QwtAbstractScaleDraw Class Reference
A abstract base class for drawing scales. More...
#include <qwt_abstract_scale_draw.h>
Public Types | |
| enum | ScaleComponent { Backbone = 1, Ticks = 2, Labels = 4 } |
Public Member Functions | |
| QwtAbstractScaleDraw () | |
| QwtAbstractScaleDraw (const QwtAbstractScaleDraw &) | |
| virtual | ~QwtAbstractScaleDraw () |
| QwtAbstractScaleDraw & | operator= (const QwtAbstractScaleDraw &) |
| void | setScaleDiv (const QwtScaleDiv &s) |
| const QwtScaleDiv & | scaleDiv () const |
| void | setTransformation (QwtScaleTransformation *) |
| const QwtScaleMap & | map () const |
| void | enableComponent (ScaleComponent, bool enable=true) |
| bool | hasComponent (ScaleComponent) const |
| void | setTickLength (QwtScaleDiv::TickType, int length) |
| int | tickLength (QwtScaleDiv::TickType) const |
| int | majTickLength () const |
| void | setSpacing (int margin) |
| int | spacing () const |
| virtual void | draw (QPainter *, const QPalette &) const |
| virtual QwtText | label (double) const |
| virtual int | extent (const QPen &, const QFont &) const =0 |
| void | setMinimumExtent (int) |
| int | minimumExtent () const |
| QwtScaleMap & | scaleMap () |
Protected Member Functions | |
| virtual void | drawTick (QPainter *painter, double value, int len) const =0 |
| virtual void | drawBackbone (QPainter *painter) const =0 |
| virtual void | drawLabel (QPainter *painter, double value) const =0 |
| void | invalidateCache () |
| const QwtText & | tickLabel (const QFont &, double value) const |
Detailed Description
A abstract base class for drawing scales.
QwtAbstractScaleDraw can be used to draw linear or logarithmic scales.
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
Constructor & Destructor Documentation
| QwtAbstractScaleDraw::QwtAbstractScaleDraw | ( | ) |
Constructor.
The range of the scale is initialized to [0, 100], The spacing (distance between ticks and labels) is set to 4, the tick lengths are set to 4,6 and 8 pixels
| QwtAbstractScaleDraw::QwtAbstractScaleDraw | ( | const QwtAbstractScaleDraw & | other | ) |
Copy constructor.
| QwtAbstractScaleDraw::~QwtAbstractScaleDraw | ( | ) | [virtual] |
Destructor.
Member Function Documentation
| void QwtAbstractScaleDraw::draw | ( | QPainter * | painter, | |
| const QPalette & | palette | |||
| ) | const [virtual] |
Draw the scale.
- Parameters:
-
painter The painter palette Palette, text color is used for the labels, foreground color for ticks and backbone
| virtual void QwtAbstractScaleDraw::drawBackbone | ( | QPainter * | painter | ) | const [protected, pure virtual] |
Draws the baseline of the scale
- Parameters:
-
painter Painter
- See also:
- drawTick(), drawLabel()
Implemented in QwtRoundScaleDraw, and QwtScaleDraw.
| virtual void QwtAbstractScaleDraw::drawLabel | ( | QPainter * | painter, | |
| double | value | |||
| ) | const [protected, pure virtual] |
Draws the label for a major scale tick
- Parameters:
-
painter Painter value Value
- See also:
- drawTick, drawBackbone
Implemented in QwtRoundScaleDraw, and QwtScaleDraw.
| virtual void QwtAbstractScaleDraw::drawTick | ( | QPainter * | painter, | |
| double | value, | |||
| int | len | |||
| ) | const [protected, pure virtual] |
Draw a tick
- Parameters:
-
painter Painter value Value of the tick len Lenght of the tick
- See also:
- drawBackbone(), drawLabel()
Implemented in QwtRoundScaleDraw, and QwtScaleDraw.
| void QwtAbstractScaleDraw::enableComponent | ( | ScaleComponent | component, | |
| bool | enable = true | |||
| ) |
En/Disable a component of the scale
- Parameters:
-
component Scale component enable On/Off
- See also:
- hasComponent()
| virtual int QwtAbstractScaleDraw::extent | ( | const QPen & | , | |
| const QFont & | ||||
| ) | const [pure virtual] |
Calculate the extent
The extent is the distcance from the baseline to the outermost pixel of the scale draw in opposite to its orientation. It is at least minimumExtent() pixels.
- See also:
- setMinimumExtent(), minimumExtent()
Implemented in QwtRoundScaleDraw, and QwtScaleDraw.
| bool QwtAbstractScaleDraw::hasComponent | ( | ScaleComponent | component | ) | const |
Check if a component is enabled
- See also:
- enableComponent()
| void QwtAbstractScaleDraw::invalidateCache | ( | ) | [protected] |
Invalidate the cache used by QwtAbstractScaleDraw::tickLabel
The cache is invalidated, when a new QwtScaleDiv is set. If the labels need to be changed. while the same QwtScaleDiv is set, QwtAbstractScaleDraw::invalidateCache needs to be called manually.
| QwtText QwtAbstractScaleDraw::label | ( | double | value | ) | const [virtual] |
Convert a value into its representing label.
The value is converted to a plain text using QLocale::system().toString(value). This method is often overloaded by applications to have individual labels.
- Parameters:
-
value Value
- Returns:
- Label string.
Reimplemented in QwtDialScaleDraw.
| int QwtAbstractScaleDraw::majTickLength | ( | ) | const |
The same as QwtAbstractScaleDraw::tickLength(QwtScaleDiv::MajorTick).
| const QwtScaleMap & QwtAbstractScaleDraw::map | ( | ) | const |
- Returns:
- Map how to translate between scale and pixel values
| int QwtAbstractScaleDraw::minimumExtent | ( | ) | const |
Get the minimum extent
- See also:
- extent(), setMinimumExtent()
| QwtAbstractScaleDraw & QwtAbstractScaleDraw::operator= | ( | const QwtAbstractScaleDraw & | other | ) |
Assignment operator.
Reimplemented in QwtRoundScaleDraw, and QwtScaleDraw.
| const QwtScaleDiv & QwtAbstractScaleDraw::scaleDiv | ( | ) | const |
- Returns:
- scale division
| QwtScaleMap & QwtAbstractScaleDraw::scaleMap | ( | ) |
- Returns:
- Map how to translate between scale and pixel values
| void QwtAbstractScaleDraw::setMinimumExtent | ( | int | minExtent | ) |
Set a minimum for the extent.
The extent is calculated from the coomponents of the scale draw. In situations, where the labels are changing and the layout depends on the extent (f.e scrolling a scale), setting an upper limit as minimum extent will avoid jumps of the layout.
- Parameters:
-
minExtent Minimum extent
- See also:
- extent(), minimumExtent()
| void QwtAbstractScaleDraw::setScaleDiv | ( | const QwtScaleDiv & | sd | ) |
Change the scale division
- Parameters:
-
sd New scale division
| void QwtAbstractScaleDraw::setSpacing | ( | int | spacing | ) |
Set the spacing between tick and labels.
The spacing is the distance between ticks and labels. The default spacing is 4 pixels.
- Parameters:
-
spacing Spacing
- See also:
- spacing()
| void QwtAbstractScaleDraw::setTickLength | ( | QwtScaleDiv::TickType | tickType, | |
| int | length | |||
| ) |
Set the length of the ticks
- Parameters:
-
tickType Tick type length New length
- Warning:
- the length is limited to [0..1000]
| void QwtAbstractScaleDraw::setTransformation | ( | QwtScaleTransformation * | transformation | ) |
Change the transformation of the scale
- Parameters:
-
transformation New scale transformation
| int QwtAbstractScaleDraw::spacing | ( | ) | const |
Get the spacing.
The spacing is the distance between ticks and labels. The default spacing is 4 pixels.
- See also:
- setSpacing()
| const QwtText & QwtAbstractScaleDraw::tickLabel | ( | const QFont & | font, | |
| double | value | |||
| ) | const [protected] |
Convert a value into its representing label and cache it.
The conversion between value and label is called very often in the layout and painting code. Unfortunately the calculation of the label sizes might be slow (really slow for rich text in Qt4), so it's necessary to cache the labels.
- Parameters:
-
font Font value Value
- Returns:
- Tick label
| int QwtAbstractScaleDraw::tickLength | ( | QwtScaleDiv::TickType | tickType | ) | const |
Return the length of the ticks
- See also:
- setTickLength(), majTickLength()
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