Rotating image / marker image on Google map V3
My js class for solving this problem is:
var RotateIcon = function(options){
this.options = options || {};
this.rImg = options.img || new Image();
this.rImg.src = this.rImg.src || this.options.url || '';
this.options.width = this.options.width || this.rImg.width || 52;
this.options.height = this.options.height || this.rImg.height || 60;
var canvas = document.createElement("canvas");
canvas.width = this.options.width;
canvas.height = this.options.height;
this.context = canvas.getContext("2d");
this.canvas = canvas;
};
RotateIcon.makeIcon = function(url) {
return new RotateIcon({url: url});
};
RotateIcon.prototype.setRotation = function(options){
var canvas = this.context,
angle = options.deg ? options.deg * Math.PI / 180:
options.rad,
centerX = this.options.width/2,
centerY = this.options.height/2;
canvas.clearRect(0, 0, this.options.width, this.options.height);
canvas.save();
canvas.translate(centerX, centerY);
canvas.rotate(angle);
canvas.translate(-centerX, -centerY);
canvas.drawImage(this.rImg, 0, 0);
canvas.restore();
return this;
};
RotateIcon.prototype.getUrl = function(){
return this.canvas.toDataURL('image/png');
};
Call it like this:
var marker = new google.maps.Marker({
icon: {
url: RotateIcon
.makeIcon(
'https://ru.gravatar.com/userimage/54712272/b8eb5f2d540a606f4a6c07c238a0bf40.png')
.setRotation({deg: 92})
.getUrl()
}})
See live example here http://jsfiddle.net/fe9grwdf/39/
I have found two extensions to the Google MAP V3: infobox.js and markerwithlabel.js Both can handle an image DOM element as content, which in turn I can rotate via the jQuery image rotate plugin.
This even works without setting the marker's image again after rotation.
Edit: As of questions / comments below:
The extension for label is required, because it can handle other DOM elements. So I can add arbitrary HTML as label, in my particular case I add the image. And then I do rotate this image (child of the label) with the rotate plugin. So assign the image an id in order to easily access it. Actually I am using one label just for the image, and another for descriptive text.
Edit 2: Due to Stephan's comment on the DOM readiness
In my code I have found the following lines. This shows that I force a draw on the label before rotating the image.
if (!this._drawn) myImageLabel.draw(); // 1st time force a draw, otherwise rotating the image will fail because an asynchronously drawn object has not all tags in place
if (this.heading != 0) this.rotateImage(this.heading, true);
Edit 3: Code example how to create the Infobox.js
this._img = document.createElement('img');
... further manipulations of _img / Size / Id / ...
var planeImageLabelOptions = {
content: this._img,
disableAutoPan: true,
boxStyle: planeImageLabelBoxStyle,
pixelOffset: new google.maps.Size(-imgOffsetW / 2, -imgOffsetH / 2),
closeBoxURL: "",
position: latlng,
zIndex: this.altitude < 0 ? 100 : this.altitude
};
var planeImageLabel = new InfoBox(planeImageLabelOptions);