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Image Manager

The ImageManager class is the recommended way to load and display images in Odysseus Studio. It provides advanced features like lazy loading and caching while it is still easy to use.

If you want to provide images with your bundle, the bundle's Activator class should manage an instance of the ImageManager. Before you can use the image manager to access the images, you must create the instance and register your images in the bundle's start method.

Set up image manager
@Override
public void start(BundleContext bundleContext) throws Exception {
    super.start(bundleContext);

	// create instance of ImageManager
	imageManager = new ImageManager(bundleContext.getBundle());

	// register image
	imageManager.register("someImageID", "icons/someImage.png");

	// ...
}

You must pass the current bundle to the constructor of the image manager. Otherwise it won't be able to access the image files located in your bundle. After the initialization of the image manager, you need to register each image using the register(...) method. The first parameter is the image ID which must be unique for the image manager instance. The second parameter is the path of your image file inside your bundle.

After you've registered your images, you can easily access and load the image. All you need to do is to access the image manager from your bundle (or any other available bundle's activator providing an image manager) and call the get(...) method passing the image ID of the requested image.

Retrieving image from image manager
Image image = MyRCPPlugIn.getImageManager().get("someImageID");

Image sets

Registering each image indvidually in the start method of the plugins Activator class tends to be very cumbersome if you have a huge number of images. Besides the many lines of code you have to write, it is requires code changes to update or add new images. Alternatively, you can use image sets to avoid these drawbacks.

An image set is a collection of one or more images that is defined in a XML-serialized Java property file. Each image is represented as a key-value pair consisting of the image ID (as the key) and the relative file path (as the value):

Image set property file example
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<properties>
	<comment>Image set configuration file. Edit only if you know what you are doing</comment>
	<entry key="DEFAULT">operator-images/default/gear.png</entry>
	<entry key="JOIN">operator-images/default/join2.png</entry>
	<!-- more image definitions -->
</properties>

Similar to single images, you must register an image set at the Image Manager before you can use it:

Register image set example
@Override
public void start(BundleContext bundleContext) throws Exception {
    super.start(bundleContext);

	// create instance of ImageManager
	imageManager = new ImageManager(bundleContext.getBundle());

	// register image set
	imageManager.registerImageSet("white", "operator-images/icons_white.xml");

	// ...
}

The registerImageSet(...) method requires two arguments. The first argument is the name of the image set which can be considered as the namespace of the images contained in the image set. It is added as prefix seperated by a dot (".") to each image id in order to avoid name clashes between different image sets. The second argument is the relative path to the property file that specifies the image set.

The OdysseusRCPPlugIn class provides different image sets (white, black, and default) each containing a number of illustrating icons for physical operators.

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