Windows 7: Customizing jump lists

BANGALORE, INDIA: We continue our series of Win 7 development by looking at one of the most useful features of Windows 7 ? Jump Lists.Jump Lists can be thought of as a mini start menu for each application. Jump Lists can consist of Tasks and Destinations organized by Categories. Tasks are stuff that the application can 'do' ? such as play the next track, open another application or create a new email. Destinations are stuff that the application can 'open' ? such as files, folders, emails, etc. Categories allow you to organize these tasks and destinations logically into groups. There are some categories that are pre-defined such as 'Recent', 'Frequent' and 'Pinned'. More about these a little later.

To add the Jump List features into your application, include the Windows API Code Pack into the project as discussed last month. Once done, you can declare an instance to use in your application like this:

JumpList jl;

jl = JumpList.CreateJumpList();

Adding tasks

Now if you wish to create anything on the Jump List, you can simply use this. For instance, if you wish to add some tasks, you can use the following code:

string systemFolder = Environment.GetFolderPath(Environment.SpecialFolder.System);

jl.AddUserTasks(new JumpListLink(Path.Combine(systemFolder, "notepad.exe"), "Open Notepad")

{IconReference = new IconReference(Path.Combine(systemFolder, "notepad.exe"), 0)});

jl.AddUserTasks(new JumpListLink(Path.Combine(systemFolder, "mspaint.exe"), "Open Paint")

{IconReference = new IconReference(Path.Combine(systemFolder, "mspaint.exe"), 0) });

jl.AddUserTasks(new JumpListSeparator());

jl.AddUserTasks(new JumpListLink (Path.Combine(systemFolder, "calc.exe"), "Open Calculator")

{IconReference = new IconReference(Path.Combine(systemFolder, "calc.exe"), 0)});

jl.Refresh();

The code adds three tasks and a separator to the Jump List. The Refresh() statement makes sure the additions are reflected correctly.

Adding Categories and Destinations

Also, we can add some destinations, or files that the application can open. There are several ways this can be done. For the current scenario, we'll add come items automatically into Jump List for the user of the application and also categorize them. To do this, simply add the following code.

JumpListCustomCategory c1 = new JumpListCustomCategory("Documents");

JumpListCustomCategory c2 = new JumpListCustomCategory("Templates");

jl.AddCustomCategories(c1, c2);

string docFolder = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);

c1.AddJumpListItems(new JumpListItem(docFolder + "\\key.txt"));

c1.AddJumpListItems(new JumpListItem(docFolder + "\\macros.txt"));

c2.AddJumpListItems(new JumpListItem(docFolder + "\\Sample Template.txt"));

jl.Refresh();

The above code creates two categories on the Jump List and then adds a few files into each categories. When you run the application, you will be able to see the Jump List containing these:

Registering File Types and known Categories

One of the most powerful features of the Jump Lists in Windows 7 is the ability for your application to display the most frequently opened, most recently opened or user's most favorite files in the Jump List, so that the user has a one-click access to them. In older versions of Windows, you would need to take care of this in code yourself. For instance, to show the most recent files accessed by your application, you will need to maintain this list yourself. The same goes for frequent (where the number of accesses would also need to be stored) and favorites.

Windows 7 manages all of these automatically for you. There are only two requirements. You must register the file type you wish to open correctly with Windows so that it can manage the access lists and in the code, you need to tell Windows which list you wish to display automatically in the Jump List.

When these are done, the application will show the correct set of items in the Jump List. The Windows API Code Pack has a registration helper code that lets you register file types to your application. This is normally done during the installation phase of the application, but can be done at any time. To register a file type with your app, just use the code like this:

RegistrationHelper.RegisterFileAssociations("Win7TieIn", false, ApplicationID, Application.ExecutablePath + " /load %1", ".txt");

This code takes the name of the application, the application ID, the EXE to use to open the file and the parameters and whether an entry is to be made in the HKCU part of the registry.

You can now 'subscribe' to the auto-lists for your Jump List like this:

Ijl.KnownCategoryToDisplay = JumpListKnownCategoryType.Recent;

You can use 'Recent', 'Frequent' or 'Neither' to set the type of list you wish to display. The best part is that the pinning of favorites and user initiated remove or reorder of the items happens without need for any other code.

Jump Lists are a great new feature of Windows 7, and once you start using them they become extremely addictive. Try and add them to your applications as well, so that the user gets the additional benefit of using your application on Windows 7.