TaurusValueSpinBox arrows do not work

[cmft]

There is a regression in TaurusValueSpinBox. Press the arrows does not change the value. It works in 4.1.1

[cpascual]

Confirmed.
The following code can be used to test if the code is affected by this bug:

from taurus.qt.qtgui.application import TaurusApplication
from taurus.qt.qtgui.input import TaurusValueSpinBox
import sys
app = TaurusApplication()
w = TaurusValueSpinBox()
model = 'sys/tg_test/1/double_scalar'
w.setModel(model)
a = w.text()
w.stepUp()
b = w.text()
assert (a != b)
print "all ok"

[cpascual]

... and using it with git bisect, we find that things got broken in 0aaa3e1 :

taurus(release-Jan18)$ git bisect start release-Jan18 4.1.1          
Bisecting: 176 revisions left to test after this (roughly 8 steps)
[c974aa1106af3aaf18918f134d7c7148bbdfd4ec] Merge remote-tracking branch 'taurus-org/develop' into delayed_subscriber
taurus((c974aa11...)|BISECTING)$ git bisect run python ~/taurusbug707.py
(...)
0aaa3e18104c1e0dadddb54c3579cf1da93d0938 is the first bad commit
(...)
Date:   Thu Jan 18 15:05:20 2018 +0100

    bugfix lineedit with units when model specifies, in fragments, to show only the magnitude

[cpascual]

I think I located the problem.

It is in TaurusValueLineEdit.setValue() where a call to displayValue(v) was changed to getDisplayValue(v) in 0aaa3e1. The problem is that while displayValue(v) returns a str representation of v, getDisplayValue() returns a str repr of the current model object value (which in this case it is the old value). In fact the current code is buggy because by passing v to getDisplayValue(), v is interpreted as the cache= arg.... which makes no sense.

I think that the solution should be based on:

• Fixing setValue for TaurusValueLineEdit
• and possibly implementing {get,set}Value for TaurusValueSpinBox

[cmft]

Yesterday, I arrived to the same conclusion. But I did not find a good solution:

This can be one, replacing
v_str = str(self.getDisplayValue(v))
by

if self.modelFragmentName and ".magnitude" in self.modelFragmentName:
     v = v.magnitude
 v_str = str(self.displayValue(v))

[cpascual]

Hi @cmft . The solution that you propose could "work" but as it is it looks a bit fragile to me.
I will propose something similar, but based on displayValue and attending to the following considerations:

• The fragments support was introduced in Spinbox was showing units even if the model use fragments to display only the magnitude #669 for solving one specific use case: allowing to display the wvalue without units. IMHO supporting fragments generically in TaurusValueLineEdit is problematic (e.g. it makes little sense to use "rvalue" as a fragment since "wvalue" will be modified when eventually applying). Therefore for now we can limit the fragment support in line edits to the "wvalue.magnitude" case.

• In general, a line edit should leave unaltered any text manually entered by the user. Therefore the fragment (or format!) should only be applied in a line edit in two situations:

  • at initialization
  • when modifying the text via step increments (either by using spinbox arrows or when using the keyboard arrows or mouse wheel on a line edit )

[cpascual]

Closed via 72ecf52