lint in titles/index.js

- use `OPPOSITE_SIDE` constants
- use `shiftSign` result in `maxshift` computation

Author: etpinard

src/components/titles/index.js

@@ -20,10 +20,7 @@ var Color = require('../color');
 var svgTextUtils = require('../../lib/svg_text_utils');
 var interactConstants = require('../../constants/interactions');
 
-module.exports = {
-    draw: draw
-};
-
+var OPPOSITE_SIDE = require('../../constants/alignment').OPPOSITE_SIDE;
 var numStripRE = / [XY][0-9]* /;
 
 /**
@@ -167,29 +164,26 @@ function draw(gd, titleClass, options) {
 
             // move toward avoid.side (= left, right, top, bottom) if needed
             // can include pad (pixels, default 2)
-            var shift = 0;
-            var backside = {
-                left: 'right',
-                right: 'left',
-                top: 'bottom',
-                bottom: 'top'
-            }[avoid.side];
-            var shiftSign = (['left', 'top'].indexOf(avoid.side) !== -1) ?
-                    -1 : 1;
+            var backside = OPPOSITE_SIDE[avoid.side];
+            var shiftSign = (avoid.side === 'left' || avoid.side === 'top') ? -1 : 1;
             var pad = isNumeric(avoid.pad) ? avoid.pad : 2;
+
             var titlebb = Drawing.bBox(titleGroup.node());
             var paperbb = {
                 left: 0,
                 top: 0,
                 right: fullLayout.width,
                 bottom: fullLayout.height
             };
-            var maxshift = avoid.maxShift || (
-                (paperbb[avoid.side] - titlebb[avoid.side]) *
-                ((avoid.side === 'left' || avoid.side === 'top') ? -1 : 1));
+
+            var maxshift = avoid.maxShift ||
+                shiftSign * (paperbb[avoid.side] - titlebb[avoid.side]);
+            var shift = 0;
+
             // Prevent the title going off the paper
-            if(maxshift < 0) shift = maxshift;
-            else {
+            if(maxshift < 0) {
+                shift = maxshift;
+            } else {
                 // so we don't have to offset each avoided element,
                 // give the title the opposite offset
                 var offsetLeft = avoid.offsetLeft || 0;
@@ -211,15 +205,15 @@ function draw(gd, titleClass, options) {
                 });
                 shift = Math.min(maxshift, shift);
             }
+
             if(shift > 0 || maxshift < 0) {
                 var shiftTemplate = {
                     left: [-shift, 0],
                     right: [shift, 0],
                     top: [0, -shift],
                     bottom: [0, shift]
                 }[avoid.side];
-                titleGroup.attr('transform',
-                    'translate(' + shiftTemplate + ')');
+                titleGroup.attr('transform', 'translate(' + shiftTemplate + ')');
             }
         }
     }
@@ -265,3 +259,7 @@ function draw(gd, titleClass, options) {
 
     return group;
 }
+
+module.exports = {
+    draw: draw
+};