perf(tooltip): improve the performance of tooltip.

src/component/tooltip/TooltipHTMLContent.ts

@@ -17,26 +17,36 @@
 * under the License.
 */
 
-import { isString, indexOf, map, each, bind, isArray, isDom } from 'zrender/src/core/util';
+import { isString, indexOf, each, bind, isArray, isDom } from 'zrender/src/core/util';
 import { toHex } from 'zrender/src/tool/color';
 import { normalizeEvent } from 'zrender/src/core/event';
 import { transformLocalCoord } from 'zrender/src/core/dom';
 import env from 'zrender/src/core/env';
 import { convertToColorString, toCamelCase, normalizeCssArray } from '../../util/format';
-import ExtensionAPI from '../../core/ExtensionAPI';
-import { ZRenderType } from 'zrender/src/zrender';
-import { TooltipOption } from './TooltipModel';
+import type ExtensionAPI from '../../core/ExtensionAPI';
+import type { ZRenderType } from 'zrender/src/zrender';
+import type { TooltipOption } from './TooltipModel';
 import Model from '../../model/Model';
-import { ZRRawEvent } from 'zrender/src/core/types';
-import { ColorString, ZRColor } from '../../util/types';
-import CanvasPainter from 'zrender/src/canvas/Painter';
-import SVGPainter from 'zrender/src/svg/Painter';
-import { shouldTooltipConfine } from './helper';
+import type { ZRRawEvent } from 'zrender/src/core/types';
+import type { ColorString, ZRColor } from '../../util/types';
+import type CanvasPainter from 'zrender/src/canvas/Painter';
+import type SVGPainter from 'zrender/src/svg/Painter';
+import {
+    shouldTooltipConfine,
+    toCSSVendorPrefix,
+    getComputedStyle,
+    TRANSFORM_VENDOR,
+    TRANSITION_VENDOR
+} from './helper';
 import { getPaddingFromTooltipModel } from './tooltipMarkup';
 
-const vendors = ['-ms-', '-moz-', '-o-', '-webkit-', ''];
+/* global document, window */
 
-const gCssText = 'position:absolute;display:block;border-style:solid;white-space:nowrap;z-index:9999999;';
+const CSS_TRANSITION_VENDOR = toCSSVendorPrefix(TRANSITION_VENDOR, 'transition');
+const CSS_TRANSFORM_VENDOR = toCSSVendorPrefix(TRANSFORM_VENDOR, 'transform');
+
+// eslint-disable-next-line
+const gCssText = `position:absolute;display:block;border-style:solid;white-space:nowrap;z-index:9999999;${env.transform3dSupported ? 'will-change:transform;' : ''}`;
 
 function mirrorPos(pos: string): string {
     pos = pos === 'left'
@@ -60,44 +70,66 @@ function assembleArrow(
 
     borderColor = convertToColorString(borderColor);
     const arrowPos = mirrorPos(arrowPosition);
-    let positionStyle = '';
-    let transformStyle = '';
+    let positionStyle = `${arrowPos}:-6px;`;
+    let transformStyle = CSS_TRANSFORM_VENDOR + ':';
     if (indexOf(['left', 'right'], arrowPos) > -1) {
-        positionStyle = `${arrowPos}:-6px;top:50%;`;
-        transformStyle = `translateY(-50%) rotate(${arrowPos === 'left' ? -225 : -45}deg)`;
+        positionStyle += 'top:50%';
+        transformStyle += `translateY(-50%) rotate(${arrowPos === 'left' ? -225 : -45}deg)`;
     }
     else {
-        positionStyle = `${arrowPos}:-6px;left:50%;`;
-        transformStyle = `translateX(-50%) rotate(${arrowPos === 'top' ? 225 : 45}deg)`;
+        positionStyle += 'left:50%';
+        transformStyle += `translateX(-50%) rotate(${arrowPos === 'top' ? 225 : 45}deg)`;
     }
 
-    transformStyle = map(vendors, function (vendorPrefix) {
-        return vendorPrefix + 'transform:' + transformStyle;
-    }).join(';');
-
+    const borderStyle = `${borderColor} solid 1px;`;
     const styleCss = [
         'position:absolute;width:10px;height:10px;',
-        `${positionStyle}${transformStyle};`,
-        `border-bottom: ${borderColor} solid 1px;`,
-        `border-right: ${borderColor} solid 1px;`,
-        `background-color: ${backgroundColor};`,
-        'box-shadow: 8px 8px 16px -3px #000;'
+        `${positionStyle};${transformStyle};`,
+        `border-bottom:${borderStyle}`,
+        `border-right:${borderStyle}`,
+        `background-color:${backgroundColor};`,
+        'box-shadow:8px 8px 16px -3px #000;'
     ];
     return `<div style="${styleCss.join('')}"></div>`;
 }
 
 function assembleTransition(duration: number, onlyFade?: boolean): string {
-    const transitionCurve = 'cubic-bezier(0.23, 1, 0.32, 1)';
-    let transitionText = 'opacity ' + (duration / 2) + 's ' + transitionCurve + ','
-                       + 'visibility ' + (duration / 2) + 's ' + transitionCurve;
+    const transitionCurve = 'cubic-bezier(0.23,1,0.32,1)';
+    let transitionOption = ` ${duration / 2}s ${transitionCurve}`;
+    let transitionText = `opacity${transitionOption},visibility${transitionOption}`;
     if (!onlyFade) {
-        transitionText += ',left ' + duration + 's ' + transitionCurve
-                        + ',top ' + duration + 's ' + transitionCurve;
+        transitionOption = ` ${duration}s ${transitionCurve}`;
+        transitionText += env.transformSupported
+            ? `,${TRANSFORM_VENDOR}${transitionOption}`
+            : `,left${transitionOption},top${transitionOption}`;
     }
 
-    return map(vendors, function (vendorPrefix) {
-        return vendorPrefix + 'transition:' + transitionText;
-    }).join(';');
+    return CSS_TRANSITION_VENDOR + ':' + transitionText;
+}
+
+function assembleTransform(el: HTMLElement, x: number, y: number, toString?: boolean) {
+    // If using float on style, the final width of the dom might
+    // keep changing slightly while mouse move. So `toFixed(0)` them.
+    let x0;
+    let y0;
+    // not support transform, use `left` and `top` instead.
+    if (!env.transformSupported) {
+        x0 = x.toFixed(0);
+        y0 = y.toFixed(0);
+        return toString
+            ? `top:${y0}px;left:${x0}px;`
+            : [['top', `${y0}px`], ['left', `${x0}px`]];
+    }
+    // support transform
+    // FIXME: the padding of parent element will affect the position of tooltip
+    const stl = getComputedStyle(el.parentElement);
+    x0 = (x - parseInt(stl.paddingLeft, 10)).toFixed(0);
+    y0 = (y - parseInt(stl.paddingTop, 10)).toFixed(0);
+    const is3d = env.transform3dSupported;
+    const translate = `translate${is3d ? '3d' : ''}(${x0}px,${y0}px${is3d ? ',0' : ''})`;
+    return toString
+        ? CSS_TRANSFORM_VENDOR + ':' + translate + ';'
+        : [[TRANSFORM_VENDOR, translate]];
 }
 
 /**
@@ -153,12 +185,12 @@ function assembleCssText(tooltipModel: Model<TooltipOption>, enableTransition?:
 
     if (backgroundColor) {
         if (env.canvasSupported) {
-            cssText.push('background-Color:' + backgroundColor);
+            cssText.push('background-color:' + backgroundColor);
         }
         else {
             // for ie
             cssText.push(
-                'background-Color:#' + toHex(backgroundColor)
+                'background-color:#' + toHex(backgroundColor)
             );
             cssText.push('filter:alpha(opacity=70)');
         }
@@ -272,7 +304,8 @@ class TooltipHTMLContent {
             document.body.appendChild(el);
         }
         else {
-            container.appendChild(el);
+            // PENDING
+            container.prepend(el);
         }
 
         this._container = container;
@@ -324,10 +357,9 @@ class TooltipHTMLContent {
         // FIXME
         // Move this logic to ec main?
         const container = this._container;
-        const stl = (container as any).currentStyle
-            || document.defaultView.getComputedStyle(container);
+        const position = getComputedStyle(container, 'position');
         const domStyle = container.style;
-        if (domStyle.position !== 'absolute' && stl.position !== 'absolute') {
+        if (domStyle.position !== 'absolute' && position !== 'absolute') {
             domStyle.position = 'relative';
         }
 
@@ -347,25 +379,25 @@ class TooltipHTMLContent {
         clearTimeout(this._hideTimeout);
         clearTimeout(this._longHideTimeout);
         const el = this.el;
+        const style = el.style;
         const styleCoord = this._styleCoord;
-        const offset = el.offsetHeight / 2;
-        nearPointColor = convertToColorString(nearPointColor);
-        el.style.cssText = gCssText + assembleCssText(tooltipModel, !this._firstShow, this._longHide)
-            // Because of the reason described in:
-            // http://stackoverflow.com/questions/21125587/css3-transition-not-working-in-chrome-anymore
-            // we should set initial value to `left` and `top`.
-            + ';left:' + styleCoord[0] + 'px;top:' + (styleCoord[1] - offset) + 'px;'
-            + `border-color: ${nearPointColor};`
-            + (tooltipModel.get('extraCssText') || '');
-
-        el.style.display = el.innerHTML ? 'block' : 'none';
-
-        // If mouse occasionally move over the tooltip, a mouseout event will be
-        // triggered by canvas, and cause some unexpectable result like dragging
-        // stop, "unfocusAdjacency". Here `pointer-events: none` is used to solve
-        // it. Although it is not supported by IE8~IE10, fortunately it is a rare
-        // scenario.
-        el.style.pointerEvents = this._enterable ? 'auto' : 'none';
+        if (!el.innerHTML) {
+            style.display = 'none';
+        }
+        else {
+            style.cssText = gCssText
+                + assembleCssText(tooltipModel, !this._firstShow, this._longHide)
+                // initial transform
+                + assembleTransform(el, styleCoord[0], styleCoord[1], true)
+                + `border-color:${convertToColorString(nearPointColor)};`
+                + (tooltipModel.get('extraCssText') || '')
+                // If mouse occasionally move over the tooltip, a mouseout event will be
+                // triggered by canvas, and cause some unexpectable result like dragging
+                // stop, "unfocusAdjacency". Here `pointer-events: none` is used to solve
+                // it. Although it is not supported by IE8~IE10, fortunately it is a rare
+                // scenario.
+                + `;pointer-event:${this._enterable ? 'auto' : 'none'}`;
+        }
 
         this._show = true;
         this._firstShow = false;
@@ -421,10 +453,13 @@ class TooltipHTMLContent {
 
         if (styleCoord[0] != null && styleCoord[1] != null) {
             const style = this.el.style;
-            // If using float on style, the final width of the dom might
-            // keep changing slightly while mouse move. So `toFixed(0)` them.
-            style.left = styleCoord[0].toFixed(0) + 'px';
-            style.top = styleCoord[1].toFixed(0) + 'px';
+            const transforms = assembleTransform(
+                this.el,
+                styleCoord[0], styleCoord[1]
+            ) as string[][];
+            each(transforms, (transform) => {
+              style[transform[0] as any] = transform[1];
+            });
         }
     }
 
@@ -444,8 +479,10 @@ class TooltipHTMLContent {
     }
 
     hide() {
-        this.el.style.visibility = 'hidden';
-        this.el.style.opacity = '0';
+        const style = this.el.style;
+        style.visibility = 'hidden';
+        style.opacity = '0';
+        env.transform3dSupported && (style.willChange = '');
         this._show = false;
         this._longHideTimeout = setTimeout(() => this._longHide = true, 500) as any;
     }
@@ -478,12 +515,10 @@ class TooltipHTMLContent {
 
         // Consider browser compatibility.
         // IE8 does not support getComputedStyle.
-        if (document.defaultView && document.defaultView.getComputedStyle) {
-            const stl = document.defaultView.getComputedStyle(this.el);
-            if (stl) {
-                width += parseInt(stl.borderLeftWidth, 10) + parseInt(stl.borderRightWidth, 10);
-                height += parseInt(stl.borderTopWidth, 10) + parseInt(stl.borderBottomWidth, 10);
-            }
+        const stl = getComputedStyle(this.el);
+        if (stl) {
+            width += parseInt(stl.borderLeftWidth, 10) + parseInt(stl.borderRightWidth, 10);
+            height += parseInt(stl.borderTopWidth, 10) + parseInt(stl.borderBottomWidth, 10);
         }
 
         return {width: width, height: height};

src/component/tooltip/TooltipView.ts

@@ -718,6 +718,7 @@ class TooltipView extends ComponentView {
             tooltipModel.get('trigger'),
             tooltipModel.get('borderColor')
         );
+        const nearPointColor = nearPoint.color;
 
         if (formatter && zrUtil.isString(formatter)) {
             const useUTC = tooltipModel.ecModel.get('useUTC');
@@ -732,7 +733,7 @@ class TooltipView extends ComponentView {
         else if (zrUtil.isFunction(formatter)) {
             const callback = bind(function (cbTicket: string, html: string | HTMLElement[]) {
                 if (cbTicket === this._ticket) {
-                    tooltipContent.setContent(html, markupStyleCreator, tooltipModel, nearPoint.color, positionExpr);
+                    tooltipContent.setContent(html, markupStyleCreator, tooltipModel, nearPointColor, positionExpr);
                     this._updatePosition(
                         tooltipModel, positionExpr, x, y, tooltipContent, params, el
                     );
@@ -742,8 +743,8 @@ class TooltipView extends ComponentView {
             html = formatter(params, asyncTicket, callback);
         }
 
-        tooltipContent.setContent(html, markupStyleCreator, tooltipModel, nearPoint.color, positionExpr);
-        tooltipContent.show(tooltipModel, nearPoint.color);
+        tooltipContent.setContent(html, markupStyleCreator, tooltipModel, nearPointColor, positionExpr);
+        tooltipContent.show(tooltipModel, nearPointColor);
         this._updatePosition(
             tooltipModel, positionExpr, x, y, tooltipContent, params, el
         );

src/component/tooltip/helper.ts

@@ -19,6 +19,10 @@
 
 import { TooltipOption } from './TooltipModel';
 import Model from '../../model/Model';
+import { toCamelCase } from '../../util/format';
+import env from 'zrender/src/core/env';
+
+/* global document */
 
 export function shouldTooltipConfine(tooltipModel: Model<TooltipOption>): boolean {
     const confineOption = tooltipModel.get('confine');
@@ -27,3 +31,43 @@ export function shouldTooltipConfine(tooltipModel: Model<TooltipOption>): boolea
         // In richText mode, the outside part can not be visible.
         : tooltipModel.get('renderMode') === 'richText';
 }
+
+function testStyle(styleProps: string[]): string | undefined {
+    if (!env.domSupported) {
+        return;
+    }
+    const style = document.documentElement.style;
+    for (let i = 0, len = styleProps.length; i < len; i++) {
+        if (styleProps[i] in style) {
+            return styleProps[i];
+        }
+    }
+}
+
+export const TRANSFORM_VENDOR = testStyle(
+    ['transform', 'webkitTransform', 'OTransform', 'MozTransform', 'msTransform']
+);
+
+export const TRANSITION_VENDOR = testStyle(
+    ['webkitTransition', 'transition', 'OTransition', 'MozTransition', 'msTransition']
+);
+
+export function toCSSVendorPrefix(styleVendor: string, styleProp: string) {
+    if (!styleVendor) {
+        return styleProp;
+    }
+    styleProp = toCamelCase(styleProp, true);
+    const idx = styleVendor.indexOf(styleProp);
+    styleVendor = idx === -1
+        ? styleProp
+        : `-${styleVendor.slice(0, idx)}-${styleProp}`;
+    return styleVendor.toLowerCase();
+}
+
+export function getComputedStyle(el: HTMLElement, style?: string) {
+    const stl = (el as any).currentStyle
+        || (document.defaultView && document.defaultView.getComputedStyle(el));
+    return stl
+        ? style ? stl[style] : stl
+        : null;
+}