Structure View
The Structure View implementation used for a specific file type can be customized on many levels.
If a custom language plugin provides an implementation of the
StructureView
interface, it can completely replace the standard structure view implementation with a custom user interface component.
However, for most languages this is not necessary, and the standard
StructureView
implementation provided by IntelliJ Platform can be reused.
The starting point for the structure view is the
PsiStructureViewFactory
interface, which is registered in the com.intellij.lang.psiStructureViewFactory extension point.
Examples:
PsiStructureViewFactoryfor Properties language plugin- Custom Language Support Tutorial: Structure View
To reuse the IntelliJ Platform implementation of the
StructureView,
the plugin returns a
TreeBasedStructureViewBuilder
from its
PsiStructureViewFactory.getStructureViewBuilder()
method.
As the model for the builder, the plugin can specify a subclass of
TextEditorBasedStructureViewModel,
and by overriding methods of this subclass it customizes the structure view for a specific language.
Example:
StructureViewModel
for
Properties language plugin
The main method to override is getRoot(), which returns the instance of a class implementing the
StructureViewTreeElement
interface.
There exists no standard implementation of this interface, so a plugin will need to implement it completely.
The structure view tree is usually built as a partial mirror of the PSI tree.
In the implementation of
StructureViewTreeElement.getChildren(),
the plugin can specify which of the child elements of a specific PSI tree node need to be represented as elements in the structure view.
Another important method is getPresentation(), which can be used to customize the text, attributes, and icon used to represent an element in the structure view.
The implementation of StructureViewTreeElement.getChildren() needs to be matched by TextEditorBasedStructureViewModel.getSuitableClasses().
The latter method returns an array of PsiElement-derived classes which can be shown as structure view elements. It is used to select the Structure View item matching the cursor position when the structure view is first opened or when the Autoscroll from source option is enabled.
Example:
StructureViewTreeElement
for
Properties language plugin