com.trolltech.qt.core
Class QRectF

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

public class QRectF
extends QtJambiObject
implements java.lang.Cloneable

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 = new QRectF(100, 200, 11, 16);
        QRectF r2 = new QRectF(new QPointF(100, 200), new QSizeF(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:





intersected() united()
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 representation One pixel wide pen




Two pixel wide pen Three 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, and QRegion.


Nested Class Summary
 
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter
QSignalEmitter.AbstractSignal, QSignalEmitter.PrivateSignal0, QSignalEmitter.PrivateSignal1, QSignalEmitter.PrivateSignal2, QSignalEmitter.PrivateSignal3, QSignalEmitter.PrivateSignal4, QSignalEmitter.PrivateSignal5, QSignalEmitter.PrivateSignal6, QSignalEmitter.PrivateSignal7, QSignalEmitter.PrivateSignal8, QSignalEmitter.PrivateSignal9, QSignalEmitter.Signal0, QSignalEmitter.Signal1, QSignalEmitter.Signal2, QSignalEmitter.Signal3, QSignalEmitter.Signal4, QSignalEmitter.Signal5, QSignalEmitter.Signal6, QSignalEmitter.Signal7, QSignalEmitter.Signal8, QSignalEmitter.Signal9
 
Nested classes/interfaces inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
com.trolltech.qt.internal.QSignalEmitterInternal.AbstractSignalInternal
 
Field Summary
 
Fields inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
currentSender
 
Constructor Summary
QRectF()
          Constructs a null rectangle.
QRectF(double left, double top, double width, double height)
          Constructs a rectangle with (x, y) 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 QRectrectangle.
 
Method Summary
 void adjust(double x1, double y1, double x2, double y2)
          Adds dx1, dy1, dx2 and dy2 respectively to the existing coordinates of the rectangle.
 QRectF adjusted(double x1, double y1, double x2, double y2)
          Returns a new rectangle with dx1, dy1, dx2 and dy2 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.
 QRectF clone()
          This method is reimplemented for internal reasons
 boolean contains(double x, double y)
          This is an overloaded member function, provided for convenience.
 boolean contains(QPointF p)
          Returns true if the given point is inside or on the edge of the rectangle; otherwise returns false.
 boolean contains(QRectF r)
          This is an overloaded member function, provided for convenience.
 double height()
          Returns the height of the rectangle.
 QRectF intersected(QRectF other)
          Returns the intersection of this rectangle and the given rectangle.
 boolean intersects(QRectF r)
          Returns true if this rectangle intersects with the given rectangle (i.
 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 y coordinate.
 void moveBottomLeft(QPointF p)
          Moves the rectangle, leaving the bottom-left corner at the given position.
 void moveBottomRight(QPointF p)
          Moves the rectangle, leaving the bottom-right corner at the given position.
 void moveCenter(QPointF p)
          Moves the rectangle, leaving the center point at the given position.
 void moveLeft(double pos)
          Moves the rectangle horizontally, leaving the rectangle's left edge at the given x coordinate.
 void moveRight(double pos)
          Moves the rectangle horizontally, leaving the rectangle's right edge at the given x coordinate.
 void moveTo(double x, double t)
          Moves the rectangle, leaving the top-left corner at the given position (x, y).
 void moveTo(QPointF p)
          This is an overloaded member function, provided for convenience.
 void moveTop(double pos)
          Moves the rectangle vertically, leaving the rectangle's top line at the given y coordinate.
 void moveTopLeft(QPointF p)
          Moves the rectangle, leaving the top-left corner at the given position.
 void moveTopRight(QPointF p)
          Moves the rectangle, leaving the top-right corner at the given position.
 QRectF normalized()
          Returns a normalized rectangle; i.
 void readFrom(QDataStream arg__1)
          Reads a QRectF
 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 y coordinate.
 void setBottomLeft(QPointF p)
          Set the bottom-left corner of the rectangle to the given position.
 void setBottomRight(QPointF p)
          Set the bottom-right corner of the rectangle to the given position.
 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 height.
 void setLeft(double pos)
          Sets the left edge of the rectangle to the given x 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 width and height.
 void setRight(double pos)
          Sets the right edge of the rectangle to the given x coordinate.
 void setSize(QSizeF s)
          Sets the size of the rectangle to the given size.
 void setTop(double pos)
          Sets the top edge of the rectangle to the given y coordinate.
 void setTopLeft(QPointF p)
          Set the top-left corner of the rectangle to the given position.
 void setTopRight(QPointF p)
          Set the top-right corner of the rectangle to the given position.
 void setWidth(double w)
          Sets the width of the rectangle to the given width.
 void setX(double pos)
          Sets the left edge of the rectangle to the given x coordinate.
 void setY(double pos)
          Sets the top edge of the rectangle to the given y 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.
 java.lang.String toString()
          Returns a string representation of the this QRectF.
 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)
          This is an overloaded member function, provided for convenience.
 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)
          This is an overloaded member function, provided for convenience.
 QRectF united(QRectF other)
          Returns the bounding rectangle of this rectangle and the given rectangle.
 double width()
          Returns the width of the rectangle.
 void writeTo(QDataStream arg__1)
          Writes thisQRectF
 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, equals, finalize, reassignNativeResources, tr, tr, tr
 
Methods inherited from class com.trolltech.qt.QSignalEmitter
blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread
 
Methods inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
__qt_signalInitialization
 
Methods inherited from class java.lang.Object
getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface com.trolltech.qt.QtJambiInterface
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership
 

Constructor Detail

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(), and setBottomRight().


QRectF

public QRectF(QPointF topleft,
              QSizeF size)
Constructs a rectangle with the given topLeft corner and the given size.

See also:
setTopLeft(), and setSize().


QRectF

public QRectF(QRect rect)
Constructs a QRectF rectangle from the given QRectrectangle.

See also:
toRect().


QRectF

public QRectF(double left,
              double top,
              double width,
              double height)
Constructs a rectangle with (x, y) 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 dx1, dy1, dx2 and dy2 respectively to the existing coordinates of the rectangle.

See also:
adjusted(), and setRect().


adjusted

public final QRectF adjusted(double x1,
                             double y1,
                             double x2,
                             double y2)
Returns a new rectangle with dx1, dy1, dx2 and dy2 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(), and bottomRight().


bottomLeft

public final QPointF bottomLeft()
Returns the position of the rectangle's bottom-left corner.

See also:
setBottomLeft(), bottom(), and left().


bottomRight

public final QPointF bottomRight()
Returns the position of the rectangle's bottom-right corner.

See also:
setBottomRight(), bottom(), and right().


center

public final QPointF center()
Returns the center point of the rectangle.

See also:
moveCenter().


contains

public final boolean contains(QPointF p)
Returns true if the given point is inside or on the edge of the rectangle; otherwise returns false.

See also:
intersects().


contains

public final boolean contains(QRectF r)
This is an overloaded member function, provided for convenience.

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


contains

public final boolean contains(double x,
                              double y)
This is an overloaded member function, provided for convenience.

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


height

public final double height()
Returns the height of the rectangle.

See also:
setHeight(), width(), and size().


intersected

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

See also:
intersects(), united(), and operator&=().


intersects

public final boolean intersects(QRectF r)
Returns true if this rectangle intersects with the given rectangle (i. . 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(), and 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(), and 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(), and normalized().


left

public final double left()
Returns the x-coordinate of the rectangle's left edge. Equivalent to x().

See also:
setLeft(), topLeft(), and bottomLeft().


moveBottom

public final void moveBottom(double pos)
Moves the rectangle vertically, leaving the rectangle's bottom edge at the given y coordinate. The rectangle's size is unchanged.

See also:
bottom(), setBottom(), and moveTop().


moveBottomLeft

public final void moveBottomLeft(QPointF p)
Moves the rectangle, leaving the bottom-left corner at the given position. The rectangle's size is unchanged.

See also:
setBottomLeft(), moveBottom(), and moveLeft().


moveBottomRight

public final void moveBottomRight(QPointF p)
Moves the rectangle, leaving the bottom-right corner at the given position. The rectangle's size is unchanged.

See also:
setBottomRight(), moveBottom(), and moveRight().


moveCenter

public final void moveCenter(QPointF p)
Moves the rectangle, leaving the center point at the given position. 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 x coordinate. The rectangle's size is unchanged.

See also:
left(), setLeft(), and moveRight().


moveRight

public final void moveRight(double pos)
Moves the rectangle horizontally, leaving the rectangle's right edge at the given x coordinate. The rectangle's size is unchanged.

See also:
right(), setRight(), and moveLeft().


moveTo

public final void moveTo(QPointF p)
This is an overloaded member function, provided for convenience.

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


moveTo

public final void moveTo(double x,
                         double t)
Moves the rectangle, leaving the top-left corner at the given position (x, y). The rectangle's size is unchanged.

See also:
translate(), and moveTopLeft().


moveTop

public final void moveTop(double pos)
Moves the rectangle vertically, leaving the rectangle's top line at the given y coordinate. The rectangle's size is unchanged.

See also:
top(), setTop(), and moveBottom().


moveTopLeft

public final void moveTopLeft(QPointF p)
Moves the rectangle, leaving the top-left corner at the given position. The rectangle's size is unchanged.

See also:
setTopLeft(), moveTop(), and moveLeft().


moveTopRight

public final void moveTopRight(QPointF p)
Moves the rectangle, leaving the top-right corner at the given position. The rectangle's size is unchanged.

See also:
setTopRight(), moveTop(), and moveRight().


normalized

public final QRectF normalized()
Returns a normalized rectangle; i. ., 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(), and isEmpty().


writeTo

public final void writeTo(QDataStream arg__1)
Writes thisQRectF


readFrom

public final void readFrom(QDataStream arg__1)
Reads a QRectF


right

public final double right()
Returns the x-coordinate of the rectangle's right edge.

See also:
setRight(), topRight(), and bottomRight().


setBottom

public final void setBottom(double pos)
Sets the bottom edge of the rectangle to the given y coordinate. May change the height, but will never change the top edge of the rectangle.

See also:
bottom(), and moveBottom().


setBottomLeft

public final void setBottomLeft(QPointF p)
Set the bottom-left corner of the rectangle to the given position. May change the size, but will never change the top-right corner of the rectangle.

See also:
bottomLeft(), and moveBottomLeft().


setBottomRight

public final void setBottomRight(QPointF p)
Set the bottom-right corner of the rectangle to the given position. May change the size, but will never change the top-left corner of the rectangle.

See also:
bottomRight(), and 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(), and setRect().


setHeight

public final void setHeight(double h)
Sets the height of the rectangle to the given height. The bottom edge is changed, but not the top one.

See also:
height(), and setSize().


setLeft

public final void setLeft(double pos)
Sets the left edge of the rectangle to the given x coordinate. May change the width, but will never change the right edge of the rectangle.

Equivalent to setX().

See also:
left(), and 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 width and height.

See also:
getRect(), and setCoords().


setRight

public final void setRight(double pos)
Sets the right edge of the rectangle to the given x coordinate. May change the width, but will never change the left edge of the rectangle.

See also:
right(), and moveRight().


setSize

public final void setSize(QSizeF s)
Sets the size of the rectangle to the given size. The top-left corner is not moved.

See also:
size(), setWidth(), and setHeight().


setTop

public final void setTop(double pos)
Sets the top edge of the rectangle to the given y coordinate. May change the height, but will never change the bottom edge of the rectangle.

Equivalent to setY().

See also:
top(), and moveTop().


setTopLeft

public final void setTopLeft(QPointF p)
Set the top-left corner of the rectangle to the given position. May change the size, but will never change the bottom-right corner of the rectangle.

See also:
topLeft(), and moveTopLeft().


setTopRight

public final void setTopRight(QPointF p)
Set the top-right corner of the rectangle to the given position. May change the size, but will never change the bottom-left corner of the rectangle.

See also:
topRight(), and moveTopRight().


setWidth

public final void setWidth(double w)
Sets the width of the rectangle to the given width. The right edge is changed, but not the left one.

See also:
width(), and setSize().


setX

public final void setX(double pos)
Sets the left edge of the rectangle to the given x coordinate. May change the width, but will never change the right edge of the rectangle.

Equivalent to setLeft().

See also:
x(), setY(), and setTopLeft().


setY

public final void setY(double pos)
Sets the top edge of the rectangle to the given y coordinate. May change the height, but will never change the bottom edge of the rectangle.

Equivalent to setTop().

See also:
y(), setX(), and setTopLeft().


size

public final QSizeF size()
Returns the size of the rectangle.

See also:
setSize(), width(), and 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(), and toAlignedRect().


top

public final double top()
Returns the y-coordinate of the rectangle's top edge. Equivalent to y().

See also:
setTop(), topLeft(), and topRight().


topLeft

public final QPointF topLeft()
Returns the position of the rectangle's top-left corner.

See also:
setTopLeft(), top(), and left().


topRight

public final QPointF topRight()
Returns the position of the rectangle's top-right corner.

See also:
setTopRight(), top(), and right().


translate

public final void translate(QPointF p)
This is an overloaded member function, provided for convenience.

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


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(), and translated().


translated

public final QRectF translated(QPointF p)
This is an overloaded member function, provided for convenience.

Returns a copy of the rectangle that is translated offset.x() along the x axis and offset.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().


united

public final QRectF united(QRectF other)
Returns the bounding rectangle of this rectangle and the given rectangle.

See also:
intersected().


width

public final double width()
Returns the width of the rectangle.

See also:
setWidth(), height(), and size().


x

public final double x()
Returns the x-coordinate of the rectangle's left edge. Equivalent to left().

See also:
setX(), y(), and topLeft().


y

public final double y()
Returns the y-coordinate of the rectangle's top edge. Equivalent to top().

See also:
setY(), x(), and topLeft().


toString

public java.lang.String toString()
Returns a string representation of the this QRectF.

Overrides:
toString in class java.lang.Object

clone

public QRectF clone()
This method is reimplemented for internal reasons

Overrides:
clone in class java.lang.Object