// 两个元素之间折线 可以拆解为三段直线连接起来了
/*
A---|
    |
    |---B
*/


var a,b,line;
window.onload = function(){
    var resetHandlerPosition = function(){
        var start = line2.start();
        var end = line2.end();
        var sign = start[0]-end[0];
        var dis = Math.abs(end[0]-start[0]);

        var x = sign<=0?start[0]+dis*0.8:end[0]+dis*0.2
        // console.log(start[0]-end[0]);
        // return [x,end[1]];

        // h_handler.setStart(line2.end()).setDisplay('block');
        h_handler.setStart([x,end[1]+1]).setDisplay('block');
    }

    var qcanvas = new Qcanvas({
        id:'qcanvas',
        width:500,
        height:500,
        mouseup:function(){ 
            resetHandlerPosition();
            create_range();
        },
        mousemove:function(){
            if(qcanvas.dragAim !== null && qcanvas.dragAim.id ==h_handler.id){
                //重新计算line2的x坐标到起点的的距离点整个宽度的比例
                percent = Math.abs((h_handler.start[1]-a.start[1])/(a.start[1] - b.start[1]))
            }
            
        }
    });

    a = qcanvas.qarc.arc({
        start:[50,50],
        r:10,
        sAngle:0,
        eAngle:360,
        fillColor:'#ffff00',
        borderColor:'#000',
         mousedown:function(){

            h_handler.setDisplay('none')
        },
        mouseup:function(){ 

            resetHandlerPosition();
            create_range();
        }
    })

    b = qcanvas.qarc.arc({
        start:[200,200],
        r:10,
        sAngle:0,
        eAngle:360,
        fillColor:'#c3c3c3',
        borderColor:'#000',
        mousedown:function(){
            h_handler.setDisplay('none')
        },
        mouseup:function(){

            resetHandlerPosition();
            create_range();
        }
    })

    var percent = 0.8;
    var range = [];
    var h_handler = {};

    //句柄划动限制区域 
    var create_range = function(){
         
         var f = function(){

            //A在左  B在右
            if(a.start[0] <= b.start[0]){
                if(a.start[1] <= b.start[1]){
                //A
                // |
                //h1 \ h2
                //   ↓
                //   B
                    return [[a.start[0],a.start[1]+5],[b.start[0],b.start[1]-5]];
                }else{
                    //    B
                    //    ↑
                    //h1 / h2
                    // |
                    //A
                    return [[a.start[0],b.start[1]+5],[b.start[0]-5,a.start[1]-5]]
                }
            }else{
            //B在左 A在右
                if(b.start[1] <= a.start[1]){
                    // B
                    // ↑
                    //h1 \ h2
                    //   |
                    //   A
                    return [[b.start[0],b.start[1]+5],[a.start[0],a.start[1]-5]]
                }else{
                    //    A
                    //    |
                    //h1 / h2
                    // ↓
                    //B
                    return [[b.start[0],a.start[1]+5],[a.start[0],b.start[1]-5]];
                }
            }

         }

         range = f();
         
    }
    create_range();

   
   //生成三条直线的坐标
    var caleHandler1 = function(a,b){ 
 

            var start = a.start;
            var end = b.start;  

 
           //模向模式
                    return {
                        'l1':function(){return [start,[start[0],(end[1]-start[1])*percent+start[1]]]},
                        'l2':function(){return [[start[0],(end[1]-start[1])*percent+start[1]],[end[0],(end[1]-start[1])*percent+start[1]]]},
                        'l3':function(){return [[end[0],(end[1]-start[1])*percent+start[1]],end]}
                    }


                // //A
                // // |
                // //h1 \ h2
                // //   ↓
                // //   B
                // // 或
                // //  A
                // //  |
                // //h2/h1
                // // ↓
                // // B
                // if(start[1]<=end[1]){ 
 
                //         // 竖向模式
                //         return {
                //             'l1':function(){return [start,[(end[0]-start[0])*percent+start[0],start[1]]]},
                //             'l2':function(){return [[(end[0]-start[0])*percent+start[0],start[1]],[(end[0]-start[0])*percent+start[0],end[1]]]},
                //             'l3':function(){return [[(end[0]-start[0])*percent+start[0],end[1]],end]}
                //         } 
 
                // }else{
                // // B
                // // ↑
                // //h1\h2
                // //  |
                // //  A
                // //或
                // //   B
                // //   ↑
                // // h2/h1
                // //  |
                // //  A 
                //     //竖向模式
                //     return {
                //         'l1':function(){return [start,[(end[0]-start[0])*percent+start[0],start[1]]]},
                //         'l2':function(){return [[(end[0]-start[0])*percent+start[0],start[1]],[(end[0]-start[0])*percent+start[0],end[1]]]},
                //         'l3':function(){return [[(end[0]-start[0])*percent+start[0],end[1]],end]} 
                //     }

                // }
 
 
 
            
    } 

    
    var tmp = null;
    var line1 = qcanvas.qline.line({
        start:function(){
            var points = tmp === null?caleHandler1(a,b):tmp;
            var t = points['l1']();
            return t[0];
        },
        end:function(){
            var points = tmp === null?caleHandler1(a,b):tmp;
            var t = points['l1']();
            return t[1];
        },
        pointerEvent:'none',
        width:1,
        color:"#000"
    })

    

    var line2 = qcanvas.qline.line({
        start:function(){
             var points = tmp === null?caleHandler1(a,b):tmp;
            var t = points['l2']();
            return t[0];
        },
        end:function(){
            var points = tmp === null?caleHandler1(a,b):tmp;
            var t = points['l2']();
            return t[1];
        },
        pointerEvent:'none',
        width:1,
        withText:'ddd',
         color:"#000"
    })

    



    var line3 = qcanvas.qline.line({
        start:function(){
             var points = tmp === null?caleHandler1(a,b):tmp;
            var t = points['l3']();
            return t[0];
        },
        end:function(){
             var points = tmp === null?caleHandler1(a,b):tmp;
            var t = points['l3']();
            return t[1];
        },
        like:'->',
        pointerEvent:'none',
        width:1,
         color:"#000"
    }) 
    
    var getStart = (function(){
        var start = line2.start();
        var end = line2.end();
        var sign = start[0]-end[0];
        var dis = Math.abs(end[0]-start[0]);

        var x = sign<=0?start[0]+dis*0.8:end[0]+dis*0.2
        // console.log(start[0]-end[0]);
        return [x,end[1]+1];
    })()
    h_handler = qcanvas.qtext.text({
        text:'=', 
        color:'red',
        textAlign:'center',
        textBaseline:'middle',
        fontSize:'24px',
        start:getStart,
        drag:'vertical', 
        // degree:45,
        dragRange:function(){return range},
        // mouseout:function(){
        //     qcanvas.dragAim =null;
        // },
        mousemove:function(){
            if(qcanvas.dragAim !== null && qcanvas.dragAim.id ==this.id){
                 //重新计算line2的x坐标到起点的的距离点整个宽度的比例
                percent = Math.abs((this.start[1]-a.start[1])/(a.start[1] - b.start[1]))
            }
        },
        mouseup:function(){
            resetHandlerPosition();
            
        }
    })

    qcanvas.raiseToTop(h_handler);
   
}