drag-and-drop - 通缉: Directions/ideas for a custom tree-to-tree drag'n'drop implementation in ExtJS

Question

我需要一些关于 ExtJS 中两棵树之间拖放的组合功能。

第一个所需功能非常简单，只是将内置拖放功能隔离到单个树。

第二个必需的功能是我不希望用户能够从左树中拖动节点并将其放在左树中的任何节点上>右树。

该操作不应从左树中删除节点，从而可能将同一节点从左树拖动到中的多个位置右树。

我的问题是:我应该采取哪种方法来组合这两个功能，利用 TreePanel 对象中现有的可能性，而无需再次发明轮子？我不是在寻找完整的解决方案(虽然这会很好;-))，而是在寻找如何处理拖放区域、事件等。

Answer 1

好的。我已经考虑这个问题有一段时间了，以下方法似乎对我有用:)

我已将左树配置如下:

listeners:
{
    beforenodedrop: function (dropEvent) {
        // Does this node come from the right tree?
        if (dropEvent.source.tree.id !== dropEvent.tree.id) {
            // The node should be discarded.
            dropEvent.dropNode.parentNode.removeChild(dropEvent.dropNode, true);

            // The node has been discarded, return drop succeeded.
            dropEvent.dropStatus = true;
            return false;
        }
        return true;
    },  
    nodedragover: function (dragevent) {
        // If the node comes from the right tree, it is allowed to be dropped here.
        if (dragevent.source.tree.id !== dragevent.tree.id) {
            return true;
        }
        // A node from this tree is not allowed to be dropped.
        return false;
    }
}

右树的配置如下:

listeners:
{   
    beforenodedrop: function (dropEvent) {
        // Does this node come from the left tree?
        if (dropEvent.source.tree.id !== dropEvent.tree.id) {
            // The node should be cloned and inserted in the right tree.

            // Copy the node.
            var node = dropEvent.dropNode; // the node that was dropped
            var nodeCopy = new Ext.tree.TreeNode( // copy it
                Ext.apply({}, node.attributes)
            );
            // Match the id's.
            nodeCopy.id = Ext.id(null,'newnode') + '_' + node.id;

            // Find the right place to put it.
            if (dropEvent.target.parentNode === dropEvent.tree.getRootNode()) {
                // The node is placed on a folder, thus drop it there.
                dropEvent.target.appendChild(nodeCopy);
            } else {
                // The node is placed inside a folder, thus place it in there.
                dropEvent.target.parentNode.appendChild(nodeCopy);
            }

            // The node has been dropped, return okay and stop further process.
            dropEvent.dropStatus = true;
            return false;
        }           
        // Just use the normal builtin drag and drop.
        return true;
    }
}

两棵树都已设置为启用拖放:

enableDD: true

所有叶节点都有以下配置:

allowDrop: true,
draggable: true

所有文件夹均设置为:

allowDrop: true,
draggable: false

结论是，我选择覆盖树面板中的一些内置拖放方法，同时仍然保留内置功能。<​​/p>