The label button is used to create or modify a text label. Labels are abstract annotation objects which do not appear in physical output. For physical text, use the logo command button.
If a label is selected before pressing the label button, then the selected label can be edited. Multiple labels can be selected, and each will receive the new label text. If more than one label is being changed, the command exits after the new text is entered on the prompt line, i.e., after Enter is pressed to terminate text entry.
If only one label is being changed, on pressing Enter the new text is ``attached'' to the mouse pointer, as for a new label. In this state, the text size, orientation, and justification can be changed as will be described below. The user can either click in a drawing window to place the label at the click location (effectively moving the selected label), or press Enter to update the selected label at the existing location.
This is the recommended way to change the size of a label: select it, press the label button, press Enter to keep the same text, adjust the size with the arrow keys, then press Enter again to update the label. This keeps the label in a standard size and aspect ratio which will match other labels. This would not be the case if the Stretch command or operation was used instead.
If no label was initially selected, after the label text has been entered, the label will appear ghost-drawn, attached to the mouse pointer. The text will be rotated or mirrored according to the current transform, as set from the pop-up provided by the xform button in the side menu. Instances of the label are placed where the user clicks in a drawing window.
Label text in entered in the prompt line. While editing, if the user clicks on an existing label in a drawing widow which is contained in the current cell, the text of that label will be inserted at the prompt line cursor. Hypertext entries (see refhypertext) in the label will be preserved. If the existing label is a ``long text'' label (described below), the long text attribute will be lost, unless the prompt line is empty before clicking on the label. Particularly in electrical mode, clicking on other objects in a drawing window will insert text at the cursor position, as will be described. Pressing Enter terminates the label text and will allow placement of copies of the new label.
The size and justification of the label can be adjusted with the arrow keys, before it is placed. The arrow keys have the following effect:
|Up||enlarge by 2|
|Right||enlarge by 10%|
|Down||reduce by 2|
|Left||reduce by 10%|
The initial size of a label is determined by the present default label height, and the magnification of the current drawing window. The default label height is 1.0 microns, which can be reset by setting the LabelDefHeight variable to a different value. The default height is the smallest size available through scaling with the arrow keys. Generally, Xic functions that create new labels will use the default label height. The default height of one micron is too large for modern semiconductor processes, so one should redefine LabelDefHeight in the technology file to a more suitable value, typically the minimum feature size.
By default, the label is anchored at the lower left corner, though this justification can be changed by holding the Shift key while pressing the arrow keys. The Left and Right arrows cycle through left, center, and right justification. The Up and Down arrow keys cycle through bottom, center, and top justification. Finally, holding the Ctrl key while pressing the arrow keys will change the current rotation angle. The arrow keys implicitly cycle through the angle choices, with Up and Right cycling in the opposite sense from Down and Left.
Labels are scalable, and can be stretched with the Stretch button in the Edit Menu or with button 1 operations.
Newlines can be embedded in the label text by pressing Shift-Enter. The displayed label will contain line breaks at those points. The justification applies to the block, and line-by-line within the block.
Labels are shown in legible orientation (i.e., left to right or down to up) by default, independent of the actual transformation. If the Label True Orient button in the Main Window sub-menu of the Attributes Menu or the sub-window Attributes menu is set accordingly, labels will be shown in their actual orientation.
Pressing the Delete key after the label text has been entered will repeat prompting for new label text. Labels have fixed size as compared with layout geometry.