A class for drawing scales.
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#include <qwt_scale_draw.h>
Public Types |
enum | Alignment { BottomScale,
TopScale,
LeftScale,
RightScale
} |
Public Member Functions |
| QwtScaleDraw () |
| Constructor.
|
virtual | ~QwtScaleDraw () |
| Destructor.
|
void | getBorderDistHint (const QFont &, int &start, int &end) const |
| Determine the minimum border distance.
|
int | minLabelDist (const QFont &) const |
int | minLength (const QFont &) const |
virtual double | extent (const QFont &) const |
void | move (double x, double y) |
void | move (const QPointF &) |
| Move the position of the scale.
|
void | setLength (double length) |
Alignment | alignment () const |
void | setAlignment (Alignment) |
Qt::Orientation | orientation () const |
QPointF | pos () const |
double | length () const |
void | setLabelAlignment (Qt::Alignment) |
| Change the label flags.
|
Qt::Alignment | labelAlignment () const |
void | setLabelRotation (double rotation) |
double | labelRotation () const |
int | maxLabelHeight (const QFont &) const |
int | maxLabelWidth (const QFont &) const |
QPointF | labelPosition (double val) const |
QRectF | labelRect (const QFont &, double val) const |
QSizeF | labelSize (const QFont &, double val) const |
QRect | boundingLabelRect (const QFont &, double val) const |
| Find the bounding rectangle for the label.
|
Protected Member Functions |
QTransform | labelTransformation (const QPointF &, const QSizeF &) const |
virtual void | drawTick (QPainter *, double val, double len) const |
virtual void | drawBackbone (QPainter *) const |
virtual void | drawLabel (QPainter *, 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()
- Enumerator:
BottomScale |
The scale is below.
|
TopScale |
The scale is above.
|
LeftScale |
The scale is left.
|
RightScale |
The scale is right.
|
Constructor & Destructor Documentation
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.
Member Function Documentation
Return alignment of the scale
- See also:
- setAlignment()
- Returns:
- Alignment of the scale
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()
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.
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 |
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
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
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
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()
- Parameters:
-
- Returns:
- the maximum height of a label
- Parameters:
-
- Returns:
- the maximum width of a label
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()
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()
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()
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()
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
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().
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().
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()
List of all members.