Update tooltip content and styling on update() (#6635)

Update tooltip content and styling on update()

src/core/core.controller.js

@@ -504,8 +504,7 @@ helpers.extend(Chart.prototype, /** @lends Chart */ {
 		// after update.
 		me.tooltip.initialize();
 
-		// Last active contains items that were previously in the tooltip.
-		// When we reset the tooltip, we need to clear it
+		// Last active contains items that were previously hovered.
 		me.lastActive = [];
 
 		// Do this before render so that any plugins that need final scale updates can use it
@@ -522,6 +521,11 @@ helpers.extend(Chart.prototype, /** @lends Chart */ {
 		} else {
 			me.render(config);
 		}
+
+		// Replay last event from before update
+		if (me._lastEvent) {
+			me.eventHandler(me._lastEvent);
+		}
 	},
 
 	/**
@@ -693,14 +697,20 @@ helpers.extend(Chart.prototype, /** @lends Chart */ {
 	 */
 	transition: function(easingValue) {
 		var me = this;
+		var i, ilen;
 
-		for (var i = 0, ilen = (me.data.datasets || []).length; i < ilen; ++i) {
+		for (i = 0, ilen = (me.data.datasets || []).length; i < ilen; ++i) {
 			if (me.isDatasetVisible(i)) {
 				me.getDatasetMeta(i).controller.transition(easingValue);
 			}
 		}
 
 		me.tooltip.transition(easingValue);
+
+		if (me._lastEvent && me.animating) {
+			// If, during animation, element under mouse changes, let's react to that.
+			me.handleEvent(me._lastEvent);
+		}
 	},
 
 	/**
@@ -982,6 +992,25 @@ helpers.extend(Chart.prototype, /** @lends Chart */ {
 		}
 	},
 
+	/**
+	 * @private
+	 */
+	_updateHoverStyles: function() {
+		var me = this;
+		var options = me.options || {};
+		var hoverOptions = options.hover;
+
+		// Remove styling for last active (even if it may still be active)
+		if (me.lastActive.length) {
+			me.updateHoverStyle(me.lastActive, hoverOptions.mode, false);
+		}
+
+		// Built-in hover styling
+		if (me.active.length && hoverOptions.mode) {
+			me.updateHoverStyle(me.active, hoverOptions.mode, true);
+		}
+	},
+
 	/**
 	 * @private
 	 */
@@ -1049,8 +1078,10 @@ helpers.extend(Chart.prototype, /** @lends Chart */ {
 		// Find Active Elements for hover and tooltips
 		if (e.type === 'mouseout') {
 			me.active = [];
+			me._lastEvent = null;
 		} else {
 			me.active = me.getElementsAtEventForMode(e, hoverOptions.mode, hoverOptions);
+			me._lastEvent = e.type === 'click' ? null : e;
 		}
 
 		// Invoke onHover hook
@@ -1064,16 +1095,7 @@ helpers.extend(Chart.prototype, /** @lends Chart */ {
 			}
 		}
 
-		// Remove styling for last active (even if it may still be active)
-		if (me.lastActive.length) {
-			me.updateHoverStyle(me.lastActive, hoverOptions.mode, false);
-		}
-
-		// Built in hover styling
-		if (me.active.length && hoverOptions.mode) {
-			me.updateHoverStyle(me.active, hoverOptions.mode, true);
-		}
-
+		me._updateHoverStyles();
 		changed = !helpers.arrayEquals(me.active, me.lastActive);
 
 		// Remember Last Actives

src/core/core.tooltip.js

@@ -77,7 +77,7 @@ defaults._set('global', {
 			labelColor: function(tooltipItem, chart) {
 				var meta = chart.getDatasetMeta(tooltipItem.datasetIndex);
 				var activeElement = meta.data[tooltipItem.index];
-				var view = activeElement._view;
+				var view = activeElement.$previousStyle || activeElement._view;
 				return {
 					borderColor: view.borderColor,
 					backgroundColor: view.backgroundColor
@@ -489,8 +489,25 @@ function getBeforeAfterBodyLines(callback) {
 
 var exports = Element.extend({
 	initialize: function() {
-		this._model = getBaseModel(this._options);
-		this._lastActive = [];
+		var me = this;
+		me._model = getBaseModel(me._options);
+		me._view = {};
+		me._lastActive = [];
+	},
+
+	transition: function(easingValue) {
+		var me = this;
+		var options = me._options;
+
+		if (me._lastEvent && me._chart.animating) {
+			// Let's react to changes during animation
+			me._active = me._chart.getElementsAtEventForMode(me._lastEvent, options.mode, options);
+			me.update(true);
+			me.pivot();
+			me._lastActive = me.active;
+		}
+
+		Element.prototype.transition.call(me, easingValue);
 	},
 
 	// Get the title
@@ -985,8 +1002,12 @@ var exports = Element.extend({
 		// Find Active Elements for tooltips
 		if (e.type === 'mouseout') {
 			me._active = [];
+			me._lastEvent = null;
 		} else {
 			me._active = me._chart.getElementsAtEventForMode(e, options.mode, options);
+			if (e.type !== 'click') {
+				me._lastEvent = e.type === 'click' ? null : e;
+			}
 			if (options.reverse) {
 				me._active.reverse();
 			}

test/specs/core.controller.tests.js

@@ -1142,7 +1142,7 @@ describe('Chart', function() {
 			expect(chart.tooltip._options).toEqual(jasmine.objectContaining(newTooltipConfig));
 		});
 
-		it ('should reset the tooltip on update', function() {
+		it ('should update the tooltip on update', function() {
 			var chart = acquireChart({
 				type: 'line',
 				data: {
@@ -1172,10 +1172,10 @@ describe('Chart', function() {
 			expect(chart.lastActive).toEqual([point]);
 			expect(tooltip._lastActive).toEqual([point]);
 
-			// Update and confirm tooltip is reset
+			// Update and confirm tooltip is updated
 			chart.update();
-			expect(chart.lastActive).toEqual([]);
-			expect(tooltip._lastActive).toEqual([]);
+			expect(chart.lastActive).toEqual([point]);
+			expect(tooltip._lastActive).toEqual([point]);
 		});
 
 		it ('should update the metadata', function() {