QwtScaleDraw Class Reference
A class for drawing scales. More...
#include <qwt_scale_draw.h>
Public Types | |
| enum | Alignment { BottomScale, TopScale, LeftScale, RightScale } |
Public Member Functions | |
| QwtScaleDraw () | |
| QwtScaleDraw (const QwtScaleDraw &) | |
| virtual | ~QwtScaleDraw () |
| QwtScaleDraw & | operator= (const QwtScaleDraw &other) |
| void | getBorderDistHint (const QFont &, int &start, int &end) const |
| int | minLabelDist (const QFont &) const |
| int | minLength (const QPen &, const QFont &) const |
| virtual int | extent (const QPen &, const QFont &) const |
| void | move (int x, int y) |
| void | move (const QPoint &) |
| void | setLength (int length) |
| Alignment | alignment () const |
| void | setAlignment (Alignment) |
| Qt::Orientation | orientation () const |
| QPoint | pos () const |
| int | length () const |
| void | setLabelAlignment (Qt::Alignment) |
| Qt::Alignment | labelAlignment () const |
| void | setLabelRotation (double rotation) |
| double | labelRotation () const |
| int | maxLabelHeight (const QFont &) const |
| int | maxLabelWidth (const QFont &) const |
| QPoint | labelPosition (double val) const |
| QRect | labelRect (const QFont &, double val) const |
| QSize | labelSize (const QFont &, double val) const |
| QRect | boundingLabelRect (const QFont &, double val) const |
Protected Member Functions | |
| QMatrix | labelMatrix (const QPoint &, const QSize &) const |
| virtual void | drawTick (QPainter *p, double val, int len) const |
| virtual void | drawBackbone (QPainter *p) const |
| virtual void | drawLabel (QPainter *p, double val) const |
Detailed Description
A class for drawing scales.
QwtScaleDraw can be used to draw linear or logarithmic scales. A scale has a position, an alignment and a length, which can be specified . The labels can be rotated and aligned to the ticks using setLabelRotation() and setLabelAlignment().
After a scale division has been specified as a QwtScaleDiv object using QwtAbstractScaleDraw::setScaleDiv(const QwtScaleDiv &s), the scale can be drawn with the QwtAbstractScaleDraw::draw() member.
Member Enumeration Documentation
Alignment of the scale draw
- See also:
- setAlignment(), alignment()
Constructor & Destructor Documentation
| QwtScaleDraw::QwtScaleDraw | ( | ) |
Constructor.
The range of the scale is initialized to [0, 100], The position is at (0, 0) with a length of 100. The orientation is QwtAbstractScaleDraw::Bottom.
| QwtScaleDraw::QwtScaleDraw | ( | const QwtScaleDraw & | other | ) |
Copy constructor.
| QwtScaleDraw::~QwtScaleDraw | ( | ) | [virtual] |
Destructor.
Member Function Documentation
| QwtScaleDraw::Alignment QwtScaleDraw::alignment | ( | ) | const |
Return alignment of the scale
- See also:
- setAlignment()
| QRect QwtScaleDraw::boundingLabelRect | ( | const QFont & | font, | |
| double | value | |||
| ) | const |
Find the bounding rect for the label. The coordinates of the rect are absolute coordinates ( calculated from pos() ). in direction of the tick.
- Parameters:
-
font Font used for painting value Value
- See also:
- labelRect()
| void QwtScaleDraw::drawBackbone | ( | QPainter * | painter | ) | const [protected, virtual] |
Draws the baseline of the scale
- Parameters:
-
painter Painter
- See also:
- drawTick(), drawLabel()
Implements QwtAbstractScaleDraw.
| void QwtScaleDraw::drawLabel | ( | QPainter * | painter, | |
| double | value | |||
| ) | const [protected, virtual] |
Draws the label for a major scale tick
- Parameters:
-
painter Painter value Value
- See also:
- drawTick(), drawBackbone(), boundingLabelRect()
Implements QwtAbstractScaleDraw.
| void QwtScaleDraw::drawTick | ( | QPainter * | painter, | |
| double | value, | |||
| int | len | |||
| ) | const [protected, virtual] |
Draw a tick
- Parameters:
-
painter Painter value Value of the tick len Lenght of the tick
- See also:
- drawBackbone(), drawLabel()
Implements QwtAbstractScaleDraw.
| int QwtScaleDraw::extent | ( | const QPen & | pen, | |
| const QFont & | font | |||
| ) | const [virtual] |
Calculate the width/height that is needed for a vertical/horizontal scale.
The extent is calculated from the pen width of the backbone, the major tick length, the spacing and the maximum width/height of the labels.
- Parameters:
-
pen Pen that is used for painting backbone and ticks font Font used for painting the labels
- See also:
- minLength()
Implements QwtAbstractScaleDraw.
| void QwtScaleDraw::getBorderDistHint | ( | const QFont & | font, | |
| int & | start, | |||
| int & | end | |||
| ) | const |
Determine the minimum border distance.
This member function returns the minimum space needed to draw the mark labels at the scale's endpoints.
- Parameters:
-
font Font start Start border distance end End border distance
| Qt::Alignment QwtScaleDraw::labelAlignment | ( | ) | const |
- Returns:
- the label flags
- See also:
- setLabelAlignment(), labelRotation()
| QMatrix QwtScaleDraw::labelMatrix | ( | const QPoint & | pos, | |
| const QSize & | size | |||
| ) | const [protected] |
Calculate the matrix that is needed to paint a label depending on its alignment and rotation.
- Parameters:
-
pos Position where to paint the label size Size of the label
- See also:
- setLabelAlignment(), setLabelRotation()
| QPoint QwtScaleDraw::labelPosition | ( | double | value | ) | const |
Find the position, where to paint a label
The position has a distance of majTickLength() + spacing() + 1 from the backbone. The direction depends on the alignment()
- Parameters:
-
value Value
| QRect QwtScaleDraw::labelRect | ( | const QFont & | font, | |
| double | value | |||
| ) | const |
Find the bounding rect for the label. The coordinates of the rect are relative to spacing + ticklength from the backbone in direction of the tick.
- Parameters:
-
font Font used for painting value Value
| double QwtScaleDraw::labelRotation | ( | ) | const |
- Returns:
- the label rotation
- See also:
- setLabelRotation(), labelAlignment()
| QSize QwtScaleDraw::labelSize | ( | const QFont & | font, | |
| double | value | |||
| ) | const |
Calculate the size that is needed to draw a label
- Parameters:
-
font Label font value Value
| int QwtScaleDraw::length | ( | ) | const |
- Returns:
- the length of the backbone
- See also:
- setLength(), pos()
| int QwtScaleDraw::maxLabelHeight | ( | const QFont & | font | ) | const |
- Parameters:
-
font Font
- Returns:
- the maximum height of a label
| int QwtScaleDraw::maxLabelWidth | ( | const QFont & | font | ) | const |
- Parameters:
-
font Font
- Returns:
- the maximum width of a label
| int QwtScaleDraw::minLabelDist | ( | const QFont & | font | ) | const |
Determine the minimum distance between two labels, that is necessary that the texts don't overlap.
- Parameters:
-
font Font
- Returns:
- The maximum width of a label
- See also:
- getBorderDistHint()
| int QwtScaleDraw::minLength | ( | const QPen & | pen, | |
| const QFont & | font | |||
| ) | const |
Calculate the minimum length that is needed to draw the scale
- Parameters:
-
pen Pen that is used for painting backbone and ticks font Font used for painting the labels
- See also:
- extent()
| void QwtScaleDraw::move | ( | const QPoint & | pos | ) |
Move the position of the scale.
The meaning of the parameter pos depends on the alignment:
- QwtScaleDraw::LeftScale
- The origin is the topmost point of the backbone. The backbone is a vertical line. Scale marks and labels are drawn at the left of the backbone.
- QwtScaleDraw::RightScale
- The origin is the topmost point of the backbone. The backbone is a vertical line. Scale marks and labels are drawn at the right of the backbone.
- QwtScaleDraw::TopScale
- The origin is the leftmost point of the backbone. The backbone is a horizontal line. Scale marks and labels are drawn above the backbone.
- QwtScaleDraw::BottomScale
- The origin is the leftmost point of the backbone. The backbone is a horizontal line Scale marks and labels are drawn below the backbone.
- Parameters:
-
pos Origin of the scale
- See also:
- pos(), setLength()
| void QwtScaleDraw::move | ( | int | x, | |
| int | y | |||
| ) | [inline] |
Move the position of the scale
- See also:
- move(const QPoint &)
| QwtScaleDraw & QwtScaleDraw::operator= | ( | const QwtScaleDraw & | other | ) |
Assignment operator.
Reimplemented from QwtAbstractScaleDraw.
| Qt::Orientation QwtScaleDraw::orientation | ( | ) | const |
Return the orientation
TopScale, BottomScale are horizontal (Qt::Horizontal) scales, LeftScale, RightScale are vertical (Qt::Vertical) scales.
- See also:
- alignment()
| void QwtScaleDraw::setAlignment | ( | Alignment | align | ) |
Set the alignment of the scale
The default alignment is QwtScaleDraw::BottomScale
- See also:
- alignment()
| void QwtScaleDraw::setLabelAlignment | ( | Qt::Alignment | alignment | ) |
Change the label flags.
Labels are aligned to the point ticklength + spacing away from the backbone.
The alignment is relative to the orientation of the label text. In case of an flags of 0 the label will be aligned depending on the orientation of the scale:
QwtScaleDraw::TopScale: Qt::AlignHCenter | Qt::AlignTop
QwtScaleDraw::BottomScale: Qt::AlignHCenter | Qt::AlignBottom
QwtScaleDraw::LeftScale: Qt::AlignLeft | Qt::AlignVCenter
QwtScaleDraw::RightScale: Qt::AlignRight | Qt::AlignVCenter
Changing the alignment is often necessary for rotated labels.
- Parameters:
-
alignment Or'd Qt::AlignmentFlags <see qnamespace.h>
- See also:
- setLabelRotation(), labelRotation(), labelAlignment()
- Warning:
- The various alignments might be confusing. The alignment of the label is not the alignment of the scale and is not the alignment of the flags (QwtText::flags()) returned from QwtAbstractScaleDraw::label().
| void QwtScaleDraw::setLabelRotation | ( | double | rotation | ) |
Rotate all labels.
When changing the rotation, it might be necessary to adjust the label flags too. Finding a useful combination is often the result of try and error.
- Parameters:
-
rotation Angle in degrees. When changing the label rotation, the label flags often needs to be adjusted too.
- See also:
- setLabelAlignment(), labelRotation(), labelAlignment().
| void QwtScaleDraw::setLength | ( | int | length | ) |
Set the length of the backbone.
The length doesn't include the space needed for overlapping labels.
- See also:
- move(), minLabelDist()
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