A class for drawing scales.
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#include <qwt_scale_draw.h>
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.
Alignment of the scale draw
- See also
- setAlignment(), alignment()
| Enumerator |
|---|
| BottomScale |
The scale is below.
|
| TopScale |
The scale is above.
|
| LeftScale |
The scale is left.
|
| RightScale |
The scale is right.
|
| 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.
Return alignment of the scale
- See also
- setAlignment()
- Returns
- Alignment of the scale
| QRect QwtScaleDraw::boundingLabelRect |
( |
const QFont & |
font, |
|
|
double |
value |
|
) |
| const |
Find the bounding rectangle for the label.
The coordinates of the rectangle are absolute ( calculated from pos() ). in direction of the tick.
- Parameters
-
| font | Font used for painting |
| value | Value |
- Returns
- Bounding rectangle
- See also
- labelRect()
| void QwtScaleDraw::drawBackbone |
( |
QPainter * |
painter | ) |
const |
|
protectedvirtual |
| void QwtScaleDraw::drawLabel |
( |
QPainter * |
painter, |
|
|
double |
value |
|
) |
| const |
|
protectedvirtual |
| void QwtScaleDraw::drawTick |
( |
QPainter * |
painter, |
|
|
double |
value, |
|
|
double |
len |
|
) |
| const |
|
protectedvirtual |
| double QwtScaleDraw::extent |
( |
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
-
| font | Font used for painting the labels |
- Returns
- Extent
- 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 |
| QPointF QwtScaleDraw::labelPosition |
( |
double |
value | ) |
const |
Find the position, where to paint a label
The position has a distance that depends on the length of the ticks in direction of the alignment().
- Parameters
-
- Returns
- Position, where to paint a label
| QRectF QwtScaleDraw::labelRect |
( |
const QFont & |
font, |
|
|
double |
value |
|
) |
| const |
Find the bounding rectangle for the label. The coordinates of the rectangle are relative to spacing + tick length from the backbone in direction of the tick.
- Parameters
-
| font | Font used for painting |
| value | Value |
- Returns
- Bounding rectangle that is needed to draw a label
| double QwtScaleDraw::labelRotation |
( |
| ) |
const |
| QSizeF QwtScaleDraw::labelSize |
( |
const QFont & |
font, |
|
|
double |
value |
|
) |
| const |
Calculate the size that is needed to draw a label
- Parameters
-
| font | Label font |
| value | Value |
- Returns
- Size that is needed to draw a label
| QTransform QwtScaleDraw::labelTransformation |
( |
const QPointF & |
pos, |
|
|
const QSizeF & |
size |
|
) |
| const |
|
protected |
Calculate the transformation 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 |
- Returns
- Transformation matrix
- See also
- setLabelAlignment(), setLabelRotation()
| double QwtScaleDraw::length |
( |
| ) |
const |
| int QwtScaleDraw::maxLabelHeight |
( |
const QFont & |
font | ) |
const |
- Parameters
-
- Returns
- the maximum height of a label
| int QwtScaleDraw::maxLabelWidth |
( |
const QFont & |
font | ) |
const |
- Parameters
-
- 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
-
- Returns
- The maximum width of a label
- See also
- getBorderDistHint()
| int QwtScaleDraw::minLength |
( |
const QFont & |
font | ) |
const |
Calculate the minimum length that is needed to draw the scale
- Parameters
-
| font | Font used for painting the labels |
- Returns
- Minimum length that is needed to draw the scale
- See also
- extent()
| void QwtScaleDraw::move |
( |
double |
x, |
|
|
double |
y |
|
) |
| |
|
inline |
| void QwtScaleDraw::move |
( |
const QPointF & |
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
-
- See also
- pos(), setLength()
| Qt::Orientation QwtScaleDraw::orientation |
( |
| ) |
const |
Return the orientation
TopScale, BottomScale are horizontal (Qt::Horizontal) scales, LeftScale, RightScale are vertical (Qt::Vertical) scales.
- Returns
- Orientation of the scale
- See also
- alignment()
| QPointF QwtScaleDraw::pos |
( |
| ) |
const |
| void QwtScaleDraw::setAlignment |
( |
Alignment |
align | ) |
|
| void QwtScaleDraw::setLabelAlignment |
( |
Qt::Alignment |
alignment | ) |
|
Change the label flags.
Labels are aligned to the point tick length + 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\n
QwtScaleDraw::BottomScale: Qt::AlignHCenter | Qt::AlignBottom\n
QwtScaleDraw::LeftScale: Qt::AlignLeft | Qt::AlignVCenter\n
QwtScaleDraw::RightScale: Qt::AlignRight | Qt::AlignVCenter\n
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 |
( |
double |
length | ) |
|
Set the length of the backbone.
The length doesn't include the space needed for overlapping labels.
- Parameters
-
| length | Length of the backbone |
- See also
- move(), minLabelDist()
Public Types inherited from QwtAbstractScaleDraw
1.8.11 
