@angular/cdk
Version:
Angular Material Component Development Kit
84 lines • 13 kB
JavaScript
/**
* @license
* Copyright Google LLC All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
/** Cached result of the way the browser handles the horizontal scroll axis in RTL mode. */
let rtlScrollAxisType;
/** Cached result of the check that indicates whether the browser supports scroll behaviors. */
let scrollBehaviorSupported;
/** Check whether the browser supports scroll behaviors. */
export function supportsScrollBehavior() {
if (scrollBehaviorSupported == null) {
// If we're not in the browser, it can't be supported.
if (typeof document !== 'object' || !document) {
scrollBehaviorSupported = false;
return scrollBehaviorSupported;
}
// If the element can have a `scrollBehavior` style, we can be sure that it's supported.
if ('scrollBehavior' in document.documentElement.style) {
scrollBehaviorSupported = true;
}
else {
// At this point we have 3 possibilities: `scrollTo` isn't supported at all, it's
// supported but it doesn't handle scroll behavior, or it has been polyfilled.
const scrollToFunction = Element.prototype.scrollTo;
if (scrollToFunction) {
// We can detect if the function has been polyfilled by calling `toString` on it. Native
// functions are obfuscated using `[native code]`, whereas if it was overwritten we'd get
// the actual function source. Via https://davidwalsh.name/detect-native-function. Consider
// polyfilled functions as supporting scroll behavior.
scrollBehaviorSupported = !/\{\s*\[native code\]\s*\}/.test(scrollToFunction.toString());
}
else {
scrollBehaviorSupported = false;
}
}
}
return scrollBehaviorSupported;
}
/**
* Checks the type of RTL scroll axis used by this browser. As of time of writing, Chrome is NORMAL,
* Firefox & Safari are NEGATED, and IE & Edge are INVERTED.
*/
export function getRtlScrollAxisType() {
// We can't check unless we're on the browser. Just assume 'normal' if we're not.
if (typeof document !== 'object' || !document) {
return 0 /* NORMAL */;
}
if (rtlScrollAxisType == null) {
// Create a 1px wide scrolling container and a 2px wide content element.
const scrollContainer = document.createElement('div');
const containerStyle = scrollContainer.style;
scrollContainer.dir = 'rtl';
containerStyle.width = '1px';
containerStyle.overflow = 'auto';
containerStyle.visibility = 'hidden';
containerStyle.pointerEvents = 'none';
containerStyle.position = 'absolute';
const content = document.createElement('div');
const contentStyle = content.style;
contentStyle.width = '2px';
contentStyle.height = '1px';
scrollContainer.appendChild(content);
document.body.appendChild(scrollContainer);
rtlScrollAxisType = 0 /* NORMAL */;
// The viewport starts scrolled all the way to the right in RTL mode. If we are in a NORMAL
// browser this would mean that the scrollLeft should be 1. If it's zero instead we know we're
// dealing with one of the other two types of browsers.
if (scrollContainer.scrollLeft === 0) {
// In a NEGATED browser the scrollLeft is always somewhere in [-maxScrollAmount, 0]. For an
// INVERTED browser it is always somewhere in [0, maxScrollAmount]. We can determine which by
// setting to the scrollLeft to 1. This is past the max for a NEGATED browser, so it will
// return 0 when we read it again.
scrollContainer.scrollLeft = 1;
rtlScrollAxisType =
scrollContainer.scrollLeft === 0 ? 1 /* NEGATED */ : 2 /* INVERTED */;
}
scrollContainer.parentNode.removeChild(scrollContainer);
}
return rtlScrollAxisType;
}
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Native\n        // functions are obfuscated using `[native code]`, whereas if it was overwritten we'd get\n        // the actual function source. Via https://davidwalsh.name/detect-native-function. Consider\n        // polyfilled functions as supporting scroll behavior.\n        scrollBehaviorSupported = !/\\{\\s*\\[native code\\]\\s*\\}/.test(scrollToFunction.toString());\n      } else {\n        scrollBehaviorSupported = false;\n      }\n    }\n  }\n\n  return scrollBehaviorSupported;\n}\n\n/**\n * Checks the type of RTL scroll axis used by this browser. As of time of writing, Chrome is NORMAL,\n * Firefox & Safari are NEGATED, and IE & Edge are INVERTED.\n */\nexport function getRtlScrollAxisType(): RtlScrollAxisType {\n  // We can't check unless we're on the browser. Just assume 'normal' if we're not.\n  if (typeof document !== 'object' || !document) {\n    return RtlScrollAxisType.NORMAL;\n  }\n\n  if (rtlScrollAxisType == null) {\n    // Create a 1px wide scrolling container and a 2px wide content element.\n    const scrollContainer = document.createElement('div');\n    const containerStyle = scrollContainer.style;\n    scrollContainer.dir = 'rtl';\n    containerStyle.width = '1px';\n    containerStyle.overflow = 'auto';\n    containerStyle.visibility = 'hidden';\n    containerStyle.pointerEvents = 'none';\n    containerStyle.position = 'absolute';\n\n    const content = document.createElement('div');\n    const contentStyle = content.style;\n    contentStyle.width = '2px';\n    contentStyle.height = '1px';\n\n    scrollContainer.appendChild(content);\n    document.body.appendChild(scrollContainer);\n\n    rtlScrollAxisType = RtlScrollAxisType.NORMAL;\n\n    // The viewport starts scrolled all the way to the right in RTL mode. If we are in a NORMAL\n    // browser this would mean that the scrollLeft should be 1. If it's zero instead we know we're\n    // dealing with one of the other two types of browsers.\n    if (scrollContainer.scrollLeft === 0) {\n      // In a NEGATED browser the scrollLeft is always somewhere in [-maxScrollAmount, 0]. For an\n      // INVERTED browser it is always somewhere in [0, maxScrollAmount]. We can determine which by\n      // setting to the scrollLeft to 1. This is past the max for a NEGATED browser, so it will\n      // return 0 when we read it again.\n      scrollContainer.scrollLeft = 1;\n      rtlScrollAxisType =\n          scrollContainer.scrollLeft === 0 ? RtlScrollAxisType.NEGATED : RtlScrollAxisType.INVERTED;\n    }\n\n    scrollContainer.parentNode!.removeChild(scrollContainer);\n  }\n  return rtlScrollAxisType;\n}\n"]}