GUI
Where can I find an overview of the user interface?
It can be found in the IntelliJ IDEA documentation. A more technical explanation can be found in the IntelliJ Platform Plugin SDK documentation.
How do I add messages to the right side of the window?
In IntelliJ IDEA it is called error stripe, in MPS MessagesGutter:
jetbrains.mps.nodeEditor.EditorComponent component = ((EditorComponent) editorContext.getEditorComponent());
NodeHighlightManager highlightManager = component.getHighlightManager();
highlightManager.mark(message);
How can I add things to the left of the editor? (e.g. breakpoints, go subclasses etc.)
The component is called LeftEditorHighlighter. A checker has to be implemented that can show messages in this component (example: OverrideMethodsChecker).
How to I add an icon to the status bar?
Have a look at the the implementation of the transient models widget and its initialisation in TransientModelsNotification.
What parts of the IntelliJ Platform SDK can't be used in MPS because they are not supported?
Everything related to text files: Documents, PSI files, Templates, QuickDoc, IDE Features Trainer, CodeSmellDetector and Custom Language Support.
How do I add an action to the menu bar of a tool window?
Example:
ToolWindow window = ToolWindowManager.getInstance(myProject).getToolWindow(ToolWindowId.PROJECT_VIEW);
if (window != null) {
window.setTitleActions(titleActions);
}
How can I have clickable icons in the left editor margin?
Specific Languages Blog — Clickable icons in the left editor margin
Are there alternatives to message boxes?
Specific Languages Blog — Use notification balloons instead of message boxes
What IDEA UI elements are available?
Specific Languages Blog — Polished UI for free: IDEA UI components
How do I create menu items with checkboxes?
Specific Languages Blog — Extended actions: Checkboxes