source: trunk/src/corelib/tools/qline.cpp@ 561

Last change on this file since 561 was 561, checked in by Dmitry A. Kuminov, 15 years ago

trunk: Merged in qt 4.6.1 sources.

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1/****************************************************************************
2**
3** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
4** All rights reserved.
5** Contact: Nokia Corporation ([email protected])
6**
7** This file is part of the QtCore module of the Qt Toolkit.
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9** $QT_BEGIN_LICENSE:LGPL$
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28** GNU General Public License Usage
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41
42#include "qline.h"
43#include "qdebug.h"
44#include "qdatastream.h"
45#include "qmath.h"
46#include <private/qnumeric_p.h>
47
48QT_BEGIN_NAMESPACE
49
50/*!
51 \class QLine
52 \ingroup painting
53
54 \brief The QLine class provides a two-dimensional vector using
55 integer precision.
56
57 A QLine describes a finite length line (or a line segment) on a
58 two-dimensional surface. The start and end points of the line are
59 specified using integer point accuracy for coordinates. Use the
60 QLineF constructor to retrieve a floating point copy.
61
62 \table
63 \row
64 \o \inlineimage qline-point.png
65 \o \inlineimage qline-coordinates.png
66 \endtable
67
68 The positions of the line's start and end points can be retrieved
69 using the p1(), x1(), y1(), p2(), x2(), and y2() functions. The
70 dx() and dy() functions return the horizontal and vertical
71 components of the line. Use isNull() to determine whether the
72 QLine represents a valid line or a null line.
73
74 Finally, the line can be translated a given offset using the
75 translate() function.
76
77 \sa QLineF, QPolygon, QRect
78*/
79
80/*!
81 \fn QLine::QLine()
82
83 Constructs a null line.
84*/
85
86/*!
87 \fn QLine::QLine(const QPoint &p1, const QPoint &p2)
88
89 Constructs a line object that represents the line between \a p1 and
90 \a p2.
91*/
92
93/*!
94 \fn QLine::QLine(int x1, int y1, int x2, int y2)
95
96 Constructs a line object that represents the line between (\a x1, \a y1) and
97 (\a x2, \a y2).
98*/
99
100/*!
101 \fn bool QLine::isNull() const
102
103 Returns true if the line is not set up with valid start and end point;
104 otherwise returns false.
105*/
106
107/*!
108 \fn QPoint QLine::p1() const
109
110 Returns the line's start point.
111
112 \sa x1(), y1(), p2()
113*/
114
115/*!
116 \fn QPoint QLine::p2() const
117
118 Returns the line's end point.
119
120 \sa x2(), y2(), p1()
121*/
122
123/*!
124 \fn int QLine::x1() const
125
126 Returns the x-coordinate of the line's start point.
127
128 \sa p1()
129*/
130
131/*!
132 \fn int QLine::y1() const
133
134 Returns the y-coordinate of the line's start point.
135
136 \sa p1()
137*/
138
139/*!
140 \fn int QLine::x2() const
141
142 Returns the x-coordinate of the line's end point.
143
144 \sa p2()
145*/
146
147/*!
148 \fn int QLine::y2() const
149
150 Returns the y-coordinate of the line's end point.
151
152 \sa p2()
153*/
154
155/*!
156 \fn int QLine::dx() const
157
158 Returns the horizontal component of the line's vector.
159
160 \sa dy()
161*/
162
163/*!
164 \fn int QLine::dy() const
165
166 Returns the vertical component of the line's vector.
167
168 \sa dx()
169*/
170
171/*!
172 \fn bool QLine::operator!=(const QLine &line) const
173
174 Returns true if the given \a line is not the same as \e this line.
175
176 A line is different from another line if any of their start or
177 end points differ, or the internal order of the points is different.
178*/
179
180/*!
181 \fn bool QLine::operator==(const QLine &line) const
182
183 Returns true if the given \a line is the same as \e this line.
184
185 A line is identical to another line if the start and end points
186 are identical, and the internal order of the points is the same.
187*/
188
189/*!
190 \fn void QLine::translate(const QPoint &offset)
191
192 Translates this line by the given \a offset.
193*/
194
195/*!
196 \fn void QLine::translate(int dx, int dy)
197 \overload
198
199 Translates this line the distance specified by \a dx and \a dy.
200*/
201
202/*!
203 \fn QLine QLine::translated(const QPoint &offset) const
204
205 \since 4.4
206
207 Returns this line translated by the given \a offset.
208*/
209
210/*!
211 \fn QLine QLine::translated(int dx, int dy) const
212 \overload
213 \since 4.4
214