Most of the detailed design information is edited and managed with property dialogs. These dialogs are common to all tools of MetaEdit+. Therefore, information about each element can be edited in any of the tools by selecting Properties... from the element related pop-up menu. Figure 3-32 shows an example of a property dialog for a VariableRef from the WatchApplication graph type.

With the Tab key you can move between the fields and buttons of the dialog (use Ctrl+Tab to move out of a text field). Pressing OK accepts the changes made and Cancel abandons changes made directly to property dialog: if you have made no changes you should exit with Cancel. The Info button opens an Info Tool as a dialog, giving you information about the current use of the element in the repository: the Info Tool is explained in the next section in more detail.

Property dialogs include several functions for reusing, sharing and editing data entered into the dialogs. These functions are related to the type of the property. In the following these functions are explained

All string, number, and text fields include cut, copy and paste functions. You can access these functions through the pop-up menu of the field. Selecting paste with Shift pressed gives a dialog showing the last five items from the text cut buffer.

Object fields include cut, copy, paste and paste special functions. Paste will make the property point to the exact same copied object. If you need to have a true copy instead, breaking the links with the original elements, choose Paste Special. A dialog will open for defining the depth of the copy (as in Figure 3-33).

The options in the Paste Special dialog are as follows:

More details about copying to various depths are given in the description of the Replace Tool in Section 3.3.5.

The text field widget provides the basic set of features for editing textual properties. To find text in text field (please note that find is case sensitive):

To change the text emphasis, press Ctrl+B (bold), Ctrl+U (underline) or Ctrl+I (italic). The emphasis is toggled for the current selection or at the cursor if there is no selection. Note: Ctrl+I normally reserved for moving between widgets in the property dialog – in text fields, use Ctrl+Alt+Tab to reach the next widget and Ctrl+Shift+Tab for the previous one.

A multi-level undo/redo is also available for text fields: press Ctrl+Z for undo and Ctrl+Y for redo. To enter characters that are not directly supported by your keyboard, use Ctrl+K compose. For example, to enter a yen sign, press the keys in the following sequence: Ctrl+K, = and Y. The compose key generally uses the same sequence as VT340, but only one of possibly several sequences is allowed.

Because the size of the property field may become too small for large textual specifications, all property fields of data type Text can be opened and edited in a text editor. You may use MetaEdit+'s built-in Text Editor (see Section 3.3.4) or use your own Text Editor (see Section 3.1.1). The Editor... function can be called from the pop-up menu of the text field.

Sometimes it is useful to link design elements to external files or programs. For this purpose MetaEdit+ has a special ‘External Element’ specification for String property types. Examples of this kind of property can be seen in the pre-defined graph types of MetaEdit+ in property types whose names end in ‘file’. For example, in UML a use case has a property type ‘documentation file’, which can contain the name of the external file or program to be run. To attach an external file or program, open the pop-up menu for the external property field, select Browse and use the file dialog to choose the file. To open the external file or run the program, choose Execute from the menu.

The external property field can include also path information: if there is none, the path is relative to the current directory, normally the main MetaEdit+ directory.

Property sharing means that a property of an object X can also be used at the same time as a property of an object Y. As a result of this operation two properties refer to the same value. Such properties are shown with a dark red font, as a reminder that changes to their values will affect the same value used in other objects.

In line with the idea of property sharing, and differing from cut, copy and paste, changes of the property value affect all elements that use it as a property. For example, the Unified Modeling Language implemented into MetaEdit+ includes the possibility to share values of properties between Class Diagrams and State Machine Diagrams: an operation name in a class can be shared with an activity name in a state transition diagram. Thus, with property sharing you only need to enter the name of the operation once, and share it between two graph types. By using property sharing, you can assure that changes of the name in one model are reflected in other models using the same property.

Note that property sharing is only possible with properties of data type String, Text or Number, and only between object, role or relationship types that specify a property of the same type.

To share a property:

As a result a dialog like that in Figure 3-34 opens allowing you to browse properties of the same type together with their values and related property sharing information. In the beginning of each row a property value is shown (the current value is marked with *), followed by the number of objects, roles or relationships that share that property (owners), and the names and types of those owners.

If you later want to add information to the property that you would not like to share with other property fields you must remove sharing before you make any changes. Removal of property sharing deletes the link to the shared value and takes a copy of the value. To remove sharing:

As a result any changes that will be done to the property field are added only to this property field.

Properties whose value is a selection from a list are shown as combo-boxes in dialogs. There are three different kinds of list properties:

In all cases the set of initial values in the list is defined in the metamodel, and in editable lists the extra values are project-specific, i.e. they are only visible in the project where they were added.

Design information is quite often too rich and complex to be shown in just one dialog. For example, there is no sense in showing the initial values of every attribute or return types of every member function or method in a property dialog for a class. Therefore, in MetaEdit+ you can have properties that have internal structure, i.e. each of which can be opened in its own property dialog. Unlike fields of string or text type, this field contains a whole object, graph, relationship or role as a value, not just its name. Such fields are shown with a grey background, to differentiate them from normal string fields where you can type. If no object has yet been attached, a field of this kind will be empty.

In property fields of this type you can add a new object into the field (Attach New Object...), reuse an existing object (Attach Existing Object...), edit the attached object (double click or Edit Object...), or remove the object from the field (Remove Object...). You can also open any existing representation for the attached object, or create a new one for it if it is a graph (Open Object). Note that because property editing is performed in a dialog, you will not be able to move to and work in the editor that you open in this way: you must first close the property dialog.

When attaching an existing object, MetaEdit+ opens a Component Selection Tool (see Section 3.3.2), which allows you to search for the object you want.

Instead of a single object as a property, a field can contain a collection of such elements. For example, a WatchFamily graph has a collection of included components. This collection is shown as a list in the property dialog of the graph (Figure 3-35), and each operation in the list can be opened into its own property dialog where it is specified in more detail. The collection list field itself has its own menu, as shown in the figure.

The collection elements can be added, edited, removed, cut, copied or pasted through the functions of the pop-up menu. Elements in a collection can also be sorted into ascending or descending order, and individual elements can be moved to a new position in the collection.

Instead of creating new elements to add to a collection, existing objects, graphs, relationship and roles can be added to the collection and thus reused. To add existing elements:

A Component Selection Tool opens, where you can select one or more existing elements (see Section 3.3.2). Add the desired element(s) from the ‘Selections list’ (Add pop-up menu) into the ‘Already selected’ list and press OK. As a result of the operation the selected elements are added to the collection.