Align interactions when plot created inside scaled and/or translated elements using CSS transform

src/components/fx/hover.js

@@ -192,7 +192,9 @@ exports.loneHover = function loneHover(hoverItems, opts) {
             d.offset -= anchor;
         });
 
-    alignHoverText(hoverLabel, fullOpts.rotateLabels);
+    var scaleX = opts.gd._fullLayout._inverseScaleX;
+    var scaleY = opts.gd._fullLayout._inverseScaleY;
+    alignHoverText(hoverLabel, fullOpts.rotateLabels, scaleX, scaleY);
 
     return multiHover ? hoverLabel : hoverLabel.node();
 };
@@ -336,6 +338,11 @@ function _hover(gd, evt, subplot, noHoverEvent) {
             xpx = evt.clientX - dbb.left;
             ypx = evt.clientY - dbb.top;
 
+            var transformedCoords = Lib.apply3DTransform(fullLayout._inverseTransform)(xpx, ypx);
+
+            xpx = transformedCoords[0];
+            ypx = transformedCoords[1];
+
             // in case hover was called from mouseout into hovertext,
             // it's possible you're not actually over the plot anymore
             if(xpx < 0 || xpx > xaArray[0]._length || ypx < 0 || ypx > yaArray[0]._length) {
@@ -716,10 +723,8 @@ function _hover(gd, evt, subplot, noHoverEvent) {
 
     if(!helpers.isUnifiedHover(hovermode)) {
         hoverAvoidOverlaps(hoverLabels, rotateLabels ? 'xa' : 'ya', fullLayout);
-        alignHoverText(hoverLabels, rotateLabels);
-    }
-
-    // TODO: tagName hack is needed to appease geo.js's hack of using evt.target=true
+        alignHoverText(hoverLabels, rotateLabels, fullLayout._inverseScaleX, fullLayout._inverseScaleY);
+    }    // TODO: tagName hack is needed to appease geo.js's hack of using evt.target=true
     // we should improve the "fx" API so other plots can use it without these hack.
     if(evt.target && evt.target.tagName) {
         var hasClickToShow = Registry.getComponentMethod('annotations', 'hasClickToShow')(gd, newhoverdata);
@@ -1477,7 +1482,10 @@ function hoverAvoidOverlaps(hoverLabels, axKey, fullLayout) {
     }
 }
 
-function alignHoverText(hoverLabels, rotateLabels) {
+function alignHoverText(hoverLabels, rotateLabels, scaleX, scaleY) {
+    var pX = function(x) { return x * scaleX; };
+    var pY = function(y) { return y * scaleY; };
+
     // finally set the text positioning relative to the data and draw the
     // box around it
     hoverLabels.each(function(d) {
@@ -1493,7 +1501,8 @@ function alignHoverText(hoverLabels, rotateLabels) {
         var offsetX = 0;
         var offsetY = d.offset;
 
-        if(anchor === 'middle') {
+        var isMiddle = anchor === 'middle';
+        if(isMiddle) {
             txx -= d.tx2width / 2;
             tx2x += d.txwidth / 2 + HOVERTEXTPAD;
         }
@@ -1502,49 +1511,50 @@ function alignHoverText(hoverLabels, rotateLabels) {
             offsetX = d.offset * YSHIFTX;
         }
 
-        g.select('path').attr('d', anchor === 'middle' ?
+        g.select('path')
+            .attr('d', isMiddle ?
             // middle aligned: rect centered on data
-            ('M-' + (d.bx / 2 + d.tx2width / 2) + ',' + (offsetY - d.by / 2) +
-              'h' + d.bx + 'v' + d.by + 'h-' + d.bx + 'Z') :
+            ('M-' + pX(d.bx / 2 + d.tx2width / 2) + ',' + pY(offsetY - d.by / 2) +
+              'h' + pX(d.bx) + 'v' + pY(d.by) + 'h-' + pX(d.bx) + 'Z') :
             // left or right aligned: side rect with arrow to data
-            ('M0,0L' + (horzSign * HOVERARROWSIZE + offsetX) + ',' + (HOVERARROWSIZE + offsetY) +
-                'v' + (d.by / 2 - HOVERARROWSIZE) +
-                'h' + (horzSign * d.bx) +
-                'v-' + d.by +
-                'H' + (horzSign * HOVERARROWSIZE + offsetX) +
-                'V' + (offsetY - HOVERARROWSIZE) +
+            ('M0,0L' + pX(horzSign * HOVERARROWSIZE + offsetX) + ',' + pY(HOVERARROWSIZE + offsetY) +
+                'v' + pY(d.by / 2 - HOVERARROWSIZE) +
+                'h' + pX(horzSign * d.bx) +
+                'v-' + pY(d.by) +
+                'H' + pX(horzSign * HOVERARROWSIZE + offsetX) +
+                'V' + pY(offsetY - HOVERARROWSIZE) +
                 'Z'));
 
-        var posX = txx + offsetX;
+        var posX = offsetX + txx;
         var posY = offsetY + d.ty0 - d.by / 2 + HOVERTEXTPAD;
         var textAlign = d.textAlign || 'auto';
 
         if(textAlign !== 'auto') {
             if(textAlign === 'left' && anchor !== 'start') {
                 tx.attr('text-anchor', 'start');
-                posX = anchor === 'middle' ?
+                posX = isMiddle ?
                     -d.bx / 2 - d.tx2width / 2 + HOVERTEXTPAD :
                     -d.bx - HOVERTEXTPAD;
             } else if(textAlign === 'right' && anchor !== 'end') {
                 tx.attr('text-anchor', 'end');
-                posX = anchor === 'middle' ?
+                posX = isMiddle ?
                     d.bx / 2 - d.tx2width / 2 - HOVERTEXTPAD :
                     d.bx + HOVERTEXTPAD;
             }
         }
 
-        tx.call(svgTextUtils.positionText, posX, posY);
+        tx.call(svgTextUtils.positionText, pX(posX), pY(posY));
 
         if(d.tx2width) {
             g.select('text.name')
                 .call(svgTextUtils.positionText,
-                    tx2x + alignShift * HOVERTEXTPAD + offsetX,
-                    offsetY + d.ty0 - d.by / 2 + HOVERTEXTPAD);
+                    pX(tx2x + alignShift * HOVERTEXTPAD + offsetX),
+                    pY(offsetY + d.ty0 - d.by / 2 + HOVERTEXTPAD));
             g.select('rect')
                 .call(Drawing.setRect,
-                    tx2x + (alignShift - 1) * d.tx2width / 2 + offsetX,
-                    offsetY - d.by / 2 - 1,
-                    d.tx2width, d.by + 2);
+                    pX(tx2x + (alignShift - 1) * d.tx2width / 2 + offsetX),
+                    pY(offsetY - d.by / 2 - 1),
+                    pX(d.tx2width), pY(d.by + 2));
         }
     });
 }

src/lib/dom.js

@@ -10,6 +10,8 @@
 
 var d3 = require('d3');
 var loggers = require('./loggers');
+var matrix = require('./matrix');
+var mat4X4 = require('gl-mat4');
 
 /**
  * Allow referencing a graph DOM element either directly
@@ -91,11 +93,71 @@ function deleteRelatedStyleRule(uid) {
     if(style) removeElement(style);
 }
 
+function getFullTransformMatrix(element) {
+    var allElements = getElementAndAncestors(element);
+    // the identity matrix
+    var out = [
+        1, 0, 0, 0,
+        0, 1, 0, 0,
+        0, 0, 1, 0,
+        0, 0, 0, 1
+    ];
+    allElements.forEach(function(e) {
+        var t = getElementTransformMatrix(e);
+        if(t) {
+            var m = matrix.convertCssMatrix(t);
+            out = mat4X4.multiply(out, out, m);
+        }
+    });
+    return out;
+}
+
+/**
+ * extracts and parses the 2d css style transform matrix from some element
+ */
+function getElementTransformMatrix(element) {
+    var style = window.getComputedStyle(element, null);
+    var transform = (
+      style.getPropertyValue('-webkit-transform') ||
+      style.getPropertyValue('-moz-transform') ||
+      style.getPropertyValue('-ms-transform') ||
+      style.getPropertyValue('-o-transform') ||
+      style.getPropertyValue('transform')
+    );
+
+    if(transform === 'none') return null;
+    // the transform is a string in the form of matrix(a, b, ...) or matrix3d(...)
+    return transform
+        .replace('matrix', '')
+        .replace('3d', '')
+        .slice(1, -1)
+        .split(',')
+        .map(function(n) { return +n; });
+}
+/**
+ * retrieve all DOM elements that are ancestors of the specified one (including itself)
+ */
+function getElementAndAncestors(element) {
+    var allElements = [];
+    while(isTransformableElement(element)) {
+        allElements.push(element);
+        element = element.parentNode;
+    }
+    return allElements;
+}
+
+function isTransformableElement(element) {
+    return element && (element instanceof Element || element instanceof HTMLElement);
+}
+
 module.exports = {
     getGraphDiv: getGraphDiv,
     isPlotDiv: isPlotDiv,
     removeElement: removeElement,
     addStyleRule: addStyleRule,
     addRelatedStyleRule: addRelatedStyleRule,
-    deleteRelatedStyleRule: deleteRelatedStyleRule
+    deleteRelatedStyleRule: deleteRelatedStyleRule,
+    getFullTransformMatrix: getFullTransformMatrix,
+    getElementTransformMatrix: getElementTransformMatrix,
+    getElementAndAncestors: getElementAndAncestors,
 };

src/lib/index.js

@@ -88,8 +88,11 @@ lib.dot = matrixModule.dot;
 lib.translationMatrix = matrixModule.translationMatrix;
 lib.rotationMatrix = matrixModule.rotationMatrix;
 lib.rotationXYMatrix = matrixModule.rotationXYMatrix;
+lib.apply3DTransform = matrixModule.apply3DTransform;
 lib.apply2DTransform = matrixModule.apply2DTransform;
 lib.apply2DTransform2 = matrixModule.apply2DTransform2;
+lib.convertCssMatrix = matrixModule.convertCssMatrix;
+lib.inverseTransformMatrix = matrixModule.inverseTransformMatrix;
 
 var anglesModule = require('./angles');
 lib.deg2rad = anglesModule.deg2rad;
@@ -145,6 +148,9 @@ lib.removeElement = domModule.removeElement;
 lib.addStyleRule = domModule.addStyleRule;
 lib.addRelatedStyleRule = domModule.addRelatedStyleRule;
 lib.deleteRelatedStyleRule = domModule.deleteRelatedStyleRule;
+lib.getFullTransformMatrix = domModule.getFullTransformMatrix;
+lib.getElementTransformMatrix = domModule.getElementTransformMatrix;
+lib.getElementAndAncestors = domModule.getElementAndAncestors;
 
 lib.clearResponsive = require('./clear_responsive');
 

src/lib/matrix.js

@@ -9,6 +9,7 @@
 
 'use strict';
 
+var mat4X4 = require('gl-mat4');
 
 exports.init2dArray = function(rowLength, colLength) {
     var array = new Array(rowLength);
@@ -84,13 +85,23 @@ exports.rotationXYMatrix = function(a, x, y) {
         exports.translationMatrix(-x, -y));
 };
 
+// applies a 3D transformation matrix to either x, y and z params
+// Note: z is optional
+exports.apply3DTransform = function(transform) {
+    return function() {
+        var args = arguments;
+        var xyz = arguments.length === 1 ? args[0] : [args[0], args[1], args[2] || 0];
+        return exports.dot(transform, [xyz[0], xyz[1], xyz[2], 1]).slice(0, 3);
+    };
+};
+
 // applies a 2D transformation matrix to either x and y params or an [x,y] array
 exports.apply2DTransform = function(transform) {
     return function() {
         var args = arguments;
         if(args.length === 3) {
             args = args[0];
-        }// from map
+        } // from map
         var xy = arguments.length === 1 ? args[0] : [args[0], args[1]];
         return exports.dot(transform, [xy[0], xy[1], 1]).slice(0, 2);
     };
@@ -103,3 +114,37 @@ exports.apply2DTransform2 = function(transform) {
         return at(xys.slice(0, 2)).concat(at(xys.slice(2, 4)));
     };
 };
+
+exports.convertCssMatrix = function(m) {
+    if(m) {
+        var len = m.length;
+        if(len === 16) return m;
+        if(len === 6) {
+            // converts a 2x3 css transform matrix to a 4x4 matrix see https://developer.mozilla.org/en-US/docs/Web/CSS/transform-function/matrix
+            return [
+                m[0], m[1], 0, 0,
+                m[2], m[3], 0, 0,
+                0, 0, 1, 0,
+                m[4], m[5], 0, 1
+            ];
+        }
+    }
+    return [
+        1, 0, 0, 0,
+        0, 1, 0, 0,
+        0, 0, 1, 0,
+        0, 0, 0, 1
+    ];
+};
+
+// find the inverse for a 4x4 affine transform matrix
+exports.inverseTransformMatrix = function(m) {
+    var out = [];
+    mat4X4.invert(out, m);
+    return [
+        [out[0], out[1], out[2], out[3]],
+        [out[4], out[5], out[6], out[7]],
+        [out[8], out[9], out[10], out[11]],
+        [out[12], out[13], out[14], out[15]]
+    ];
+};

src/lib/svg_text_utils.js

@@ -743,9 +743,17 @@ function alignHTMLWith(_base, container, options) {
 
     return function() {
         thisRect = this.node().getBoundingClientRect();
+
+        var x0 = getLeft() - cRect.left;
+        var y0 = getTop() - cRect.top;
+        var gd = options.gd || {};
+        var transformedCoords = Lib.apply3DTransform(gd._fullLayout._inverseTransform)(x0, y0);
+        x0 = transformedCoords[0];
+        y0 = transformedCoords[1];
+
         this.style({
-            top: (getTop() - cRect.top) + 'px',
-            left: (getLeft() - cRect.left) + 'px',
+            top: y0 + 'px',
+            left: x0 + 'px',
             'z-index': 1000
         });
         return this;

src/plot_api/plot_api.js

@@ -3714,6 +3714,11 @@ function purge(gd) {
 function makePlotFramework(gd) {
     var gd3 = d3.select(gd);
     var fullLayout = gd._fullLayout;
+    if(fullLayout._inverseTransform === undefined) {
+        var m = fullLayout._inverseTransform = Lib.inverseTransformMatrix(Lib.getFullTransformMatrix(gd));
+        fullLayout._inverseScaleX = Math.sqrt(m[0][0] * m[0][0] + m[0][1] * m[0][1] + m[0][2] * m[0][2]);
+        fullLayout._inverseScaleY = Math.sqrt(m[1][0] * m[1][0] + m[1][1] * m[1][1] + m[1][2] * m[1][2]);
+    }
 
     // Plot container
     fullLayout._container = gd3.selectAll('.plot-container').data([0]);