Bethany Designer

A visual form designer for Bethany, a library that brings the Lazarus LCL to C++ and Python with an API similar to C++Builder.

Design a form on a canvas that looks like the Windows LCL, then generate the C++ (beth.hpp) or Python (beth) code for it. The form is stored in a JSON file (*.bfm.json) that you can also edit as text.

Preview. Bethany and this extension are at version 0.x. The format of *.bfm.json and the generated code may change.

Features

• Canvas: place controls from the palette, move and resize them with the mouse, and see Align, Anchors, BorderSpacing and Constraints laid out as the LCL does. Main menus and non-visual components are shown on the form.
• Structure tree and Object Inspector: edit properties (including nested objects, sets, references and TStrings), menu items and event handler names.
• Code generation: the Generate Code command writes a form class (class TMainForm : public TForm) to your source files. Only the regions between the designer's markers are replaced, so your own code, including event handlers, is kept.
• Forms view: the Bethany Designer icon in the Activity Bar lists the forms in your workspace. Open a form with a click, create one with the + button, or generate code from the list.
• Projects: a project file (*.bfproj.json) lists the forms of an application and its main form, and sets the languages to generate ("codegen": { "cpp": {}, "python": {} }). With projects, the Forms view groups the forms by project and marks the main form with a star. Renaming, moving or deleting a form in VS Code updates the projects that contain it.
• Application startup code: Generate Code on a project writes Project1.cpp / Project1.py, which initializes the application, creates the forms (the main form first, then the others as in C++Builder; Don't Create at Startup excludes a form) and runs it.
• Validation: problems in *.bfm.json are shown in the Problems panel, and a JSON Schema is provided for text editing.
• English and Japanese.

Getting started

1. Open the Bethany Designer view from the Activity Bar and choose Create New Form (or right-click a folder in the Explorer, or use File > New File...).
2. Design the form, then run Generate Code from the editor title bar.
3. Build the generated code with Bethany. For C++, see the C++ section of the Bethany README.

Using other forms

As in C++Builder, a form created at startup can be used from other forms through its variable.

// MainForm.cpp
#include "Form2.hpp"

void TMainForm::OpenButtonClick(TObject* Sender)
{
    Form2->ShowModal();
}

# MainForm.py
import Form2

class TMainForm(TForm):
    ...
    def OpenButtonClick(self, Sender):
        Form2.Form2.ShowModal()

In Python, forms may import each other (MainForm imports Form2 and Form2 imports MainForm). Follow these rules:

• Write import Form2 and use Form2.Form2. Do not write from Form2 import Form2: it copies the value at import time (None), and fails with a circular import error when the forms import each other.
• Use other forms only inside methods (event handlers, FormCreate), not at module level or in a class definition.
• Start the application from Project1.py. Running a form's .py directly loads it twice (as __main__ and as the module).

Settings

Known limitations

• The canvas approximates the appearance of the Windows LCL in HTML. Sizes that depend on fonts (for example AutoSize) can differ from the running application.
• There is no preview with the real LCL yet, and no alignment tools, tab-order editor or copy and paste.

日本語

Bethany(Lazarus の LCL を C++Builder に似た API で C++・Python から使うライブラリ)のフォームデザイナーです。 キャンバスでフォームを設計し、C++ または Python のコードを生成します。フォームは *.bfm.json に保存され、テキストとしても編集できます。 生成するのはマーカーで囲まれた区間だけで、イベントハンドラなど利用者が書いたコードは残ります。 Python でほかのフォームを使うときは、import Form2 と書いて Form2.Form2 で使います(from Form2 import Form2 は使いません)。 設計の資料は docs/designer にあります。

License

MIT