Develop Reference

customize google maps with popups

Is there an platform that you know of that I can use google maps and make it completely customized to look like this:
michigan_map_idea
Also it is important that we would be able to add a hover popup as well as a selection popup from the location dots. I just want to know whether it is possible to do this. The end goal is to upload the map to wordpress. We are open to coding with javascript, html and css.

This might help in regards to styling your map the way you want: https://mapstyle.withgoogle.com/
For the yellow dot as marker, I would make custom markers, more info here: https://developers.google.com/maps/documentation/javascript/custom-markers
For hover events you can follow the marker click event guide by google, but instead of click - you guessed it - use hover (if this does not work mouseenter and mouseleave):
https://developers.google.com/maps/documentation/javascript/examples/event-simple

using a different style sheet on page load depending on radio buttons

I have been put in charge of a site for one of our clients that was built by an outside company. One of the additional requests is that she wants to be able to position an image on their news page either on the left, right or centred.
There is an administration system in place where the client can create a news article and add an image however I need to know if there is anyway I can change the image position on the 'news items' page depending on whether the left, right or centred radio button has been checked on the administration panels 'add a news item' page.
I think it is possible with Java but it's not something I have had to do before and am looking for a nudge in the right direction really.
I think it is possible with Java but the tutorials I have found show me how to change the css with Java on the current page but not on a different page.
Any advice would be much appreciated

Write 2 css classes, class1: for left alignment and class2: for right alignment. Suppose if there are 2 radio buttons. On click of each radio you can toggle value of class.
$("#radioId1").click(function () {
$('#para1').removeClass('class1');
$('#para1').addClass('class2');
});
$("#radioId2").click(function () {
$('#para1').removeClass('class2');
$('#para1').addClass('class1');
});

HTML gallery page in Swing with drag-drop functionality

I was asked to write a JDialog separated into left and right panel. The left panel shows a demo HTML template gallery (small sized), and right panel shows series or list of images. I want to make it such that I can drag image on the list and place it on the gallery (or maybe drag out some image from the gallery). The problem is I don't know where to start with this, can anybody give me some idea?

An HTML gallery typically uses JS to do the 'heavy lifting' (I'm guessing it will require a slideshow as well). While Swing components support HTML (to an extent) they do not support JS.
I recommend not trying to render the HTML/JS in the GUI, instead, provide a JList in the GUI of the image+name objects chosen by the user (using JFileChooser). When each image is selected, you can show the 'preferred name' in a JTextField that allows the user to edit it.
Image order can be shown by the order in the list. To change the order, implement Drag'n'Drop. See the Drag and Drop and Data Transfer lesson for more details.
You will probably need a JLabel in the CENTER of the GUI to display the (full size) selected image, and show the order & timing of the slideshow.
Once the user is happy with the image selections, the order, the names & timing. Offer them a button to write all the details to a single directory including the HTML, script & images (easier). Once the HTML is written, invoke Desktop.open(File) to display the finished product to the user.
As to how you do all that, it is really beyond the scope of an answer on SO. You would need to do the tutorial on each part, and come back with more specific questions.

JTable Header contains Image and on top of that image I want to place 3 buttons in a single header

JTable Header contains Image and on top of that image I want to place 3 buttons in a single header. My requirement is to Create a "Play List" table in which user can add their favourite songs.
So in the header I want to put a "Play List" title and "+" button to insert new playlists and "Export" and "Import" buttons.
How I can do that? Thanks in Advance.

I doubt(1) this use-case actually calls for cramming extra components into a JTable header. E.G. Take the UI of DukeBox.
We can see the play list on the left (a JTable) with a Filter text field and Random check-box above it, and the Enqueue & History buttons below.
This was created with a nested layout. The 'outer layout' is BorderLayout, that panel has the table in the CENTER, and nested panels in the NORTH & SOUTH. The NORTH panel has another BorderLayout, while the SOUTH uses a GridLayout.
If using a nested layout does not give you some ideas, I suggest you post a drawing or better, ASCII art, of the UI as it should appear at the smallest size, as well as a representation of it when it is resized (where is the extra width/height assigned?).
1) I have that suspicion every time I hear words to the effect "Wouldn't it be great if we had a component that..?". Of course, there are some classic counter-examples where the standard widget tool-kit seems lacking (e.g. a date picker or switch list), but these are common components to which a name can be put. If the person asking cannot put a 'catchy name' to the custom component, there is a good chance they are over (or under) thinking the matter.

GWT - Best way to implement a horizontal navbar

What is the best way to implement a horizontal navbar in GWT? Using a MenuBar, a TabLayoutPanel, or coding something by hand, that is take a bunch of divs an float them within another div? If played around using TabLayoutPanel but wasn't able to style it to fit my needs.
EDIT
Here's what I intend to do: I have a MasterPage, laid out using a DockLayoutPanel. I have a header, footer, and a content area. After login, the content are should be filled with some sort of navigation and an area showing some panel with some widgets.

The problem with MenuBar (and MenuItems) is its rendering. GWT is rendering everything regarding menus as table and bunch of s and s. This usually messes up the layout of the rest of the page since GWT 2.0+ uses s for most of the widgets.
So, until GWT comes up with the "Layout" version for the MenuBar custom solution is probably the best solution.

A horizontal MenuBar works great for us. Give each MenuItem a Command that triggers your navigation system, or just swap controls in and out of your content area directly.
A MenuBar will be more flexible than using a TabLayoutPanel, but less flexible than a bunch of custom-coded divs.