To operate on diagram elements, you have to select them first. Selections never appear in printed diagram images and are never saved with the diagram. Unselect all diagram elements by a click in an empty space of the drawing area.

Shape and Connector Selection

Select individual shapes by a single click in their header area. Select individual connectors by a single click on their line or one of their segments. Continue with a multiple selection by holding the Ctrl key down. An alternative for multiple selections is to start with a click in an empty space, move the mouse to another position and release the button: all shapes and connectors partially included in the multiple selection frame will be selected.

Selected shapes get a blue selection frame with blue selectors (i.e. circles or rectangles on edges and corners), which give information and help you perform operations on the element. Selected connectors become blue and show two or more selectors on their path, which show if they are automatically rerouted and give access to manual routing operations.

Selections are never saved with the diagram and never appear in the printed images. Selected shape shows other hidden information, such as:

• a top-right corner chevron icon, to collapse or expand the shape;
• a scrollbar for the items area, if items are partially hidden by the reduced shape size;
• manually strikethrough hidden items;
• empty or collapse categories,  automatically hidden when the shape is not selected;
• collapse/expand +/- icons for the category items.

For instance, all elements below have been multiple selected, to see how they look. Selected DriveInfo shape shows a collapsing chevron, a scrollbar because invisible items are available below, collapsed Dependencies and Constructors category items (made invisible when shape is unselected) with their icons:

Implementors (like the one for ISerializable before) and instantiators have a top-left rectangular selector, filled-up if the shape is not in its default position (on the top-left corner of the related base shape, above or on the left). Click the selector for a default positioning.

The other kinds of shapes, including comments, can be minimized. The top-left small filled-up circle selector can be clicked to minimize or restore a minimized shape. The Name property is linked to such a minimized shape, which usually shows only a circle with the shape icon. These shapes can be also made transparent. The similar top-right small empty circle selector can be used to switch the transparent state. Note these operations, and many other, can also be performed on multiple selections at once. For instance, a click on the transparency selector of DriveInfo here would make all selected shapes transparent (if they are not already), while the same click on the minimized shape (already transparent) would remove transparency for any selected shape.

Comment shapes have a small triangle in the middle of the bottom edge, which can be dragged to create comment links to any another shapes. This is how the link to DriveInfo has been created.

Shape Resizing and Connector Rerouting

All other rectangular shape selectors give information and can be used for resizing. Am empty selector means auto-resizing is in effect on that direction, the dimension is optimal and the system will further try to automatically adjust the width or height upon collapse or expand actions. All shapes are usually optimal when created, unless they did not fit entirely in the diagram or user manually adjusted their size. For instance, DriveInfo shows optimal width, but not optimal height: when the shape will be collapsed, its width will be automatically readjusted to its new title width only. But when shape items will be collapsed or expanded (i.e. moved back or outside the shape), its height will remain the same and may need manual resizing. Remark that collapsed shapes, like DriveType, have always fixed height (the full height of their visible header) and cannot be resized on the vertical axes. Its likely its width has been previously changed by the user, by dragging one of its lateral selectors.

A double-click on a filled-up resizing selector will try to recalculate the optimal dimension and move back to auto-resizing. For corner selectors, this would apply for both width and height. Optimal size for parent nested shapes is when all inner elements are centered within the items area or within the comment shape.

All connectors, when selected, present by default at least two rectangular selectors. For non-straight multi-segment connectors, they can be dragged to change the default automatic routing on that side. For instance, the DriveType property connector has the selector close to the DriveType shape moved by the user to another location. In the rare cases when you need complex routing and more than two selectors, hold Ctrl key down while dragging an existing selector, and a new one will be generated for you. For instance, a third intermediate selector has been generated this way in the middle of the connector to ISerializable. A double click inside a connector selector will either cancel the manual routing (and the selector becomes again empty), or get rid of the intermediate selector.

Item and Node Selection

Selecting diagram shape or connector items is similar to selecting nodes, in the Metadata tree or the Diagrams list, in the Editor. Click on any item or node to single select it. For items, its parent shape or connector element becomes selected as well. All other diagram elements will be unselected. Items and nodes are always fully and automatically resized to their content, unless their container partially hides them. When selected, they get a blue background and white text color.

Multiple item or node selections are possible only when they belong to the same parent element. This allows operations on multiple selections such as hiding, collapsing, expanding, changing order etc. Hold the Ctrl key down while selecting individual items or nodes by single clicks. Or press Shift while clicking on a second node, to select a range of items or nodes. Or keep Shift down while using the Up/Down keys, to move to the previous/next item or node. The DriveInfo shape items below have been selecting using one of these techniques:

Selecting a connector automatically selects all visible items related to the connector. This makes it easier to determine which items belong to it and where they are in the diagram: