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com.trolltech.qt.core
Class QRectF

java.lang.Object
  extended by com.trolltech.qt.QSignalEmitter
      extended by com.trolltech.qt.QtJambiObject
          extended by com.trolltech.qt.core.QRectF
All Implemented Interfaces:
QtJambiInterface

public class QRectF
extends QtJambiObject

The QRectF class defines a rectangle in the plane using floating point precision.

A rectangle is normally expressed as an upper-left corner and a size. The size (width and height) of a QRectF is always equivalent to the mathematical rectangle that forms the basis for its rendering.

A QRectF can be constructed with a set of left, top, width and height integers, or from a QPoint and a QSize. The following code creates two identical rectangles.

    QRectF r1(100, 200, 11, 16);
    QRectF r2(QPoint(100, 200), QSize(11, 16));

There is also a third constructor creating a QRectF from a QRect, and a corresponding toRect function that returns a QRect object based on the values of this rectangle (note that the coordinates in the returned rectangle are rounded to the nearest integer).

The QRectF class provides a collection of functions that return the various rectangle coordinates, and enable manipulation of these. QRectF also provide functions to move the rectangle relative to the various coordinates. In addition there is a moveTo function that moves the rectangle, leaving its top left corner at the given coordinates. Alternatively, the translate function moves the rectangle the given offset relative to the current position, and the translated function returns a translated copy of this rectangle.

The size function returns the rectange's dimensions as a QSize. The dimensions can also be retrieved separately using the width and height functions. To manipulate the dimensions use the setSize, setWidth or setHeight functions. Alternatively, the size can be changed by applying either of the functions setting the rectangle coordinates, for example, setBottom or setRight.

The contains function tells whether a given point is inside the rectangle or not, and the intersects function returns true if this rectangle intersects with a given rectangle (otherwise false). The QRectF class also provides the intersected function which returns the intersection rectangle, and the united function which returns the rectangle that encloses the given rectangle and this:

intersectedunited

The isEmpty function returns true if the rectangle's width or height is less than, or equal to, 0. Note that an empty rectangle is not valid: The isValid function returns true if both width and height is larger than 0. A null rectangle (isNull == true) on the other hand, has both width and height set to 0.

Note that due to the way QRect and QRectF are defined, an empty QRectF is defined in essentially the same way as QRect.

Finally, QRectF objects can be streamed as well as compared.

Rendering

When using an anti-aliased painter, the boundary line of a QRectF will be rendered symmetrically on both sides of the mathematical rectangle's boundary line. But when using an aliased painter (the default) other rules apply.

Then, when rendering with a one pixel wide pen the QRectF's boundary line will be rendered to the right and below the mathematical rectangle's boundary line.

When rendering with a two pixels wide pen the boundary line will be split in the middle by the mathematical rectangle. This will be the case whenever the pen is set to an even number of pixels, while rendering with a pen with an odd number of pixels, the spare pixel will be rendered to the right and below the mathematical rectangle as in the one pixel case.

Logical representationOne pixel wide pen
Two pixel wide penThree pixel wide pen

Coordinates

The QRectF class provides a collection of functions that return the various rectangle coordinates, and enable manipulation of these. QRectF also provide functions to move the rectangle relative to the various coordinates.

For example: the bottom, setBottom and moveBottom functions: bottom returns the y-coordinate of the rectangle's bottom edge, setBottom sets the bottom edge of the rectangle to the given y coordinate (it may change the height, but will never change the rectangle's top edge) and moveBottom moves the entire rectangle vertically, leaving the rectangle's bottom edge at the given y coordinate and its size unchanged.

It is also possible to add offsets to this rectangle's coordinates using the adjust function, as well as retrieve a new rectangle based on adjustments of the original one using the adjusted function. If either of the width and height is negative, use the normalized function to retrieve a rectangle where the corners are swapped.

In addition, QRectF provides the getCoords() function which extracts the position of the rectangle's top-left and bottom-right corner, and the getRect() function which extracts the rectangle's top-left corner, width and height. Use the setCoords and setRect function to manipulate the rectangle's coordinates and dimensions in one go.

See Also:
QRect, QRegion

Nested Class Summary
 
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter
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
QRectF()
          Constructs a null rectangle.
QRectF(double left, double top, double width, double height)
          Constructs a rectangle with (left, top) as its top-left corner and the given width and height.
QRectF(QPointF topleft, QPointF bottomRight)
          Constructs a rectangle with the given topleft and bottomRight corners.
QRectF(QPointF topleft, QSizeF size)
          Constructs a rectangle with the given topleft corner and the given size.
QRectF(QRect rect)
          Constructs a QRectF rectangle from the given QRect rect.
 
Method Summary
 void adjust(double x1, double y1, double x2, double y2)
          Adds x1, y1, x2 and y2 respectively to the existing coordinates of the rectangle.
 QRectF adjusted(double x1, double y1, double x2, double y2)
          Returns a new rectangle with x1, y1, x2 and y2 added respectively to the existing coordinates of this rectangle.
 double bottom()
          Returns the y-coordinate of the rectangle's bottom edge.
 QPointF bottomLeft()
          Returns the position of the rectangle's bottom-left corner.
 QPointF bottomRight()
          Returns the position of the rectangle's bottom-right corner.
 QPointF center()
          Returns the center point of the rectangle.
 boolean contains(double x, double y)
          Returns true if the point (x, y) is inside or on the edge of the rectangle; otherwise returns false.
 boolean contains(QPointF p)
          Returns true if the given p is inside or on the edge of the rectangle; otherwise returns false.
 boolean contains(QRectF r)
          Returns true if the given r is inside this rectangle; otherwise returns false.
 boolean equals(java.lang.Object other)
          
static QRectF fromNativePointer(QNativePointer nativePointer)
          This function returns the QRectF instance pointed to by nativePointer
 double height()
          Returns the height of the rectangle.
 QRectF intersected(QRectF other)
          Returns the intersection of this rectangle and the given other.
 boolean intersects(QRectF r)
          Returns true if this rectangle intersects with the given r (i.e. there is a non-empty area of overlap between them), otherwise returns false.
 boolean isEmpty()
          Returns true if the rectangle is empty, otherwise returns false.
 boolean isNull()
          Returns true if the rectangle is a null rectangle, otherwise returns false.
 boolean isValid()
          Returns true if the rectangle is valid, otherwise returns false.
 double left()
          Returns the x-coordinate of the rectangle's left edge.
 void moveBottom(double pos)
          Moves the rectangle vertically, leaving the rectangle's bottom edge at the given pos coordinate.
 void moveBottomLeft(QPointF p)
          Moves the rectangle, leaving the bottom-left corner at the given p.
 void moveBottomRight(QPointF p)
          Moves the rectangle, leaving the bottom-right corner at the given p.
 void moveCenter(QPointF p)
          Moves the rectangle, leaving the center point at the given p.
 void moveLeft(double pos)
          Moves the rectangle horizontally, leaving the rectangle's left edge at the given pos coordinate.
 void moveRight(double pos)
          Moves the rectangle horizontally, leaving the rectangle's right edge at the given pos coordinate.
 void moveTo(double x, double t)
          Moves the rectangle, leaving the top-left corner at the given position (x, t).
 void moveTo(QPointF p)
          Moves the rectangle, leaving the top-left corner at the given p.
 void moveTop(double pos)
          Moves the rectangle vertically, leaving the rectangle's top line at the given pos coordinate.
 void moveTopLeft(QPointF p)
          Moves the rectangle, leaving the top-left corner at the given p.
 void moveTopRight(QPointF p)
          Moves the rectangle, leaving the top-right corner at the given p.
static QNativePointer nativePointerArray(QRectF[] array)
          This function returns a QNativePointer that is pointing to the specified QRectF array.
 QRectF normalized()
          Returns a normalized rectangle; i.e., a rectangle that has a non-negative width and height.
 void readFrom(QDataStream arg__1)
          Reads a QRectF from arg__1.
 double right()
          Returns the x-coordinate of the rectangle's right edge.
 void setBottom(double pos)
          Sets the bottom edge of the rectangle to the given pos coordinate.
 void setBottomLeft(QPointF p)
          Set the bottom-left corner of the rectangle to the given p.
 void setBottomRight(QPointF p)
          Set the top-right corner of the rectangle to the given p.
 void setCoords(double x1, double y1, double x2, double y2)
          Sets the coordinates of the rectangle's top-left corner to (x1, y1), and the coordinates of its bottom-right corner to (x2, y2).
 void setHeight(double h)
          Sets the height of the rectangle to the given h.
 void setLeft(double pos)
          Sets the left edge of the rectangle to the given pos coordinate.
 void setRect(double x, double y, double w, double h)
          Sets the coordinates of the rectangle's top-left corner to (x, y), and its size to the given w and h.
 void setRight(double pos)
          Sets the right edge of the rectangle to the given pos coordinate.
 void setSize(QSizeF s)
          Sets the size of the rectangle to the given s.
 void setTop(double pos)
          Sets the top edge of the rectangle to the given pos coordinate.
 void setTopLeft(QPointF p)
          Set the top-left corner of the rectangle to the given p.
 void setTopRight(QPointF p)
          Set the top-right corner of the rectangle to the given p.
 void setWidth(double w)
          Sets the width of the rectangle to the given w.
 void setX(double pos)
          Sets the left edge of the rectangle to the given pos coordinate.
 void setY(double pos)
          Sets the top edge of the rectangle to the given pos coordinate.
 QSizeF size()
          Returns the size of the rectangle.
 QRect toAlignedRect()
          Returns a QRect based on the values of this rectangle that is the smallest possible integer rectangle that completely contains this rectangle.
 double top()
          Returns the y-coordinate of the rectangle's top edge.
 QPointF topLeft()
          Returns the position of the rectangle's top-left corner.
 QPointF topRight()
          Returns the position of the rectangle's top-right corner.
 QRect toRect()
          Returns a QRect based on the values of this rectangle.
 void translate(double dx, double dy)
          Moves the rectangle dx along the x-axis and dy along the y-axis, relative to the current position.
 void translate(QPointF p)
          Moves the rectangle p.x() along the x axis and p.y() along the y axis, relative to the current position.
 QRectF translated(double dx, double dy)
          Returns a copy of the rectangle that is translated dx along the x axis and dy along the y axis, relative to the current position.
 QRectF translated(QPointF p)
          Returns a copy of the rectangle that is translated p.x() along the x axis and p.y() along the y axis, relative to the current position.
 QRectF united(QRectF other)
          Returns the bounding rectangle of this rectangle and the given other.
 double width()
          Returns the width of the rectangle.
 void writeTo(QDataStream arg__1)
          Writes thisQRectF to arg__1.
 double x()
          Returns the x-coordinate of the rectangle's left edge.
 double y()
          Returns the y-coordinate of the rectangle's top edge.
 
Methods inherited from class com.trolltech.qt.QtJambiObject
dispose, disposed, finalize, reassignNativeResources, tr, tr, tr
 
Methods inherited from class com.trolltech.qt.QSignalEmitter
blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread
 
Methods inherited from class java.lang.Object
clone, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface com.trolltech.qt.QtJambiInterface
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership
 

Constructor Detail

QRectF

public QRectF(QRect rect)

Constructs a QRectF rectangle from the given QRect rect.

See Also:
toRect

QRectF

public QRectF()

Constructs a null rectangle.

See Also:
isNull

QRectF

public QRectF(QPointF topleft,
              QPointF bottomRight)

Constructs a rectangle with the given topleft and bottomRight corners.

See Also:
setTopLeft, setBottomRight

QRectF

public QRectF(QPointF topleft,
              QSizeF size)

Constructs a rectangle with the given topleft corner and the given size.

See Also:
setTopLeft, setSize

QRectF

public QRectF(double left,
              double top,
              double width,
              double height)

Constructs a rectangle with (left, top) as its top-left corner and the given width and height.

See Also:
setRect
Method Detail

adjust

public final void adjust(double x1,
                         double y1,
                         double x2,
                         double y2)

Adds x1, y1, x2 and y2 respectively to the existing coordinates of the rectangle.

See Also:
adjusted, setRect

adjusted

public final QRectF adjusted(double x1,
                             double y1,
                             double x2,
                             double y2)

Returns a new rectangle with x1, y1, x2 and y2 added respectively to the existing coordinates of this rectangle.

See Also:
adjust

bottom

public final double bottom()

Returns the y-coordinate of the rectangle's bottom edge.

See Also:
setBottom, bottomLeft, bottomRight

bottomLeft

public final QPointF bottomLeft()

Returns the position of the rectangle's bottom-left corner.

See Also:
setBottomLeft, bottom, left

bottomRight

public final QPointF bottomRight()

Returns the position of the rectangle's bottom-right corner.

See Also:
setBottomRight, bottom, right

center

public final QPointF center()

Returns the center point of the rectangle.

See Also:
moveCenter

contains

public final boolean contains(QRectF r)

Returns true if the given r is inside this rectangle; otherwise returns false.


contains

public final boolean contains(double x,
                              double y)

Returns true if the point (x, y) is inside or on the edge of the rectangle; otherwise returns false.


contains

public final boolean contains(QPointF p)

Returns true if the given p is inside or on the edge of the rectangle; otherwise returns false.

See Also:
intersects

height

public final double height()

Returns the height of the rectangle.

See Also:
setHeight, width, size

intersected

public final QRectF intersected(QRectF other)

Returns the intersection of this rectangle and the given other. Note that r.intersected(s) is equivalent to r & s.

See Also:
intersects, united, operator&=

intersects

public final boolean intersects(QRectF r)

Returns true if this rectangle intersects with the given r (i.e. there is a non-empty area of overlap between them), otherwise returns false.

The intersection rectangle can be retrieved using the intersected function.

See Also:
contains

isEmpty

public final boolean isEmpty()

Returns true if the rectangle is empty, otherwise returns false.

An empty rectangle has width <= 0 or height <= 0. An empty rectangle is not valid (i.e., isEmpty == !isValid).

Use the normalized function to retrieve a rectangle where the corners are swapped.

See Also:
isNull, isValid, normalized

isNull

public final boolean isNull()

Returns true if the rectangle is a null rectangle, otherwise returns false.

A null rectangle has both the width and the height set to 0. A null rectangle is also empty, and hence not valid.

See Also:
isEmpty, isValid

isValid

public final boolean isValid()

Returns true if the rectangle is valid, otherwise returns false.

A valid rectangle has a width > 0 and height > 0. Note that non-trivial operations like intersections are not defined for invalid rectangles. A valid rectangle is not empty (i.e., isValid == !isEmpty).

See Also:
isNull, isEmpty, normalized

left

public final double left()

Returns the x-coordinate of the rectangle's left edge. Equivalent to x.

See Also:
setLeft, topLeft, bottomLeft

moveBottom

public final void moveBottom(double pos)

Moves the rectangle vertically, leaving the rectangle's bottom edge at the given pos coordinate. The rectangle's size is unchanged.

See Also:
bottom, setBottom, moveTop

moveBottomLeft

public final void moveBottomLeft(QPointF p)

Moves the rectangle, leaving the bottom-left corner at the given p. The rectangle's size is unchanged.

See Also:
setBottomLeft, moveBottom, moveLeft

moveBottomRight

public final void moveBottomRight(QPointF p)

Moves the rectangle, leaving the bottom-right corner at the given p. The rectangle's size is unchanged.

See Also:
setBottomRight, moveBottom, moveRight

moveCenter

public final void moveCenter(QPointF p)

Moves the rectangle, leaving the center point at the given p. The rectangle's size is unchanged.

See Also:
center

moveLeft

public final void moveLeft(double pos)

Moves the rectangle horizontally, leaving the rectangle's left edge at the given pos coordinate. The rectangle's size is unchanged.

See Also:
left, setLeft, moveRight

moveRight

public final void moveRight(double pos)

Moves the rectangle horizontally, leaving the rectangle's right edge at the given pos coordinate. The rectangle's size is unchanged.

See Also:
right, setRight, moveLeft

moveTo

public final void moveTo(double x,
                         double t)

Moves the rectangle, leaving the top-left corner at the given position (x, t). The rectangle's size is unchanged.

See Also:
translate, moveTopLeft

moveTo

public final void moveTo(QPointF p)

Moves the rectangle, leaving the top-left corner at the given p.


moveTop

public final void moveTop(double pos)

Moves the rectangle vertically, leaving the rectangle's top line at the given pos coordinate. The rectangle's size is unchanged.

See Also:
top, setTop, moveBottom

moveTopLeft

public final void moveTopLeft(QPointF p)

Moves the rectangle, leaving the top-left corner at the given p. The rectangle's size is unchanged.

See Also:
setTopLeft, moveTop, moveLeft

moveTopRight

public final void moveTopRight(QPointF p)

Moves the rectangle, leaving the top-right corner at the given p. The rectangle's size is unchanged.

See Also:
setTopRight, moveTop, moveRight

normalized

public final QRectF normalized()

Returns a normalized rectangle; i.e., a rectangle that has a non-negative width and height.

If width < 0 the function swaps the left and right corners, and it swaps the top and bottom corners if height < 0.

See Also:
isValid, isEmpty

writeTo

public final void writeTo(QDataStream arg__1)
Writes thisQRectF to arg__1.


readFrom

public final void readFrom(QDataStream arg__1)
Reads a QRectF from arg__1.


right

public final double right()

Returns the x-coordinate of the rectangle's right edge.

See Also:
setRight, topRight, bottomRight

setBottom

public final void setBottom(double pos)

Sets the bottom edge of the rectangle to the given pos coordinate. May change the height, but will never change the top edge of the rectangle.

See Also:
bottom, moveBottom

setBottomLeft

public final void setBottomLeft(QPointF p)

Set the bottom-left corner of the rectangle to the given p. May change the size, but will the never change the top-right corner of the rectangle.

See Also:
bottomLeft, moveBottomLeft

setBottomRight

public final void setBottomRight(QPointF p)

Set the top-right corner of the rectangle to the given p. May change the size, but will the never change the top-left corner of the rectangle.

See Also:
bottomRight, moveBottomRight

setCoords

public final void setCoords(double x1,
                            double y1,
                            double x2,
                            double y2)

Sets the coordinates of the rectangle's top-left corner to (x1, y1), and the coordinates of its bottom-right corner to (x2, y2).

See Also:
getCoords, setRect

setHeight

public final void setHeight(double h)

Sets the height of the rectangle to the given h. The bottom edge is changed, but not the top one.

See Also:
height, setSize

setLeft

public final void setLeft(double pos)

Sets the left edge of the rectangle to the given pos coordinate. May change the width, but will never change the right edge of the rectangle.

Equivalent to setX.

See Also:
left, moveLeft

setRect

public final void setRect(double x,
                          double y,
                          double w,
                          double h)

Sets the coordinates of the rectangle's top-left corner to (x, y), and its size to the given w and h.

See Also:
getRect, setCoords

setRight

public final void setRight(double pos)

Sets the right edge of the rectangle to the given pos coordinate. May change the width, but will never change the left edge of the rectangle.

See Also:
right, moveRight

setSize

public final void setSize(QSizeF s)

Sets the size of the rectangle to the given s. The top-left corner is not moved.

See Also:
size, setWidth, setHeight

setTop

public final void setTop(double pos)

Sets the top edge of the rectangle to the given pos coordinate. May change the height, but will never change the bottom edge of the rectangle.

Equivalent to setY.

See Also:
top, moveTop

setTopLeft

public final void setTopLeft(QPointF p)

Set the top-left corner of the rectangle to the given p. May change the size, but will the never change the bottom-right corner of the rectangle.

See Also:
topLeft, moveTopLeft

setTopRight

public final void setTopRight(QPointF p)

Set the top-right corner of the rectangle to the given p. May change the size, but will the never change the bottom-left corner of the rectangle.

See Also:
topRight, moveTopRight

setWidth

public final void setWidth(double w)

Sets the width of the rectangle to the given w. The right edge is changed, but not the left one.

See Also:
width, setSize

setX

public final void setX(double pos)

Sets the left edge of the rectangle to the given pos coordinate. May change the width, but will never change the right edge of the rectangle.

Equivalent to setLeft.

See Also:
x, setY, setTopLeft

setY

public final void setY(double pos)

Sets the top edge of the rectangle to the given pos coordinate. May change the height, but will never change the bottom edge of the rectangle.

Equivalent to setTop.

See Also:
y, setX, setTopLeft

size

public final QSizeF size()

Returns the size of the rectangle.

See Also:
setSize, width, height

toAlignedRect

public final QRect toAlignedRect()

Returns a QRect based on the values of this rectangle that is the smallest possible integer rectangle that completely contains this rectangle.

See Also:
toRect

toRect

public final QRect toRect()

Returns a QRect based on the values of this rectangle. Note that the coordinates in the returned rectangle are rounded to the nearest integer.

See Also:
QRectF, toAlignedRect

top

public final double top()

Returns the y-coordinate of the rectangle's top edge. Equivalent to y.

See Also:
setTop, topLeft, topRight

topLeft

public final QPointF topLeft()

Returns the position of the rectangle's top-left corner.

See Also:
setTopLeft, top, left

topRight

public final QPointF topRight()

Returns the position of the rectangle's top-right corner.

See Also:
setTopRight, top, right

translate

public final void translate(double dx,
                            double dy)

Moves the rectangle dx along the x-axis and dy along the y-axis, relative to the current position. Positive values move the rectangle to the right and downwards.

See Also:
moveTopLeft, moveTo, translated

translate

public final void translate(QPointF p)

Moves the rectangle p.x() along the x axis and p.y() along the y axis, relative to the current position.


translated

public final QRectF translated(double dx,
                               double dy)

Returns a copy of the rectangle that is translated dx along the x axis and dy along the y axis, relative to the current position. Positive values move the rectangle to the right and down.

See Also:
translate

translated

public final QRectF translated(QPointF p)

Returns a copy of the rectangle that is translated p.x() along the x axis and p.y() along the y axis, relative to the current position.


united

public final QRectF united(QRectF other)

Returns the bounding rectangle of this rectangle and the given other.

See Also:
intersected

width

public final double width()

Returns the width of the rectangle.

See Also:
setWidth, height, size

x

public final double x()

Returns the x-coordinate of the rectangle's left edge. Equivalent to left.

See Also:
setX, y, topLeft

y

public final double y()

Returns the y-coordinate of the rectangle's top edge. Equivalent to top.

See Also:
setY, x, topLeft

fromNativePointer

public static QRectF fromNativePointer(QNativePointer nativePointer)
This function returns the QRectF instance pointed to by nativePointer

Parameters:
nativePointer - the QNativePointer of which object should be returned.

nativePointerArray

public static QNativePointer nativePointerArray(QRectF[] array)
This function returns a QNativePointer that is pointing to the specified QRectF array.

Parameters:
array - the array that the returned pointer will point to.
Returns:
a QNativePointer that is pointing to the specified array.

equals

public boolean equals(java.lang.Object other)

Overrides:
equals in class java.lang.Object

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