OcdFileExport: Zero angle on non-rotatable objects

[lpechacek]

Text and point objects with non-rotatable symbol appear orientated to north in Mapper. When writing XML, Mapper skips the rotation attribute in Object::save(QXmlStreamWriter&).

However, if a map is opened from OCD format, the north rotation lock is silently removed from point symbols. The user may restore the rotation lock by either replacing the symbol set or a manual intervention. Then if the map is saved in OCD format, the symbol has north orientation (rotation lock) and the object has rotation angle set. If the map is reopened in Mapper, the cycle repeats - there is a rotated object with a point symbol, so Mapper removes the lock again.

The text symbols do not have the rotation lock removal logic in OCD import and text appears rotated regardless of the lock setting. As a result, north oriented text is rendered as rotated and cannot be straightened by the Rotate pattern tool. The Rotate object tool, which is enabled for the object in question, creates funny effects.

This patch aligns the export logic in OCD export path with the XML counterpart.

[dl3sdo]

Text and point objects with non-rotatable symbol appear orientated to north in Mapper. When writing XML, Mapper skips the rotation attribute in Object::save(QXmlStreamWriter&).

Partly, due to text appears rotated regardless of the lock setting (as you pointed out), text objects with non-rotatable symbol don't always appear orientated to north in Mapper (but I propose to change that).

However, if a map is opened from OCD format, the north rotation lock is silently removed from point symbols. The user may restore the rotation lock by either replacing the symbol set or a manual intervention. Then if the map is saved in OCD format, the symbol has north orientation (rotation lock) and the object has rotation angle set. If the map is reopened in Mapper, the cycle repeats - there is a rotated object with a point symbol, so Mapper removes the lock again.

The north rotation lock is not always removed from the point symbol, it depends on the rotation value: only if there is a rotation, it's being removed (and thus the objects appears the same as in OCAD), with the exception in #2498.

The text symbols do not have the rotation lock removal logic in OCD import and text appears rotated regardless of the lock setting. As a result, north oriented text is rendered as rotated and cannot be straightened by the Rotate pattern tool. The Rotate object tool, which is enabled for the object in question, creates funny effects.

This patch aligns the export logic in OCD export path with the XML counterpart.

Yes, it does but the patch will also break OCD roundtrip: importing a rotated text object might result in loosing the rotation on export to OCD whereas for rotated point objects rotated point objects would always loose their rotation.

Right now there is an inconsistency especially for text objects:
If the text symbol is made rotatable, the text object is rotated and if then the text symbol is made not-rotatable, the text will still be rendered rotated (which is indeed confusing). Saving such a file as XML will remove the rotation value and thus the visual appearance will change on reopening, something which should not happen. For OCD export everything would be fine today (same visual appearance).
For point objects:
If the point symbol is made rotatable, the point object is rotated and if then the point symbol is made not-rotatable, the point will be rendered not-rotated. Saving such a file as XML will remove the rotation value and thus the visual appearance will not change on reopening. For OCD export the object would be exported rotated and thus the visual appearance would be different.

I propose to change the behavior in text appears rotated regardless of the lock setting to auto rotation_rad = symbol->isRotatable() ? text_object->getRotation() : qreal(0);
to align rendering of text objects with point objects.
If the text rendering change is applied, then applying your patch will

• lead to the same visual appearance in OCAD as in Mapper
• and align the export logic in OCD export path with the XML counterpart.