The Component Designer is the primary tool for developing application models. It opens when you create or edit a diagram (.dgm file).
The Component Designer features:
- An editing canvas that displays a diagram of the component and subcomponents that you are editing. Rectangles represent the components and contain text labels indicating their content. Lines connecting components represent relationships.
- A palette from which you select elements to add to the diagram. The list of available elements depends on the model definition for the component type. You click on the desired element type and then on the canvas to place the element.
The visual representation that you create is stored as a diagram file with a .dgm extension. Each time you save a diagram, the logical elements that it depicts are automatically stored in the associated model.
Using the palette
By default, the palette is at the right edge of the Component Designer window and is closed. It opens when you position the cursor over the Palette bar, stays open as long as the cursor is inside the palette area, and closes when you move the cursor outside the area.
If you prefer to keep the palette open, click the left arrow
() At the top of the Palette bar. The
symbol becomes a right arrow (
), which you can click to close the palette
again.
To move the palette to the opposite side of the Component Designer window, open it, move the cursor to the title bar at the top, left-click and drag across the window, and release the mouse button.
Elements that you can add from the palette are organized in labeled sections called
drawers. You open a drawer by clicking its label (for example, New Components). By
default, only one drawer is open at one time; if you open a new drawer, the other
closes. To keep a drawer open, click the pin symbol () at the right edge of the label; click the pin
again to let the drawer close.
Selection tools
At the top of the palette are two cursor options that offer different methods for selecting objects on the canvas:
- Select - Lets you select single objects by pointing and clicking, or multiple objects, one at a time, by shift-clicking. When this tool is active, the cursor appears as an arrow.
- Marquee - Lets you drag a temporary rectangle to enclose the objects that you want to select. When this tool is active, the cursor appears as a pair of crosshairs.
Click to choose one of these cursors. When you click an element in a palette drawer, the select cursor is automatically activated.
Placing elements on the canvas
To add an element to the diagram, click its label (for example, New Column) in the drawer, and then click the area of the canvas where you want to place it. Some elements must be placed inside existing elements on the canvas; for example, a column must be placed inside a table. Others must be placed outside any other elements; for example, a table must be placed directly on a blank area of the canvas.
The appearance of the cursor indicates whether an element can be placed at the current position. An arrow with a plus sign indicates that the element can be placed. A circle with a diagonal bar through it indicates an ineligible area of the canvas.
If you click an element in a drawer and then decide not to place it, press Esc or click another element.
You can reposition a rectangular object, such as a table, on the canvas. Select one or more objects by clicking or shift-clicking any non-text area of the rectangle with the arrow cursor, or by enclosing them with the marquee cursor. Then, using the select cursor, click and drag the selection to the desired position.