Adding Clickable Hotspots to Images
An ImageMap allows you to attach URLs to specific areas, called hotspots, on a picture in your document. An image map is a group of one or more hotspots.
You can draw three types of hotspots: rectangles, ellipses, and polygons. When you click a hotspot, the URL is opened in the browser window or frame that you specify. You can also specify the text that appears when your mouse rests on the hotspot.
To add a clickable hotspot to an image
Position the cursor where you want the ImageMap in your document.
Choose Insert - Image, select and insert a bitmap image.
With the image selected, choose to open the ImageMap Editor, which displays the selected image and contains the hotspot editing tools.
Use the icons in the ImageMap Editor to draw a hotspot shape, for example a rectangle, over the image at the background.
You can see an extended help text on the functions of each icon when you enable Extended Help in LibreOffice - PreferencesTools - Options - LibreOffice - General.
Enter the "Address" URL that will be shown in a Web browser when the user clicks the hotspot.
Optionally, enter the "Text" that will be shown as a tip when the user points the mouse to the hotspot.
Click the Apply button to apply your changes, and close the ImageMap Editor.
Save the document in the LibreOffice or HTML format.
You may save the ImageMap as a file and upload that file to a Web server, for example.
An ImageMap is a reference-sensitive graphic or frame. You can click on defined areas of the graphic or frame to go to a target (URL), which is linked with the area. The reference areas, along with the linked URLs and corresponding text displayed when resting the mouse pointer on these areas, are defined in the ImageMap Editor.
There are two different types of ImageMaps. A Client Side ImageMap is evaluated on the client computer, which loaded the graphic from the Internet, while a Server Side ImageMap is evaluated on the server computer which provides the HTML page on the Internet. In server evaluation, clicking an ImageMap sends the relative coordinates of the cursor within the image to the server, and a dedicated program on the server responds. In the client evaluation, clicking a defined hotspot of the ImageMap activates the URL, as if it were a normal text link. The URL appears below the mouse pointer when passing across the ImageMap.
As ImageMaps can be used in different ways, they can be stored in different formats.
ImageMaps are basically divided between those that are analyzed on the server (i. e. your Internet provider) and those analyzed on the web browser of the reader's computer.
Server Side ImageMaps
Server Side ImageMaps appear for the reader as a picture or frame on the page. Click on the ImageMap with the mouse, and the coordinates of the relative position are sent to the server. Aided by an extra program, the server then determines the next step to take. There are several incompatible methods to define this process, the two most common being:
LibreOffice creates ImageMaps for both methods. Select the format from the File type list in the Save As dialog in the ImageMap Editor. Separate Map Files are created which you must upload to the server. You will need to ask your provider or network administrator which type of ImageMaps are supported by the server and how to access the evaluation program.
Client Side ImageMap
The area of the picture or frame where the reader can click is indicated by the appearance of the linked URL when the mouse passes over the area. The ImageMap is stored in a layer below the picture and contains information about the referenced regions. The only disadvantage of Client Side ImageMaps is that older Web browsers cannot read them; a disadvantage that will, however, resolve itself in time.
When saving the ImageMap, select the file type SIP - StarView ImageMap. This saves the ImageMap directly in a format which can be applied to every active picture or frame in your document. However, if you just want to use the ImageMap on the current picture or frame, you do not have to save it in any special format. After defining the regions, simply click Apply. Nothing more is necessary. Client Side ImageMaps saved in HTML format are inserted directly into the page in HTML code.