered using the given font and color. :attr:`title_font` is
   a string describing a font (e.g. '12 pt bold italic',
   'swiss family Arial' or 'default 12'; see
   :class:`~kiva.kiva_font_trait.TraitKivaFont` for details).
   Finally, :attr:`title_spacing` is the space between the axis line and the
-  title (either the number of pixels or 'auto', default).
+  title (either the number of pixels or 'auto', default) and
+  :attr:`title_angle` can be overridden to change the rotation angle (in deg,
+  wrt horizontal).
 
 
 :attr:`~chaco.axis.PlotAxis.tick_weight`,

examples/demo/basic/line_plot1.py

@@ -34,10 +34,11 @@ def _create_plot_component():
         pd.set_data("y" + str(i), jn(i,x))
 
     # Create some line plots of some of the data
-    plot1 = Plot(pd, title="Line Plot", padding=50, border_visible=True)
+    plot1 = Plot(pd, title="Line Plot", padding=60, border_visible=True)
     plot1.legend.visible = True
     plot1.plot(("index", "y0", "y1", "y2"), name="j_n, n<3", color="red")
     plot1.plot(("index", "y3"), name="j_3", color="blue")
+    plot1.value_axis.title = "J0, J1, J2, J3"
 
     # Attach some tools to the plot
     plot1.tools.append(PanTool(plot1))
@@ -46,10 +47,15 @@ def _create_plot_component():
 
     # Create a second scatter plot of one of the datasets, linking its
     # range to the first plot
-    plot2 = Plot(pd, range2d=plot1.range2d, title="Scatter plot", padding=50,
+    plot2 = Plot(pd, range2d=plot1.range2d, title="Scatter plot", padding=60,
                  border_visible=True)
     plot2.plot(('index', 'y3'), type="scatter", color="blue", marker="circle")
 
+    # Configure the vertical axis:
+    plot2.value_axis.title = "J3"
+    plot2.value_axis.orientation = "right"
+    plot2.value_axis.title_angle = 0.0  # instead of default 270 deg
+
     # Create a container and add our plots
     container = HPlotContainer()
     container.add(plot1)