javascript - 如何避免在 mxgraph 中重复拖动

问题描述

我想避免在mxgraph画布上重复放置。

假设我Pipe第二次在画布上拖动它不应该允许它被拖动到画布上。

问题： 如何避免画布上的重复放置

这是我的工作代码拖动，允许重复

拖放

var graph = {};

function initCanvas() {

  //This function is called onload of body itself and it will make the mxgraph canvas
  graph = new mxGraph(document.getElementById('graph-wrapper'));
  graph.htmlLabels = true;
  graph.cellsEditable = false;

  // render as HTML node always. You probably won't want that in real world though
  graph.convertValueToString = function(cell) {
    return cell.value;
  }

  const createDropHandler = function (cells, allowSplit) {
    return function (graph, evt, target, x, y) {
      const select = graph.importCells(cells, x, y, target);
      graph.setSelectionCells(select);
    };
  };

  const createDragPreview = function (width, height) {
    var elt = document.createElement('div');
    elt.style.border = '1px dashed black';
    elt.style.width = width + 'px';
    elt.style.height = height + 'px';
    return elt;
  };

  const createDragSource = function (elt, dropHandler, preview) {
    return mxUtils.makeDraggable(elt, graph, dropHandler, preview, 0, 0, graph.autoscroll, true, true);
  };

  const createItem = (id) => {

    const elt = document.getElementById(id);
    const width = elt.clientWidth;
    const height = elt.clientHeight;

    const cell = new mxCell('', new mxGeometry(0, 0, width, height), 'fillColor=none;strokeColor=none');
    cell.vertex = true;
    graph.model.setValue(cell, elt);

    const cells = [cell];

    const bounds = new mxRectangle(0, 0, width, height);
    createDragSource(elt, createDropHandler(cells, true, false, bounds), createDragPreview(width, height), cells, bounds);
  };


  createItem("shape_1");
  createItem("shape_2");
  createItem("shape_3");
}

#graph-wrapper {
  background: #333;
  width: 100%;
  height: 528px;
 }

<html>

<head>
    <title>Toolbar example for mxGraph</title>

    <script type="text/javascript">
        mxBasePath = 'https://jgraph.github.io/mxgraph/javascript/src';
    </script>
    <script src="https://jgraph.github.io/mxgraph/javascript/src/js/mxClient.js"></script>
    <script src="./app.js"></script>
</head>

<body onload="initCanvas()">
    <h4>Drag same box 2 times on the canvas. see duplicate is allowed</h4>

    <div>
        <div id="shape_1"
            style="width: 100px; height: 100px; border-radius: 50%; background: red; display: inline-flex; text-align: center; color: #fff; align-items: center; justify-content: center;">
            Pipe
        </div>

        <div draggable="true" id="shape_2"
            style="width: 100px; height: 100px; border-radius: 5%; background: orange; display: inline-flex; text-align: center; color: #fff; align-items: center; justify-content: center;">
            Team
        </div>
        
        <div draggable="true" id="shape_3"
            style="width: 100px; height: 64px; background: #009688; display: inline-flex; text-align: center; color: #fff; align-items: center; justify-content: center; border-radius: 207px; flex-direction: column;">
            <div> <svg xmlns="http://www.w3.org/2000/svg" height="24px" viewBox="0 0 24 24" width="24px" fill="#000000">
                    <path d="M0 0h24v24H0V0z" fill="none" />
                    <path
                        d="M11 7h2v2h-2zm0 4h2v6h-2zm1-9C6.48 2 2 6.48 2 12s4.48 10 10 10 10-4.48 10-10S17.52 2 12 2zm0 18c-4.41 0-8-3.59-8-8s3.59-8 8-8 8 3.59 8 8-3.59 8-8 8z" />
                </svg></div>
            <div>Info</div>
        </div>
    </div>

    <div id="graph-wrapper">

    </div>
</body>

</html>

标签： javascriptjquerymxgraph

解决方案

maxgarph您只需要检查in的所有当前单元格值createDropHandler。因此，获取所有单元格graph.getModel().cells，然后检查您要添加的单元格是否存在：

let allcells = graph.getModel().cells;
for (var i in allcells)
    if (allcells[i].value && (allcells[i].value.id == cells[0].value.id))
        return;

var graph = {};

function initCanvas() {
    //This function is called onload of body itself and it will make the mxgraph canvas
    graph = new mxGraph(document.getElementById('graph-wrapper'));
    graph.htmlLabels = true;
    graph.cellsEditable = false;

    // render as HTML node always. You probably won't want that in real world though
    graph.convertValueToString = function (cell) {
        return cell.value;
    }

    const createDropHandler = function (cells, allowSplit) {
        return function (graph, evt, target, x, y) {
            debugger
            let allcells = graph.getModel().cells;
            for (var i in allcells)
                if (allcells[i].value && (allcells[i].value.id == cells[0].value.id))
                    return;
            const select = graph.importCells(cells, x, y, target);
            graph.setSelectionCells(select);
        };
    };

    const createDragPreview = function (width, height) {
        var elt = document.createElement('div');
        elt.style.border = '1px dashed black';
        elt.style.width = width + 'px';
        elt.style.height = height + 'px';
        return elt;
    };

    const createDragSource = function (elt, dropHandler, preview) {
        return mxUtils.makeDraggable(elt, graph, dropHandler, preview, 0, 0, graph.autoscroll, true, true);
    };

    const createItem = (id) => {
        const elt = document.getElementById(id);
        const width = elt.clientWidth;
        const height = elt.clientHeight;

        const cell = new mxCell('', new mxGeometry(0, 0, width, height), 'fillColor=none;strokeColor=none');
        cell.vertex = true;
        graph.model.setValue(cell, elt);

        const cells = [cell];

        const bounds = new mxRectangle(0, 0, width, height);
        createDragSource(elt, createDropHandler(cells, true, false, bounds), createDragPreview(width, height), cells, bounds);
    };


    createItem("shape_1");
    createItem("shape_2");
    createItem("shape_3");
}

<html>

<head>
    <title>Toolbar example for mxGraph</title>

    <script type="text/javascript">
        mxBasePath = 'https://jgraph.github.io/mxgraph/javascript/src';
    </script>
    <script src="https://jgraph.github.io/mxgraph/javascript/src/js/mxClient.js"></script>
    <script src="./app.js"></script>
    <style>
        #graph-wrapper {
            background: #333;
            width: 100%;
            height: 528px;
        }
    </style>
</head>

<body onload="initCanvas()">
    <h4>Drag same box 2 times on the canvas. see duplicate is allowed</h4>

    <div>
        <div id="shape_1"
             style="width: 100px; height: 100px; border-radius: 50%; background: red; display: inline-flex; text-align: center; color: #fff; align-items: center; justify-content: center;">
            Pipe
        </div>

        <div draggable="true" id="shape_2"
             style="width: 100px; height: 100px; border-radius: 5%; background: orange; display: inline-flex; text-align: center; color: #fff; align-items: center; justify-content: center;">
            Team
        </div>

        <div draggable="true" id="shape_3"
             style="width: 100px; height: 64px; background: #009688; display: inline-flex; text-align: center; color: #fff; align-items: center; justify-content: center; border-radius: 207px; flex-direction: column;">
            <div>
                <svg xmlns="http://www.w3.org/2000/svg" height="24px" viewBox="0 0 24 24" width="24px" fill="#000000">
                    <path d="M0 0h24v24H0V0z" fill="none" />
                    <path d="M11 7h2v2h-2zm0 4h2v6h-2zm1-9C6.48 2 2 6.48 2 12s4.48 10 10 10 10-4.48 10-10S17.52 2 12 2zm0 18c-4.41 0-8-3.59-8-8s3.59-8 8-8 8 3.59 8 8-3.59 8-8 8z" />
                </svg>
            </div>
            <div>Info</div>
        </div>
    </div>

    <div id="graph-wrapper">

    </div>

javascript - 如何避免在 mxgraph 中重复拖动

问题描述

解决方案

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