Removing overlays

    "Overlays"....!!! What is this now! Never heard or used it before? You might immediately say "NO"...But, actually all of you have already seen what an overlay is and you have also used it! Now you would say "When!?!?" Well, all of the markers, polylines, polygons that you have created are overlays. Overlays are objects on the map that are tied to latitude/ longitude coordinates, so they move when you drag or zoom the map. Overlays reflect objects that you add to the map to designate points, lines, areas or collection of objects.

    Till now we have seen how to create an overlay. In today's example we will see how to remove an overlay. In this example we will create markers on click. But the difference will be that when you create a new marker, the earlier one will disappear from the map. So at any given time there would only be one single marker on the map! Note that removing the marker does not delete the overlay; it simply removes the overlay from the map.

    Let's head on to the example. You can copy the following code in a text file and save it with .html extension. Now click on this file and it will open up in your default browser and you will see the map in action!

    The code is very simple. You should have no problems in understanding the same. If you have any queries or doubts regarding the code, you can leave a comment or drop me a mail. The output of the above example is as seen in the result section above.

Comments

Recommended for You

Is Google cheating?

I found this piece of interesting fact, accidently while browsing the internet. Google shows different maps for India, China and USA. Confused hun! Well don’t be…Just read on… In Indian version of Google Maps, you can see Arunachal Pradesh and eastern part of Jammu and Kashmir as integral part of India. In US version of Google Maps, you can see Arunachal Pradesh and Jammu and Kashmir as a disputed region. In the Chinese version of the Google Maps, you can see Arunachal Pradesh and JnK as not a part of India. Many people complained this issue to Google. A Google employee responded : “ We do show different versions of this border, because we required to by law. Indian law requires us to show it one way, and the Chinese law requires us to show it another way . If we can legally do so, we strive to present b...

Retriving co-ordinates...

We have seen 2 Google Maps API v3 examples wherein we have retrieved the latitude-longitude co-ordinates of the point of click on the map. In the first example we have displayed the co-ordinates in the information window and in the second , we have displayed the co-ordinates in a form in the information window. Today we will create a code to retrieve the latitude longitude co-ordinates in a text box while simultaneously a marker appears on the map as well. So, here goes the code. <html> <head> <title> Google Maps API v3 - Adding marker on Click and retrieving the co-ordinates in a text box </title> <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script> <script type="text/javascript"> var map; //When using event as a parameter to a function declare map, strictly as a global variable fun...

Form info window

Today we will look at a Google Maps API v3 example to add a form in the information bubble! This is usually required when we wish to accept some data/information from the user! This data can be saved to a server in the form of an XML file or a database! The information can then be retrieved back at a later stage, when necessary! In this example we will only look at form in the information bubble! The connectivity part with the server will be discussed in another post! So, today's code snippet is as seen below! <html> <head> <title> Google Maps API v3 - Adding marker and info window on Click and creating a form in the infowindow with the lat-lng information in it. </title> <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script> <script type="text/javascript"> var map; //When using ev...

Drive along - Cool coding

This is something that will demonstrate to you the power of mapping! This is a Google Maps API v2 example, but just copy and paste the code in an html file and you will see something very cool! This will prove that mapping is real fun! Let's have a look at the code first. Copy this code in your html file. Don't worry about the length of the code and the post in general. Just execute the code and you will surely enjoy what you see! <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"/> <title> Drive Along </title> <script src="http://maps.google.com/maps?file=api&v=2&sensor=false&key=ABQIAAAAu3HXU_hLdVPTFGqLed_FCxT2yXp_ZAY8_ufC3CFXhHIE1NvwkxQbblEPYBGNoRsuuSU9aBfSq4VAZA" type="text/javascript"> </script> <script src="http://econym.org.uk/gmap/epoly.js" type="text/javascript"> ...

A Giant called Google...

Wondering what you will be reading in this post today and what is "Google Giant"! Well, I was working on a simple project a couple of months back and that is the time when I was amazed and by the size of data that Google Maps servers might be having! As most of the readers (developers and enthusiast included) would know or might have noticed, Google maps are rendered by stitching small images together. You must have observed this on quite a number of occasions, when you see grey tiles when you have a slow internet connection in particular. It takes time for the images or tiles as we call them to be displayed. Let us try and estimate what could be the size of the Google Maps data! Before proceeding, let's make a few assumptions and considerations. 1. Let's consider the Google Street View maps only. 2. The zoom level that is considered for the calculations is 21 - the max zoom level allowed on Google Maps API. 3. All the numbers are just an esti...

The UI Dev

Search This Blog