To turn on design mode press F2 or design icon at left bottom corner.
In design mode component are highlighted with blue frame on hover and also design button appear at top left and top right corners.
There are two kinds of components - layout and data components. Layout components (f.e. Scrollbox, Splitview) contains no data and only serve as placeholders for other components.
For layout components, design button is located at top right corner, for data components - at top left corner.
Design menu has the following options:
Design - show component designer
Copy - copy component to clipboard
Events - define component event handlers
Replace with - replace component with another component and place existing component inside new component. For example, replacing with Pages will add Pages component and place current component on first page.
Delete - delete component.
Frame Source - show frame source editor.
Export Frame - export frame and related objects to file.