Command Manager in WPF Diagram

18 Nov 20187 minutes to read

The CommandManager is used to map user gestures (keyboard and mouse) to Diagram commands and helps to include new gesture commands in WPF Diagram.

The CommandManager can be accessed through the Diagram instance and is used to manage built-in and custom gesture commands.

C#

// Initialize the Diagram
SfDiagram diagram = new SfDiagram();

// Access the CommandManager
CommandManager commandManager = diagram.CommandManager;

Refer to the following table for built-in commands with Key gesture and Mouse gesture.

List of Commands and Key Gestures:

Command	Key	Key Modifiers
Copy	C	Control
Cut	X	Control
Paste	V	Control
Duplicate	D	Control
Undo	Z	Control
Redo	Y	Control
MoveLeft	Left
MoveRight	Right
MoveUp	Up
MoveDown	Down
Delete	Delete
SelectAll	A	Control
Group	G	Control
UnGroup	U	Control+Shift
SendToBack	[	Control+Shift
SendBackward	[	Control
BringToFront	]	Control+Shift
BringForward	]	Control

List of Commands and Mouse Gestures with Parameters

Command	Key	KeyModifier	Parameter
Zoom	-	Control	new ZoomPositionParameter { ZoomCommand=ZoomCommand.ZoomOut}
Zoom	+	Control	new ZoomPositionParameter { ZoomCommand = ZoomCommand.ZoomIn }
Reset	0	Control	new ResetParameter { Reset = Diagram.Reset.ZoomPan }
FitToPage	W	Control + Shift	new FitToPageParameter { FitToPage = Diagram.FitToPage.FitToPage, Margin = new Thickness(20) }

List of Commands and Mouse Gestures with Parameters

Command	Scroll State	Parameter
Vertical Scroll using ‘Zoom’ command	Scroll	new ZoomPointerParameter { ZoomCommand = ZoomCommand.VerticalScroll}

List of Commands and Key and Mouse Gestures with Parameter

Command	KeyModifier	Scroll State	Parameter
Horizontal Scroll using ‘Zoom’ command	Shift	Scroll	new ZoomPointerParameter { ZoomCommand = ZoomCommand.HorizontalScroll}
Zoom	Control	Scroll	new ZoomPointerParameter { ZoomCommand = ZoomCommand.ZoomIn	ZoomCommand.ZoomOut}

When multiple commands are registered for the same key or mouse gesture, gesture conflicts can occur. In such cases, handle the command execution logic to determine which command should be executed for the registered gesture.

The built-in key and mouse gestures are scoped to the SfDiagram control and are available when the diagram has input focus. These gestures do not apply globally across the application.

Custom command

CommandManager provides support to define custom commands. The custom commands are executed when the specified key gesture is recognized. The GestureCommand and Gesture help you to define a custom command.

In the following example, Save represents a user-defined ICommand instance that must be created before registering it with the CommandManager.

The following code example represents how to define a custom Save command (Control + S).

C#

// To define the mouse and keyboard gesture for the commands
GestureCommand saveGesture = new GestureCommand()
{
    // Define the command with custom command
    Command = Save,
    // Define gesture for custom Command
    Gesture = new Gesture
    {
        KeyModifiers = ModifierKeys.Control,
        KeyState = KeyStates.Down,
        Key = Key.S
    },
    // Parameter for command - file name for save command
    Parameter = "diagram"
};

// Add the custom command to the existing command collection.
diagram.CommandManager.Commands.Add(saveGesture);

View sample in GitHub

See Also

How to map the custom commands to existing gestures (keyboard shortcuts and mouse)?

How to add a custom gesture command in the WPF Diagram ?