触摸事件如何在单击按钮时侦听图层上的形状?

时间:2018-04-06 16:30:46

标签: javascript textarea layer konvajs

在KonvaJS中,是否可以在单击按钮时使图层处于非活动状态(但不是不可见),然后单击另一个按钮激活?我试过“text_overlay.listening(false);”但它不起作用。我可以使用“textNode0.listening(false);”停用单个textNode,这会阻止用户编辑该文本,但这些textNodes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textarea阻止用户点击下面的多边形(例如,改变其填充颜色)。此外,还有40多个textNodes需要处理,因此最好停用1层!

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图层的text-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);

1 个答案:

答案 0 :(得分:1)

从实验中,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画布。例如,您可能希望在图层背景上切换跟踪鼠标移动,但是图层子图形仍然是连续监听,因此您需要这样做。

您可以使用getchildren function

设置对孩子的聆听
// 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过滤器组合以创建子对象的子集,因此您可以切换所有文本元素,或所有多边形,或所有圆等。它非常时髦。

作为旁注,并且不要将此作为批评,你的编码风格似乎不是DRY。我的意思是,你的textNode0,textNode15和textNode16的点击事件是重复的 - 我想每当你意识到你需要对一个人进行更改时,你必须手动对所有人进行更改。这让你可以通过cut&amp; amp;粘贴或遗漏。最好制作一个标准的myTextNode对象,并让它包含textNode中所需的所有功能,然后在创建每个对象时传入唯一参数。这样就可以改变myTextNode&#39; class&#39;一次影响所有这些。这个标签是“JS对象”,但是如果你谷歌那么你将会被重载信息。请阅读this at W3 Schools以了解&#39;到这个主题。如果你知道这一切,请原谅我,但你的textNodes有很多国家。

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