Data defined size does not block the normal size menu

[qgib]

Author Name: matteo ghetta (@ghtmtt)
Original Redmine Issue: 22073
Affected QGIS version: 3.6.2
Redmine category:symbology

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Happens both in the Style panel and in the main Symbology dialog.

Basically when a data defined value is used to overwrite the default size of the marker in the sub dialog it is still possible to change the size value (and the preview updates accordingly). The layer keeps the data defined values entered.

Two pictures worth a thousand words

QGI 3.4.6 and master

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• b2.gif (matteo ghetta)
• b1.png (matteo ghetta)
• ksnip_20190520-135720.png (matteo ghetta)

[qgib]

Author Name: Alessandro Pasotti (@elpaso)

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Big question: is this issue limited to these two widgets or is it a general issue for ALL widgets and controls that have a Data-Defined property?

Because if it's the second, we might better think of a general solution instead of patching the widgets one by one.

[qgib]

Author Name: Alessandro Pasotti (@elpaso)

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• status_id was changed from Open to Feedback

[qgib]

Author Name: matteo ghetta (@ghtmtt)

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I think it is a general situation for all the widgets. I tried with some of them (rotation, size) entering a field value while the same happens also for an expression entered ('solid' in the stroke style). Image attached.

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• 14955 was configured as ksnip_20190520-135720.png

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• ksnip_20190520-135720.png (matteo ghetta)

[qgib]

Author Name: Nyall Dawson (@nyalldawson)

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This is by design - the data defined overrides are overrides, and the original value is used whenever the override is null. So it's important to be able to change it even when an override is in place.

[qgib]

Author Name: matteo ghetta (@ghtmtt)

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but it seems weird to me that, e.g. in case of the size, in the "main" dock panel the chance to enter a value is greyed out while, always for the size, it is available in the nested dock menu.

[qgib]

Author Name: Alessandro Pasotti (@elpaso)

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Maybe we could change the tooltip to tell the user that DD is active and the value will be used as a default when DD expression is null.