如何在 MapBox 地图上的动画 canvas 点上获取点击处理程序?
How to get click handler on animated canvas dot on MapBox map?
我正在从 MapBox 查看 this demo:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Add an animated icon to the map</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no">
<link href="https://api.mapbox.com/mapbox-gl-js/v2.3.1/mapbox-gl.css" rel="stylesheet">
<script src="https://api.mapbox.com/mapbox-gl-js/v2.3.1/mapbox-gl.js"></script>
<style>
body { margin: 0; padding: 0; }
#map { position: absolute; top: 0; bottom: 0; width: 100%; }
</style>
</head>
<body>
<div id="map"></div>
<script>
mapboxgl.accessToken = 'pk.thekey.12345';
var map = new mapboxgl.Map({
container: 'map',
style: 'mapbox://styles/mapbox/streets-v9'
});
var size = 200;
// This implements `StyleImageInterface`
// to draw a pulsing dot icon on the map.
var pulsingDot = {
width: size,
height: size,
data: new Uint8Array(size * size * 4),
// When the layer is added to the map,
// get the rendering context for the map canvas.
onAdd: function() {
var canvas = document.createElement('canvas');
canvas.width = this.width;
canvas.height = this.height;
this.context = canvas.getContext('2d');
},
// Call once before every frame where the icon will be used.
render: function() {
var duration = 1000;
var t = (performance.now() % duration) / duration;
var radius = (size / 2) * 0.3;
var outerRadius = (size / 2) * 0.7 * t + radius;
var context = this.context;
// Draw the outer circle.
context.clearRect(0, 0, this.width, this.height);
context.beginPath();
context.arc(
this.width / 2,
this.height / 2,
outerRadius,
0,
Math.PI * 2
);
context.fillStyle = 'rgba(255, 200, 200,' + (1 - t) + ')';
context.fill();
// Draw the inner circle.
context.beginPath();
context.arc(
this.width / 2,
this.height / 2,
radius,
0,
Math.PI * 2
);
context.fillStyle = 'rgba(255, 100, 100, 1)';
context.strokeStyle = 'white';
context.lineWidth = 2 + 4 * (1 - t);
context.fill();
context.stroke();
// Update this image's data with data from the canvas.
this.data = context.getImageData(
0,
0,
this.width,
this.height
).data;
// Continuously repaint the map, resulting
// in the smooth animation of the dot.
map.triggerRepaint();
// Return `true` to let the map know that the image was updated.
return true;
}
};
map.on('load', function() {
map.addImage('pulsing-dot', pulsingDot, {
pixelRatio: 2
});
map.addSource('dot-point', {
'type': 'geojson',
'data': {
'type': 'FeatureCollection',
'features': [{
'type': 'Feature',
'geometry': {
'type': 'Point',
'coordinates': [0, 0] // icon position [lng, lat]
}
}]
}
});
map.addLayer({
'id': 'layer-with-pulsing-dot',
'type': 'symbol',
'source': 'dot-point',
'layout': {
'icon-image': 'pulsing-dot'
}
});
});
</script>
</body>
</html>
如何制作它以便我可以处理点上的点击,并在将光标悬停在它上面时使光标成为指针?
事情其实并没有看起来那么难。正如其他人所建议的那样,您可以通过一些技巧来做到这一点 - 但不需要它,因为所需的功能已内置到 Mapbox 本身中!
如果您在 API reference 中查找它自己的 map
对象,您会注意到有几个有趣的事件:
click、mouseenter 和 mouseleave
通常这些绑定到实际地图并添加如下:
map.on('click', function() {
console.log('clicked');
});
现在您可能会问自己,什么对您有好处。如果我们回顾一下您提供的示例代码,我们可以看到动画点已添加到地图上它自己的图层 layer-with-pulsing-dot
。
API 参考文献没有真正提到的一件事是,.on()
方法还有一个额外的第二个参数,让您可以为特定层指定一个 ID。
所以我们要做的就是向 layer-with-pulsing-dot
层添加一些监听器。
点击事件当然很明显,mouseenter
和 mouseleave
事件用于将鼠标光标转换为指针并返回。
尝试在 map.addLayer({ ... });
之后添加此代码块
map.on('click', 'layer-with-pulsing-dot', function(e) {
alert('Someone clicked long:' + e.lngLat.lng + ' lat:' + e.lngLat.lat)
});
map.on('mouseenter', 'layer-with-pulsing-dot', function() {
map.getCanvas().style.cursor = 'pointer';
});
map.on('mouseleave', 'layer-with-pulsing-dot', function() {
map.getCanvas().style.cursor = '';
});
您的 canvas 中有圆点的坐标。
在鼠标移动事件中,检查鼠标坐标是否在点的坐标中。
我正在从 MapBox 查看 this demo:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Add an animated icon to the map</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no">
<link href="https://api.mapbox.com/mapbox-gl-js/v2.3.1/mapbox-gl.css" rel="stylesheet">
<script src="https://api.mapbox.com/mapbox-gl-js/v2.3.1/mapbox-gl.js"></script>
<style>
body { margin: 0; padding: 0; }
#map { position: absolute; top: 0; bottom: 0; width: 100%; }
</style>
</head>
<body>
<div id="map"></div>
<script>
mapboxgl.accessToken = 'pk.thekey.12345';
var map = new mapboxgl.Map({
container: 'map',
style: 'mapbox://styles/mapbox/streets-v9'
});
var size = 200;
// This implements `StyleImageInterface`
// to draw a pulsing dot icon on the map.
var pulsingDot = {
width: size,
height: size,
data: new Uint8Array(size * size * 4),
// When the layer is added to the map,
// get the rendering context for the map canvas.
onAdd: function() {
var canvas = document.createElement('canvas');
canvas.width = this.width;
canvas.height = this.height;
this.context = canvas.getContext('2d');
},
// Call once before every frame where the icon will be used.
render: function() {
var duration = 1000;
var t = (performance.now() % duration) / duration;
var radius = (size / 2) * 0.3;
var outerRadius = (size / 2) * 0.7 * t + radius;
var context = this.context;
// Draw the outer circle.
context.clearRect(0, 0, this.width, this.height);
context.beginPath();
context.arc(
this.width / 2,
this.height / 2,
outerRadius,
0,
Math.PI * 2
);
context.fillStyle = 'rgba(255, 200, 200,' + (1 - t) + ')';
context.fill();
// Draw the inner circle.
context.beginPath();
context.arc(
this.width / 2,
this.height / 2,
radius,
0,
Math.PI * 2
);
context.fillStyle = 'rgba(255, 100, 100, 1)';
context.strokeStyle = 'white';
context.lineWidth = 2 + 4 * (1 - t);
context.fill();
context.stroke();
// Update this image's data with data from the canvas.
this.data = context.getImageData(
0,
0,
this.width,
this.height
).data;
// Continuously repaint the map, resulting
// in the smooth animation of the dot.
map.triggerRepaint();
// Return `true` to let the map know that the image was updated.
return true;
}
};
map.on('load', function() {
map.addImage('pulsing-dot', pulsingDot, {
pixelRatio: 2
});
map.addSource('dot-point', {
'type': 'geojson',
'data': {
'type': 'FeatureCollection',
'features': [{
'type': 'Feature',
'geometry': {
'type': 'Point',
'coordinates': [0, 0] // icon position [lng, lat]
}
}]
}
});
map.addLayer({
'id': 'layer-with-pulsing-dot',
'type': 'symbol',
'source': 'dot-point',
'layout': {
'icon-image': 'pulsing-dot'
}
});
});
</script>
</body>
</html>
如何制作它以便我可以处理点上的点击,并在将光标悬停在它上面时使光标成为指针?
事情其实并没有看起来那么难。正如其他人所建议的那样,您可以通过一些技巧来做到这一点 - 但不需要它,因为所需的功能已内置到 Mapbox 本身中!
如果您在 API reference 中查找它自己的 map
对象,您会注意到有几个有趣的事件:
click、mouseenter 和 mouseleave
通常这些绑定到实际地图并添加如下:
map.on('click', function() {
console.log('clicked');
});
现在您可能会问自己,什么对您有好处。如果我们回顾一下您提供的示例代码,我们可以看到动画点已添加到地图上它自己的图层 layer-with-pulsing-dot
。
API 参考文献没有真正提到的一件事是,.on()
方法还有一个额外的第二个参数,让您可以为特定层指定一个 ID。
所以我们要做的就是向 layer-with-pulsing-dot
层添加一些监听器。
点击事件当然很明显,mouseenter
和 mouseleave
事件用于将鼠标光标转换为指针并返回。
尝试在 map.addLayer({ ... });
map.on('click', 'layer-with-pulsing-dot', function(e) {
alert('Someone clicked long:' + e.lngLat.lng + ' lat:' + e.lngLat.lat)
});
map.on('mouseenter', 'layer-with-pulsing-dot', function() {
map.getCanvas().style.cursor = 'pointer';
});
map.on('mouseleave', 'layer-with-pulsing-dot', function() {
map.getCanvas().style.cursor = '';
});
您的 canvas 中有圆点的坐标。 在鼠标移动事件中,检查鼠标坐标是否在点的坐标中。