Improvements to hoveranywhere / clickanywhere feature

draftlogs/7966_add.md

@@ -0,0 +1,2 @@
+- Add top-level `xPixel` and `yPixel` keys to hover and click event data, corresponding to the pixel position of the cursor relative to the top-left corner of the graph div [[#7966](https://github.com/plotly/plotly.js/pull/7966)]
+- When `hoveranywhere` is enabled, emit a `plotly_unhover` event when the cursor leaves the plot area [[#7966](https://github.com/plotly/plotly.js/pull/7966)]

src/components/dragelement/unhover.js

@@ -16,19 +16,38 @@ unhover.wrapped = function(gd, evt, subplot) {
         throttle.clear(gd._fullLayout._uid + hoverConstants.HOVERID);
     }
 
-    unhover.raw(gd, evt, subplot);
+    const oldhoverdata = gd._hoverdata;
+
+    const shouldEmitUnhover = unhover.raw(gd, evt, subplot);
+
+    // Special handling for `hoveranywhere`, to ensure we emit exactly one unhover event
+    // when the cursor leaves the plot area.
+    // gd._hoverAnywhereActive is set in fx/hover.js when we emit an empty-space hover event.
+    if(shouldEmitUnhover && gd._hoverAnywhereActive) {
+        gd._hoverAnywhereActive = false;
+
+        // Make sure hoveranywhere is still enabled
+        if(gd._fullLayout?.hoveranywhere && evt?.target && !oldhoverdata) {
+            gd.emit('plotly_unhover', {
+                event: evt,
+                points: []
+            });
+        }
+    }
 };
 
 
 // remove hover effects on mouse out, and emit unhover event
+// returns false if unhover was skipped due to the plotly_beforehover handler returning false;
+// returns true otherwise
 unhover.raw = function raw(gd, evt) {
     var fullLayout = gd._fullLayout;
     var oldhoverdata = gd._hoverdata;
 
     if(!evt) evt = {};
     if(evt.target && !gd._dragged &&
        Events.triggerHandler(gd, 'plotly_beforehover', evt) === false) {
-        return;
+        return false;
     }
 
     fullLayout._hoverlayer.selectAll('g').remove();
@@ -42,4 +61,5 @@ unhover.raw = function raw(gd, evt) {
             points: oldhoverdata
         });
     }
+    return true;
 };

src/components/fx/click.js

@@ -24,6 +24,8 @@ module.exports = function click(gd, evt, subplot) {
         clickData.yaxes ??= gd._hoverYAxes;
         clickData.xvals ??= gd._hoverXVals && helpers.c2dApply(gd._hoverXAxes, gd._hoverXVals);
         clickData.yvals ??= gd._hoverYVals && helpers.c2dApply(gd._hoverYAxes, gd._hoverYVals);
+        clickData.xPixel ??= gd._hoverPointerX;
+        clickData.yPixel ??= gd._hoverPointerY;
 
         gd.emit('plotly_click', clickData);
     }

src/components/fx/hover.js

@@ -471,6 +471,11 @@ function _hover(gd, evt, subplot, noHoverEvent, eventTarget) {
         if ('yval' in evt) yvalArray = helpers.flat(subplots, evt.yval);
         else yvalArray = helpers.p2c(yaArray, ypx);
 
+        // Save pointer position to gd so that it can be included in all hover/click event data,
+        // even when hoveranywhere and clickanywhere are not enabled
+        gd._hoverPointerX = evt.pointerX;
+        gd._hoverPointerY = evt.pointerY;
+
         if (!isNumeric(xvalArray[0]) || !isNumeric(yvalArray[0])) {
             Lib.warn('Fx.hover failed', evt, gd);
             return dragElement.unhoverRaw(gd, evt);
@@ -818,6 +823,11 @@ function _hover(gd, evt, subplot, noHoverEvent, eventTarget) {
                 gd._hoverdata = [];
             }
             emitHover([]);
+
+            // Set a flag to note that an empty-space hover event is being emitted,
+            // so that we know to emit an unhover event when the mouse leaves the plot area.
+            // See dragelement/unhover.js.
+            gd._hoverAnywhereActive = true;
         }
         return result;
     }
@@ -977,7 +987,11 @@ function _hover(gd, evt, subplot, noHoverEvent, eventTarget) {
             xaxes: xaArray,
             yaxes: yaArray,
             xvals: helpers.c2dApply(xaArray, xvalArray),
-            yvals: helpers.c2dApply(yaArray, yvalArray)
+            yvals: helpers.c2dApply(yaArray, yvalArray),
+            // Note: top-level xPixel/yPixel correspond to the pixel position of the cursor.
+            // Inside `points` array, points[i].xPixel/yPixel correspond to the pixel position of the point itself.
+            xPixel: evt.pointerX,
+            yPixel: evt.pointerY
         });
     }
 }

src/components/fx/layout_attributes.js

@@ -112,7 +112,10 @@ module.exports = {
             'If true, `plotly_hover` events will fire for any cursor position',
             'within the plot area, not just over traces.',
             'When the cursor is not over a trace, the event will have an empty `points` array',
-            'but will include `xvals` and `yvals` with cursor coordinates in data space.'
+            'but will include `xvals` and `yvals` with cursor coordinates in data space,',
+            'and `xPixel` and `yPixel` with cursor coordinates in pixels,',
+            'relative to the top-left corner of the graph div.',
+            'A `plotly_unhover` event fires when the cursor leaves the plot area.'
         ].join(' ')
     },
     clickanywhere: {
@@ -123,7 +126,9 @@ module.exports = {
             'If true, `plotly_click` events will fire for any click position',
             'within the plot area, not just over traces.',
             'When clicking where there is no trace data, the event will have an empty `points` array',
-            'but will include `xvals` and `yvals` with click coordinates in data space.'
+            'but will include `xvals` and `yvals` with click coordinates in data space,',
+            'and `xPixel` and `yPixel` with click coordinates in pixels,',
+            'relative to the top-left corner of the graph div.'
         ].join(' ')
     },
     hoverdistance: {

src/types/core/events.d.ts

@@ -104,6 +104,9 @@ export interface PlotMouseEvent {
     points: PlotDatum[];
     /** The original DOM mouse event. */
     event: MouseEvent;
+    /** x and y pixel position of the mouse */
+    xPixel: number;
+    yPixel: number;
 }
 
 /** Payload for `plotly_hover` — augments `PlotMouseEvent` with axis values. */

src/types/generated/schema.d.ts

@@ -15945,7 +15945,7 @@ export interface Layout {
      */
     calendar?: Calendar;
     /**
-     * If true, `plotly_click` events will fire for any click position within the plot area, not just over traces. When clicking where there is no trace data, the event will have an empty `points` array but will include `xvals` and `yvals` with click coordinates in data space.
+     * If true, `plotly_click` events will fire for any click position within the plot area, not just over traces. When clicking where there is no trace data, the event will have an empty `points` array but will include `xvals` and `yvals` with click coordinates in data space, and `xPixel` and `yPixel` with click coordinates in pixels, relative to the top-left corner of the graph div.
      * @default false
      */
     clickanywhere?: boolean;
@@ -16058,7 +16058,7 @@ export interface Layout {
      */
     height?: number;
     /**
-     * If true, `plotly_hover` events will fire for any cursor position within the plot area, not just over traces. When the cursor is not over a trace, the event will have an empty `points` array but will include `xvals` and `yvals` with cursor coordinates in data space.
+     * If true, `plotly_hover` events will fire for any cursor position within the plot area, not just over traces. When the cursor is not over a trace, the event will have an empty `points` array but will include `xvals` and `yvals` with cursor coordinates in data space, and `xPixel` and `yPixel` with cursor coordinates in pixels, relative to the top-left corner of the graph div. A `plotly_unhover` event fires when the cursor leaves the plot area.
      * @default false
      */
     hoveranywhere?: boolean;

test/jasmine/tests/click_test.js

@@ -110,6 +110,23 @@ describe('Test click interactions:', function() {
             expect(contextPassthroughs).toBe(0);
         });
 
+        function checkData() {
+            expect(Object.keys(futureData).sort()).toEqual([
+                'event', 'points', 'xaxes', 'yaxes', 'xvals', 'yvals', 'xPixel', 'yPixel'
+            ].sort());
+
+            expect(futureData.event).not.toBe(null);
+            checkPointData();
+            // xvals, yvals, xaxes, and yaxes should all be undefined since clickanywhere is not enabled
+            expect(futureData.xvals).toBe(undefined);
+            expect(futureData.yvals).toBe(undefined);
+            expect(futureData.xaxes).toBe(undefined);
+            expect(futureData.yaxes).toBe(undefined);
+            // However, xPixel and yPixel should be defined and match the click position
+            expect(futureData.xPixel).toEqual(pointPos[0]);
+            expect(futureData.yPixel).toEqual(pointPos[1]);
+        }
+
         function checkPointData() {
             expect(futureData.points.length).toEqual(1);
             expect(clickPassthroughs).toBe(2);
@@ -131,14 +148,14 @@ describe('Test click interactions:', function() {
             expect(evt.clientY).toEqual(pointPos[1]);
         }
 
-        it('should contain the correct fields', function() {
+        it('should contain the correct fields with the correct values', function() {
             click(pointPos[0], pointPos[1]);
-            checkPointData();
+            checkData();
         });
 
         it('should work with a sloppy click (shift < minDrag before mouseup)', function() {
             click(pointPos[0], pointPos[1], {slop: [4, 4]});
-            checkPointData();
+            checkData();
         });
 
         it('works with fixedrange axes', function(done) {