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.
• Event handlers: double-click a control on the canvas, or press + on the Events tab, to add a handler (OkButtonClick) and jump to it in the generated code, as in C++Builder. → jumps to a handler that is already set.
• 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.
• C++ settings: in codegen.cpp of the project file, set a namespace for the forms, the include guard (macro or pragma), the file extensions (.h, .cc, ...) and separate folders for headers and sources (headerDir, sourceDir). overrides change them for some forms only (for example, another namespace for the forms in dialogs/). The generated code includes Bethany as #include <bethany/beth.hpp>.
• Project settings: a project file opens in a settings screen (like the project options of C++Builder): the main form, the forms created at startup and their order, the languages and the C++ and Python settings, with a preview of the output files. Generate Code for the Whole Project generates the code of all the forms and the startup code at once.
• 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. Code is generated for forms in a project (*.bfproj.json), which sets the languages and the output folders; the first time, you are asked to add the form to a project.
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