Inverse-transform text on layout transition

src/components/drawing/index.js

@@ -692,6 +692,36 @@ drawing.setPointGroupScale = function(selection, x, y) {
     return scale;
 };
 
+var TEXT_POINT_LAST_TRANSLATION_RE = /translate\([^)]*\)\s*$/;
+
+drawing.setTextPointsScale = function(selection, xScale, yScale) {
+    selection.each(function() {
+        var transforms;
+        var el = d3.select(this);
+        var text = el.select('text');
+        var x = parseFloat(text.attr('x') || 0);
+        var y = parseFloat(text.attr('y') || 0);
+
+        var existingTransform = (el.attr('transform') || '').match(TEXT_POINT_LAST_TRANSLATION_RE);
+
+        if(xScale === 1 && yScale === 1) {
+            transforms = [];
+        } else {
+            transforms = [
+                'translate(' + x + ',' + y + ')',
+                'scale(' + xScale + ',' + yScale + ')',
+                'translate(' + (-x) + ',' + (-y) + ')',
+            ];
+        }
+
+        if(existingTransform) {
+            transforms.push(existingTransform);
+        }
+
+        el.attr('transform', transforms.join(' '));
+    });
+};
+
 drawing.measureText = function(tester, text, font) {
     var dummyText = tester.append('text')
         .text(text)

src/plots/cartesian/dragbox.js

@@ -30,7 +30,6 @@ var constants = require('./constants');
 var MINDRAG = constants.MINDRAG;
 var MINZOOM = constants.MINZOOM;
 
-
 // flag for showing "doubleclick to zoom out" only at the beginning
 var SHOWZOOMOUTTIP = true;
 
@@ -747,6 +746,10 @@ module.exports = function dragBox(gd, plotinfo, x, y, w, h, ns, ew) {
                 // as a whole:
                 .select('.scatterlayer').selectAll('.points').selectAll('.point')
                     .call(Drawing.setPointGroupScale, xScaleFactor2, yScaleFactor2);
+
+            subplot.plot.select('.scatterlayer')
+                .selectAll('.points').selectAll('.textpoint')
+                .call(Drawing.setTextPointsScale, xScaleFactor2, yScaleFactor2);
         }
     }
 

src/plots/cartesian/transition_axes.js

@@ -148,9 +148,11 @@ module.exports = function transitionAxes(gd, newLayout, transitionOpts, makeOnCo
             // This is specifically directed at scatter traces, applying an inverse
             // scale to individual points to counteract the scale of the trace
             // as a whole:
-            .selectAll('.points').selectAll('.point')
+            .select('.scatterlayer').selectAll('.points').selectAll('.point')
                 .call(Drawing.setPointGroupScale, 1, 1);
 
+        subplot.plot.select('.scatterlayer').selectAll('.points').selectAll('.textpoint')
+            .call(Drawing.setTextPointsScale, 1, 1);
     }
 
     function updateSubplot(subplot, progress) {
@@ -229,6 +231,8 @@ module.exports = function transitionAxes(gd, newLayout, transitionOpts, makeOnCo
             .selectAll('.points').selectAll('.point')
                 .call(Drawing.setPointGroupScale, 1 / xScaleFactor, 1 / yScaleFactor);
 
+        subplot.plot.selectAll('.points').selectAll('.textpoint')
+            .call(Drawing.setTextPointsScale, 1 / xScaleFactor, 1 / yScaleFactor);
     }
 
     var onComplete;

src/traces/scatter/plot.js

@@ -452,15 +452,14 @@ function plotOne(gd, idx, plotinfo, cdscatter, cdscatterAll, element, transition
 
         // each text needs to go in its own 'g' in case
         // it gets converted to mathjax
-        join.enter().append('g').append('text');
+        join.enter().append('g').classed('textpoint', true).append('text');
 
         join.each(function(d) {
             var sel = transition(d3.select(this).select('text'));
             Drawing.translatePoint(d, sel, xa, ya);
         });
 
         join.selectAll('text')
-            .classed('textpoint', true)
             .call(Drawing.textPointStyle, trace)
             .each(function(d) {
 

test/jasmine/tests/drawing_test.js

@@ -308,4 +308,38 @@ describe('Drawing', function() {
             expect(el.getAttribute('transform')).toBe('translate(1,2)');
         });
     });
+
+    describe('setTextPointsScale', function() {
+        var svg, g, text;
+
+        beforeEach(function() {
+            svg = d3.select(document.createElement('svg'));
+            g = svg.append('g');
+            text = g.append('text');
+        });
+
+        it('sets the transform on an empty element', function() {
+            Drawing.setTextPointsScale(g, 2, 3);
+            expect(g.attr('transform')).toEqual('translate(0,0) scale(2,3) translate(0,0)');
+        });
+
+        it('unsets the transform', function() {
+            Drawing.setTextPointsScale(g, 1, 1);
+            expect(g.attr('transform')).toEqual('');
+        });
+
+        it('preserves a leading translate', function() {
+            Drawing.setTextPointsScale(g, 1, 1);
+            g.attr('transform', 'translate(1, 2)');
+            expect(g.attr('transform')).toEqual('translate(1, 2)');
+        });
+
+        it('preserves transforms', function() {
+            text.attr('x', 8);
+            text.attr('y', 9);
+            g.attr('transform', 'translate(1, 2)');
+            Drawing.setTextPointsScale(g, 4, 5);
+            expect(g.attr('transform')).toEqual('translate(8,9) scale(4,5) translate(-8,-9) translate(1, 2)');
+        });
+    });
 });