expression_variable_widgets_floating_dialog_allvars.py

# 2022-08 Johannes Kröger (WhereGroup), GPLv3

# Silly interface to interactively adjust (project) variable
# values in real time. Meant to be used with expressions.
# Use @variable_name in expressions and have a go at it.

# - Displays widgets for editing int/float project variables
# - Refreshes canvas after any change in value

# WIP, might make it a plugin some day

from functools import partial

def update_var(var_name, value):
    #print(f"update_var({value=}, {var_name=})")  # only for debugging, slow!
    QgsExpressionContextUtils.setProjectVariable(QgsProject.instance(), var_name, str(value))  # must be str again...
    iface.mapCanvas().refreshAllLayers()  # TODO check if something more lean works... .refresh() does not!
    

widgets = []  # -> list of (var_name, widget)

project_scope = QgsExpressionContextUtils.projectScope(QgsProject.instance())
variable_names = sorted(project_scope.variableNames())
for var_name in variable_names:
    
    # var "project_filename" gave:
    # TypeError: unable to convert a C++ 'QVariantList' instance to a Python object
    try:
        var_value = project_scope.variable(var_name)
    except TypeError:
        continue

    # lets be lazy for now and skip all default ones (and potentially more)
    if "project" in var_name or var_name == 'layer_ids':
        continue

    # float to float, int to int, str ignored for now (TODO add str for colors etc)
    value = None
    try:
        value = int(var_value)
    except (ValueError, TypeError):
        try:
            value = float(var_value)
        except (ValueError, TypeError):
            pass

    print(f"{var_name}: {var_value} ({type(value)}")

    widget = None
    #not_zero_additor = 0.00000000000000001  # to avoid 0 being uneditable
    if isinstance(value, float):
        double_spinbox = QDoubleSpinBox()
        #double_spinbox.setRange(-(value+not_zero_additor)*10, (value+not_zero_additor)*10)
        #double_spinbox.setSingleStep(0.1)
        widget = double_spinbox
    elif isinstance(value, int):
        slider = QSlider(Qt.Horizontal)
        #slider.setRange(-(value+not_zero_additor)*10, (value+not_zero_additor)*10)
        #slider.setSingleStep(1)
        widget = slider
    else:
        # skip unsupported types for now
        continue

    widget.setValue(value)
    widget.valueChanged.connect(partial(update_var, var_name))

    widgets.append((var_name, widget))

dlg = QDialog(iface.mainWindow())
dlg.setWindowTitle("Project Variable Manipulator 3000")

layout = QVBoxLayout()
for var_name, widget in widgets:
    sublayout = QHBoxLayout()
    sublayout.addWidget(QLabel(var_name))
    sublayout.addWidget(widget)
    layout.addLayout(sublayout)
dlg.setLayout(layout)

dlg.show()

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