cocos creator Touch事件应用(触控选择多个子节点的实例)

  • 2022-04-28 23:41:37

最近参与了cocos creator的研究,开发小游戏,结果被一个事件坑得不行不行的。现在终于解决了,分享给大家。

原理

1.触控事件是针对节点的

2.触控事件的冒泡,是直接关系冒泡,父子可以,孙子不行,就是不能隔代冒泡

3.父节点不响应触控事件,肯定是被孩子节点遮挡了,只要孩子节点也监听一下事件,父节点就可以响应了

4.触控位置是绝对坐标,相对于整个canvas,节点位置相对于父节点,相对位置可以与绝对坐标相互转化

5.节点是否被触控到,touch start事件可以肯定被触摸到,但是一个节点触摸到必须等待其结束,另一个节点才能响应touch事件

6.判断是否框选中,根据坐标计算相互交叉即是选中。就是说我从触控起点->触控终点 构成的矩形区域,与节点的矩形存在重叠,就是被框选。本例中,采用比较粗略的算法实现,根据横坐标的范围是否包含子节点的横坐标判断是否选中。

7.计算某个数值是否在某一范围内,首先计算出范围的最大值、最小值,然后作比较即可。

核心代码

cc.class({
 extends: cc.component,

 properties: {
  // foo: {
  // default: null,  // the default value will be used only when the component attaching
  //       to a node for the first time
  // url: cc.texture2d, // optional, default is typeof default
  // serializable: true, // optional, default is true
  // visible: true,  // optional, default is true
  // displayname: 'foo', // optional
  // readonly: false, // optional, default is false
  // },
  // ...
   poker:{
    default:null,
    type:cc.node
   },
   cardmask:{
    default:null,
    type: cc.prefab
   }
 },

 // use this for initialization
 onload: function () {
   
   //牌
   this.cards = this.poker.children;

   //牌初始位置
   this.cardinity = this.cards[0].y;

   //触摸选择到的牌
   this.touchedcards = [];

   //选中的牌
   this.selectedcards = [];

   console.info(this.cards);
  },
  
  start: function () {
   // this.cards = this.poker.children;
   // console.info(this.cards);
   
   this.addtouchevent();
  },

  /**
   * 添加事件
   */
  addtouchevent:function(){

   //父节点监听touch事件(直接子节点必须注册同样的事件方能触发)
   this.poker.on(cc.node.eventtype.touch_start, function (event) {
    console.log('poker touch_start');
    
    //牌
    var card = event.target;
    
    //起始触摸位置(和第一张card一样,相对于poker的位置)
    this.touchstartlocation = this.cards[0].converttouchtonodespace(event);
    console.log('touch start location:'+ json.stringify(this.touchstartlocation));
    
    //计算牌位置
    var index = 0;
    for(var i=0;i<this.cards.length;i++){
     var c = this.cards[i];
     if(c.name == card.name){
      index = i;
      break;
     }
    }

    //暂存第一次触摸到的牌
    var touchedcard = {
     index:index,
     card:card
    };
    this.firsttouchedcard = touchedcard;
    //暂存
    this.pushtouchedcards(touchedcard.index,touchedcard.card);

   }, this);
  
   //父节点监听touch事件(直接子节点必须注册同样的事件方能触发)
   this.poker.on(cc.node.eventtype.touch_move, function (event) {
    console.log('poker touch_move');
    //先清除原先触摸到的牌
    this.cleartouchedcards();
    //保存第一张牌
    this.pushtouchedcards(this.firsttouchedcard.index,this.firsttouchedcard.card);

    //触摸点转换为card节点坐标
    var nodelocation = this.cards[0].converttouchtonodespace(event);
    console.log('touch nodelocation:'+ json.stringify(nodelocation));
    var x = nodelocation.x;
    var y = nodelocation.y; 

    //找到当前选中的牌
    var currentcard = null;
    for(var i=0;i< this.cards.length;i++){
     var card = this.cards[i];
     var cardx = card.x;
     var cardy = card.y;
     console.log('card x='+cardx+',y='+cardy);


     //某张牌范围包括了鼠标位置,选中此牌与触摸开头的所有牌
     var cardwidth = i==5 ? card.width:19;
     var cardheight = card.height;
     if(cardx<=x && x <= cardx+cardwidth && cardy<=y && y<= cardy+cardheight){
      currentcard = card;
    
      //暂存触摸到的牌
      this.pushtouchedcards(i,card);
      
      break;
     }
    }
    
    //添加开头与此牌直接的所有牌
    var starttouchlocation = this.touchstartlocation;
    for(var i=0;i< this.cards.length;i++){
     var card = this.cards[i];
     var cardx = card.x;
     //框选的范围包括了的牌
     var min,max;
     if(starttouchlocation.x < nodelocation.x){
      min = starttouchlocation.x;
      max = nodelocation.x;
     }else{
      min = nodelocation.x;
      max = starttouchlocation.x;
     }
     console.log('min='+min+', max='+max);

     if(min <= cardx && cardx <= max){
      //暂存触摸到的牌
      this.pushtouchedcards(i,card);
     }
    }
    

   }, this);
  
  //父节点监听touch事件(直接子节点必须注册同样的事件方能触发)
  this.poker.on(cc.node.eventtype.touch_end, function (event) {
   console.log('poker touch_end');
   this.doselectcard();
  }, this);
  
  //父节点监听touch事件(直接子节点必须注册同样的事件方能触发)
  this.poker.on(cc.node.eventtype.touch_cancel, function (event) {
   console.log('poker touch_cancel');
   this.doselectcard();
  }, this);
  
  //给所有的牌注册事件,会自动冒泡到poker节点
  for(var i=0;i< this.cards.length;i++){
   var cards = this.cards;
   //闭包传递i值
   (function(i){
    var card = cards[i];
    card.on(cc.node.eventtype.touch_start, function (event) {
     console.log('card touch_start');
    }, card);
    
    card.on(cc.node.eventtype.touch_move, function (event) {
     console.log('card touch_move');
    }, card);

    card.on(cc.node.eventtype.touch_end, function (event) {
     console.log('card touch_end');
    }, card);
 
    card.on(cc.node.eventtype.touch_cancel, function (event) {
     console.log('card touch_cancel');
    }, card);

   
   })(i)
   
  }
  
 },

 /**
  * 暂存触摸到的牌
  */
 pushtouchedcards:function(index,card){
  //构造牌对象
  var cardobj = {
   index:index,
   name:card.name,
   isselected:card.y==this.cardinity?false:true //高度不一样,表示选中
  };
  
  //防止重复添加
  var existcard = this.touchedcards.find(function(obj){
   if(obj.name == card.name){
    return obj;
   }else{
    return null;
   }
  });
  if(!existcard){
   //添加暂存
   this.touchedcards.push(cardobj);

   //包含提示
   this.addcardmask(card);
  }
 },

 /**
  * 清除原先暂存的触摸到的牌
  */
 cleartouchedcards:function(){
  for(var i=0;i<this.touchedcards.length;i++){
   var cardindex = this.touchedcards[i].index;
   var card = this.cards[cardindex];
   card.removechild(card.children[0]);
  }
  this.touchedcards = [];
 },

 /**
  * 选择牌
  */
 doselectcard:function(){
  this.selectedcards = [];

  console.log(this.touchedcards);

  //改变牌状态
  for(var i = 0; i< this.touchedcards.length;i++){
   var cardobj = this.touchedcards[i];
   var card = this.cards[cardobj.index];
   if(cardobj.isselected){ //如果是选中改为不选中
    card.y = card.y - 30;
   }else{ //不选中改为选中状态
    card.y = card.y + 30;
   }
  }

  //重置
  this.cleartouchedcards();

  //显示选中的牌
  this.showselectedcards();
 },

 /**
  * 包含牌遮罩
  */
 addcardmask:function(card){
  var cardmask = cc.instantiate(this.cardmask);
  cardmask.setposition(cc.p(0, 0));
  card.addchild(cardmask);
  },

 /**
 * 显示选中的牌
 */
 showselectedcards:function(){
  this.selectedcards = [];
  for(var i=0;i< this.cards.length;i++){
   var card = this.cards[i];
   var isselected = card.y==this.cardinity?false:true;
   if(isselected){
    this.selectedcards.push(card.name);
   }
  }
  //输出
  console.info("selected cards is: "+ json.stringify(this.selectedcards));
 },

 
 // called every frame, uncomment this function to activate update callback
 // update: function (dt) {

 // },
});

效果

cocos creator Touch事件应用(触控选择多个子节点的实例)

以上这篇cocos creator touch事件应用(触控选择多个子节点的实例)就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持。

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