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java.lang.Objectcom.trolltech.qt.QSignalEmitter
com.trolltech.qt.QtJambiObject
com.trolltech.qt.gui.QLineF
public class QLineF
The QLineF class provides a two-dimensional vector using floating point precision.
A QLineF describes a finite length line (or line segment) on a two-dimensional surface. QLineF defines the start and end points of the line using floating point accuracy for coordinates. Use the toLine function to retrieve an integer based copy of this line.
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The positions of the line's start and end points can be retrieved using the p1, x1, y1, p2, x2, and y2 functions. The dx and dy functions return the horizontal and vertical components of the line, respectively.
The line's length can be retrieved using the length function, and altered using the setLength function. Use the isNull function to determine whether the QLineF represents a valid line or a null line.
The intersect() function determines the IntersectType for this line and a given line, while the angle function returns the angle between the lines. In addition, the unitVector function returns a line that has the same starting point as this line, but with a length of only 1, while the normalVector function returns a line that is perpendicular to this line with the same starting point and length.
Finally, the line can be translated a given offset using the translate function, and can be traversed using the pointAt function.
Nested Class Summary | |
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static class |
QLineF.IntersectType
Describes the intersection between two lines. |
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter |
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QSignalEmitter.AbstractSignal, QSignalEmitter.Signal0, QSignalEmitter.Signal1<A>, QSignalEmitter.Signal2<A,B>, QSignalEmitter.Signal3<A,B,C>, QSignalEmitter.Signal4<A,B,C,D>, QSignalEmitter.Signal5<A,B,C,D,E>, QSignalEmitter.Signal6<A,B,C,D,E,F>, QSignalEmitter.Signal7<A,B,C,D,E,F,G>, QSignalEmitter.Signal8<A,B,C,D,E,F,G,H>, QSignalEmitter.Signal9<A,B,C,D,E,F,G,H,I> |
Constructor Summary | |
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QLineF()
Constructs a null line. |
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QLineF(double x1,
double y1,
double x2,
double y2)
Constructs a line object that represents the line between (x1, y1) and (x2, y2). |
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QLineF(QLine line)
Construct a QLineF object from the given integer-based line. |
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QLineF(QPointF pt1,
QPointF pt2)
Constructs a line object that represents the line between pt1 and pt2. |
Method Summary | |
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double |
angle(QLineF l)
Returns the angle (in degrees) between this line and the given l, taking the direction of the lines into account. |
double |
dx()
Returns the horizontal component of the line's vector. |
double |
dy()
Returns the vertical component of the line's vector. |
boolean |
equals(java.lang.Object other)
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static QLineF |
fromNativePointer(QNativePointer nativePointer)
This function returns the QLineF instance pointed to by nativePointer |
QLineF.IntersectType |
intersect(QLineF line,
QPointF intersectionPoint)
Returns a value indicating whether or not this line intersects with the given line. |
boolean |
isNull()
Returns true if the line is not set up with valid start and end point; otherwise returns false. |
double |
length()
Returns the length of the line. |
static QNativePointer |
nativePointerArray(QLineF[] array)
This function returns a QNativePointer that is pointing to the specified QLineF array. |
QLineF |
normalVector()
Returns a line that is perpendicular to this line with the same starting point and length. |
QPointF |
p1()
Returns the line's start point. |
QPointF |
p2()
Returns the line's end point. |
QPointF |
pointAt(double t)
Returns the point at the parameterized position specified by t. |
void |
readFrom(QDataStream arg__1)
Reads a QLineF from arg__1. |
void |
setLength(double len)
Sets the length of the line to the given len. |
QLine |
toLine()
Returns an integer based copy of this line. |
void |
translate(double dx,
double dy)
Translates this line the distance specified by dx and dy. |
void |
translate(QPointF p)
Translates this line by the given p. |
QLineF |
unitVector()
Returns the unit vector for this line, i.e a line starting at the same point as this line with a length of 1.0. |
void |
writeTo(QDataStream arg__1)
Writes thisQLineF to arg__1. |
double |
x1()
Returns the x-coordinate of the line's start point. |
double |
x2()
Returns the x-coordinate of the line's end point. |
double |
y1()
Returns the y-coordinate of the line's start point. |
double |
y2()
Returns the y-coordinate of the line's end point. |
Methods inherited from class com.trolltech.qt.QtJambiObject |
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dispose, disposed, finalize, reassignNativeResources, tr, tr, tr |
Methods inherited from class com.trolltech.qt.QSignalEmitter |
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blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread |
Methods inherited from class java.lang.Object |
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clone, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Methods inherited from interface com.trolltech.qt.QtJambiInterface |
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disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership |
Constructor Detail |
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public QLineF(double x1, double y1, double x2, double y2)
Constructs a line object that represents the line between (x1, y1) and (x2, y2).
public QLineF(QPointF pt1, QPointF pt2)
Constructs a line object that represents the line between pt1 and pt2.
public QLineF(QLine line)
Construct a QLineF object from the given integer-based line.
public QLineF()
Constructs a null line.
Method Detail |
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public final double angle(QLineF l)
Returns the angle (in degrees) between this line and the given l, taking the direction of the lines into account. If the lines do not intersect within their range, it is the intersection point of the extended lines that serves as origo (see QLineF::UnboundedIntersection).
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When the lines are parallel, this function returns 0 if they have the same direction; otherwise it returns 180.
public final double dx()
Returns the horizontal component of the line's vector.
public final double dy()
Returns the vertical component of the line's vector.
public final boolean isNull()
Returns true if the line is not set up with valid start and end point; otherwise returns false.
public final double length()
Returns the length of the line.
public final QLineF normalVector()
Returns a line that is perpendicular to this line with the same starting point and length.
public final void writeTo(QDataStream arg__1)
public final void readFrom(QDataStream arg__1)
public final QPointF p1()
Returns the line's start point.
public final QPointF p2()
Returns the line's end point.
public final QPointF pointAt(double t)
Returns the point at the parameterized position specified by t. The function returns the line's start point if t = 0, and its end point if t = 1.
public final void setLength(double len)
Sets the length of the line to the given len. If the line is a null line, the length will remain zero regardless of the length specified.
public final QLine toLine()
Returns an integer based copy of this line.
Note that the returned line's start and end points are rounded to the nearest integer.
public final void translate(QPointF p)
Translates this line by the given p.
public final void translate(double dx, double dy)
Translates this line the distance specified by dx and dy.
public final QLineF unitVector()
Returns the unit vector for this line, i.e a line starting at the same point as this line with a length of 1.0.
public final double x1()
Returns the x-coordinate of the line's start point.
public final double x2()
Returns the x-coordinate of the line's end point.
public final double y1()
Returns the y-coordinate of the line's start point.
public final double y2()
Returns the y-coordinate of the line's end point.
public static QLineF fromNativePointer(QNativePointer nativePointer)
nativePointer
- the QNativePointer of which object should be returned.public static QNativePointer nativePointerArray(QLineF[] array)
array
- the array that the returned pointer will point to.
public boolean equals(java.lang.Object other)
equals
in class java.lang.Object
public final QLineF.IntersectType intersect(QLineF line, QPointF intersectionPoint)
The actual intersection point is extracted to intersectionPoint (if the pointer is valid). If the lines are parallel, the intersection point is undefined.
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