Quick Start

Basics

In magicgui, you can convert functions into widgets. For instance,

from magicgui import magicgui

@magicgui
def print_text(text: str):
    print(text)

print_text.show()

will create a widget that is composed of a line edit (for the input argument text) and a call button.

Similarly, with magicclass decorator, you can convert a Python class into a magicgui's Container widget and its methods appear as push buttons. When a button is clicked, the corresponding magicgui will be popped up.

from magicclass import magicclass

@magicclass
class MyClass:
    def set_value(self, value: str):
        self.value = value

    def print_value(self):
        print(self.value)

ui = MyClass()
ui.show()

Note

Methods whose names start with "_" are considered as private functions so that they will not be converted into widgets.

Note

ui.print_value is a method, and ui["print_value"] is a button widget. To get the FunctionGui widget, use get_function_gui function.

from magicclass import get_function_gui

print(get_function_gui(ui.print_value))

With exactly the same class design, you can also create a menu bar, a context menu or a tool bar, using @magicmenu, @magiccontext and @magictoolbar respectively. See here for more details.

Use Other Widgets in magic-class

Other magicgui's widgets can also be used inside magic-classes by using field.

from magicgui.widgets import LineEdit, Slider
from magicclass import magicclass, field

@magicclass
class MyClass:
    s = field(LineEdit, label="Name:")
    i = field(Slider, label="Age:", options={"max": 100})

    def print(self):
        print(f"{self.s.value} ({self.i.value})")

ui = MyClass()
ui.show()

If a method is decorated with @magicgui, it will directly added in the container widget, in place of a push button. This is natural because decorated methods are no longer functions, but FunctionGui widgets.

from magicgui import magicgui
from magicclass import magicclass

@magicclass
class MyClass:
    @magicgui
    def input_parameters(self, s: str, i: int):
        self.s = s
        self.i = i

    def print(self):
        print(f"{self.s} ({self.i})")

ui = MyClass()
ui.show()

GUI-specific Settings

In :mod:magicclass, GUI-specific settings are defined by decorators to keep code tidy.

"GUI-specific settings" include

Widget options (such as the limits of a slider)
Widget designs (such as the text of a button)
Whether to be recorded to macro.

Parameter Options

In magicgui you can define parameter options with keyword arguments:

@magicgui(a={"widget_type": "Slider", "step": 10})
def f(a: int): ...

However, magic classes need another way to do this because magicgui will never be called by users.

magicclass uses set_options decorator instead.

from magicclass import magicclass, set_options

@magicclass
class Main:
    @set_options(a={"widget_type": "Slider", "step": 10})
    def f(self, a: int): ...

ui = Main()
ui.show()

Change Button Designs

Aside from those options of magicgui popup widget to run functions, you may also want to change the design of button itself. magicclass uses set_design decorator to do this.

from magicclass import magicclass, set_design

@magicclass
class Main:
    @set_design(text="Click (if you want)", min_height=120)
    def f(self): ...

ui = Main()
ui.show()

Post Initialization

Widgets are constructed only after __init__ is called. To change widget designs or geometries, you should not call those methods in __init__ because they are not constructed yet.

Similar to the builtin dataclass, __post_init__ method is used as the post initalization procedure. It is called after widget is completely built.

@magicclass
class Main:
    def __init__(self):
        # self["func"] <-- this is not correct. Button "func" is not ready!
        ...

    def __post_init__(self):
        self["func"].min_height = 100

    def func(self): ...

Code Completion

A problem of using decorators to overwrite classes is code completion. When you are coding, the classes do not inherits magic classes yet, so IDE and console don't know they will have attributes such as self.parent_viewer or self.name.

All the magic classes inherits MagicTemplate class. This class is designed in a way which does not interfere with magic class decorators, while provides enough information of typings and annotations.

from magicclass import magicclass, MagicTemplate

@magicclass
class MyClass(MagicTemplate): # inherit here
    ...

Macro Recording

Another outstanding feature of magic class is its macro recorder functionalities. Function calls and value changes in child widgets are all recorded and you can generate executable Python script at any time.

Recorded macro is stored in the macro attribute. You can generate Python script as string just by passing it to str.

macro_string = str(ui.macro)
print(macro_string)

A macro editor widget is always tagged at macro.widget. It is a magicgui widget so you can open it by show() method or directly append it to GUI.

ui.macro.widget.show() # show widget as a separate window.
ui.append(ui.macro.widget) # append macro as a child widget.

By default, the script shown in the macro editor is synchronized, that is, automatically updated whenever macro itself is updated.

You may want some functions not to record macro (such as a function that only shows some information). It could also be redundant to record value changes of some widgets. You can prevent macro recording with do_not_record decorator for methods (or record=False argument for fields).

from magicclass import magicclass, do_not_record

@magicclass
class Main:
    @do_not_record
    def f(self):
        """this function will never be recorded"""

ui = Main()
ui.show()

Command palette is very useful if you have many functions and widgets in your UI. Since each magic-class instance is well organized, you can build a command palette widget without any additional effort.

To use this feature, you need to install qt-command-palette package.

pip install qt-command-palette

You may want to use the command palette with the bind_key decorator.

from magicclass import magicclass, magicmenu, bind_key
from magicclass.command_palette import exec_command_palette

@magicclass
class Main:
    # many functions and widgets here.
    @magicmenu
    class SubClass:
        def func_sub(self): ...

    def func(self): ...

    @bind_key("Ctrl+Shift+P")
    def _show_palette(self):
        exec_command_palette(self)

In the example above, two commands Main: func and Main.SubClass: func sub will be registered.

Add Functions after Construction

Making a button or menu action dynamically is also useful, especially when you already have a UI platform but you still want some extensions like plugin system. You don't have to worry about that since magic class construction itself is dynamic. Just append well-typed functions to magic class object.

def new_function(i: int, s: str):
    ...

ui.append(new_function) # then a proper widget appears in the GUI

Note

If you want to convert the function into a menu action, your code will look like this.

@magicclass
class A:
    @magicmenu
    class Menu:
        ...

ui = A()
ui.Menu.append(new_function)

Quick Start

Basics

Use Other Widgets in magic-class

GUI-specific Settings

Parameter Options

Change Button Designs

Post Initialization

Code Completion

Macro Recording

Build Command Palette Widget Automatically

Add Functions after Construction