com.luciad.input.mouse

Class MouseGestureRecognizer

java.lang.Object

com.luciad.input.mouse.MouseGestureRecognizer

All Implemented Interfaces:

AutoCloseable

public final class MouseGestureRecognizer
extends Object
implements AutoCloseable

This class generates high-level mouse gesture events from low-level input events.

High level events are subclasses of IInputEvent such as MouseClickEvent. Low levels are used to create those high level events and are dropped afterwards.

For example, a mouse pressed + (possibly multiple) mouse moved + a mouse released sequence is recognized as a drag gesture. A mouse pressed + a mouse released sequence is recognized as a click gesture. This class is useful when adding integration with a platform that does not provide these more high-level events.

A typical use of such a class is to wire it to a UI framework specific class (such as Qt , see QQuickMapObject in the sample code) and make the controller react to the high level event instead of every low level event the framework can fire.

The use of the MouseGestureRecognizer is optional. Events containing MouseButton#unknown() as the mouse button are not processed. A controller implementation can use custom conversion code if needed, for example if you want to manage the low level events yourself and create other high level IInputEvent instances.

The events passed to this class are expected to be defined in device independent pixels.

Constructor Summary

Constructors

Constructor and Description
MouseGestureRecognizer(IInputEventCallback callback) Creates a MouseGestureRecognizer that passes the generated high level IInputEvents to the given callback.

Method Summary

Modifier and Type	Method and Description
void	close()
protected void	finalize()
double	getDisplayScale()
double	getDpi()
ScreenDistance	getDragThreshold()
long	getMultiClickInterval() Returns the interval used to detect multiple clicks (default is 400 ms).
void	onKeyEvent(KeyEvent keyEvent) Entry point for the key events of the gesture recognizer.
void	onMouseMoveEvent(MouseMoveEvent mouseMoveEvent) Entry point for the mouse move events of the gesture recognizer.
void	onMousePressedEvent(MousePressedEvent mousePressedEvent) Entry point for the mouse pressed events of the gesture recognizer.
void	onMouseReleasedEvent(MouseReleasedEvent mouseReleasedEvent) Entry point for the mouse released events of the gesture recognizer.
void	onScrollEvent(ScrollEvent scrollEvent) Entry point for the scroll events of the gesture recognizer.
void	setDisplayScale(double scale) Set the display scale factor.
void	setDpi(double dpi) Set the display pixel density in dots per inch.
void	setDragThreshold(ScreenDistance threshold) Sets the screen distance that is used as threshold to detect if a drag is performed.
void	setMultiClickInterval(long interval) Set the interval used to detect multiple clicks (default is 400 ms).

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MouseGestureRecognizer

public MouseGestureRecognizer(@NotNull
                              IInputEventCallback callback)
                       throws NullPointerException

Creates a MouseGestureRecognizer that passes the generated high level IInputEvents to the given callback.

Parameters:

callback - the callback that receive generated IInputEvents. Can not be null.

Throws:

NullPointerException - If callback is null.

Method Detail

finalize

protected void finalize()

Overrides:

finalize in class Object

close

public void close()

Specified by:

close in interface AutoCloseable

onMousePressedEvent

public void onMousePressedEvent(@NotNull
                                MousePressedEvent mousePressedEvent)

Entry point for the mouse pressed events of the gesture recognizer.

Parameters:

mousePressedEvent - the low level mouse press event.

onMouseReleasedEvent

public void onMouseReleasedEvent(@NotNull
                                 MouseReleasedEvent mouseReleasedEvent)

Entry point for the mouse released events of the gesture recognizer.

Parameters:

mouseReleasedEvent - the low level mouse released event.

onMouseMoveEvent

public void onMouseMoveEvent(@NotNull
                             MouseMoveEvent mouseMoveEvent)

Entry point for the mouse move events of the gesture recognizer.

Parameters:

mouseMoveEvent - the low level mouse move event.

onScrollEvent

public void onScrollEvent(@NotNull
                          ScrollEvent scrollEvent)

Entry point for the scroll events of the gesture recognizer.

Parameters:

scrollEvent - the low level mouse scroll event.

onKeyEvent

public void onKeyEvent(@NotNull
                       KeyEvent keyEvent)

Entry point for the key events of the gesture recognizer.

Parameters:

keyEvent - the low level key event.

setMultiClickInterval

public void setMultiClickInterval(long interval)

Set the interval used to detect multiple clicks (default is 400 ms).

Parameters:

interval - the maximum time (in milliseconds) between multiple clicks. If the interval is set to 0, no multiple clicks will be detected.

getMultiClickInterval

public long getMultiClickInterval()

Returns the interval used to detect multiple clicks (default is 400 ms).

setDragThreshold

public void setDragThreshold(@NotNull
                             ScreenDistance threshold)

Sets the screen distance that is used as threshold to detect if a drag is performed.

It means that the mouse cursor has to move at least that amount of pixels before it can be detected as a drag gesture.

The default value in device independent pixels is 2 pixels.

Parameters:

threshold - the threshold

getDragThreshold

@NotNull
public ScreenDistance getDragThreshold()

Returns:

the screen distance that is used as a threshold to detect if a drag is performed. It means that the mouse cursor has to move at least that distance before it can be detected as a drag gesture.

setDpi

public void setDpi(double dpi)

Set the display pixel density in dots per inch.

If no value is provided, the platform standard pixel density is assumed.

Parameters:

dpi - the pixel density in dots per inch

getDpi

public double getDpi()

Returns:

the display pixel density, expressed in dots per inch.

setDisplayScale

public void setDisplayScale(double scale)

Set the display scale factor.

If no value is provided, a scale factor of 1.0 is assumed.

Parameters:

scale - the display scale factor (adimensional scale value)

getDisplayScale

public double getDisplayScale()

Returns:

the display scale factor.