Class InputEvent

Namespace

Northwoods.Go

Assembly

Northwoods.GoDiagram.WinForms.dll

An InputEvent represents a mouse or keyboard or touch event.

public class InputEvent

Inheritance

object

InputEvent

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Remarks

The principal properties hold information about a particular input event. These properties include the DocumentPoint at which a mouse event occurred in document coordinates, the corresponding point in view/element coordinates, ViewPoint, the Key for keyboard events, and the Modifiers and Button at the time. Additional descriptive properties include ClickCount, Delta, Timestamp, and the source event Event (if available).

Many of its properties are provided for convenient access to the state of the input event, such as asking whether the Control key was held down at the time, or the TargetElement (a GraphObject) that the mouse was over .

When real events fire on the Diagram, InputEvents are created automatically set update the value of LastInput. These events set the value of Event with the backing browser-defined Event, which may be a MouseEvent, KeyboardEvent, PointerEvent, TouchEvent, and so on.

InputEvents backed by MouseEvents set both Button, the button that caused the action, and Buttons, the set of buttons currently pressed after the action has happened. By default a user-created InputEvent sets Button and Buttons as if the event was a left-click.

You can create InputEvents and set the value of LastInput in order to simulate user actions in tools.

Constructors

InputEvent()

The InputEvent class constructor produces an empty InputEvent.

public InputEvent()

Remarks

You should never need to call this constructor. But if you do, you must first set Diagram to the Diagram before any other use.

InputEvent(InputEvent)

Make a copy of an InputEvent.

public InputEvent(InputEvent evt)

Parameters

evt InputEvent

Properties

Alt

Gets or sets whether the alt key is being held down.

public bool Alt { get; set; }

Property Value

bool

Remarks

This is true if the key was pressed at the time of the event.

See Also

Modifiers

Control

Shift

Meta

Button

Gets or sets the numerical value representing the mouse button that caused this event.

public double Button { get; set; }

Property Value

double

Remarks

Only one mouse button can cause an event at a time, but the set of all buttons currently pressed is kept in Buttons.

This property describes nothing during a mousemove event, since no button press causes the event. Instead, use the convenience properties Left, Middle, or Right, or use the value of Buttons to determine which mouse buttons are held during mousemove events.

Common values for this property:

• 0: left mouse button
• 1: middle mouse button
• 2: right mouse button

Other values are possible if the mouse has additional buttons.

If there is no associated Event, setting this also sets the Buttons flags to only this button.

This property is valid if this is a mouse event.

See Also

Buttons

Left

Middle

Right

Buttons

Gets or sets the set of buttons that are currently being held down.

public long Buttons { get; set; }

Property Value

long

Remarks

If this is a mouseup event, this set of buttons does not include the button that was just released, which will be the value of Button.

Common values for this property:

• 0: not holding down any button
• 1: left mouse button
• 2: right mouse button
• 3: both left and right mouse buttons
• 4: middle mouse button
• 5: middle and left mouse buttons
• 6: middle and right mouse buttons
• 7: all three common mouse buttons

Other values are possible if the mouse has additional buttons.

This property is valid if this is a mouse event.

See Also

Button

Left

Middle

Right

ClickCount

Gets or sets whether this event represents a click or a double-click.

public double ClickCount { get; set; }

Property Value

double

Remarks

It is zero if not a click; one if a single-click; two if a double-click. This property is valid if this is a mouse event.

Control

Gets or sets whether the control key is being held down.

public bool Control { get; set; }

Property Value

bool

Remarks

This is true if the key was pressed at the time of the event.

See Also

Modifiers

Shift

Alt

Meta

Delta

Gets or sets the amount of change associated with a mouse-wheel rotation.

public double Delta { get; set; }

Property Value

double

Remarks

It is an abstract double, either positive or negative. This property is valid if this is a mouse-wheel event.

Diagram

Gets or sets the source diagram associated with the event.

public Diagram Diagram { get; set; }

Property Value

Diagram

DocumentPoint

Gets or sets the point at which this input event occurred, in document coordinates.

public Point DocumentPoint { get; set; }

Property Value

Point

Remarks

The Point is in document coordinates, the same as the Position for Parts in the diagram. This should be valid for mouse events. For keyboard events, this is the last available mouse point.

See Also

ViewPoint

TransformViewToDoc(Point)

TransformDocToView(Point)

Down

Gets or sets whether the InputEvent represents a mouse-down or a key-down event.

public bool Down { get; set; }

Property Value

bool

Remarks

The default value is false.

Event

Gets or sets the platform's user-agent-supplied event for this event.

public object Event { get; set; }

Property Value

object

Remarks

It may be null if no underlying event exists.

See Also

Timestamp

Handled

Gets or sets whether an InputEvent that applies to a GraphObject and bubbles up the chain of containing Panels is stopped from continuing up the chain.

public bool Handled { get; set; }

Property Value

bool

Remarks

Some event handlers may set this to true to avoid getting any behavior from the containing Panels. The default value is false.

IsMultiTouch

This property is true when the InputEvent is caused by a touch event that registered more than one touch.

public bool IsMultiTouch { get; set; }

Property Value

bool

See Also

IsTouchEvent

IsTouchEvent

This read-only property is true when the InputEvent is caused by a touch event.

public bool IsTouchEvent { get; }

Property Value

bool

See Also

IsMultiTouch

Key

Gets or sets the key pressed or released as this event. If it is a letter, the value is the uppercase version.

public string Key { get; set; }

Property Value

string

Remarks

This property is valid if this is a keyboard event.

Left

Gets or sets whether the logical left mouse button is being held down.

public bool Left { get; set; }

Property Value

bool

Remarks

This is true if the button was pressed at the time of the event.

If this InputEvent was a "mouseup" or "mousedown", this property uses the value of Button. Otherwise, it uses the value of Buttons.

When setting, this sets the value of Buttons.

See Also

Button

Middle

Right

Meta

Gets or sets whether the meta key is being held down.

public bool Meta { get; set; }

Property Value

bool

Remarks

This is true if the key was pressed at the time of the event.

See Also

Modifiers

Control

Shift

Alt

Middle

Gets or sets whether the logical middle mouse button is being held down.

public bool Middle { get; set; }

Property Value

bool

Remarks

This is true if the button was pressed at the time of the event.

See Also

Button

Left

Right

Modifiers

Gets or sets the modifier keys that were used with the mouse or keyboard event.

public int Modifiers { get; set; }

Property Value

int

Remarks

The int will be a combination of flags representing Control, Shift, Alt or Meta.

See Also

Control

Shift

Alt

Meta

Right

Gets or sets whether the logical right mouse button is being held down.

public bool Right { get; set; }

Property Value

bool

Remarks

This is true if the button was pressed at the time of the event.

See Also

Button

Left

Middle

Shift

Gets or sets whether the shift key is being held down.

public bool Shift { get; set; }

Property Value

bool

Remarks

This is true if the key was pressed at the time of the event.

See Also

Modifiers

Control

Alt

Meta

TargetDiagram

Gets or sets the diagram associated with the canvas that the event is currently targeting.

public Diagram TargetDiagram { get; set; }

Property Value

Diagram

TargetElement

Gets or sets the GraphObject that is at the current mouse point, if any.

public GraphObject TargetElement { get; set; }

Property Value

GraphObject

Remarks

For those events that are bubbled up the chain of parent Panels, this property provides access to the original GraphObject where the input event occurred.

See Also

Handled

Timestamp

Gets or sets the time at which the event occurred, in milliseconds.

public DateTime Timestamp { get; set; }

Property Value

DateTime

Up

Gets or sets whether the InputEvent represents a mouse-up or a key-up event.

public bool Up { get; set; }

Property Value

bool

Remarks

The default value is false.

ViewPoint

Gets or sets the point at which this input event occurred.

public Point ViewPoint { get; set; }

Property Value

Point

Remarks

The Point is in view coordinates within the viewport, not in document coordinates. This should be valid for mouse events. For keyboard events, this is the last available mouse point.

See Also

DocumentPoint

TransformViewToDoc(Point)

TransformDocToView(Point)