Eclipse4/RCP/Modeled UI/Tags

Most model elements support additional annotations called "tags". In addition to tags, a key/value store can also be defined which is called "persistedState". The tags an persisted state are free-form; the model renderer may interpret certain tags or persisted state to configure how an element is to be rendered. You can also use the tags and persisted state yourself to put information in the model.

How did we find these tags

Until now, these tags were only documented in the Java source code.

To find these tags, we used the Model Spy and examined the Eclipse IDE Runtime model. Then we searched the source code for the documentation and pasted it here.

This list is not complete. If you know of some more tags/state used by the rendering engine or other standard mechanisms then please add them here.

Tags and Persisted State elements

Eclipse E4 Model Tags and Persisted State elements

Type	Value	Description	Applies to	Defined by
Tag	Active	This is the tag name that indicates that the model element is active.	MUIElement, MPart, ??	IPresentationEngine.ACTIVE
Tag	categoryTag:name	Puts the PlaceHolder in the category with this name	PlaceHolder, ??	ViewContentProvider.CATEGORY_TAG
State	Custom Renderer	This is a persisted state 'key' whose value is expected to be the URI of a subclass of ABstractPartRenderer that is to be used to render the element	MUIElement, ??	IPresentationEngine.CUSTOM_RENDERER_KEY
Tag	Draggable	This is the tag name that enables the DND support for the element. The element's tags list has to be updated with the tag in order to enable the DND processing.	Toolbar, ??	IPresentationEngine.NO_CLOSE
State	e4_disabled_icon_image_key	This key should be used to add an optional String to an element that is a URI to the elements disabled icon. This is used, for example, by Toolbar Items which, in Eclipse SDK, provide a unique icon for disabled tool items that look better than the OS default graying on the default icon. There is a strong argument to be made that this disabledIconURI actually be part of the model	ToolbarItem, ??	IPresentationEngine.DISABLED_ICON_IMAGE_KEY
State	e4_override_icon_image_key	This key should be used to add an optional org.eclipse.swt.graphics.Image to an element's TRANSIENTDATA. If present, the image will be used to override that elements icon URI. An example is drawing the error icon on a minimized problems view stack.NOTE: This image must be checked to ensure that it hasn't been disposed of on retrieval.	ToolbarItem, ??	IPresentationEngine.OVERRIDE_ICON_IMAGE_KEY
Tag	Editor	Mark the PlaceHolder or Part as an Eclipse Editor.	MPlaceHolder, MPart, ??	Workbench.EDITOR_TAG
Tag	glue	A TrimBar will replace ToolControls with a "stretch" tag with stretchable space. A ToolControl with "glue" will ensure its siblings are kept together on the same line. The following example will cause the "find" control to be placed flush right:	MTrimBar	TrimBarLayout.GLUE
Tag	Horizontal	This tag can be applied to an element as a hint to the renderers that the element would prefer to be horizontal. For an MPart this could be used both as a hint to how to show the view when it's in the trim but could also be used when picking a stack to add a newly opening part to. It could also be used for example to control where the tabs appear on an MPartStack.	MPart, MPartStack, ??	IPresentationEngine.ORIENTATION_HORIZONTAL
Tag	Maximized	When added to an element's 'tags' this should cause the presentation to minimize all other presentation elements. In the default implementation, you can only apply this tag to an MPartStack or the MPlaceholder of the MArea.	MPartStack, MPlaceholder	IPresentationEngine.MAXIMIZED
Tag	Minimized	When added to an element's 'tags' this should cause the presentation to move that element to the trim. In the default implementation, you can only apply this tag to an MPartStack or the MPlaceholder of the MArea.	MPartStack, MPlaceholder	IPresentationEngine.MINIMIZED
Tag	MinimizedByZoom	This tag should be applied to any element that had its MINIMIZED tag set due to a different element going maximized. This allows the restore operation to only restore elements that the user did not explicitly minimize.	MPartStack, MPlaceholder	IPresentationEngine.MINIMIZED_BY_ZOOM
Tag	MinMaximizeableChildrenArea	When applied to an MArea causes it to behave like a MPartSashContainer allowing the different parts to be minimized/maximized separately.	MArea	IPE.MIN_MAXIMIZEABLE_CHILDREN_AREA_TAG
Tag	NoClose	Parts within a part stack can be annotated with a "NoClose" tag to indicate that the part should not be closeable. The SWT renderer will configure the corresponding CTabFolder to not display an "X" to close the part.	MPartStack	IPresentationEngine.NO_CLOSE
Tag	NoDetach	When applied as a tag to an MUIElement inhibits detaching the element (ie.through DnD...	MUIElement, ??	IPresentationEngine.NO_DETACH
Tag	NoMove	A part can be annotated with a "NoMove" tag to indicate that the drag-and-drop system should not allow the user to move this part.	MPart	IPresentationEngine.NO_MOVE
Tag	NoRestore	When applied as a tag to an MPartDescriptor marks the part as not restorable.	MPartDescriptor	IPresentationEngine.NO_RESTORE
Tag	NoTitle	Parts within a part stack can be annotated with a "NoTitle" tag to indicate that the part should not have a rendered title.	MPart	IPresentationEngine.NO_TITLE
Tag	Opaque	A tag value that indicates a menu, menu item, menu separator, or tool item is 'opaque'	Menu, MenuSeparator, DirectMenuItem, ??	OpaqueElementUtil.OPAQUE_TAG
State	persistState {false:true}	Whether the workbench should save and restore its state. Individual model elements can add it to their persisted state with the value of "false" to declare that they should not be persisted.	Toolbar, MPart, ??	IWorkbench.PERSIST_STATE
State	Rendering Parent	This key can be used, if the model element does not have a parent and a parent needs to be specified for the renderer to create the widget	Toolbar, MPart, ??	IPresentationEngine.RENDERING_PARENT_KEY
Tag	shellMaximized	When applied to an MWindow causes the renderer to maximize the resulting control.	MWindow	IPresentationEngine.WINDOW_MAXIMIZED_TAG
Tag	shellMinimized	When applied to an MWindow, it causes the renderer to minimize the resulting control.	MWindow	IPresentationEngine.WINDOW_MINIMIZED_TAG
Tag	shellTopLevel	When applied to an MWindow causes the renderer to render the resulting control as a top level window.	MWindow	IPresentationEngine.WINDOW_TOP_LEVEL
Tag	Split Horizontal	This tag can be applied to an element (usually an MPart) to indicate that the element should be split with the result being side by side.	MPart, ??	IPresentationEngine.SPLIT_HORIZONTAL
Tag	Split Vertical	This tag can be applied to an element (usually an MPart) to indicate that the element shouldbe split with the result being one above the other.	MPart, ??	IPresentationEngine.SPLIT_VERTICAL
Tag	Standalone	Declare the stack as containing a single 'standalone' view. These stacks will not allow either dragging the view out of the stack nor dragging other views in.	MPartStack, ??	IPresentationEngine.STANDALONE
Tag	stretch	A TrimBar will replace ToolControls with a "stretch" tag with stretchable space. A ToolControl with "glue" will ensure its siblings are kept together on the same line. The following example will cause the "find" control to be placed flush right:	MTrimBar	TrimBarLayout.SPACER
Tag	Vertical	This tag can be applied to an element as a hint to the renderers that the element would prefer to be vertical. For an MPart this could be used both as a hint to how to show the view when it's in the trim but could also be used when picking a stack to add a newly opening part to. It could also be used for example to control where the tabs appear on an MPartStack.	MPart, MPartStack, ??	IPresentationEngine.ORIENTATION_VERTICAL
Tag	View	Mark the PlaceHolder as an Eclipse View.	MPlaceHolder, ??	ViewRegistry.VIEW_TAG