MEvent Class Reference

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Detailed Description

System event information.

The MEvent class is used for querying system events such as mouse presses.

Events are handled by an MPxContext derived class in which MEvents are passed and can be accessed.

Since Maya has default actions for several events, only a subset are avalaible through the API. The events that can be accessed are:

• buttonPress - mouse button press event (left & middle only)
• buttonRelease - mouse buttons release event (left & middle only)
• mouseDrag - mouse button drag event (left & middle only)
• hold - mouse button hold event (left & middle only)
• deleteEvent - delete/backspace key event
• commandCompletion - complete key event

Several modifiers for events are also accessible through the API. Modifiers are actions that occur during an event. For example, holding down the shift key while pressing a mouse button causes a button press event to occur with a shift modifier.

A modifier can be used to determine if two mouse events occur simulaneously. The second mouse event is registered as a modifier in the hold event of the first mouse button. So if you wanted to determine if both the left and middle buttons are pressed then you would query the modifier in the hold event of the first mouse button using the isModifierMiddleMouseButton() and isModifierLeftMouseButton() methods.

Examples:

componentScaleManip.cpp, customAttrManip.cpp, helixTool.cpp, lassoTool.cpp, marqueeTool.cpp, meshRemapTool.cpp, meshRemapTool.h, meshReorderTool.cpp, meshReorderTool.h, moveManip.cpp, moveNumericTool.cpp, moveTool.cpp, rotateManip.cpp, and surfaceBumpManip.cpp.

#include <MEvent.h>

List of all members.

Public Types
enum	ModifierType { shiftKey = 1<<0, controlKey = 1<<2 }
	Modifier key types. More...
enum	MouseButtonType { kLeftMouse = 1<<6, kMiddleMouse = kLeftMouse<<1 }
	Mouse button types. More...
Public Member Functions
	MEvent ()
	Constructor.
virtual	~MEvent ()
	Destructor.
MStatus	getPosition (short &x_pos, short &y_pos) const
	Get the location of the event in view co-ordinates.
MStatus	setPosition (short x_pos, short y_pos)
	set the location of the event to the specified location.
MStatus	getWindowPosition (short &x_pos, short &y_pos) const
	This routine is used by responders to query the position of the pointer when the event occurred.
MouseButtonType	mouseButton (MStatus *ReturnStatus=NULL) const
	Get the mouse button of the last event.
bool	isModifierKeyRelease (MStatus *ReturnStatus=NULL) const
	Was a modifier key released.
ModifierType	modifiers (MStatus *ReturnStatus=NULL) const
	This routine is used by responders to find the state of the modifiers during the event.
MStatus	setModifiers (const ModifierType &modType)
	set the event modifiers.
bool	isModifierNone (MStatus *ReturnStatus=NULL) const
	Determines if there are any modifiers for this event.
bool	isModifierShift (MStatus *ReturnStatus=NULL) const
	return state of shift key.
bool	isModifierControl (MStatus *ReturnStatus=NULL) const
	return state of control key.
bool	isModifierLeftMouseButton (MStatus *ReturnStatus=NULL) const
	Return the state of the left mouse button.
bool	isModifierMiddleMouseButton (MStatus *ReturnStatus=NULL) const
	Return the state of the middle mouse button.
Static Public Member Functions
static const char *	className ()
	Returns the name of this class.

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Member Enumeration Documentation

enum ModifierType

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Modifier key types.

Enumerator:

shiftKey	Search for all occurrences
controlKey	Search for all occurrences

enum MouseButtonType

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Mouse button types.

Enumerator:

kLeftMouse	Search for all occurrences
kMiddleMouse	Search for all occurrences

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Member Function Documentation

MStatus getPosition	(	short &	x_pos,
		short &	y_pos
	)		const

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Get the location of the event in view co-ordinates.

The origin is at the lower left corner of the window.

Parameters:

[out]	x_pos	storage for horizonal position
[out]	y_pos	storage for vertical position

Returns:

Status Code

Status Codes:

• MS::kSuccess The method was successful.
• MS::kFailure Object error.

MStatus setPosition	(	short	x_pos,
		short	y_pos
	)

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set the location of the event to the specified location.

The origin is at the lower left corner of the window.

Parameters:

[in]	x_pos	horizonal position to set
[in]	y_pos	vertical position to set

Returns:

Status Code

Status Codes:

• MS::kSuccess The method was successful.
• MS::kFailure Object error.

MStatus getWindowPosition	(	short &	x_pos,
		short &	y_pos
	)		const

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This routine is used by responders to query the position of the pointer when the event occurred.

It is given in screen co-ordinates.

The origin is at the upper left corner of the window.

Parameters:

[out]	x_pos	storage for horizonal position
[out]	y_pos	storage for vertical position

Returns:

Status Code

Status Codes:

• MS::kSuccess The method was successful.
• MS::kFailure Object error.

MEvent::MouseButtonType mouseButton

(

MStatus *

ReturnStatus = NULL

)

const

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Get the mouse button of the last event.

Parameters:

[out]

ReturnStatus

Returns:

Mouse button from last event.

Status Codes:

• MS::kSuccess The method was successful.
• MS::kFailure Object error.

bool isModifierKeyRelease

(

MStatus *

ReturnStatus = NULL

)

const

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Was a modifier key released.

Parameters:

[out]

ReturnStatus

Returns:

• true A modifier key was released.
• false No modifier key was released.

Status Codes:

• MS::kSuccess The method was successful.
• MS::kFailure Object error.

MEvent::ModifierType modifiers

(

MStatus *

ReturnStatus = NULL

)

const

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This routine is used by responders to find the state of the modifiers during the event.

Parameters:

[out]

ReturnStatus

Returns:

Modifier type.

Status Codes:

• MS::kSuccess The method was successful.
• MS::kFailure Object error.

MStatus setModifiers

(

const ModifierType &

modType

)

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set the event modifiers.

Parameters:

[in]

modType

Type of modifier to set to.

Returns:

Status Code

Status Codes:

• MS::kSuccess The method was successful.
• MS::kFailure Object error.

bool isModifierNone

(

MStatus *

ReturnStatus = NULL

)

const

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Determines if there are any modifiers for this event.

Parameters:

[out]

ReturnStatus

Returns:

• true There are modifiers for this event.
• false There are NO modifiers for this event.

Status Codes:

• MS::kSuccess The method was successful.
• MS::kFailure Object error.

bool isModifierShift

(

MStatus *

ReturnStatus = NULL

)

const

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return state of shift key.

Parameters:

[out]

ReturnStatus

Returns:

• true Shift key triggered this event.
• false The shift key did not cause this event.

Status Codes:

• MS::kSuccess The method was successful.
• MS::kFailure Object error.

Examples:

lassoTool.cpp, and marqueeTool.cpp.

bool isModifierControl

(

MStatus *

ReturnStatus = NULL

)

const

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return state of control key.

Parameters:

[out]

ReturnStatus

Returns:

• true Control key triggered this event.
• false The control key did not cause this event.

Status Codes:

• MS::kSuccess The method was successful.
• MS::kFailure Object error.

Examples:

lassoTool.cpp, and marqueeTool.cpp.

bool isModifierLeftMouseButton

(

MStatus *

ReturnStatus = NULL

)

const

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Return the state of the left mouse button.

This method is only valid when called in the hold event for another mouse press.

Parameters:

[out]

ReturnStatus

Returns:

• true Left mouse button triggered this event.
• false The left moust button did not cause this event.

Status Codes:

• MS::kSuccess The method was successful.
• MS::kFailure Object error.

bool isModifierMiddleMouseButton

(

MStatus *

ReturnStatus = NULL

)

const

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Return the state of the middle mouse button.

This method is only valid when called in the hold event for another mouse press.

Parameters:

[out]

ReturnStatus

Returns:

• true Middle mouse button triggered this event.
• false The middle moust button did not cause this event.

Status Codes:

• MS::kSuccess The method was successful.
• MS::kFailure Object error.

const char * className

(

)

[static]

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Returns the name of this class.

Returns:

The name of this class.