Html程序  |  112行  |  4.07 KB

<html>
<head>
<style>
#dropTarget, #dragMe { text-align: center; display: table-cell; vertical-align: middle }
#dropTarget {width: 256px; height: 256px; border: 1px dashed}
#dragMe {-webkit-user-drag: element; -webkit-user-select: none; background: #ff0000; width: 64px; height: 64px; color: white}
.pass { font-weight: bold; color: green; }
.fail { font-weight: bold; color: red; }
</style>
<script>
    var dragMe;
    var dropTarget;
    var messageElm;
    var defaultMessageElm;
    var event;
    
    var ALLOWED_EFFECTS = 'move';
    var DROP_EFFECT = 'copy';
    
    window.onload = function()
    {
        dragMe = document.getElementById("dragMe");
        dropTarget = document.getElementById("dropTarget");
        messageElm = document.getElementById("message");
        defaultMessageElm = document.getElementById("default-message");
        
        if (!dragMe || !dropTarget || !messageElm || !defaultMessageElm)
            return;
        
        dragMe.ondragstart = dragStart;
        dragMe.ondragend = dragEnd;
        
        dropTarget.ondragenter = dragEntered;
        dropTarget.ondragover = dragOver;
        dropTarget.ondrop = drop;
    }
    
    function dragStart(e)
    {
        event = e;
        e.dataTransfer.effectAllowed = ALLOWED_EFFECTS;
        e.dataTransfer.setData('Text', e.target.textContent);
    }
    
    function dragEnd(e)
    {
        messageElm.style.visibility = "hidden";
        defaultMessageElm.style.visibility = "visible";
        return;
    }
    
    function dragEntered(e)
    {
        messageElm.style.visibility = "visible";
        defaultMessageElm.style.visibility = "hidden";
        dragEnteredAndUpdated(e);
    }
    
    function dragOver(e)
    {
        dragEnteredAndUpdated(e);
    }
    
    function dragEnteredAndUpdated(e)
    {
        event = e;
        e.dataTransfer.dropEffect = DROP_EFFECT;
        cancelDrag(e);
    }
    
    function drop(e)
    {
        cancelDrag(e);
    }
    
    function cancelDrag(e)
    {
        if (e.preventDefault)
            e.preventDefault();
        else {
            // Assume this script is executing within Internet Explorer
            e.returnValue = false;
        }
    }
</script>
</head>
<body>
    <p id="description">This test can be used to verify that the not-allowed cursor is shown during an invalid drag-and-drop operation. 
        In particular, if the effectAllowed is <code><script>document.write(ALLOWED_EFFECTS)</script></code> and the dropEffect of the 
        drop target is <code><script>document.write(DROP_EFFECT)</script></code> then the drop is not allowed and the cursor should
        change to the not-allowed cursor. Note, this test only pertains to the Windows build since the Mac build does not show a drop cursor
        for a not-allowed drop operation (see bug #25925).
        <br/><br/>
        Drag the red square over the drop target (demarcated by the dashed boundary). While hovering over the drop target, if the cursor 
        is <img alt="not-allowed" src="data:image/gif;base64,R0lGODlhEgASAIAAAAAAAP///yH5BAAAAAAALAAAAAASABIAAAIvjA+px6ifmnmM1ijDmlbuuHmAhoWXaTqYKq7sObZw3HwgXd8cPr8yDGxBXEJioAAAOw=="> then the test <span class="pass">PASSED</span>. Otherwise, the test <span class="fail">FAILED</span>.</p>
    <div id="test-container">
        <label for="effectAllowed">effectAllowed:</label> <code><script>document.write(ALLOWED_EFFECTS)</script></code>
        <br/><br/>
        <div id="dropTarget">
            <div id="default-message">Drag the red square over me.<br/><br/>
                <label for="dropEffect">Expects dropEffect:</label> <code><script>document.write(DROP_EFFECT)</script></code>
            </div>
            <div id="message" style="visibility:hidden">The cursor should be <img alt="not-allowed" src="data:image/gif;base64,R0lGODlhEgASAIAAAAAAAP///yH5BAAAAAAALAAAAAASABIAAAIvjA+px6ifmnmM1ijDmlbuuHmAhoWXaTqYKq7sObZw3HwgXd8cPr8yDGxBXEJioAAAOw==">. Is it?</div>
        </div>
        <hr/>
        <p>Items that can be dragged to the drop target:</p>
        <div id="dragMe" draggable="true">Square</div>
        <hr/>
    </div>
</body>
</html>