Custom dialogs

[stevebeisner]

I'm porting an app using another language/gui framework, that is structured as a series of custom dialogs, each dialog followed by a gui-independent action. Each custom dialog consists of a variety of widgets. Each dialog sets or returns values when it is completed and the dialog is closed. I suppose creating such custom dialogs in Toga is possible, perhaps based on Window (?), but I'm not sure what such an implementation would look like. Any suggestions, pointers, or examples? Thanks!

[freakboy3742]

Your instinct is correct - the best approach at present would be an instance of Window.

Create the instance of Window, possibly with closable=False and/or resizable=False (to ensure that the user can't dismiss the window, or make it a weird size). Add window content matching your widget's input requirement, adding an "OK" button (or whatever acceptance mechanism you want) to the bottom of the window. Add a handler to the OK button that does whatever acceptance handling is required, plus possibly invokes close on the window. Show the window with window.show().

If you want, you can wrap up your custom dialog as a subclass of Window; for extra bonus points, you can make the subclass awaitable so that you can use your dialog in a similar way to other dialogs in Toga. A sample implementation that has paid no attention to actual widget layout, just puts a text input and a button in a dialog:

class SampleDialog(toga.Window):
    def __init__(self):
        super().__init__(title="My Dialog", resizable=False, size=(400, 300))

        self.textinput = toga.TextInput()
        self.ok_button = toga.Button("OK", on_press=self.on_accept)
        self.content = toga.Box(children=[self.textinput, self.ok_button])
        self.future = self.app.loop.create_future()

    def on_accept(self, widget, **kwargs):
        self.future.set_result(self.textinput.value)
        self.close()

    def __await__(self):
        return self.future.__await__()

Displaying the dialog can then be triggered with:

        dialog = SampleDialog()
        dialog.show()
        result = await dialog
        print("Dialog result is {result}")

This will show the dialog, then wait for the OK button to be pressed; when it is, the print statement will execute.

[stevebeisner]

Perfect!

[hemna]

unfortunately this doesn't work on ios as it doesn't support secondary windows.

[freakboy3742]

Sure - that's why I said "the best approach at present". There's absolutely a need to be able to customise dialogs; right now, the only viable workaround (other than platform-native code) is a custom window.