Rectangle elements are used for filled and unfilled rectangles
and rounded rectangles.
To create a rectangle:
the Rectangle button in the
the cursor in the drawing area to where you want a corner of the rectangle to
and hold down the left mouse button, drag the cursor into the point where you
want to place the opposite corner, and release the mouse
The resulting rectangle is
displayed in the drawing area. You can drag the yellow handle at the top-left
corner towards the center of the rectangle to round the corners of the
The default formatting for rectangle is solid, black 1
pixel line and white fill. To change the formatting, select the rectangle, press
the right mouse button to open its pop-up menu, and then select Format...
from the menu. Double-clicking the rectangle or pressing Enter when it is
selected will achieve the same result. A Format Dialog
shown in Figure 3–5
Figure 3–5. Format Dialog for line shape.
three tabs in the dialog. The first one, Line and
(as shown in Figure 3–5
), enables you to change
the color, style and weight of the line of the rectangle, and the fill color
inside the rectangle. You can pick the line color from the Color
pull-down list. If there is no suitable color available in the pre-defined color
palette, choose Select a New Color...
and define the color of your choice
in the dialog that opens (Figure
). Select a color by clicking a colored square, using the sliders
on the top and the right or entering the values in HSV, RGG or HTML fields, and
Figure 3–6. Selecting color.
The line widths from
hairline to 10 pixels can be chosen from the Weight
menu. The line style
(dotted, dashed etc.) can be set from the Style
The second tab in the Format Dialog, Position and
, contains the values for the position, size and
scale of the element (Figure
). You can change these freely either by entering new values into
the fields or by using the spin buttons next to the fields. If you want the
element to retain its original aspect ratio when you are changing size or scale,
check the Lock aspect ratio
Figure 3–7. Format Dialog for shape’s position and size.
final tab, Condition
, controls the visibility of
the symbol element (Figure 3–8
All elements except Connectables can have a condition that must be met for the
element to be displayed.
Figure 3–8. Condition dialog.
The conditions are
matched against either property values or generator outputs and the matching is
done with plain strings or regular expressions
condition source is defined on the top part of the Condition tab. For property
condition source, check the Property radio button and select the source property
from the pull-down list next to it (the menu includes all the property types
defined for symbol’s non-property type). For generator source, check the
radio button and enter the MERL code for
the generator body (no name or header) into the text field next to it (for more
information about defining generators, see Section 5
). Checking the Generator
button will enable the Editor
button – pressing this button will
open the Generator Editor for editing the MERL code for the generator.
The symbol element will be shown if the value of the
selected property or the output of the generator matches the condition string or
regular expression that is entered in the Condition
text box in the lower
part of the dialog. The type of the required match, either String
, is defined by checking the appropriate radio button and selecting
the desired match operator from the accompanying pull-down list. The possible
match operators for String are =
(exact comparison), =~
; and for RegExp =
. In String wildcard
comparisons # (any single character) and * (0 or more characters) can be used.
More complex partial matches can be done with regular expressions. For more
information about how to use regular expression, see Appendix A: Regular
When using Boolean properties as the condition source,
note that you should compare to T for Boolean value true and F for false (i.e.
checkbox checked and not checked).
To remove a condition completely, press the Clear