画像切り替え switcher スイッチャー swiper スワイパー

/**
 * 画像切り替え
 *
 * @author ao-system, Inc.
 * @date 2022-10-06
 * @date 2024-01-15
 * @date 2024-01-17 Rewrite the code using the class syntax.
 *

<section class="switchpanel">
	<div>
		<div id="switchPanelStage"></div>
	</div>
</section>

<style>
section.switchPanel {
	background-color: #000;
	> div {
		max-width: 1920px;
		margin: 0 auto;
		overflow: hidden;
		> #switchPanelStage {
			user-select: none;
			display: grid;
			grid-template-rows: 1fr;
			grid-template-columns: 1fr;
			> img:nth-of-type(1) {
				z-index: 0;
				grid-row: 1/2;
				grid-column: 1/2;
				width: 100%;
			}
			> img:nth-of-type(2) {
				z-index: 1;
				grid-row: 1/2;
				grid-column: 1/2;
				width: 100%;
				cursor: ew-resize;
			}
			> div {
				grid-row: 1/2;
				grid-column: 1/2;
				z-index: 2;
				justify-self: flex-end;
				align-self: end;
				display: flex;
				justify-content: center;
				align-items: center;
				column-gap: 5px;
				padding: 0 20px 17px 0;
				@media (width < 670px) {
					column-gap: 3px;
					padding: 0 4px 4px 0;
					> span {
						> img {
							width: 16px;
						}
					}
				}
				> span {
					cursor: pointer;
					> img:nth-of-type(1) {
						display: block;
					}
					> img:nth-of-type(2) {
						display: none;
					}
					&.on {
						> img:nth-of-type(1) {
							display: none;
						}
						> img:nth-of-type(2) {
							display: block;
						}
					}
				}
			}
		}
	}
}
</style>
 *
 */

(() => {
	'use strict';
	class SwitchImage {
		#constProperties = [
			{prop: 'stage',					value: document.getElementById('switchPanelStage')},
			{prop: 'layerImg0',				value: document.createElement('img')},
			{prop: 'layerImg1',				value: document.createElement('img')},
			{prop: 'layerNav',				value: document.createElement('div')},
			{prop: 'markPause',				value: './image/panel_pause.svg'},
			{prop: 'markPlay',				value: './image/panel_play.svg'},
			{prop: 'markNavOn',				value: './image/panel_ball_on.svg'},
			{prop: 'markNavOff',			value: './image/panel_ball_off.svg'},
			{prop: 'buttonPause',			value: document.createElement('span')},
			{prop: 'buttonPlay',			value: document.createElement('span')},
			{prop: 'imageChangeInterval',	value: 4000},	//画像と画像の時間間隔
			{prop: 'slideWidth',			value: 50},		//切り替わるスライド幅
			{prop: 'slideTime',				value: 500},	//スライド時間
			{prop: 'swipeShreshold',		value: 50},		//スワイプ判定幅
		];
		#loopTimeoutId			= null;		//自動動作のタイマー
		#isBusy					= false;	//動作中
		#pausePlayFlag			= true;		//falseで停止
		#focusFlag				= true;		//フォーカスが外れている時は動作させないため
		#valueIndex				= 0;		//this.#valuesの添え字
		#slideDirection			= 1;		//1|-1	正方向,逆方向
		#swipeStartX			= 0;		//スワイプ開始位置
		#isSwiping				= false;	//スワイプ中
		#config					= {};
		#values					= [];
		//
		constructor(config, values) {
			this.#config = config;
			this.#values = values;
			this.#constProperties.forEach((obj) => Object.defineProperty(this, obj.prop, {value:obj.value, writable:false}));
			this.#init();
		}
		#init() {
			//this.#values = shuffle(this.#values);	//シャッフルさせる場合
			//window.addEventListener('focus',() => { this.#focusFlag = true;});	//out focusで停止させる場合の処理
			//window.addEventListener('blur',() => { this.#focusFlag = false;});	//out focusで停止させる場合の処理
			//
			this.stage.appendChild(this.layerImg0);
			this.stage.appendChild(this.layerImg1);
			this.stage.appendChild(this.layerNav);
			this.layerImg0.setAttribute('draggable','false');
			this.layerImg1.setAttribute('draggable','false');
			this.layerImg1.src = this.#getImage(1);
			this.layerImg1.animate(
				[{opacity: 0}],
				{delay:0,duration:1, easing:'linear',fill:'forwards', },
			);
			this.layerImg0.src = this.#getImage(0);
			this.layerImg0.onload = () => {
				this.#initNav();
				this.#initSwipe();
				this.#ballOn();
				this.#autoSlide();
			};
		}
		#shuffle(array) {
			for (let i = array.length - 1; i > 0; i--) {
				const j = Math.floor(Math.random() * (i + 1));
				[array[i], array[j]] = [array[j], array[i]];
			}
			return array;
		}
		#getIsLarge() {
			return window.matchMedia('(width >= ' + this.#config.breakpoint + 'px)').matches;
		}
		#getImage(ptr) {
			return this.#getIsLarge() ? this.#values[ptr].image1 : this.#values[ptr].image2;
		}
		#initNav() {
			this.#values.map((x,index) => {
				const span = document.createElement('span');
				span.addEventListener('click',() => {
					if (this.#isBusy) {
						return;
					}
					this.#slideAction(index);
				});
				span.innerHTML = '<img src="' + this.markNavOff + '"><img src="' + this.markNavOn + '">';
				this.layerNav.appendChild(span);
			});
			const pauseImg = new Image();
			pauseImg.src = this.markPause;
			this.buttonPause.appendChild(pauseImg);
			this.layerNav.appendChild(this.buttonPause);
			const playImg = new Image();
			playImg.src = this.markPlay;
			this.buttonPlay.appendChild(playImg);
			this.layerNav.appendChild(this.buttonPlay);
			this.buttonPlay.style.display = 'none';
			this.buttonPause.addEventListener('click',() => this.#setPause());
			this.buttonPlay.addEventListener('click',() => this.#setPlay());
		}
		#initSwipe() {
			this.layerImg1.addEventListener('click', (e) => { e.preventDefault();});
			this.layerImg1.addEventListener('mousedown', (e) => { this.#swipeStart(e.clientX); });
			this.layerImg1.addEventListener('mouseup', (e) => { this.#swipeEnd(e.clientX); });
			this.layerImg1.addEventListener('touchstart', (e) => { this.#swipeStart(e.touches[0].clientX); });
			this.layerImg1.addEventListener('touchend', (e) => { this.#swipeEnd(e.changedTouches[0].clientX); });
		}
		#swipeStart(positionX) {
			if (this.#isBusy) {
				return;
			}
			this.#swipeStartX = positionX;
			this.stage.style.cursor = 'grabbing';
			this.#isSwiping = true;
		}
		#swipeEnd(positionX) {
			if (this.#isSwiping == false) {
				return;
			}
			if (this.#swipeStartX - positionX > this.swipeShreshold) {
				this.#slideAction(this.#withinRange(this.#valueIndex + 1));
			} else if (this.#swipeStartX - positionX < -this.swipeShreshold) {
				this.#slideDirection = -1;
				this.#slideAction(this.#withinRange(this.#valueIndex - 1));
			} else {
				if (this.#values[this.#valueIndex].link) {
					if (this.#values[this.#valueIndex].external) {
						window.open(this.#values[this.#valueIndex].link, '_blank');
					} else {
						window.location.href = this.#values[this.#valueIndex].link;
					}
					return;
				}
			}
			this.stage.style.cursor = '';
			this.#isSwiping = false;
		}
		#setPause() {
			this.#pausePlayFlag = false;
			this.buttonPause.style.display = 'none';
			this.buttonPlay.style.display = 'block';
		}
		#setPlay() {
			this.#pausePlayFlag = true;
			this.buttonPause.style.display = 'block';
			this.buttonPlay.style.display = 'none';
		}
		#slideForward() {
			if (this.#isBusy) {
				return;
			}
			this.#isBusy = true;
			this.#ballOn();
			this.layerImg1.src = this.#getImage(this.#valueIndex);
			this.layerImg1.onload = () => {
				this.layerImg1.animate(
					[
						{opacity: 0,transform:'translateX(' + (this.slideWidth * this.#slideDirection) + 'px)'},
						{opacity: 1,transform:'translateX(0px)'},
					],
					{delay:0,duration:this.slideTime, easing:'ease-out',fill:'forwards', },
				);
				setTimeout(() => {
					this.layerImg0.src = this.#getImage(this.#valueIndex);
					this.layerImg0.onload = () => {
						this.layerImg1.animate(
							[{opacity: 0}],
							{delay:0,duration:1, easing:'linear',fill:'forwards', },
						);
					};
					this.#slideDirection = 1;
					this.#isBusy = false;
				},this.slideTime + 100);
			};
		}
		#autoSlide() {
			this.#loopTimeoutId = setTimeout(() => {
				if (this.#pausePlayFlag && this.#focusFlag) {
					this.#slideAction();
				} else {
					this.#autoSlide();
				}
			}, this.imageChangeInterval - this.slideTime);
		}
		#slideAction(num = this.#valueIndex + 1) {
			clearTimeout(this.#loopTimeoutId);
			this.#valueIndex = this.#withinRange(num);
			this.#slideForward();
			this.#autoSlide();
		}
		#ballOn() {
			const spans = this.layerNav.querySelectorAll('span');
			spans.forEach((elm) => elm.classList.remove('on'));
			spans[this.#valueIndex].classList.add('on');
		}
		#withinRange(nextNumber) {
			const num = (nextNumber >= 0) ? nextNumber : this.#values.length - 1;
			return num % this.#values.length;
		}
	}
	//
	new SwitchImage(
		//config
		{
			'breakpoint': 700,
		},
		//values
		[
			{
				'link': '',
				'external': false,
				'image1': './image/panel01.webp',
				'image2': './image/panel01b.webp',
			},
			{
				'link': '',
				'external': false,
				'image1': './image/panel02.webp',
				'image2': './image/panel02b.webp',
			},
			{
				'link': '',
				'external': false,
				'image1': './image/panel03.webp',
				'image2': './image/panel03b.webp',
			},
			{
				'link': '',
				'external': false,
				'image1': './image/panel04.webp',
				'image2': './image/panel04b.webp',
			},
			{
				'link': '',
				'external': false,
				'image1': './image/panel05.webp',
				'image2': './image/panel05b.webp',
			},
			{
				'link': '',
				'external': false,
				'image1': './image/panel06.webp',
				'image2': './image/panel06b.webp',
			},
		]
	);
})();