collagraph custom QLayout

[jamesdbrock]

Following up on https://github.com/orgs/fork-tongue/discussions/104

I would like use a custom QLayout like https://doc.qt.io/qtforpython-6/examples/example_widgets_layouts_flowlayout.html

renderer = PySideRenderer(autoshow=False)
renderer.register("FlowLayout", FlowLayout)

        cg.h(
            "FlowLayout",
            {},
            cg.h(
                "Button",
                {
                    "text": "New Project",
                },
            ),
        )

TypeError: Specified type '<class 'flowlayout.FlowLayout'>' not a subclass of QWidget

Is there a way to register custom QLayouts like we register custom QWidgets?

[jamesdbrock]

I get the feeling that adding QLayouts would require changes to https://github.com/fork-tongue/collagraph/blob/master/collagraph/renderers/pyside/objects/widget.py

[berendkleinhaneveld]

Currently it is not supported: only the basic QBoxLayout, QGridLayout and QFormLayout are supported through a special layout attribute for a widget. You can see how that works here:

collagraph/collagraph/renderers/pyside/objects/widget.py

Line 66 in c23e173

if attr == "layout":

An example of that can be seen here: https://github.com/fork-tongue/collagraph/blob/master/examples/layout-example.py
You need to pass a "layout" dict as a prop to the widget, and pass a "type" to select the type of layout to use.

We could add an extra if-else statement in the widget.set_attribute call to check whether the layout type name is present in TYPE_MAPPING dict. This would make it possible to register a custom layout with a certain name and then use it as a "type" in the "layout" dict:

renderer = PySideRenderer()
renderer.register("flow", FlowLayout)

cg.h(
    "widget",
    {
        "layout": {
            "type": "flow",
            # ... and any other attributes
            # that should be applied to the
            # layout object
        }
    },
    cg.h(
        "Button",
        {
            "text": "New Project",
        },
    ),
)

[berendkleinhaneveld]

FYI: I've opened #113 which makes it possible to register custom layouts, like so:

renderer = PySideRenderer()
renderer.register_layout("flow", FlowLayout)
...

# or with a decorator
@PySideRenderer.register_layout("flow")
class FlowLayout(QLayout):
    ...

Also custom widgets (and insert/remove/set_attr) can be registered with decorators.