/**
* @license
* Copyright The Closure Library Authors.
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @fileoverview Shared unit tests for scrollbar measurement.
*/
goog.provide('goog.styleScrollbarTester');
goog.require('goog.dom');
goog.require('goog.dom.TagName');
goog.require('goog.style');
goog.require('goog.testing.asserts');
goog.setTestOnly('goog.styleScrollbarTester');
/**
* Tests the scrollbar width calculation. Assumes that there is an element with
* id 'test-scrollbarwidth' in the page.
*/
function testScrollbarWidth() {
var width = goog.style.getScrollbarWidth();
assertTrue(width > 0);
var outer = goog.dom.getElement('test-scrollbarwidth');
var inner = goog.dom.getElementsByTagNameAndClass(
goog.dom.TagName.DIV, null, outer)[0];
assertTrue('should have a scroll bar', hasVerticalScroll(outer));
assertTrue('should have a scroll bar', hasHorizontalScroll(outer));
// Get the inner div absolute width
goog.style.setStyle(outer, 'width', '100%');
assertTrue('should have a scroll bar', hasVerticalScroll(outer));
assertFalse('should not have a scroll bar', hasHorizontalScroll(outer));
var innerAbsoluteWidth = inner.offsetWidth;
// Leave the vertical scroll and remove the horizontal by using the scroll
// bar width calculation.
goog.style.setStyle(outer, 'width', (innerAbsoluteWidth + width) + 'px');
assertTrue('should have a scroll bar', hasVerticalScroll(outer));
assertFalse('should not have a scroll bar', hasHorizontalScroll(outer));
// verify by adding 1 more pixel (brings back the vertical scroll bar).
goog.style.setStyle(outer, 'width', (innerAbsoluteWidth + width - 1) + 'px');
assertTrue('should have a scroll bar', hasVerticalScroll(outer));
assertTrue('should have a scroll bar', hasHorizontalScroll(outer));
}
function hasVerticalScroll(el) {
return el.clientWidth != 0 && el.offsetWidth - el.clientWidth > 0;
}
function hasHorizontalScroll(el) {
return el.clientHeight != 0 && el.offsetHeight - el.clientHeight > 0;
}