NAME

VB - Visual Builder for the Prima toolkit

SYNOPSIS

Run the VB command in your terminal

DESCRIPTION

Visual Builder is a RAD-style suite for designing forms using the Prima toolkit. It provides a rich set of perl-based widgets which can be inserted into a window-based form by simple actions. The form can be stored in a file and loaded by either a user program or a simple wrapper, utils/prima-fmview.pl; the form can be also stored as a valid perl program.

A form file has the .fm extension and can be loaded fairly simply by using the Prima::VB::VBLoader module. The following code is the only content of the prima-fmview.pl program:

        use Prima qw(Application VB::VBLoader);
        my $ret = Prima::VBLoad( $ARGV[0] );
        die "$@\n" unless $ret;
        $ret-> execute;

Such code is usually sufficient for executing a form file.

Help

The builder provides three main windows, that are used for interactive design. These are called main panel, object inspector, and form window. When the builder is started, the form window is empty.

The main panel consists of the menu bar, speed buttons, and the widget buttons. If the user presses a widget button and then clicks the mouse on the form window, the selected widget is inserted into the form and becomes a child of the form window. If the click was made on a visible widget in the form window, the newly inserted widget becomes a child of that widget. After the widget is inserted, its properties are accessible in the object inspector window.

The menu bar contains the following commands:

File

New

Closes the current form and opens a new empty form. If the old form was not saved, the user is asked if the changes made are to be saved.

This command is an alias to the 'new file' icon on the panel.

Open

Invokes the file open dialog so a .fm form file can be opened. After a successful file load, all form widgets are visible and available for editing.

This command is an alias to the 'open folder' icon on the panel.

Save

Stores the form into a file. The user here can select a type of the file to be saved. If the form is saved as a .fm form file then it can be re-loaded either in the builder or a user program ( see Prima::VB::VBLoader for details ). If the form is saved as a .pl program, then it can not be loaded; instead, the program can be run immediately without the builder or any supplementary code.

This command is an alias to the 'save on disk' icon on the panel.

Save as

Same as Save, except that a new name or type of file is asked every time the command is invoked.

Close

Closes the form and removes the form window. If the form window was changed, the user is asked if the changes made are to be saved.

Edit

Copy

Copies the selected widgets into the clipboard so they can be inserted later by using the Paste command. The form window itself can not be copied, only the widgets it contains.

Paste

Reads the information put by the builder Copy command into the clipboard and inserts the widgets into the form window. The child-parent relation is kept by the names of the widgets; if the widget with the name of the parent of the clipboard-read widgets is not found, the widgets are inserted into the form window. The form window is not affected by this command.

Delete

Deletes the selected widgets. The form window itself can not be deleted.

Select all

Selects all of the widgets inserted in the form window except the form window itself.

Duplicate

Duplicates the selected widgets. The form window is not affected by this command.

Align

This menu item contains z-ordering actions that are performed on selected widgets. These are:

   Bring to front
   Send to back
   Step forward
   Step backward
   Restore order

Change class

Changes the class of the selected widget. This is an advanced option and can lead to confusion or errors if the default widget class and the supplied class differ too much. It is used when the widget that has to be inserted is not present in the builder installation. Also, it is called implicitly when the loaded form does not contain a valid widget class; in such case the Prima::Widget class is assigned.

Creation order

Opens the dialog that manages the creation order of the widgets. It is not that important for the widget child-parent relation, since the builder tracks these, and does not allow a child to be created before its parent. However, the explicit order might be helpful in a case when, for example, the tabOrder property is left to its default value, so it is assigned according to the order of widget creation.

Toggle lock

Changes the lock status for selected widgets. The lock, if set, prevents widgets from being selected by the mouse to avoid occasional positional changes. This is useful when a widget is used as an owner for many sub-widgets.

The ctrl+mouse combination click locks and unlocks widgets.

View

Object inspector

Brings the object inspector window, if it was hidden or closed.

Add widgets

Opens the file dialog to install additional VB widgets. The modules are used for providing custom widgets and properties for the builder. As an example, the Prima/VB/examples/Widgety.pm module is provided with the builder and the toolkit. Look inside this file for the implementation details.

Reset guidelines

Resets the guidelines on the form window into the center.

Snap to guidelines

Specifies if the moving and resizing widget actions must treat the form window guidelines as snapping areas.

Snap to grid

Specifies if the moving and resizing widget actions must use the form window grid granularity instead of the pixel granularity.

Run

This command hides the form and object inspector windows and 'executes' the form as if it would be run by prima-fmview.pl. The execution session ends either by closing the form window or by calling the Break command.

This command is an alias to the 'run' icon on the panel.

Break

Explicitly terminates the execution session initiated by the Run command.

Help

About

Displays the information about the visual builder.

Help

Displays the information about the usage of the visual builder.

Widget property

Invokes the help viewer on the Prima::Widget manpage and tries to open the topic corresponding to the current selection of the object inspector property or event. While the manpage covers far not all ( but still many ) properties and events, it is still a little bit more convenient than nothing.

Form window

The form widget is the common parent for all widgets created by the builder. The form window provides the following basic navigation.

Guidelines

The form window contains two guidelines, the horizontal and the vertical, drawn as blue dashed lines. Dragging with the mouse can move these lines. If the menu option "Snap to guidelines" is checked, the widgets' moving and sizing operations treat the guidelines as snapping areas.

Selection

A widget can be selected by clicking with the mouse on it. There can be more than one selected widget at a time, or none at all. To explicitly select a widget in addition to the already selected ones, hold the shift key while clicking on a widget. This combination also deselects the widget. To select all widgets on the form window, call the "Select all" command from the menu. To prevent widgets from being occasionally selected, lock them with the "Edit/Toggle lock" command or Ctrl+mouse click.

Moving

Dragging the mouse can move the selected widgets. Widgets can be snapped to the grid or the guidelines during the move. If one of the moving widgets is selected in the object inspector window, the coordinate changes are reflected in the origin property.

If the Tab key is pressed during the move, the mouse pointer is changed between three states, each reflecting the currently accessible coordinates for dragging. The default accessible coordinates are both the horizontal and the vertical; the other two are the horizontal only and the vertical only.

Sizing

The sizeable widgets can be dynamically resized. Only one widget at a time can be resized. If the resized widget is selected in the object inspector window, the size changes are reflected in the size property.

Context menus

The right-click (or the other system-defined pop-up menu invocation command) provides the menu, identical to the main panel's Edit submenu.

The alternative context menus can be provided with some widgets ( for example, TabbedNotebook ), and are accessible with the control + right click combination.

Object inspector window

The inspector window reflects the events and properties of a widget. To explicitly select a widget, it must be either clicked by the mouse on the form window or selected in the widget combo box. Depending on whether properties or events are selected, the left panel of the inspector provides a list of properties or events, and the right panel - a value of the currently selected property or event. To toggle between the properties and the events use the button below the list.

The adjustable properties of a widget include an incomplete set of the properties returned by the class method profile_default ( for a detailed explanation see Prima::Object). Among these are such basic properties as origin, size, name, color, font, visible, enabled, owner, and many others. Each property can be selected by the property selector; in such case the name of a property is highlighted in the list - that means, that the property is initialized. To remove a property from the initialization list, double-click on it, so it is grayed again. Some very basic properties as name can not be deselected. This is because no widgets of the same name can coexist simultaneously in the builder.

The events, much like the properties, are accessible for direct change. All the events provide a small editor, so the custom code can be supplied. This code is executed when the form is run or loaded via the Prima::VB::VBLoader interface.

The full explanation of properties and events is not provided here. It is not even the goal of this document because the builder can work with the widgets irrespective of their property or event capabilities; this information is provided by the toolkit. To read what each property or event means, use the documentation on the class of interest; Prima::Widget is a good start because it encompasses the basic Prima::Widget functionality. The other widgets are documented in their respective modules, for example, the Prima::ScrollBar documentation can be found in Prima::ScrollBar.

SEE ALSO

Prima, Prima::VB::VBLoader

AUTHOR

Dmitry Karasik, <dmitry@karasik.eu.org>.

COPYRIGHT

This program is distributed under the BSD License.