draw labels on contour plots only when colring is heatmap

 - corect label positions for histograd2dcontours

Author: archmoj

src/traces/contour/defaults.js

@@ -33,11 +33,6 @@ module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout
     coerce('hovertext');
     coerce('hoverongaps');
     coerce('hovertemplate');
-    coerce('texttemplate');
-
-    var fontDflt = Lib.extendFlat({}, layout.font);
-    fontDflt.color = undefined; // color contrast by default
-    Lib.coerceFont(coerce, 'textfont', fontDflt);
 
     var isConstraint = (coerce('contours.type') === 'constraint');
     coerce('connectgaps', Lib.isArray1D(traceOut.z));
@@ -48,4 +43,15 @@ module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout
         handleContoursDefaults(traceIn, traceOut, coerce, coerce2);
         handleStyleDefaults(traceIn, traceOut, coerce, layout);
     }
+
+    if(
+        traceOut.contours &&
+        traceOut.contours.coloring === 'heatmap'
+    ) {
+        coerce('texttemplate');
+
+        var fontDflt = Lib.extendFlat({}, layout.font);
+        fontDflt.color = undefined; // color contrast by default
+        Lib.coerceFont(coerce, 'textfont', fontDflt);
+    }
 };

src/traces/heatmap/plot.js

@@ -366,10 +366,15 @@ module.exports = function(gd, plotinfo, cdheatmaps, heatmapLayer) {
                 _numFormat: xa._numFormat
             };
 
+            var isHistogram2dContour = trace.type === 'histogram2dcontour';
+
             var textData = [];
             for(i = 0; i < m; i++) {
                 var yVal;
-                if(cd0.yCenter) {
+                if(isHistogram2dContour) {
+                    if(i === 0 || i === m - 1) continue;
+                    yVal = cd0.y[i];
+                } else if(cd0.yCenter) {
                     yVal = cd0.yCenter[i];
                 } else {
                     if(i + 1 === m && cd0.y[i + 1] === undefined) continue;
@@ -381,7 +386,10 @@ module.exports = function(gd, plotinfo, cdheatmaps, heatmapLayer) {
 
                 for(j = 0; j < n; j++) {
                     var xVal;
-                    if(cd0.xCenter) {
+                    if(isHistogram2dContour) {
+                        if(j === 0 || j === n - 1) continue;
+                        xVal = cd0.x[j];
+                    } else if(cd0.xCenter) {
                         xVal = cd0.xCenter[j];
                     } else {
                         if(j + 1 === n && cd0.x[j + 1] === undefined) continue;

src/traces/histogram2dcontour/defaults.js

@@ -22,13 +22,17 @@ module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout
 
     handleContoursDefaults(traceIn, traceOut, coerce, coerce2);
     handleStyleDefaults(traceIn, traceOut, coerce, layout);
-    coerce('hovertemplate');
-    coerce('texttemplate');
-
-    var fontDflt = Lib.extendFlat({}, layout.font);
-    fontDflt.color = undefined; // color contrast by default
-    Lib.coerceFont(coerce, 'textfont', fontDflt);
-
     coerce('xhoverformat');
     coerce('yhoverformat');
+    coerce('hovertemplate');
+    if(
+        traceOut.contours &&
+        traceOut.contours.coloring === 'heatmap'
+    ) {
+        coerce('texttemplate');
+
+        var fontDflt = Lib.extendFlat({}, layout.font);
+        fontDflt.color = undefined; // color contrast by default
+        Lib.coerceFont(coerce, 'textfont', fontDflt);
+    }
 };

test/image/baselines/contour_legend-colorscale.png

@@ -58,6 +58,13 @@
         }
     ],
     "layout": {
+        "template": {
+            "data": {
+                "contour": [{
+                    "texttemplate": "%{z:.2s}"
+                }]
+            }
+        },
         "title": {"text": "<b>contour legends with heatmap coloring</b><br>red-blue should be equal to reversed blue-red.<br>i.e. display identical legends for identical graphs"},
         "margin": {
             "t": 125,

test/image/baselines/histogram2d_legend.png

@@ -98,6 +98,7 @@
             "showlegend": true,
             "showscale": false,
             "texttemplate": "%{z}",
+            "contours": {"coloring": "heatmap"},
             "type": "histogram2dcontour",
             "name": "histogram2dcontour"
         },
@@ -133,6 +134,7 @@
             "showscale": false,
             "reversescale": true,
             "texttemplate": "%{z}",
+            "contours": {"coloring": "heatmap"},
             "type": "histogram2dcontour",
             "name": "histogram2dcontour reversed scale"
         }