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Working with Lines
The main operations provided by the SDL Editor on lines, and their associated text attributes are:
- Selecting Lines
- Drawing Lines
- Re-Routing and Reshaping Lines
- Redirecting and Bidirecting Lines
- Adjusting Lines to the Grid
In addition, text editing functions are provided for the text associated with the lines.
Operations on lines are performed slightly different depending if you are editing
The main difference between the two is that flow pages may only allow vertical and horizontal lines.
Some restrictions also apply when connecting symbols in flow pages, depending upon whether or not the syntax checking is enabled
Selecting Lines
You select lines and extend and reduce selections of lines with standardized selection commands.
Selecting a Line That Has Associated Objects
When you select a line, you implicitly select the associated attributes as well. To be able to edit a text attribute you must click on the text attribute and a text cursor will be inserted directly in the text, at the same time the text window will be updated to contain the text.
Displaying Selected Line Attributes
Selected line attributes are displayed as follows:
- Each text attribute is displayed inside a text selection rectangle.
- The following attributes are displayed with a filled selection square:
Selecting Overlapping Objects
On a page, objects may overlap each other. A layer order is defined so that it is possible to determine how overlapping objects are stacked.
Drawing Lines
This section describes how to interconnect symbols with lines. Two modes are supported in the SDL Editor.
Drawing a Line with Layout Syntax Checking Enabled
The way that you draw a line differs somewhat depending upon whether you are working on an interaction page or a flow page. The differences will be pointed out later in this section.
When syntax checking is enabled, you are only allowed to draw lines that are correct according to the SDL rules. When syntax checking is disabled, the rules are less strict.
Designating the Start Point
- Select the symbol from which the line will originate.
- Point to the handle and drag it to begin forming the line. The line that is formed ends where the mouse pointer is located. Note that the mouse button can be released as soon as you have moved the mouse pointer.
Designating the End Point
- Designate the start point. See previous section.
- You can route the line and specify where it will end either automatically or manually.
- To route the line automatically:
- To route the line manually, indicating where line breakpoints are to be inserted, follow the steps below.
- To enter manual mode, click any location in the drawing area other than a valid destination symbol.
- Click each location where you want to insert a line breakpoint.
- Click on a valid destination symbol.
Drawing Multiple Lines
When you draw lines between symbols and keep the <Control> key pressed, the start point for the next line to draw is automatically transferred to the target symbol.
This feature provides the easiest way to draw multiple lines in rapid succession.
Differences between Flow and Interaction in Line Drawing
The way that you draw a line differs somewhat depending upon whether you are working on an interaction page or a flow page:
- On an interaction page, you can draw lines in all possible directions.
- On a flow page, you can only draw lines horizontally or vertically. The last line breakpoint, even if determined manually, will be adjusted so that the destination symbol is connected correctly, normally in the middle of the upper edge of the symbol. Exceptions are made for comment and text extension symbols, which are connected to the center of the right or left edge of the symbol.
Cancelling the Line Drawing Operation
You can cancel a line drawing operation in either of the following ways:
Drawing a Line with Layout Syntax Checking Disabled
The process of drawing a line is the same regardless of whether or not syntax checking is enabled. To enable and disable syntax checking, see Turning Syntax Checking On and Off.
When drawing lines with syntax checking disabled, you may interconnect symbols in any way you want.
Re-Routing and Reshaping Lines
Reshaping a line refers to changing the path that the line follows. This operation does not affect the endpoints of the line. The flow lines only move in either a horizontal or vertical way.
Re-routing a line denotes changing the ending point of the line from one symbol to another symbol.
Reshaping a Flow Line
- Point to one of the segments of the line.
- Press the mouse and, holding down the mouse button, drag the segment to the required position.
- Release the mouse button.
Re-Routing a Flow Line
You can move the ending point of a flow line, and reconnect it to any valid destination symbol. You can redraw the line either manually or automatically.
To move a line's ending point:
- Point at the ending point that you want to reconnect.
- Press the mouse. Start dragging the ending point. As soon as you move the mouse, the line's last segment follows the mouse motion and you can release the mouse button.
- You can click additional line breakpoints where you like.
- Click the destination symbol to complete the operation. If it is a valid symbol, the line will be re-routed automatically.
Re-Routing an Interaction Line
You can move any starting or endpoint to and from a symbol and the environment.
- Point to the starting or ending point of the line.
- Press the mouse and, holding the mouse down, drag it to the desired symbol.
- If required, click to add line breakpoints at desired positions.
- Terminate by clicking on the new symbol. The line is redrawn accordingly.
Moving an Interaction Line Breakpoint
To move a line breakpoint in an interaction page:
- Point to the breakpoint that you want to move.
- Press the mouse and drag the breakpoint to the desired location.
- Release the mouse button to redraw the line.
Inserting Breakpoints in an Interaction Line
- Point at the middle of a line segment. When the line is selected a tiny selection square will be displayed at this point.
- Press the mouse and drag it to shape the breakpoint.
An alternative way to insert breakpoints on an interaction line:
- Press <Ctrl>
- Point in a line segment where you want to insert a new breakpoint.
- Press the mouse and drag it to shape the breakpoint.
- Release the <Ctrl> key.
Moving an Interaction Line Segment
You can move a line segment in an interaction page as long as it is not a starting segment or ending segment.
- Point to the line segment to be moved.
- Press the mouse and drag the line segment to the desired location.
- Release the mouse button. The line segment and the adjacent line segments are redrawn accordingly.
Moving Arrows
Arrows on channels, gates and signal routes denote the orientation of flow on that line. They are assigned default locations when creating the line.
You can manually move arrows on channels along the line.
- Point to the arrow.
- Press the mouse. Still holding the mouse down, drag it until the arrow reaches the new place.
- Release the mouse. The arrow and the signal list are redrawn accordingly.
To create a non-delay channel you simply drag the arrow to the starting or ending breakpoint.
Moving a Line and Its Connection Point
A channel or a signal route may be connected to a connection point (usually located close to the line, immediately outside the frame).
Moving the line's ending point with the connection point unselected will move the line only and create a new connection point. The old connection point is removed.
To move the line and the connection point:
- Click on the ending point of the line. Make sure the connection point is selected (i.e. the selection rectangle appears).
- Drag the line's ending point to the new location. The connection point follows the mouse motion as well.
- If the line's new ending point coincides with a gate symbol and the connection point has a name, a dialog is issued. The meaning of this message is described in Connecting a Gate Symbol with a Channel or Signal Route.
Moving a Line Text Attribute
A line text attribute is a textual element that is related to a line. The following lines have associated text attributes:
When drawing a line, the SDL Editor positions the text attribute close to the source symbol and originating line, so that it is easy to identify what line the text attribute is related to. You are however free to move the text attribute to any location in the drawing area within the frame.
To move a line text attribute:
- Point to the border of the text attribute.
- Press the mouse, and, still holding the mouse down, drag the text attribute to its new location.
- Release the mouse button.
Redirecting and Bidirecting Lines
When you add a channel or signal route to an interaction diagram, the line is initially drawn in a uni-directional manner, originating from the source symbol and pointing to the target symbol.
The only way to draw a line from the environment to a symbol is to first draw it from the symbol and then redirect it.
Redirecting a Line
Bidirecting a Line
- Select the line.
- Choose Bidirect from the Edit menu. The line is bidirected.
- Fill in the second signal list.
Uni-Directing a Bidirected Line
- Select the bidirected line.
- Choose Unidirect from the Edit menu. A dialog will appear asking what arrow to keep.
Adjusting Lines to the Grid
When you move or reshape interaction lines, the line breakpoints are adjusted to the line grid, which cannot be disabled and has a fixed resolution of 2.5 mm.
Flow line segments and line text attributes are always placed so that they match the resolution of the line grid.
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