单击按钮时如何触发事件监听图层上的形状？

Question

在 KonvaJS 中，是否可以在单击按钮时使层处于非活动状态（但不是不可见），然后在单击另一个按钮时处于活动状态？我已经尝试 "text_overlay.listening(false);" 但它不起作用。我可以使用 "textNode0.listening(false);" 停用单个文本节点，这确实会阻止用户编辑该文本，但这些文本节点位于多边形上，其中一些非常小（例如，欧洲地图上的卢森堡）并且文本区域会阻止用户单击下面的多边形（例如，更改其填充颜色）。此外，将有超过 40 个文本节点需要处理，因此停用 1 层是更可取的！

这是 HTML 文件的按钮部分：

<script src="js/text-input21.js"></script>
<!-- button events -->
<script>
    // button states on load
    var btnLabelClicked = true;
    var btnColorClicked = false;
    var btnDrawLinesClicked = false;
    //color chip buttons
    var btnViolet = document.getElementById("fillViolet");
    var btnOrange = document.getElementById("fillOrange");
    var btnYellow = document.getElementById("fillYellow");
    //color chip buttons' fill when btnLabelClicked = true
    btnViolet.style.background = disableBtnFill;
    btnOrange.style.background = disableBtnFill;
    btnYellow.style.background = disableBtnFill;

    var buttonID = 'btnLabel';

    function replyClick(clickedID) {
        buttonID = (clickedID);
        if (buttonID === 'btnColor') {
            textNode0.listening(false);
            textNode15.listening(false);
            textNode16.listening(false);
            btnViolet.disabled = false;
            btnViolet.style.background = '#842dce';
            btnOrange.disabled = false;
            btnOrange.style.background = '#ffa500';
            btnYellow.disabled = false;
            btnYellow.style.background = '#ffff00';

            btnLabelClicked = false;
            btnColorClicked = true;
            btnDrawLinesClicked = false;

        } else if (btnColorClicked && (buttonID === 'fillViolet' || buttonID === 'fillOrange' || buttonID === 'fillYellow')) {
            //text_overlay.listening(false);
            textNode0.listening(false);
            textNode15.listening(false);
            textNode16.listening(false);
            newFill = document.getElementById(buttonID).style.background;
        } else if (buttonID === 'btnLabel' || buttonID === 'btnDrawLines' || buttonID === 'btnEraseLines' || buttonID === 'btnExport') {
            //disable color buttons
            btnColorClicked = false;
            btnViolet.disabled = true;
            btnViolet.style.background = disableBtnFill;
            btnOrange.disabled = true;
            btnOrange.style.background = disableBtnFill;
            btnYellow.disabled = true;
            btnYellow.style.background = disableBtnFill;
            if (buttonID === 'btnLabel') {
                textNode0.listening(true);
                textNode15.listening(true);
                textNode16.listening(true);
                btnLabelClicked = true;
                btnDrawLinesClicked = false;
            } else { //buttonID is not btnLabel or any of the color buttons
                textNode0.listening(false);
                textNode15.listening(false);
                textNode16.listening(false);
                btnLabelClicked = false;
                btnDrawLinesClicked = true;
            }
        }
    }
</script>

这是包含 text_overlay 层的文本-input21.js 文件：

var text_overlay = new Konva.Layer({
    listening: true
});

stage.add(text_overlay);

var textNode0 = new Konva.Text({
    text: 'X',
    x: 80, // centered between Ireland & Great Britain
    y: 125,
    width: 150,
    height: 15,
    fontFamily: 'Arial, Helvetica, "sans-serif"',
    fontSize: 14,
    align: 'center',
    listening: true
});

var textNode15 = new Konva.Text({
    text: 'X',
    x: 230, // Luxembourg
    y: 225,
    width: 100,
    height: 15,
    fontFamily: 'Arial, Helvetica, "sans-serif"',
    fontSize: 14,
    align: 'center',
    listening: true
});

var textNode16 = new Konva.Text({
    text: 'X',
    x: 175, // France
    y: 290,
    width: 100,
    height: 15,
    fontFamily: 'Arial, Helvetica, "sans-serif"',
    fontSize: 14,
    align: 'center',
    listening: true
});

text_overlay.add(textNode0);
text_overlay.add(textNode15);
text_overlay.add(textNode16);
text_overlay.draw();

console.log(text_overlay.getZIndex());

textNode0.on('click', () => {
    // create textarea over canvas with absolute position

    // first we need to find its position
    var textPosition = textNode0.getAbsolutePosition();
    var stageBox = stage.getContainer().getBoundingClientRect();

    var areaPosition = {
        x: textPosition.x + stageBox.left,
        y: textPosition.y + stageBox.top
    };

    // create textarea and style it
    var textarea = document.createElement('textarea');
    document.body.appendChild(textarea);

    textarea.value = textNode0.text();
    textarea.style.textAlign = 'center';
    textarea.style.resize = 'none';
    textarea.style.position = 'absolute';
    textarea.style.left = areaPosition.x + 'px'; //positioning needs work
    textarea.style.top = areaPosition.y + 'px';
    textarea.style.width = textNode0.width();
    textarea.style.background = 'transparent';
    textarea.style.border = 1; // final border = 0
    textarea.style.outline = 'none';
    textarea.style.fontFamily = 'Arial, Helvetica, "sans-serif"';
    textarea.style.fontSize = 14;

    textarea.focus();

    textarea.addEventListener('keydown', function (e) {
        // hide on enter
        if (e.keyCode === 13) {
            textNode0.text(textarea.value);
            text_overlay.draw();
            document.body.removeChild(textarea);
        }
    });
})

textNode15.on('click', () => {
    // create textarea over canvas with absolute position

    // first we need to find its position
    var textPosition = textNode15.getAbsolutePosition();
    var stageBox = stage.getContainer().getBoundingClientRect();

    var areaPosition = {
        x: textPosition.x + stageBox.left,
        y: textPosition.y + stageBox.top
    };

    // create textarea and style it
    var textarea = document.createElement('textarea');
    document.body.appendChild(textarea);

    textarea.value = textNode15.text();
    textarea.style.textAlign = 'center';
    textarea.style.resize = 'none';
    textarea.style.position = 'absolute';
    textarea.style.left = areaPosition.x - 20 + 'px'; //positioning needs work
    textarea.style.top = areaPosition.y - 20 + 'px';
    textarea.style.width = textNode15.width();
    textarea.style.background = 'transparent';
    textarea.style.border = 1; // final border = 0
    textarea.style.outline = 'none';
    textarea.style.fontFamily = 'Arial, Helvetica, "sans-serif"';
    textarea.style.fontSize = 14;

    textarea.focus();

    textarea.addEventListener('keydown', function (e) {
        // hide on enter
        if (e.keyCode === 13) {
            textNode15.text(textarea.value);
            text_overlay.draw();
            document.body.removeChild(textarea);
        }
    });
})

textNode16.on('click', () => {
    // create textarea over canvas with absolute position

    // first we need to find its position
    var textPosition = textNode16.getAbsolutePosition();
    var stageBox = stage.getContainer().getBoundingClientRect();

    var areaPosition = {
        x: textPosition.x + stageBox.left,
        y: textPosition.y + stageBox.top
    };

    // create textarea and style it
    var textarea = document.createElement('textarea');
    document.body.appendChild(textarea);

    textarea.value = textNode16.text();
    textarea.style.textAlign = 'center';
    textarea.style.resize = 'none';
    textarea.style.position = 'absolute';
    textarea.style.left = areaPosition.x - 45 + 'px'; //positioning needs work
    textarea.style.top = areaPosition.y - 20 + 'px';
    textarea.style.width = textNode16.width();
    textarea.style.background = 'transparent';
    textarea.style.border = 1; // final border = 0
    textarea.style.outline = 'none';
    textarea.style.fontFamily = 'Arial, Helvetica, "sans-serif"';
    textarea.style.fontSize = 14;

    textarea.focus();

    textarea.addEventListener('keydown', function (e) {
        // hide on enter
        if (e.keyCode === 13) {
            textNode16.text(textarea.value);
            text_overlay.draw();
            document.body.removeChild(textarea);
        }
    });
})

// add the layer to the stage
stage.add(text_overlay);

Answer 1

根据实验，layer.listening() 设置监听图层而不是其内容。它不直观，但它是有道理的，因为一个层实际上是一个 HTML5 canvas。例如，您可能想要在层背景上切换鼠标移动跟踪，但层 child 形状仍然连续监听，所以您需要这个。

您可以使用 getchildren function

在 children 上设置监听

// get all children
var children = layer.getChildren();

然后迭代列表并对每个成员使用 setListening()。 getChildren() 函数可以与 className 过滤器结合使用以创建 child objects 的子集，因此您可以切换所有文本元素、所有多边形或所有圆等。这很时髦。

作为旁注，不要将此视为批评，您的编码风格似乎不是 DRY. What I mean is, your click events for the textNode0, textNode15 and textNode16 are repetitive - I guess each time you realise you need to make a change to one you have to make it manually to all. That leaves you open to bugs by cut & paste or omission. Better to make a standard myTextNode object and have it include all the functionality that you want in a textNode, then pass in the unique parameters when you create each object. That way making a change to the myTextNode 'class' affects all of them at once. The label for this is 'JS Objects', but if you Google that you will be overloaded with information. Have a read of this at W3 Schools 对于 'way in' 主题。如果您知道所有这些，请原谅我，但是您的文本节点有很多国家/地区。

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