support colorbar.title.text alignment (for orientation=v)

Author: Lexachoc

src/components/colorbar/attributes.js

@@ -226,6 +226,15 @@ module.exports = overrideAll({
                 'Defaults to *top* when `orientation` if *v* and ',
                 'defaults to *right* when `orientation` if *h*.',
             ].join(' ')
+        },
+        align: {
+            valType: 'enumerated',
+            values: ['start', 'middle', 'end'],
+            description: [
+                'Sets the alignment of the color bar\'s title.',
+                'Defaults to *start* when `orientation` if *v*.',
+                'Note: This only takes affect when `orientation` is *v*.'
+            ].join(' ')
         }
     },
 }, 'colorbars', 'from-root');

src/components/colorbar/defaults.js

@@ -133,4 +133,5 @@ module.exports = function colorbarDefaults(containerIn, containerOut, layout) {
     });
     Lib.coerceFont(coerce, 'title.font', dfltTitleFont);
     coerce('title.side', isVertical ? 'top' : 'right');
+    coerce('title.align', isVertical ? 'start' : 'middle');
 };

src/components/colorbar/draw.js

@@ -373,7 +373,7 @@ function drawColorBar(g, opts, gd) {
             }
 
             drawTitle(ax._id + 'title', {
-                attributes: {x: x, y: y, 'text-anchor': isVertical ? 'start' : 'middle'}
+                attributes: {x: x, y: y, 'text-anchor': isVertical ? title.align : 'middle'}
             });
         }
     }