tongchengred/components/uni-swipe-action-item/index.wxs

var MIN_DISTANCE = 10;

/**
 * 监听页面内值的变化,主要用于动态开关swipe-action
 * @param {Object} newValue
 * @param {Object} oldValue
 * @param {Object} ownerInstance
 * @param {Object} instance
 */
function sizeReady(newValue, oldValue, ownerInstance, instance) {
	var state = instance.getState()
	var buttonPositions = JSON.parse(newValue)
	if (!buttonPositions || !buttonPositions.data || buttonPositions.data.length === 0) return
	state.leftWidth = buttonPositions.data[0].width
	state.rightWidth = buttonPositions.data[1].width
	state.threshold = instance.getDataset().threshold

	if (buttonPositions.show && buttonPositions.show !== 'none') {
		openState(buttonPositions.show, instance, ownerInstance)
		return
	}

	if (state.left) {
		openState('none', instance, ownerInstance)
	}
	resetTouchStatus(instance)
}

/**
 * 开始触摸操作
 * @param {Object} e
 * @param {Object} ins
 */
function touchstart(e, ins) {
	var instance = e.instance;
	var disabled = instance.getDataset().disabled
	var state = instance.getState();
	// fix by mehaotian, TODO 兼容 app-vue 获取dataset为字符串 , h5 获取 为 undefined 的问题,待框架修复
	disabled = (typeof(disabled) === 'string' ? JSON.parse(disabled) : disabled) || false;
	if (disabled) return
	// 开始触摸时移除动画类
	instance.requestAnimationFrame(function(){
		instance.removeClass('ani');
		ins.callMethod('closeSwipe');
	})

	// 记录上次的位置
	state.x = state.left || 0
	// 计算滑动开始位置
	stopTouchStart(e, ins)
}

/**
 * 开始滑动操作
 * @param {Object} e
 * @param {Object} ownerInstance
 */
function touchmove(e, ownerInstance) {

	var instance = e.instance;
	var disabled = instance.getDataset().disabled
	var state = instance.getState()
	// fix by mehaotian, TODO 兼容 app-vue 获取dataset为字符串 , h5 获取 为 undefined 的问题,待框架修复
	disabled = (typeof(disabled) === 'string' ? JSON.parse(disabled) : disabled) || false;
	if (disabled) return
	// 是否可以滑动页面
	stopTouchMove(e);
	if (state.direction !== 'horizontal') {
		return;
	}

	if (e.preventDefault) {
		// 阻止页面滚动
		e.preventDefault()
	}

	move(state.x + state.deltaX, instance, ownerInstance)
}

/**
 * 结束触摸操作
 * @param {Object} e
 * @param {Object} ownerInstance
 */
function touchend(e, ownerInstance) {
	var instance = e.instance;
	var disabled = instance.getDataset().disabled
	var state = instance.getState()
	// fix by mehaotian, TODO 兼容 app-vue 获取dataset为字符串 , h5 获取 为 undefined 的问题,待框架修复
	disabled = (typeof(disabled) === 'string' ? JSON.parse(disabled) : disabled) || false;

	if (disabled) return
	// 滑动过程中触摸结束,通过阙值判断是开启还是关闭
	// fixed by mehaotian 定时器解决点击按钮，touchend 触发比 click 事件时机早的问题 ，主要是 ios13
	moveDirection(state.left, instance, ownerInstance)

}

/**
 * 设置移动距离
 * @param {Object} value
 * @param {Object} instance
 * @param {Object} ownerInstance
 */
function move(value, instance, ownerInstance) {
	value = value || 0
	var state = instance.getState()
	var leftWidth = state.leftWidth
	var rightWidth = state.rightWidth
	// 获取可滑动范围
	state.left = range(value, -rightWidth, leftWidth);
	instance.requestAnimationFrame(function(){
		instance.setStyle({
			transform: 'translateX(' + state.left + 'px)',
			'-webkit-transform': 'translateX(' + state.left + 'px)'
		})
	})

}

/**
 * 获取范围
 * @param {Object} num
 * @param {Object} min
 * @param {Object} max
 */
function range(num, min, max) {
	return Math.min(Math.max(num, min), max);
}


/**
 * 移动方向判断
 * @param {Object} left
 * @param {Object} value
 * @param {Object} ownerInstance
 * @param {Object} ins
 */
function moveDirection(left, ins, ownerInstance) {
	var state = ins.getState()
	var threshold = state.threshold
	var position = state.position
	var isopen = state.isopen || 'none'
	var leftWidth = state.leftWidth
	var rightWidth = state.rightWidth
	if (state.deltaX === 0) {
		openState('none', ins, ownerInstance)
		return
	}
	if ((isopen === 'none' && rightWidth > 0 && -left > threshold) || (isopen !== 'none' && rightWidth > 0 && rightWidth +
			left < threshold)) {
		// right
		openState('right', ins, ownerInstance)
	} else if ((isopen === 'none' && leftWidth > 0 && left > threshold) || (isopen !== 'none' && leftWidth > 0 &&
			leftWidth - left < threshold)) {
		// left
		openState('left', ins, ownerInstance)
	} else {
		// default
		openState('none', ins, ownerInstance)
	}
}


/**
 * 开启状态
 * @param {Boolean} type
 * @param {Object} ins
 * @param {Object} ownerInstance
 */
function openState(type, ins, ownerInstance) {
	var state = ins.getState()
	var position = state.position
	var leftWidth = state.leftWidth
	var rightWidth = state.rightWidth
	var left = ''
	state.isopen = state.isopen ? state.isopen : 'none'
	switch (type) {
		case "left":
			left = leftWidth
			break
		case "right":
			left = -rightWidth
			break
		default:
			left = 0
	}

	// && !state.throttle

	if (state.isopen !== type ) {
		state.throttle = true
		ownerInstance.callMethod('change', {
			open: type
		})

	}

	state.isopen = type
	// 添加动画类
	ins.requestAnimationFrame(function(){
		ins.addClass('ani');
		move(left, ins, ownerInstance)
	})
	// 设置最终移动位置,理论上只要进入到这个函数，肯定是要打开的
}


function getDirection(x, y) {
	if (x > y && x > MIN_DISTANCE) {
		return 'horizontal';
	}
	if (y > x && y > MIN_DISTANCE) {
		return 'vertical';
	}
	return '';
}

/**
 * 重置滑动状态
 * @param {Object} event
 */
function resetTouchStatus(instance) {
	var state = instance.getState();
	state.direction = '';
	state.deltaX = 0;
	state.deltaY = 0;
	state.offsetX = 0;
	state.offsetY = 0;
}

/**
 * 设置滑动开始位置
 * @param {Object} event
 */
function stopTouchStart(event) {
	var instance = event.instance;
	var state = instance.getState();
	resetTouchStatus(instance);
	var touch = event.touches[0];
	state.startX = touch.clientX;
	state.startY = touch.clientY;
}

/**
 * 滑动中，是否禁止打开
 * @param {Object} event
 */
function stopTouchMove(event) {
	var instance = event.instance;
	var state = instance.getState();
	var touch = event.touches[0];
	state.deltaX = touch.clientX - state.startX;
	state.deltaY = touch.clientY - state.startY;
	state.offsetX = Math.abs(state.deltaX);
	state.offsetY = Math.abs(state.deltaY);
	state.direction = state.direction || getDirection(state.offsetX, state.offsetY);
}


module.exports = {
	sizeReady: sizeReady,
	touchstart: touchstart,
	touchmove: touchmove,
	touchend: touchend
}