This is the code to repeatedly dray lines on increasing the value on a ComboBox. But how can I delete the number of lines on decreasing this value?
main.qml
Qt Code: 
  1. ComboBox {
  2.                     id: combo
  3.                     editable: false
  4.                     model: ListModel {
  5.                         id: numoflines
  6.                         ListElement { text: "1"; color: "Black" }
  7.                         ListElement { text: "2"; color: "Black" }
  8.                         ListElement { text: "3"; color: "Black" }
  9.                         ListElement { text: "4"; color: "Black" }
  10.                         ListElement { text: "5"; color: "Black" }
  11.                         ListElement { text: "6"; color: "Black" }
  12.                         ListElement { text: "7"; color: "Black" }
  13.                     }
  14.                     onAccepted: {
  15.                         if (combo.find(currentText) === -1) {
  16.                             model.append({text: editText})
  17.                             currentIndex = combo.find(editText)
  18.                         }
  19.                     }
  20.                     onCurrentTextChanged: {
  21.                         Global.numoflines = parseInt(currentIndex) + 1;
  22.                         console.log(Global.numoflines);
  23.                         Qt.createComponent("Analysis.qml").createObject(parent), {x: 100, y: 200};
  24.                     }
  25.                 }
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Analysis.qml:
Qt Code: 
  1. Rectangle {
  2.         id: base;
  3.         x: 50;
  4.         y: 480;
  5.  
  6.         Column {
  7.             spacing: -12;
  8.  
  9.             Repeater {
  10.                 model: Global.numoflines;
  11.                 delegate: Rectangle {
  12.                     width: 800;
  13.                     height: 1;
  14.                     //color: "white";
  15.                     border { width: 1; color: "black" }
  16.                     radius: 3;
  17.  
  18.                 }
  19.  
  20.             }
  21.  
  22.         }
  23.     }
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