NAME¶
VB - Visual Builder for the Prima toolkit
DESCRIPTION¶
Visual Builder is a RAD-style suite for designing forms under the Prima toolkit.
It provides rich set of perl-composed widgets, whose can be inserted into a
form by simple actions. The form can be stored in a file and loaded by either
user program or a simple wrapper, "utils/fmview.pl"; the form can be
also stored as a valid perl program.
A form file typically has
.fm extension, an can be loaded by using
Prima::VB::VBLoader module. The following example is the only content of
"fmview.pl":
use Prima qw(Application VB::VBLoader);
my $ret = Prima::VBLoad( $ARGV[0] );
die "$@\n" unless $ret;
$ret-> execute;
and is usually sufficient for executing a form file.
Help¶
The builder provides three main windows, that are used for designing. 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 designated 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 children of that widget. After the widget
is inserted, its properties are accessible via 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 have to be
saved.
This command is an alias to a 'new file' icon on the panel.
- Open
- Invokes a file open dialog, so a .fm form file can
be opened. After the successful file load, all form widgets are visible
and available for editing.
This command is an alias to an '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 .fm form
file, then it can be re-loaded either in the builder or in the user
program ( see Prima::VB::VBLoader for details ). If the form is saved as
.pl program, then it can not be loaded; instead, the program can be
run immediately without the builder or any supplementary code.
Once the user assigned a name and a type for the form, it is never asked
when selecting this command.
This command is an alias to a 'save on disk' icon on the panel.
- Save as
- Same as Save, except that a new name or type of file are
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 have to be
saved.
- Edit
- Copy
- Copies the selected widgets into the clipboard, so they can
be inserted later by using Paste command. The form window can not be
copied.
- 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 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 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 an inserted widget. This is an
advanced option, and can lead to confusions 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 a loaded form does not contain a valid
widget class; in such case 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, "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 a widget from being selected by mouse, to avoid occasional
positional changes. This is useful when a widget is used as owner for many
sub-widgets.
Ctrl+mouse click locks and unlocks a widget.
- View
- Object inspector
- Brings the object inspector window, if it was hidden or
closed.
- Add widgets
- Opens a file dialog, where the additional VB modules can be
located. 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
- Reset the guidelines on the form window into a center
position.
- 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 "fmview.pl".
The execution session ends either by closing the form window or by calling
Break command.
This command is an alias to a 'run' icon on the panel.
- Break
- Explicitly terminates the execution session, initiated by
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 a help viewer on Prima::Widget manpage and tries to
open a topic, corresponding to the current selection of the object
inspector property or event list. While this manpage covers far not all (
but still many ) properties and events, it is still a little bit more
convenient than nothing.
The form widget is a common parent for all widgets, created by the builder. The
form window provides the following basic navigation functionality.
- 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 menu option "Snap to guidelines" is on, the
widgets moving and sizing operations treat the guidelines as the 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
"Select all" command from the menu. To prevent widgets from
being occasionally selected, lock them with "Edit/Toggle lock"
command or Ctrl+mouse click.
- Moving
- Dragging the mouse can move the selected widgets. The
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; other two are the horizontal only and the
vertical only.
- Sizing
- The sizeable widgets can be dynamically resized. Regardless
to the amount of the selected widgets, 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
"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 the
properties or the events are selected, the left panel of the inspector
provides the properties or events list, 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" ( the
detailed explanation see in Prima::Object). Among these are such basic
properties as "origin", "size", "name",
"color", "font", "visible", "enabled",
"owner" and many others. All the widgets share some common
denominator, but almost all provide their own intrinsic properties. Each
property can be selected by the right-pane hosted 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 the builder keeps a
name-keyed list; another consequence of this fact is that no widgets of same
name can exist simultaneously within 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 "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
extracted by native toolkit functionality. To read on what each property or
event means, use the documentation on the class of interest; Prima::Widget is
a good start because it encompasses the ground "Prima::Widget"
functionality. The other widgets are ( hopefully ) documented in their
modules, for example, "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.