DelphiVCL is a Python module giving Python GUI apps on Windows access to Delphi’s VCL for robust and high-performance native Windows visual widgets. It uses the Python4Delphi library as a bridge between Delphi’s VCL (Visual Component Library) and Python. DelphiVCL is currently for Windows, while DelphiFMX is coming soon with support for other platforms, including Linux, macOS, and Android.
The DelphiVCL Python module makes ‘the whole VCL’ available in Python! No Delphi or Object Pascal experience or knowledge is necessary for you as a Python developer to take full advantage of the Native GUI benefits.
This is why Native GUI is important:
- Performance: Windows provides hardware acceleration for native controls.
- Windows Handles: Native Windows controls have Windows handles providing better OS and intra-application integration.
- Consistent Behavior: The use of native controls gives users consistent behavior between all applications they use.
- Supported with Microsoft Active Accessibility (MSAA): It is the framework that leverages native controls to provide better user interface accessibility, like screen readers or on-screen keyboards.
Table of Contents
1. What is VCL, and Why is it Important?
The Visual Component Library (VCL) is a set of visual component-based object-oriented frameworks for the rapid development of Microsoft Windows applications. The code is natively compiled from Delphi’s Object Pascal code.
VCL contains a wide variety of visual, non-visual, and utility classes for tasks such as building Windows applications, web applications, database applications, and console applications.
VCL components cover Windows controls like windows (TForm class), controls (e.g., TButton, TCheckBox, TLabel classes). Delphi’s VCL is also extended with many powerful and flexible 3rd party components. We won’t get into using those from Python right now but know there is a lot more available than what we will show you in DelphiVCL for Python today.
Similar to Windows themes, VCL styles make it easy to radically change the appearance of your VCL applications, giving your applications the next level of polish and professionalism.
2. What is Python4Delphi, and Why is it Important?
Python4Delphi (P4D) is the library that provides the integration between Python and Delphi. You don’t need to install it or Delphi to use the DelphiVCL Python module.
P4D is a bidirectional bridge that allows Delphi to execute Python code and call Python libraries and allows Python to call modules written in Delphi to otherwise interact with Delphi code, objects, interfaces, records, etc. This makes it super easy to combine the strengths of Python and Delphi. For example to add Python scripting to a Delphi application, or to use Delphi’s robust VCL library from Python applications.
For now, we will focus on how you, as a Python Developer, can simply use the DelphiVCL.pyd module in your Python applications to add all the amazing VCL features without needing to understand Delphi, Object Pascal, or the Python4Delphi library. In the future, we will explore how you can make use of the Delphi designers (even via the free Community Edition of Delphi) to take your GUI development to the next level.
Watch this comprehensive introduction to Python GUI Development with DelphiVCL library video by Jim McKeeth: