| 1 |
- import{VantComponent}from'../common/component';import{isObj,range}from'../common/utils';const DEFAULT_DURATION=200;VantComponent({classes:['active-class'],props:{valueKey:String,className:String,itemHeight:Number,visibleItemCount:Number,initialOptions:{type:Array,value:[]},defaultIndex:{type:Number,value:0}},data:{startY:0,offset:0,duration:0,startOffset:0,options:[],currentIndex:0},created(){const{defaultIndex,initialOptions}=this.data;this.set({currentIndex:defaultIndex,options:initialOptions}).then(()=>{this.setIndex(defaultIndex)})},watch:{defaultIndex(value){this.setIndex(value)}},methods:{getCount(){return this.data.options.length},onTouchStart(event){this.setData({startY:event.touches[0].clientY,startOffset:this.data.offset,duration:0})},onTouchMove(event){const{data}=this;const deltaY=event.touches[0].clientY-data.startY;this.setData({offset:range(data.startOffset+deltaY,-(this.getCount()*data.itemHeight),data.itemHeight)})},onTouchEnd(){const{data}=this;if(data.offset!==data.startOffset){this.setData({duration:DEFAULT_DURATION});const index=range(Math.round(-data.offset/data.itemHeight),0,this.getCount()-1);this.setIndex(index,true)}},onClickItem(event){const{index}=event.currentTarget.dataset;this.setIndex(index,true)},adjustIndex(index){const{data}=this;const count=this.getCount();index=range(index,0,count);for(let i=index;i<count;i++){if(!this.isDisabled(data.options[i]))return i}for(let i=index-1;i>=0;i--){if(!this.isDisabled(data.options[i]))return i}},isDisabled(option){return isObj(option)&&option.disabled},getOptionText(option){const{data}=this;return isObj(option)&&data.valueKey in option?option[data.valueKey]:option},setIndex(index,userAction){const{data}=this;index=this.adjustIndex(index)||0;const offset=-index*data.itemHeight;if(index!==data.currentIndex){return this.set({offset,currentIndex:index}).then(()=>{userAction&&this.$emit('change',index)})}return this.set({offset})},setValue(value){const{options}=this.data;for(let i=0;i<options.length;i++){if(this.getOptionText(options[i])===value){return this.setIndex(i)}}return Promise.resolve()},getValue(){const{data}=this;return data.options[data.currentIndex]}}});
|
