QDoubleSpinBox allows the user to choose a value by clicking the up and down buttons or by pressing Up or Down on the keyboard to increase or decrease the value currently displayed. The user can also type the value in manually. The spin box supports double values but can be extended to use different strings with
Every time the value changes
valueChanged() and signals, the former providing a double and the latter a
QString . The signal provides the value with both
suffix() . The current value can be fetched with
value() and set with
Clicking the up and down buttons or using the keyboard accelerator’s Up and Down arrows will increase or decrease the current value in steps of size
singleStep() . If you want to change this behavior you can reimplement the virtual function
stepBy() . The minimum and maximum value and the step size can be set using one of the constructors, and can be changed later with
setSingleStep() . The spinbox has a default precision of 2 decimal places but this can be changed using
Most spin boxes are directional, but
QDoubleSpinBox can also operate as a circular spin box, i.e. if the range is 0.0-99.9 and the current value is 99.9, clicking “up” will give 0 if
wrapping() is set to true. Use
setWrapping() if you want circular behavior.
The displayed value can be prepended and appended with arbitrary strings indicating, for example, currency or the unit of measurement. See
setSuffix() . The text in the spin box is retrieved with
text() (which includes any
suffix() ), or with
cleanText() (which has no
prefix() , no
suffix() and no leading or trailing whitespace).
The displayed value of the
QDoubleSpinBox is limited to 18 characters in addition to eventual prefix and suffix content. This limitation is used to keep the double spin box usable even with extremely large values.
Constructs a spin box with 0.0 as minimum value and 99.99 as maximum value, a step value of 1.0 and a precision of 2 decimal places. The value is initially set to 0.00. The spin box has the given
- Return type
Convenience function to set the
maximum values with a single function call.
Note: The maximum and minimum values will be rounded to match the decimals property.
is equivalent to:
Sets the step type for the spin box to
stepType, which is single step or adaptive decimal step.
Adaptive decimal step means that the step size will continuously be adjusted to one power of ten below the current
value . So when the value is 1100, the step is set to 100, so stepping up once increases it to 1200. For 1200 stepping up takes it to 1300. For negative values, stepping down from -1100 goes to -1200.
It also works for any decimal values, 0.041 is increased to 0.042 by stepping once.
Step direction is taken into account to handle edges cases, so that stepping down from 100 takes the value to 99 instead of 90. Thus a step up followed by a step down – or vice versa – always lands on the starting value; 99 -> 100 -> 99.
arg__1 – str
- Return type
This virtual function is used by the spin box whenever it needs to display the given
value. The default implementation returns a string containing
value printed using
decimals() ) and will remove the thousand separator unless
setGroupSeparatorShown() is set. Reimplementations may return anything.
If you reimplement this, you may also need to reimplement
text – str
- Return type
This virtual function is used by the spin box whenever it needs to interpret
text entered by the user as a value.
Subclasses that need to display spin box values in a non-numeric way need to reimplement this function.
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