add support for 'text' (scalar value only)

Author: etpinard

src/traces/streamtube/attributes.js

@@ -89,16 +89,16 @@ var attrs = {
         description: ''
     },
 
-    // TODO maybe just remove completely?
     text: {
         valType: 'string',
         role: 'info',
         dflt: '',
         editType: 'calc',
         description: [
-            'Sets the text elements associated with the cones.',
-            'If trace `hoverinfo` contains a *text* flag and *hovertext* is not set,',
-            'these elements will be seen in the hover labels.'
+            'Sets a text element associated with this trace.',
+            'If trace `hoverinfo` contains a *text* flag,',
+            'this text element will be seen in all hover labels.',
+            'Note that streamtube traces do not support array `text` values.'
         ].join(' ')
     }
 };

src/traces/streamtube/convert.js

@@ -55,6 +55,8 @@ proto.handlePick = function(selection) {
             selection.data.divergence
         ];
 
+        selection.textLabel = this.data.text;
+
         return true;
     }
 };

test/jasmine/tests/streamtube_test.js

@@ -274,6 +274,15 @@ describe('@gl Test streamtube hover', function() {
         .then(_hover)
         .then(function() {
             assertHoverLabelContent({nums: 'divergence: 0.465'});
+            return Plotly.restyle(gd, {
+                hoverinfo: 'text',
+                text: '!SCALAR TX!'
+            });
+        })
+        .then(delay(20))
+        .then(_hover)
+        .then(function() {
+            assertHoverLabelContent({nums: '!SCALAR TX!'});
         })
         .catch(failTest)
         .then(done);