add fx supplyDefaults method

- to coerce hoverlabel container in a DRY way

Author: etpinard

src/components/fx/attributes.js

@@ -0,0 +1,38 @@
+/**
+* Copyright 2012-2017, Plotly, Inc.
+* All rights reserved.
+*
+* This source code is licensed under the MIT license found in the
+* LICENSE file in the root directory of this source tree.
+*/
+
+'use strict';
+
+var extendFlat = require('../../lib/extend').extendFlat;
+var fontAttrs = require('../../plots/font_attributes');
+
+module.exports = {
+    hoverlabel: {
+        bgcolor: {
+            valType: 'color',
+            role: 'style',
+            arrayOk: true,
+            description: [
+                'Sets the background color of the hover labels for this trace'
+            ].join(' ')
+        },
+        bordercolor: {
+            valType: 'color',
+            role: 'style',
+            arrayOk: true,
+            description: [
+                'Sets the border color of the hover labels for this trace.'
+            ].join(' ')
+        },
+        font: {
+            family: extendFlat({}, fontAttrs.family, { arrayOk: true }),
+            size: extendFlat({}, fontAttrs.size, { arrayOk: true }),
+            color: extendFlat({}, fontAttrs.color, { arrayOk: true })
+        }
+    }
+};

src/components/fx/defaults.js

@@ -0,0 +1,21 @@
+/**
+* Copyright 2012-2017, Plotly, Inc.
+* All rights reserved.
+*
+* This source code is licensed under the MIT license found in the
+* LICENSE file in the root directory of this source tree.
+*/
+
+'use strict';
+
+var Lib = require('../../lib');
+var attributes = require('./attributes');
+var handleHoverLabelDefaults = require('./hoverlabel_defaults');
+
+module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout) {
+    function coerce(attr, dflt) {
+        return Lib.coerce(traceIn, traceOut, attributes, attr, dflt);
+    }
+
+    handleHoverLabelDefaults(traceIn, traceOut, coerce, layout.hoverlabel);
+};

src/components/fx/hoverlabel_defaults.js

@@ -0,0 +1,19 @@
+/**
+* Copyright 2012-2017, Plotly, Inc.
+* All rights reserved.
+*
+* This source code is licensed under the MIT license found in the
+* LICENSE file in the root directory of this source tree.
+*/
+
+'use strict';
+
+var Lib = require('../../lib');
+
+module.exports = function handleHoverLabelDefaults(contIn, contOut, coerce, opts) {
+    opts = opts || {};
+
+    coerce('hoverlabel.bgcolor', opts.bgcolor);
+    coerce('hoverlabel.bordercolor', opts.bordercolor);
+    Lib.coerceFont(coerce, 'hoverlabel.font', opts.font);
+};

src/components/fx/index.js

@@ -23,7 +23,9 @@ module.exports = {
         layout: layoutAttributes
     },
 
+    attributes: require('./attributes'),
     layoutAttributes: layoutAttributes,
+    supplyDefaults: require('./defaults'),
     supplyLayoutDefaults: require('./layout_defaults'),
 
     calc: require('./calc'),

src/plots/plots.js

@@ -846,9 +846,10 @@ plots.supplyTraceDefaults = function(traceIn, traceOutIndex, layout, traceInInde
             coerce('legendgroup');
         }
 
-        coerce('hoverlabel.bgcolor');
-        coerce('hoverlabel.bordercolor');
-        Lib.coerceFont(coerce, 'hoverlabel.font');
+        Registry.getComponentMethod(
+            'fx',
+            'supplyDefaults'
+        )(traceIn, traceOut, defaultColor, layout);
 
         // TODO add per-base-plot-module trace defaults step