Drop-down Bar
The drop-down bar is provided at the top of the code window and contains two drop-down lists.
Drop-Down Bar Interfaces
In Visual C++, for example, the drop-down bar contains lists for Visual C++ Items and Visual C++ Items Member Functions, as shown in the following picture.
Drop-down bar
.gif "Drop-down Bars")
When implementing a drop-down bar, there are four interfaces of primary importance:
-
Implement this interface to insert the content of the drop-down bar. Each drop-down combination can contain plain text or fancy text (bold, underline, or italic), can have window text font coloring or grayed out font coloring, and can optionally provide a small bitmap next to the drop-down item. Similar to the IVsCompletionSet interface, bitmap images are provided in image lists. Each drop-down combination can have a different image list; however, each image list must contain images of the same height. Additionally, using the GetComboTipText method, you can provide a tooltip for each combination.
-
Call this interface to either create or destroy the drop-down bar for a code window. This interface can also be used to determine whether a drop-down bar is already attached to a code window by calling the GetDropdownBar method. Call QueryInterface for IVsDropdownBarManager from IVsCodeWindow.
-
Call this interface to communicate directly with the drop-down bar. You can use this interface to force a refresh of the drop-down bar contents or to change the selection in one of the list boxes.
-
If you have registered the ShowDropdownBarOption in your language service registry key, then your code window manager must monitor this event to synchronize with user preferences regarding whether the drop-down bar should be displayed. If you do not register this option in your language service key, then the option to show or hide the drop-down bar is disabled on the Options menu.
Attaching a Drop-Down Bar to a Code Window
To attach a drop-down bar to the code window when it is created, a language service should attach to the drop-down bar when the AddAdornments method is called. If a call to the GetDropdownBar method indicates that a drop-down bar does not already exist, then call AddDropdownBar. To access the IVsDropdownBarManager interface, call QueryInterface from the IVsCodeWindow pointer returned to you when your IVsCodeWindowManager implementation was attached.