UI: It's not possible to add a separator to EnumProperty via Python #68260

New Issue

artem ivanov · 2019-08-05T14:28:11+02:00

artem ivanov commented

2019-08-05 14:28:11 +02:00

System Information
Operating system: Win 10
Graphics card: GTX 1070

Blender Version
Broken: 2.81 9620b8f6bb and earlier

Short description of error

Currently it is not possible to add a separator to EnumProperty via python.

What

Separator in EnumProperty is EnumPropertyItem which looks like that:

EnumPropertyItem sepr = {0, "", 0, NULL, NULL};

*sepr.value       == 0* sepr.identifier  == ""
*sepr.icon        == 0* sepr.name        == NULL
*sepr.description == NULL* Notice `sepr.name == NULL`.

Such items are used for example in Cycles Math node (defined in C):

Why

However, currently it's not possible to make an EnumPropertyItem from python with required sepr.name = NULL (or with other field equal to nullptr).

Part that is responsible for checking if an item is a separator is:
/source/blender/editors/interface/interface.c:ui_def_but_rna__menu
It uses item->identifier- [x] == 0 and item->name == nullptr checks to determine if an item is a separator. (But item->name will never be nullptr if it's created through python).

Code for parsing EnumPropertyItem from python object:

bpy_types.c:1470
        (tmp.name = _PyUnicode_AsStringAndSize(PyTuple_GET_ITEM(item, 1), &name_str_size)) &&

_PyUnicode_AsStringAndSize (which is PyUnicode_AsUTF8AndSize) never returns NULL unless an error occurred.

Solution

Add check for item->name = empty string in ui_def_but_rna__menu. That won't change the behaviour of existing nodes (which use identifier- [x] ==0 && name == nullptr) but will enable separator creation from python via tuple ("", "", "", "", 0).

**System Information** Operating system: Win 10 Graphics card: GTX 1070 **Blender Version** Broken: 2.81 9620b8f6bbcf and earlier **Short description of error** Currently it is not possible to add a separator to **EnumProperty** via python. ### What Separator in **EnumProperty** is **EnumPropertyItem** which looks like that: ``` EnumPropertyItem sepr = {0, "", 0, NULL, NULL}; *sepr.value == 0* sepr.identifier == "" *sepr.icon == 0* sepr.name == NULL *sepr.description == NULL* Notice `sepr.name == NULL`. ``` Such items are used for example in Cycles **Math** node (defined in C): ![image.png](https://archive.blender.org/developer/F7650102/image.png) ### Why However, currently it's not possible to make an **EnumPropertyItem** from python with required `sepr.name = NULL` (or with other field equal to nullptr). Part that is responsible for checking if an item is a separator is: `/source/blender/editors/interface/interface.c:ui_def_but_rna__menu` It uses `item->identifier- [x] == 0` and `item->name == nullptr` checks to determine if an item is a separator. (But `item->name` will never be `nullptr` if it's created through python). ---- Code for parsing **EnumPropertyItem** from python object: ``` bpy_types.c:1470 (tmp.name = _PyUnicode_AsStringAndSize(PyTuple_GET_ITEM(item, 1), &name_str_size)) && ``` `_PyUnicode_AsStringAndSize` (which is `PyUnicode_AsUTF8AndSize`) never returns `NULL` unless an error occurred. ### Solution Add check for `item->name = empty string` in `ui_def_but_rna__menu`. That won't change the behaviour of existing nodes (which use `identifier- [x] ==0 && name == nullptr`) but will enable separator creation from python via tuple ("", "", "", "", 0).

artem ivanov commented

2019-08-05 14:28:11 +02:00

Added subscriber: @ixd

artem ivanov commented

2019-08-05 14:38:59 +02:00

Patch: https://developer.blender.org/D5414

blender-admin commented

2019-08-05 15:10:44 +02:00

This issue was referenced by 916e51a407

This issue was referenced by 916e51a4078b452774b2696d1daeb7286ab3f085

Campbell Barton commented

2019-08-05 15:15:36 +02:00

Changed status from 'Open' to: 'Resolved'

Campbell Barton closed this issue

2019-08-05 15:15:36 +02:00

Campbell Barton self-assigned this 2019-08-05 15:15:36 +02:00

Rombout Versluijs commented

2020-03-18 04:28:16 +01:00

Added subscriber: @RomboutVersluijs

Rombout Versluijs commented

2020-03-18 04:28:16 +01:00

Im tried using this in an enum menu and it divides dropdown into two parts? I also tried with ("", "", "", "", 0) but shows the same. Leaving out 0 returns error. Using bl2.82 on OSX

bpy.types.Scene.sortMenu = bpy.props.EnumProperty(
        name = "Sorting",
        description = "My enum description",
        items = [
            ("reset", "Reset Colors", "Resets color order in active palette"),
            ("", "", "",0),
            ("simple", "Simple", "Simple sorting"),
            ("hsl", "HSL", "HSL sorting"),
            ("hsv", "HSV", "HSV sorting"),
            ("lum", "LUM", "Lumnosity sorting"),
            ("step", "Step 1", "Step sorting"),
            ("stepTwo", "Step 2", "Step sorting clean noise")],
        update=update_Palette)

Im tried using this in an enum menu and it divides dropdown into two parts? I also tried with ("", "", "", "", 0) but shows the same. Leaving out 0 returns error. Using bl2.82 on OSX ``` bpy.types.Scene.sortMenu = bpy.props.EnumProperty( name = "Sorting", description = "My enum description", items = [ ("reset", "Reset Colors", "Resets color order in active palette"), ("", "", "",0), ("simple", "Simple", "Simple sorting"), ("hsl", "HSL", "HSL sorting"), ("hsv", "HSV", "HSV sorting"), ("lum", "LUM", "Lumnosity sorting"), ("step", "Step 1", "Step sorting"), ("stepTwo", "Step 2", "Step sorting clean noise")], update=update_Palette) ``` ![Screen Shot 2020-03-17 at 23.26.12.png](https://archive.blender.org/developer/F8413198/Screen_Shot_2020-03-17_at_23.26.12.png)

Rombout Versluijs commented

2020-03-18 04:37:26 +01:00

It seems it makes columns using that, not the separator as does with a menu

I did a test making the enum longer, repeated it 3 times. It results in 4 columns.

It seems it makes columns using that, not the separator as does with a menu I did a test making the enum longer, repeated it 3 times. It results in 4 columns. ![Screen Shot 2020-03-17 at 23.36.07.png](https://archive.blender.org/developer/F8413208/Screen_Shot_2020-03-17_at_23.36.07.png) ![Screen Shot 2020-03-17 at 23.35.59.png](https://archive.blender.org/developer/F8413207/Screen_Shot_2020-03-17_at_23.35.59.png)

Rombout Versluijs commented

2020-03-18 05:03:30 +01:00

BLender API shows a different solution i just noticed.

Separators may be added using None instead of a tuple. For dynamic values a callback can be passed which returns a list in the same format as the static list. This function must take 2 arguments (self, context), context may be None.

bpy.types.Scene.sortMenu = bpy.props.EnumProperty(
        name = "Sorting",
        description = "My enum description",
        items = [
            ("reset", "Reset Colors", "Resets color order in active palette",0),
            (None),
            ("simple", "Simple", "Simple sorting",2),
            ("hsl", "HSL", "HSL sorting",3),
            ("hsv", "HSV", "HSV sorting",4),
            ("lum", "LUM", "Lumnosity sorting",5),
            ("step", "Step 1", "Step sorting",6),
            ("stepTwo", "Step 2", "Step sorting clean noise",7)
            ],
        update=update_Palette
        )

See at the bottom, now using None it does work

BLender API shows a different solution i just noticed. > Separators may be added using None instead of a tuple. For dynamic values a callback can be passed which returns a list in the same format as the static list. This function must take 2 arguments (self, context), context may be None. > ``` bpy.types.Scene.sortMenu = bpy.props.EnumProperty( name = "Sorting", description = "My enum description", items = [ ("reset", "Reset Colors", "Resets color order in active palette",0), (None), ("simple", "Simple", "Simple sorting",2), ("hsl", "HSL", "HSL sorting",3), ("hsv", "HSV", "HSV sorting",4), ("lum", "LUM", "Lumnosity sorting",5), ("step", "Step 1", "Step sorting",6), ("stepTwo", "Step 2", "Step sorting clean noise",7) ], update=update_Palette ) ``` See at the bottom, now using None it does work ![Screen Shot 2020-03-18 at 00.02.39.png](https://archive.blender.org/developer/F8413236/Screen_Shot_2020-03-18_at_00.02.39.png)

Rombout Versluijs commented

2020-03-19 21:39:51 +01:00

PS i noticed some of Blender enum menu's also show this weird horizontal tabbing. For instance in Preferences > Addons > Sort Menu
Perhaps here its intentional since its probably more clear to read like this compared to a big list. But it looks kinda sloppy, its not aligning nice

PS i noticed some of Blender enum menu's also show this weird horizontal tabbing. For instance in Preferences > Addons > Sort Menu Perhaps here its intentional since its probably more clear to read like this compared to a big list. But it looks kinda sloppy, its not aligning nice ![keyfilter_wrong enum list usage.png](https://archive.blender.org/developer/F8416427/keyfilter_wrong_enum_list_usage.png)

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UI: It's not possible to add a separator to EnumProperty via Python #68260

What

Why

Solution