The QLine class provides a two-dimensional vector using integer precision. More...

` #include <QLine>`

QLine () | |

QLine ( const QPoint & p1, const QPoint & p2 ) | |

QLine ( int x1, int y1, int x2, int y2 ) | |

QPoint | p1 () const |

QPoint | p2 () const |

int | x1 () const |

int | x2 () const |

int | y1 () const |

int | y2 () const |

int | dx () const |

int | dy () const |

bool | isNull () const |

void | setP1 ( const QPoint & p1 ) |

void | setP2 ( const QPoint & p2 ) |

void | setLine ( int x1, int y1, int x2, int y2 ) |

void | setPoints ( const QPoint & p1, const QPoint & p2 ) |

void | translate ( const QPoint & offset ) |

void | translate ( int dx, int dy ) |

QLine | translated ( const QPoint & offset ) const |

QLine | translated ( int dx, int dy ) const |

bool | operator!= ( const QLine & line ) const |

bool | operator== ( const QLine & line ) const |

QDataStream & | operator<< ( QDataStream & stream, const QLine & line ) |

QDataStream & | operator>> ( QDataStream & stream, QLine & line ) |

The QLine class provides a two-dimensional vector using integer precision.

A QLine describes a finite length line (or a line segment) on a two-dimensional surface. The start and end points of the line are specified using integer point accuracy for coordinates. Use the QLineF constructor to retrieve a floating point copy.

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. Use isNull() to determine whether the QLine represents a valid line or a null line.

Finally, the line can be translated a given offset using the translate() function.

**See also **QLineF, QPolygon, and QRect.

Constructs a null line.

Constructs a line object that represents the line between *p1* and *p2*.

Constructs a line object that represents the line between (*x1*, *y1*) and (*x2*, *y2*).

Returns the line's start point.

**See also **setP1(), x1(), y1(), and p2().

Returns the line's end point.

**See also **setP2(), x2(), y2(), and p1().

Returns the x-coordinate of the line's start point.

**See also **p1().

Returns the x-coordinate of the line's end point.

**See also **p2().

Returns the y-coordinate of the line's start point.

**See also **p1().

Returns the y-coordinate of the line's end point.

**See also **p2().

Returns the horizontal component of the line's vector.

**See also **dy().

Returns the vertical component of the line's vector.

**See also **dx().

Returns true if the line is not set up with valid start and end point; otherwise returns false.

Sets the starting point of this line to *p1*.

This function was introduced in Qt 4.4.

Sets the end point of this line to *p2*.

This function was introduced in Qt 4.4.

Sets this line to the start in *x1*, *y1* and end in *x2*, *y2*.

This function was introduced in Qt 4.4.

**See also **setP1(), setP2(), p1(), and p2().

Sets the start point of this line to *p1* and the end point of this line to *p2*.

This function was introduced in Qt 4.4.

**See also **setP1(), setP2(), p1(), and p2().

Translates this line by the given *offset*.

This is an overloaded function.

Translates this line the distance specified by *dx* and *dy*.

Returns this line translated by the given *offset*.

This function was introduced in Qt 4.4.

This is an overloaded function.

Returns this line translated the distance specified by *dx* and *dy*.

This function was introduced in Qt 4.4.

Returns true if the given *line* is not the same as *this* line.

A line is different from another line if any of their start or end points differ, or the internal order of the points is different.

Returns true if the given *line* is the same as *this* line.

A line is identical to another line if the start and end points are identical, and the internal order of the points is the same.

Writes the given *line* to the given *stream* and returns a reference to the stream.

**See also **Serializing Qt Data Types.

Reads a line from the given *stream* into the given *line* and returns a reference to the stream.

**See also **Serializing Qt Data Types.