Form (gb.qt4)

The parent class of every form of a program.

This class inherits Window.

This class can be used like an object by creating a hidden instance on demand.

This class is creatable.

This class acts like a read-only array.

Inherited constants

Above	This constants is used by the Stacking property for windows that must stay above other windows.
Below	This constants is used by the Stacking property for windows that must stay below other windows.
Normal	This constants is used by the Stacking property for windows that have a normal stacking order.

Static methods

Load	Creates the hidden default instance of the form.
Main	This method allows the Development Environment to use forms as startup classes.

Inherited properties

Action	Returns or sets the action string associated with the control.
Arrangement	Returns or sets how this container arrange its children controls.
AutoResize	Returns or sets if the window will automatically resize to fit its contents.
Background	Returns or sets the background color used by the control.
Border	Return or set if the window has a border.
Caption	A synonymous for the Text property.
Centered	Center controls horizontally or vertically according to the container arrangement.
Children	Returns a collection of each control included in the container.
ClientH	A synonymous for the ClientHeight property.
ClientHeight	Returns the height of the area containing the controls.
ClientW	A synonymous for the ClientWidth property.
ClientWidth	Returns the width of the area containing the controls.
ClientX	Returns the position of the left border of the area containing the controls.
ClientY	Returns the position of the top border of the area containing the controls.
Closed	Returns if the window has been closed.
Controls	Returns a collection of all controls that belong to this window.
Cursor	Use this property for assigning a custom cursor to a control.
Design	Indicates that the control is in design mode.
Direction	Return or set the control text direction.
Drop	Returns or sets if a control accepts drops.
Enabled	Indicates that the control is enabled.
Expand	Returns or sets if a control will expand if included in a container that arranges its contents.
Font	Returns or sets the font used to draw text in the control.
Foreground	Returns or sets the foreground color used by the control.
FullScreen	Returns or sets if the window is shown in fullscreen mode.
Geometry	Return the last geometry of the window when it was in normal state.
H	A synonymous for the Height property.
Handle	Returns the internal X11 window handle of the control.
HasFocus	Returns whether the control has the focus.
Height	Returns or sets the height of the control.
Hovered	Returns whether the mouse cursor is inside the control.
Icon	Returns or sets the picture used as an icon by the window.
Id	A synonymous for the Handle property.
Ignore	Returns or sets if a control must be ignored when its parent arranges its children.
Indent	Returns or sets if the children controls of the container are indented.
Invert	Return or set if the horizontal or vertical arrangement direction is inverted.
Left	Returns or sets the position of the left border of the control relative to its parent.
Margin	Returns or sets if there is a margin between the container border and all its children.
Mask	Returns or sets if Picture must be used as a shape mask by the window.
Maximized	Returns or sets if the window is maximized.
Menus	Returns a collection of all menus of the window menu bar.
MinH	Return or set the minimum height of the window.
MinHeight	Return or set the minimum height of the window.
MinW	Return or set the minimum width of the window.
MinWidth	Return or set the minimum width of the window.
Minimized	Returns or sets if the window is minimized.
Modal	Returns if a window is currently displayed modal.
Mouse	Returns or sets the appearence of the cursor when it points inside the control.
Name	Returns or sets the name of the control.
Next	Returns the next control having the same parent.
NoTabFocus	Return or set if a control cannot be focused with the TAB key.
Opacity	Return or set the of the window.
Padding	Returns or sets the number of pixels used as space between children controls, or container inner margin.
Parent	Returns the control container.
Persistent	Indicates if the window is persistent, i.e. if it is not destroyed but only hidden when the users closes it.
Picture	Returns the picture displayed in the window background.
PopupMenu	Return or set the name of the menu that will be popped-up when the user presses the right mouse button or the keyboard `MENU` key.
Previous	Returns the previous control having the same parent.
Proxy	Return or set the "proxy" of a control.
ProxyFor	Return which control that control is a proxy for.
Resizable	Constant used by the Border property to indicate that the window is freely resizable.
RightToLeft	Return if the control is right to left oriented.
Screen	Return the monitor index where the window is located.
ScreenX	Returns the position of the left border of the control in screen coordinates.
ScreenY	Returns the position of the top border of the control in screen coordinates.
SkipTaskbar	Indicates if the window is displayed or not in the desktop task bar.
Spacing	Returns or sets if the children of the container are spaced out.
Stacking	Returns or sets the stacking group of the window.
Sticky	Returns or sets if the window is visible in all virtual desktops.
Tag	Returns or sets the control tag.
TakeFocus	Return or set if the window takes the focus automatically when it is opened.
Text	Returns or sets the title of the window.
Title	A synonymous for the Text property.
Tooltip	Returns or sets the tooltip shown when the mouse stays on the control for a short time.
Top	Returns or sets the position of the top border of the control relative to its parent.
TopLevel	Returns if a window is a top-level window.
TopOnly	Returns or sets if a window stays on top on all other windows.
Tracking	Returns or sets if the control will receive MouseMove events.
Transparent	Return or set if the window background is transparent, i.e. if it takes the alpha components of its background color or picture into account.
Utility	Return or set if the window is an utility window, as defined by the freedesktop standard.
Visible	Returns or sets if a window is visible.
W	A synonymous for the Width property.
Width	Returns or sets the width of the control.
Window	Returns the top-level window that contains the control.
X	Returns or sets the position of the left border of the control relative to its parent.
Y	Returns or sets the position of the top border of the control relative to its parent.

Inherited methods

Activate	Activates the window.
Center	Centers the window on screen.
Close	Closes the window, and returns an optional integer value used by the
Delete	Deletes the window.
Drag	Starts a drag & drop process.
FindChild	Finds the first child control pointed by the X and Y coordinates.
Grab	Grab the keyboard and the mouse so that all keyboard and mouse events are received by the control.
Hide	Hides the control.
Lower	Sends the control to the background of its parent.
Move	Moves and/or resizes the control.
MoveScaled	Moves and/or resizes the control.
Raise	Raises the window.
Refresh	Trigger a redraw of the control.
Reparent	Changes the container of a control.
Resize	Resizes the control.
ResizeScaled	Resizes the control.
SetFocus	Gives the focus to the control.
Show	Shows the window in non-modal mode.
ShowDialog	A synonymous for the ShowModal method.
ShowModal	Shows the window in modal mode.
ShowPopup	Use that window to display a popup.

Inherited events

Activate	Raised when the window is activated.
Arrange	This event is raised when a container has just finished arranging its contents.
BeforeArrange	This event is raised just before a container arranges its contents.
Close	Raised when the window is going to be closed.
DblClick	Raised when the user quickly clicks twice on the control.
Deactivate	Raised when the window is deactivated.
Drag	This event is raised when the mouse enters the control during a drag & drop process.
DragLeave	This event is raised when the mouse leaves the control during a drag & drop operation.
DragMove	This event is raised while the mouse moves inside the control during a drag & drop process.
Drop	This event is raised when a drag is dropped in the control.
Enter	Raised when the mouse enters the control.
Font	This event is raised when the window font changes.
GotFocus	Raised when the control has got the focus.
Hide	Raised when the window is hidden.
Icon	This event is raised when the window icon changes.
KeyPress	Raised when a key is pressed while the control has the focus.
KeyRelease	Raised when a key is released while the control has the focus.
Leave	Raised when the mouse leaves the control.
LostFocus	Raised when the control has lost the focus.
Menu	Raised when the user clicks on the control with the right mouse button, or if it hits the `MENU` key.
MouseDown	Raised when a mouse button is pressed while the cursor is inside the control.
MouseDrag	This event is raised when a drag operation should be started.
MouseMove	Raised when the mouse moves inside the control while a mouse button is pressed.
MouseUp	Raised when a mouse button is depressed while the cursor is inside the control.
MouseWheel	This event is raised when the user moves or presses the mouse wheel while the mouse is inside the control.
Move	Raised when the window is moved.
NewChild	This event is raised when a new child Control has just been inserted into the container.
Open	Raised when the window is going to be visible for the first time.
Resize	Raised when the window is resized.
Show	Raised when the window is shown.
State	This event is raised when the Minimized, Maximized or FullScreen property changes.
Title	This event is raised when the window title changes.

Event management

By default, a form is its own event observer.

It means that all the events raised by the Form object are caught by event handlers defined in the form source code.

Automatic instance

Forms internally manages an automatic singleton instance.

It means that you can use the form class name as a form instance. The first time you do that, the internal singleton is automatically created.

You can force the creation of the automatic instance by using the Load method.

Startup form

A form can be the startup class of the project, as it implements a Main method. In that case, the automatic instance of the form is used.

Examples

' Instanciate the automatic instance, move it and show it MyForm.Move(90, 150) MyForm.Title = "Automatic instance" MyForm.Show ' Do the same thing with another instance of the same form Dim hForm As MyForm hForm = New MyForm hForm.Title = "Another instance" hForm.Move(110, 170) hForm.Show ... ' Event handler in the MyForm source code Public Sub Form_Open() Print "Showing form: "; Me.Title End

Warning about wayland...

There are some serious issues with wayland that you should be aware of with regards to positioning a "Top level" form.
For a standard GUI (open and close) application this may not present a problem but for a desktop background GUI with no border you may find issues if some kind of custom positioning is required.

It is currently NOT possible to position the main form by code on a wayland system.

wayland is in full control of form positioning and we can do nothing about it with code.

A Form with a border/titlebar can be moved as expected with a mouse click on the titlebar but you cannot move a form without a titlebar using code.

You also cannot save/restore From positions using Settings.Read() Setting.Write()

Form_Move() event will also not trigger. (except when the form opens)
Getting or Setting Form.X and Form.Y will not work. The X and Y values are not to the parent screen as wayland considers the applications main window to be the "top level" not the Screen so it's screen position cannot be determined.

Using Form.Move(X, Y) command will also not work.