Class Toplevel

Toplevel views can be modally executed. They are used for both an application's main view (filling the entire screeN and for pop-up views such as Dialog, MessageBox, and Wizard.
Inheritance
System.Object
Responder
View
Toplevel
Border.ToplevelContainer
Window
Implements
System.IDisposable
System.ComponentModel.ISupportInitializeNotification
System.ComponentModel.ISupportInitialize
Remarks

Toplevels can be modally executing views, started by calling Run(Toplevel, Func<Exception, Boolean>). They return control to the caller when RequestStop(Toplevel) has been called (which sets the Running property to false).

A Toplevel is created when an application initializes Terminal.Gui by calling Init(ConsoleDriver, IMainLoopDriver). The application Toplevel can be accessed via Top. Additional Toplevels can be created and run (e.g. Dialogs. To run a Toplevel, create the Toplevel and call Run(Toplevel, Func<Exception, Boolean>).

Toplevels can also opt-in to more sophisticated initialization by implementing System.ComponentModel.ISupportInitialize. When they do so, the System.ComponentModel.ISupportInitialize.BeginInit and System.ComponentModel.ISupportInitialize.EndInit methods will be called before running the view. If first-run-only initialization is preferred, the System.ComponentModel.ISupportInitializeNotification can be implemented too, in which case the System.ComponentModel.ISupportInitialize methods will only be called if System.ComponentModel.ISupportInitializeNotification.IsInitialized is false. This allows proper View inheritance hierarchies to override base class layout code optimally by doing so only on first run, instead of on every run.

Inherited Members
Namespace: Terminal.Gui
Assembly: Terminal.Gui.dll
Syntax
public class Toplevel : View

Constructors

Toplevel()

Initializes a new instance of the Toplevel class with Computed layout, defaulting to full screen.
Declaration
public Toplevel()

Toplevel(Rect)

Initializes a new instance of the Toplevel class with the specified Absolute layout.
Declaration
public Toplevel(Rect frame)
Parameters
Type Name Description
Rect frame A superview-relative rectangle specifying the location and size for the new Toplevel

Properties

CanFocus

Gets or sets a value indicating whether this Toplevel can focus.
Declaration
public override bool CanFocus { get; }
Property Value
Type Description
System.Boolean true if can focus; otherwise, false.
Overrides

IsMdiChild

Gets or sets if this Toplevel is a Mdi child.
Declaration
public bool IsMdiChild { get; }
Property Value
Type Description
System.Boolean

IsMdiContainer

Gets or sets if this Toplevel is a Mdi container.
Declaration
public bool IsMdiContainer { get; set; }
Property Value
Type Description
System.Boolean

MenuBar

Gets or sets the menu for this Toplevel.
Declaration
public virtual MenuBar MenuBar { get; set; }
Property Value
Type Description
MenuBar

Modal

Determines whether the Toplevel is modal or not. If set to false (the default):
  • ProcessKey(KeyEvent) events will propagate keys upwards.
  • The Toplevel will act as an embedded view (not a modal/pop-up).
If set to true:
Declaration
public bool Modal { get; set; }
Property Value
Type Description
System.Boolean

Running

Gets or sets whether the MainLoop for this Toplevel is running or not.
Declaration
public bool Running { get; set; }
Property Value
Type Description
System.Boolean

StatusBar

Gets or sets the status bar for this Toplevel.
Declaration
public virtual StatusBar StatusBar { get; set; }
Property Value
Type Description
StatusBar

Methods

Add(View)

Adds a subview (child) to this view.
Declaration
public override void Add(View view)
Parameters
Type Name Description
View view
Overrides

Create()

Convenience factory method that creates a new Toplevel with the current terminal dimensions.
Declaration
public static Toplevel Create()
Returns
Type Description
Toplevel The created Toplevel.

GetTopMdiChild(Type, String[])

Gets the current visible Toplevel Mdi child that matches the arguments pattern.
Declaration
public View GetTopMdiChild(Type type = null, string[] exclude = null)
Parameters
Type Name Description
System.Type type The type.
System.String[] exclude The strings to exclude.
Returns
Type Description
View The matched view.

MouseEvent(MouseEvent)

Method invoked when a mouse event is generated
Declaration
public override bool MouseEvent(MouseEvent mouseEvent)
Parameters
Type Name Description
MouseEvent mouseEvent Contains the details about the mouse event.
Returns
Type Description
System.Boolean true, if the event was handled, false otherwise.
Overrides

MoveNext()

Move to the next Mdi child from the MdiTop.
Declaration
public virtual void MoveNext()

MovePrevious()

Move to the previous Mdi child from the MdiTop.
Declaration
public virtual void MovePrevious()

OnAlternateBackwardKeyChanged(Key)

Virtual method to invoke the AlternateBackwardKeyChanged event.
Declaration
public virtual void OnAlternateBackwardKeyChanged(Key oldKey)
Parameters
Type Name Description
Key oldKey

OnAlternateForwardKeyChanged(Key)

Virtual method to invoke the AlternateForwardKeyChanged event.
Declaration
public virtual void OnAlternateForwardKeyChanged(Key oldKey)
Parameters
Type Name Description
Key oldKey

OnKeyDown(KeyEvent)

Method invoked when a key is pressed.
Declaration
public override bool OnKeyDown(KeyEvent keyEvent)
Parameters
Type Name Description
KeyEvent keyEvent Contains the details about the key that produced the event.
Returns
Type Description
System.Boolean true if the event was handled
Overrides

OnKeyUp(KeyEvent)

Method invoked when a key is released.
Declaration
public override bool OnKeyUp(KeyEvent keyEvent)
Parameters
Type Name Description
KeyEvent keyEvent Contains the details about the key that produced the event.
Returns
Type Description
System.Boolean true if the event was handled
Overrides

OnLoaded()

Called from Begin(Toplevel) before the Toplevel redraws for the first time.
Declaration
public virtual void OnLoaded()

OnQuitKeyChanged(Key)

Virtual method to invoke the QuitKeyChanged event.
Declaration
public virtual void OnQuitKeyChanged(Key oldKey)
Parameters
Type Name Description
Key oldKey

PositionCursor()

Positions the cursor in the right position based on the currently focused view in the chain.
Declaration
public override void PositionCursor()
Overrides

PositionToplevel(Toplevel)

Virtual method enabling implementation of specific positions for inherited Toplevel views.
Declaration
public virtual void PositionToplevel(Toplevel top)
Parameters
Type Name Description
Toplevel top The toplevel.

ProcessColdKey(KeyEvent)

This method can be overwritten by views that want to provide accelerator functionality (Alt-key for example), but without interefering with normal ProcessKey behavior.
Declaration
public override bool ProcessColdKey(KeyEvent keyEvent)
Parameters
Type Name Description
KeyEvent keyEvent Contains the details about the key that produced the event.
Returns
Type Description
System.Boolean
Overrides

ProcessKey(KeyEvent)

If the view is focused, gives the view a chance to process the keystroke.
Declaration
public override bool ProcessKey(KeyEvent keyEvent)
Parameters
Type Name Description
KeyEvent keyEvent Contains the details about the key that produced the event.
Returns
Type Description
System.Boolean
Overrides

Redraw(Rect)

Redraws this view and its subviews; only redraws the views that have been flagged for a re-display.
Declaration
public override void Redraw(Rect bounds)
Parameters
Type Name Description
Rect bounds The bounds (view-relative region) to redraw.
Overrides

Remove(View)

Removes a subview added via Add(View) or Add(View[]) from this View.
Declaration
public override void Remove(View view)
Parameters
Type Name Description
View view
Overrides

RemoveAll()

Removes all subviews (children) added via Add(View) or Add(View[]) from this View.
Declaration
public override void RemoveAll()
Overrides

RequestStop()

Stops and closes this Toplevel. If this Toplevel is the top-most Toplevel, RequestStop(Toplevel) will be called, causing the application to exit.
Declaration
public virtual void RequestStop()

RequestStop(Toplevel)

Stops and closes the Toplevel specified by top. If top is the top-most Toplevel, RequestStop(Toplevel) will be called, causing the application to exit.
Declaration
public virtual void RequestStop(Toplevel top)
Parameters
Type Name Description
Toplevel top The toplevel to request stop.

ShowChild(Toplevel)

Shows the Mdi child indicated by top, setting it as Current.
Declaration
public virtual bool ShowChild(Toplevel top = null)
Parameters
Type Name Description
Toplevel top The Toplevel.
Returns
Type Description
System.Boolean true if the toplevel can be shown or false if not.

WillPresent()

Invoked by Begin(Toplevel) as part of Run(Toplevel, Func<Exception, Boolean>) after the views have been laid out, and before the views are drawn for the first time.
Declaration
public virtual void WillPresent()

Events

Activate

Invoked when the Toplevel Application.RunState becomes the Current Toplevel.
Declaration
public event Action<Toplevel> Activate
Event Type
Type Description
System.Action<Toplevel>

AllChildClosed

Invoked when the last child of the Toplevel Application.RunState is closed from by Terminal.Gui.Application.End(Terminal.Gui.View).
Declaration
public event Action AllChildClosed
Event Type
Type Description
System.Action

AlternateBackwardKeyChanged

Invoked when the AlternateBackwardKey is changed.
Declaration
public event Action<Key> AlternateBackwardKeyChanged
Event Type
Type Description
System.Action<Key>

AlternateForwardKeyChanged

Invoked when the AlternateForwardKey is changed.
Declaration
public event Action<Key> AlternateForwardKeyChanged
Event Type
Type Description
System.Action<Key>

ChildClosed

Invoked when a child of the Toplevel Application.RunState is closed by Terminal.Gui.Application.End(Terminal.Gui.View).
Declaration
public event Action<Toplevel> ChildClosed
Event Type
Type Description
System.Action<Toplevel>

ChildLoaded

Invoked when a child Toplevel's Application.RunState has been loaded.
Declaration
public event Action<Toplevel> ChildLoaded
Event Type
Type Description
System.Action<Toplevel>

ChildUnloaded

Invoked when a cjhild Toplevel's Application.RunState has been unloaded.
Declaration
public event Action<Toplevel> ChildUnloaded
Event Type
Type Description
System.Action<Toplevel>

Closed

Invoked when the Toplevel's Application.RunState is closed by Terminal.Gui.Application.End(Terminal.Gui.View).
Declaration
public event Action<Toplevel> Closed
Event Type
Type Description
System.Action<Toplevel>

Closing

Invoked when the Toplevel's Application.RunState is being closed by RequestStop(Toplevel).
Declaration
public event Action<ToplevelClosingEventArgs> Closing
Event Type
Type Description
System.Action<ToplevelClosingEventArgs>

Deactivate

Invoked when the ToplevelApplication.RunState ceases to be the Current Toplevel.
Declaration
public event Action<Toplevel> Deactivate
Event Type
Type Description
System.Action<Toplevel>

Loaded

Invoked when the Toplevel Application.RunState has begin loaded. A Loaded event handler is a good place to finalize initialization before calling RunLoop(Application.RunState, Boolean).
Declaration
public event Action Loaded
Event Type
Type Description
System.Action

QuitKeyChanged

Invoked when the QuitKey is changed.
Declaration
public event Action<Key> QuitKeyChanged
Event Type
Type Description
System.Action<Key>

Ready

Invoked when the Toplevel MainLoop has started it's first iteration. Subscribe to this event to perform tasks when the Toplevel has been laid out and focus has been set. changes.

A Ready event handler is a good place to finalize initialization after calling Run(Func<Exception, Boolean>) on this Toplevel.

Declaration
public event Action Ready
Event Type
Type Description
System.Action

Resized

Invoked when the terminal has been resized. The new Size of the terminal is provided.
Declaration
public event Action<Size> Resized
Event Type
Type Description
System.Action<Size>

Unloaded

Invoked when the Toplevel Application.RunState has been unloaded. A Unloaded event handler is a good place to dispose objects after calling End(Application.RunState).
Declaration
public event Action Unloaded
Event Type
Type Description
System.Action

Implements

System.IDisposable
System.ComponentModel.ISupportInitializeNotification
System.ComponentModel.ISupportInitialize