我正在使用 Leaflet，并且正在使用 FullCanvas plugin 的修改版本在 map 上画线。
$(document).ready(function() {
var map = L.map('map').setView([0, 0], 13).setZoom(2);
L.tileLayer('http://c.tile.openstreetmap.se/hydda/full/{z}/{x}/{y}.png').addTo(map);
var markerLocations = [{
"slat": 38.54,
"slon": -100.19,
"tlat": 52.37,
"tlon": 4.89
}, {
"slat": 40.69,
"slon": -74.04,
"tlat": -33.93,
"tlon": 18.42
}, {
"slat": 35.96,
"slon": 138.70,
"tlat": -22.59,
"tlon": 138.60
}, {
"slat": 13.92,
"slon": 103.04,
"tlat": 13.92,
"tlon": 104.04
}, {
"slat": 36.31,
"slon": -117.07,
"tlat": 43.83,
"tlon": 142.38
}];
var layer = new L.SupplyChain();
layer.setData(markerLocations);
layer.addLayerTo(map);
L.marker([38.54, -100.19], {
icon: L.divIcon({
// Specify a class name we can refer to in CSS.
className: 'count-icon',
// Define what HTML goes in each marker.
html: '<div>I want on top!</div>',
// Set a markers width and height.
iconSize: [40, 40]
})
}).addTo(map);
});
if (typeof(L) !== 'undefined') {
L.SupplyChain = L.Class.extend({
options: this.options || {},
initialize: function() {
this._myCanvas = document.createElement('canvas');
// this._myCanvas.style.position = 'absolute';
this._myCanvas.style.top = 0;
this._myCanvas.style.left = 0;
this._myContext = this._myCanvas.getContext('2d');
this.options.filterPointsInBounds = false; // als je deze op true zet, verdwijnen supply chains uit beeld als het startpunt buiten beeld valt (handig voor tragere computers).
},
setData: function(data) {
var me = this;
var bounds = new L.LatLngBounds([-90, -180], [90, 180]);
this._myQuad = new QuadTree(this.boundsToQuery(bounds), false, 50, 10);
data.forEach(function(d) {
me._myQuad.insert({
x: d.slat,
y: d.slon,
data: d
});
if (d.ty && d.tx) {
me._myQuad.insert({
x: d.tlat,
y: d.tlon,
data: d
});
}
});
},
onAdd: function(map) {
this._myMap = map;
if (!map._panes.staticPane) {
map._panes.staticPane = map._createPane('leaflet-tile-pane', map._container);
}
this._staticPane = map._panes.staticPane
this._staticPane.appendChild(this._myCanvas);
map.on('viewreset', this.canvasReset, this);
map.on('move', this.canvasReset, this);
map.on('resize', this.canvasReset, this);
this.canvasReset();
},
addLayerTo: function(map) {
map.addLayer(this);
return this;
},
addTo: function(map) {
this.addLayerTo(map);
return this;
},
getCanvas: function() {
return this._myCanvas;
},
getOptions: function() {
return this.options;
},
canvasReset: function() {
var size = this._myMap.getSize();
this._myCanvas.width = size.x;
this._myCanvas.height = size.y;
this.drawCanvas();
},
onRemove: function(map) {
map._container.removeChild(this._staticPane);
map.off('viewreset', this.canvasReset, this);
map.off('move', this.canvasReset, this);
map.off('resize', this.canvasReset, this);
},
addData: function(d) {
this._myQuad.insert({
x: d.slat, //lon
y: d.slon, //lat
data: d
});
if (d.ty && d.tx) {
this._myQuad.insert({
x: d.tlat, //lon
y: d.tlon, //lat
data: d
});
}
this.drawCanvas();
},
drawCanvas: function() {
var canvas = this.getCanvas();
var ctx = canvas.getContext('2d');
var me = this;
// clear canvas
ctx.clearRect(0, 0, canvas.width, canvas.height);
var bounds = this._myMap.getBounds();
if (!this.options.filterPointsInBounds) bounds = new L.LatLngBounds([-90, -180], [90, 180]);
var points = this._myQuad.retrieveInBounds(this.boundsToQuery(bounds));
points.forEach(function(point) {
var d = point.data;
if (d.draw && !d.draw(d)) return; // allows dynamic filtering of curves
var spoint = me._myMap.latLngToContainerPoint(new L.LatLng(d.slat, d.slon));
// me.drawPoint(spoint, "rgba(255,0,0, 0.5)");
if (d.tlat && d.tlon) {
var tpoint = me._myMap.latLngToContainerPoint(new L.LatLng(d.tlat, d.tlon));
// me.drawPoint(tpoint, "rgba(0,255,0, 0.5)");
me.drawCurve(point, spoint, tpoint, d.style ? d.style(d) : null);
}
});
},
redraw: function() {
this.drawCanvas();
},
boundsToQuery: function(bounds) {
return {
x: bounds.getSouthWest().lat,
y: bounds.getSouthWest().lng,
width: bounds.getNorthEast().lat - bounds.getSouthWest().lat,
height: bounds.getNorthEast().lng - bounds.getSouthWest().lng
};
},
//drawPoint: function (point, colour) {
// var ctx = this.getCanvas().getContext("2d");
// ctx.beginPath();
// ctx.arc(point.x, point.y, 10, 0, 2 * Math.PI, true);
// ctx.fillStyle = colour;
// ctx.fill();
//},
drawCurve: function(point, startPoint, endPoint, style) {
var ctx = this.getCanvas().getContext("2d");
var arrowSize = 20;
var defaultColour = (style && style.strokeStyle) ? style.strokeStyle : "rgb(0,0,255)";
ctx.strokeStyle = defaultColour
ctx.lineWidth = (style && style.lineWidth) ? style.lineWidth : 6;
var x = (startPoint.x + endPoint.x) / 2;
var y = (startPoint.y + endPoint.y) / 2;
var le = (endPoint.y - endPoint.y) / (startPoint.x - endPoint.x);
var angle = Math.atan(le);
var sx = Math.pow((startPoint.x - endPoint.x), 2);
var sy = Math.pow((endPoint.y - endPoint.y), 2);
var d = Math.sqrt(sx + sy) / 2;
var px = x - d * Math.sin(angle);
var py;
var sHigh = point.data.slat > 0;
var sLow = point.data.slat < 0;
var tHigh = point.data.tlat > 0;
var tLow = point.data.tlat < 0;
if ((sHigh && tHigh) || (sLow && tHigh)) {
py = y + d * Math.cos(angle) * -1;
} else if ((sLow && tLow) || (sHigh && tLow)) {
py = y + d * Math.cos(angle);
}
ctx.moveTo(startPoint.x, startPoint.y);
ctx.quadraticCurveTo(px, py, endPoint.x, endPoint.y);
ctx.stroke();
//var arrowDirection = Math.atan2(endPoint.y - py, endPoint.x - px) * 180 / Math.PI;
//console.log(arrowDirection);
//ctx.beginPath();
//ctx.fillStyle = defaultColour;
//ctx.moveTo(endPoint.x, endPoint.y);
//ctx.lineTo(endPoint.x + arrowSize / 2, endPoint.y + arrowSize);
//ctx.lineTo(endPoint.x - arrowSize / 2, endPoint.y + arrowSize);
//ctx.lineTo(endPoint.x + arrowSize * Math.cos(arrowDirection + 90), endPoint.y + arrowSize * Math.sin(arrowDirection + 90));
//ctx.closePath();
//ctx.fill();
},
});
}
// voor de bovenstaande code heb ik de onderstaande code van Github gebruikt. Deze zorgt voor betere performance als er veel supply chains tegelijk in beeld zijn.
// Zie https://github.com/jsmarkus/ExamplesByMesh/tree/master/JavaScript/QuadTree voor meer uitleg.
/*
The MIT License
Copyright (c) 2011 Mike Chambers
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
/*
From https://github.com/jsmarkus/ExamplesByMesh/tree/master/JavaScript/QuadTree, slightly modified
*/
/**
* A QuadTree implementation in JavaScript, a 2d spatial subdivision algorithm.
* @module QuadTree
**/
(function(window) {
/****************** QuadTree ****************/
/**
* QuadTree data structure.
* @class QuadTree
* @constructor
* @param {Object} An object representing the bounds of the top level of the QuadTree. The object
* should contain the following properties : x, y, width, height
* @param {Boolean} pointQuad Whether the QuadTree will contain points (true), or items with bounds
* (width / height)(false). Default value is false.
* @param {Number} maxDepth The maximum number of levels that the quadtree will create. Default is 4.
* @param {Number} maxChildren The maximum number of children that a node can contain before it is split into sub-nodes.
**/
function QuadTree(bounds, pointQuad, maxDepth, maxChildren) {
var node;
if (pointQuad) {
node = new Node(bounds, 0, maxDepth, maxChildren);
} else {
node = new BoundsNode(bounds, 0, maxDepth, maxChildren);
}
this.root = node;
}
/**
* The root node of the QuadTree which covers the entire area being segmented.
* @property root
* @type Node
**/
QuadTree.prototype.root = null;
/**
* Inserts an item into the QuadTree.
* @method insert
* @param {Object|Array} item The item or Array of items to be inserted into the QuadTree. The item should expose x, y
* properties that represents its position in 2D space.
**/
QuadTree.prototype.insert = function(item) {
if (item instanceof Array) {
var len = item.length;
for (var i = 0; i < len; i++) {
this.root.insert(item[i]);
}
} else {
this.root.insert(item);
}
};
/**
* Clears all nodes and children from the QuadTree
* @method clear
**/
QuadTree.prototype.clear = function() {
this.root.clear();
};
/**
* Retrieves all items / points in the same node as the specified item / point. If the specified item
* overlaps the bounds of a node, then all children in both nodes will be returned.
* @method retrieve
* @param {Object} item An object representing a 2D coordinate point (with x, y properties), or a shape
* with dimensions (x, y, width, height) properties.
**/
QuadTree.prototype.retrieve = function(item) {
//get a copy of the array of items
var out = this.root.retrieve(item).slice(0);
//return QuadTree._filterResults(out, {x:item.x, y:item.y, width:0, height:0});
return out;
};
QuadTree.prototype.retrieveInBounds = function(bounds) {
var treeResult = this.root.retrieveInBounds(bounds);
return QuadTree._filterResults(treeResult, bounds);
};
QuadTree._filterResults = function(treeResult, bounds) {
var filteredResult = [];
if (this.root instanceof BoundsNode) {
for (var i = 0; i < treeResult.length; i++) {
var node = treeResult[i];
if (QuadTree._isBoundOverlappingBound(node, bounds)) {
filteredResult.push(node);
}
}
} else {
treeResult.forEach(function(node) {
if (QuadTree._isPointInsideBounds(node, bounds)) {
filteredResult.push(node);
}
});
}
return filteredResult;
};
QuadTree._isPointInsideBounds = function(point, bounds) {
return (
(point.x >= bounds.x) &&
(point.x <= bounds.x + bounds.width) &&
(point.y >= bounds.y) &&
(point.y <= bounds.y + bounds.height)
);
};
QuadTree._isBoundOverlappingBound = function(b1, b2) {
return !(
b1.x > (b2.x + b2.width) ||
b2.x > (b1.x + b1.width) ||
b1.y > (b2.y + b2.height) ||
b2.y > (b1.y + b1.height)
);
};
/************** Node ********************/
function Node(bounds, depth, maxDepth, maxChildren) {
this._bounds = bounds;
this.children = [];
this.nodes = [];
if (maxChildren) {
this._maxChildren = maxChildren;
}
if (maxDepth) {
this._maxDepth = maxDepth;
}
if (depth) {
this._depth = depth;
}
};
//subnodes
Node.prototype.nodes = null;
Node.prototype._classConstructor = Node;
//children contained directly in the node
Node.prototype.children = null;
Node.prototype._bounds = null;
//read only
Node.prototype._depth = 0;
Node.prototype._maxChildren = 4;
Node.prototype._maxDepth = 4;
Node.TOP_LEFT = 0;
Node.TOP_RIGHT = 1;
Node.BOTTOM_LEFT = 2;
Node.BOTTOM_RIGHT = 3;
Node.prototype.insert = function(item) {
if (this.nodes.length) {
var index = this._findIndex(item);
this.nodes[index].insert(item);
return;
}
this.children.push(item);
var len = this.children.length;
if (!(this._depth >= this._maxDepth) &&
len > this._maxChildren) {
this.subdivide();
for (var i = 0; i < len; i++) {
this.insert(this.children[i]);
}
this.children.length = 0;
}
};
Node.prototype.retrieve = function(item) {
if (this.nodes.length) {
var index = this._findIndex(item);
return this.nodes[index].retrieve(item);
}
return this.children;
};
Node.prototype.retrieveInBounds = function(bounds) {
var result = [];
if (this.collidesWith(bounds)) {
result = result.concat(this._stuckChildren);
if (this.children.length) {
result = result.concat(this.children);
} else {
if (this.nodes.length) {
for (var i = 0; i < this.nodes.length; i++) {
result = result.concat(this.nodes[i].retrieveInBounds(bounds));
}
}
}
}
return result;
};
Node.prototype.collidesWith = function(bounds) {
var b1 = this._bounds;
var b2 = bounds;
return !(
b1.x > (b2.x + b2.width) ||
b2.x > (b1.x + b1.width) ||
b1.y > (b2.y + b2.height) ||
b2.y > (b1.y + b1.height)
);
};
Node.prototype._findIndex = function(item) {
var b = this._bounds;
var left = (item.x > b.x + b.width / 2) ? false : true;
var top = (item.y > b.y + b.height / 2) ? false : true;
//top left
var index = Node.TOP_LEFT;
if (left) {
//left side
if (!top) {
//bottom left
index = Node.BOTTOM_LEFT;
}
} else {
//right side
if (top) {
//top right
index = Node.TOP_RIGHT;
} else {
//bottom right
index = Node.BOTTOM_RIGHT;
}
}
return index;
};
Node.prototype.subdivide = function() {
var depth = this._depth + 1;
var bx = this._bounds.x;
var by = this._bounds.y;
//floor the values
var b_w_h = (this._bounds.width / 2) | 0;
var b_h_h = (this._bounds.height / 2) | 0;
var bx_b_w_h = bx + b_w_h;
var by_b_h_h = by + b_h_h;
//top left
this.nodes[Node.TOP_LEFT] = new this._classConstructor({
x: bx,
y: by,
width: b_w_h,
height: b_h_h
},
depth, this._maxDepth, this._maxChildren);
//top right
this.nodes[Node.TOP_RIGHT] = new this._classConstructor({
x: bx_b_w_h,
y: by,
width: b_w_h,
height: b_h_h
},
depth, this._maxDepth, this._maxChildren);
//bottom left
this.nodes[Node.BOTTOM_LEFT] = new this._classConstructor({
x: bx,
y: by_b_h_h,
width: b_w_h,
height: b_h_h
},
depth, this._maxDepth, this._maxChildren);
//bottom right
this.nodes[Node.BOTTOM_RIGHT] = new this._classConstructor({
x: bx_b_w_h,
y: by_b_h_h,
width: b_w_h,
height: b_h_h
},
depth, this._maxDepth, this._maxChildren);
};
Node.prototype.clear = function() {
this.children.length = 0;
var len = this.nodes.length;
for (var i = 0; i < len; i++) {
this.nodes[i].clear();
}
this.nodes.length = 0;
};
/******************** BoundsQuadTree ****************/
function BoundsNode(bounds, depth, maxChildren, maxDepth) {
Node.call(this, bounds, depth, maxChildren, maxDepth);
this._stuckChildren = [];
}
BoundsNode.prototype = new Node();
BoundsNode.prototype._classConstructor = BoundsNode;
BoundsNode.prototype._stuckChildren = null;
//we use this to collect and conctenate items being retrieved. This way
//we dont have to continuously create new Array instances.
//Note, when returned from QuadTree.retrieve, we then copy the array
BoundsNode.prototype._out = [];
BoundsNode.prototype.insert = function(item) {
if (this.nodes.length) {
var index = this._findIndex(item);
var node = this.nodes[index];
//todo: make _bounds bounds
if (item.x >= node._bounds.x &&
item.x + item.width <= node._bounds.x + node._bounds.width &&
item.y >= node._bounds.y &&
item.y + item.height <= node._bounds.y + node._bounds.height) {
this.nodes[index].insert(item);
} else {
this._stuckChildren.push(item);
}
return;
}
this.children.push(item);
var len = this.children.length;
if (this._depth < this._maxDepth &&
len > this._maxChildren) {
this.subdivide();
for (var i = 0; i < len; i++) {
this.insert(this.children[i]);
}
this.children.length = 0;
}
};
BoundsNode.prototype.getChildren = function() {
return this.children.concat(this._stuckChildren);
};
BoundsNode.prototype.retrieve = function(item) {
var out = this._out;
out.length = 0;
if (this.nodes.length) {
var index = this._findIndex(item);
out.push.apply(out, this.nodes[index].retrieve(item));
}
out.push.apply(out, this._stuckChildren);
out.push.apply(out, this.children);
return out;
};
BoundsNode.prototype.clear = function() {
this._stuckChildren.length = 0;
//array
this.children.length = 0;
var len = this.nodes.length;
if (!len) {
return;
}
for (var i = 0; i < len; i++) {
this.nodes[i].clear();
}
//array
this.nodes.length = 0;
//we could call the super clear function but for now, im just going to inline it
//call the hidden super.clear, and make sure its called with this = this instance
//Object.getPrototypeOf(BoundsNode.prototype).clear.call(this);
};
//BoundsNode.prototype.getChildCount
window.QuadTree = QuadTree;
/*
//http://ejohn.org/blog/objectgetprototypeof/
if ( typeof Object.getPrototypeOf !== "function" ) {
if ( typeof "test".__proto__ === "object" ) {
Object.getPrototypeOf = function(object){
return object.__proto__;
};
} else {
Object.getPrototypeOf = function(object){
// May break if the constructor has been tampered with
return object.constructor.prototype;
};
}
}
*/
}(this));.count-icon {
background-color: #ff0000;
width: 250px;
height: 250px;
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="http://cdn.leafletjs.com/leaflet-0.7.3/leaflet.js"></script>
<link href="http://cdn.leafletjs.com/leaflet-0.7.3/leaflet.css" rel="stylesheet" />
<div id="map" style="height: 800px; width:1000px"></div>在Firebug中检查元素时，红色方 block 有绝对定位，而canvas元素没有定位。 canvas 元素具有以下样式:
element {
top: 0px;
left: 0px;
}
.leaflet-container {
font: 12px/1.5 "Helvetica Neue",Arial,Helvetica,sans-serif;
}
.leaflet-container {
cursor: grab;
}
红色方 block 的样式是这样的:
element {
margin-left: -20px;
margin-top: -20px;
width: 40px;
height: 40px;
transform: translate(215px, 281px);
z-index: 281;
}
.count-icon {
background-color: #F00;
width: 250px;
height: 250px;
}
.leaflet-clickable {
cursor: pointer;
}
.leaflet-marker-icon, .leaflet-marker-shadow {
display: block;
}
.leaflet-tile, .leaflet-marker-icon, .leaflet-marker-shadow {
-moz-user-select: none;
}
.leaflet-map-pane, .leaflet-tile, .leaflet-marker-icon, .leaflet-marker-shadow, .leaflet-tile-pane, .leaflet-tile-container, .leaflet-overlay-pane, .leaflet-shadow-pane, .leaflet-marker-pane, .leaflet-popup-pane, .leaflet-overlay-pane svg, .leaflet-zoom-box, .leaflet-image-layer, .leaflet-layer {
position: absolute;
left: 0px;
top: 0px;
}
.leaflet-container {
font: 12px/1.5 "Helvetica Neue",Arial,Helvetica,sans-serif;
我怎样才能得到蓝线上方的红色方 block ？
最佳答案
.leaflet-map-pane 使用 transform: translate3d(x,y,z) 定位。由于 translate3d 现在控制 z 轴，因此 z-index 被忽略。 (如果您在检查器/开发工具中删除/切换 .leaflet-map-pane 的 translate3d 属性，您会看到它起作用。)
我看不到代码中设置此 translate3d 样式的位置(大概是 leaflet.js)，但您可以将其替换为绝对定位。
更新:这里有几个屏幕截图显示了我所指的元素。
屏幕截图 1:leaflet-map-pane 应用了 translate3d。
屏幕截图 2:检查器中禁用了 translate3d 样式。
关于javascript - 绝对div不能在 Canvas 元素之上，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/27782659/