win32_gui #

Win32 API GUI in Object-Oriented style with some helpers. Uses package win32 and dart:ffi.

Screenshot #

Example screenshot:

Usage #

Here's a simple Hello World window:

import 'dart:io';

import 'package:win32_gui/win32_gui.dart';

Future<void> main() async {
  // Your custom main Window class declared bellow:
  var mainWindow = MainWindow(
    width: 640,
    height: 480,
  );

  // Create the window:
  print('-- mainWindow.create...');
  await mainWindow.create();
  
  // Exit when the Window is closed and destroyed:
  // See `MainWindow.processClose` below:
  mainWindow.onDestroy.listen((window) {
    print('-- Window Destroyed> $window');
    exit(0);
  });

  // Shows the window:
  print('-- mainWindow.show...');
  mainWindow.show();

  // Run the Win32 Window message loop.
  print('-- Window.runMessageLoopAsync...');
  await Window.runMessageLoopAsync();
}

// A custom main Window:
class MainWindow extends Window {
  // Declare the main window custom class:
  static final mainWindowClass = WindowClass.custom(
    className: 'mainWindow',
    windowProc: Pointer.fromFunction<WindowProc>(mainWindowProc, 0),
    bgColor: RGB(255, 255, 255),
    useDarkMode: true,
    titleColor: RGB(32, 32, 32),
  );

  // Redirect to default implementation [WindowClass.windowProcDefault].
  static int mainWindowProc(int hwnd, int uMsg, int wParam, int lParam) =>
          WindowClass.windowProcDefault(
                  hwnd, uMsg, wParam, lParam, mainWindowClass);
  
  MainWindow({super.width, super.height})
          : super(
    defaultRepaint: false, // Tells that `repaint()` below will be used. 
    windowName: 'Win32 GUI - Example', // The Window title.
    windowClass: mainWindowClass,
    windowStyles: WS_MINIMIZEBOX | WS_SYSMENU,
  ) ;

  late final String imageDartLogoPath;
  late final String iconDartLogoPath;
  
  // Load resources (called by `create()`):
  @override
  Future<void> load() async {
    imageDartLogoPath = await Window.resolveFilePath(
            'package:win32_gui/resources/dart-logo.bmp');
    
    iconDartLogoPath = await Window.resolveFilePath(
            'package:win32_gui/resources/dart-icon.ico');
  }

  // Called when processing a `WM_CREATE` message (generated by `create()`):
  @override
  void build(int hwnd, int hdc) {
    super.build(hwnd, hdc);

    SetTextColor(hdc, RGB(255, 255, 255));
    SetBkColor(hdc, RGB(96, 96, 96));

    // Sets the Window icon: 
    setIcon(iconDartLogoPath);
  }
  
  // Customize close operation:
  @override
  bool? processClose() {
    // Inform default close behavior (`destroy()` Window):
    return null;
  }
  
  // Custom repaint. Called when processing a `WM_PAINT` message and `this.defaultRepaint = false`:
  @override
  void repaint(int hwnd, int hdc) {
    // Loads a 24-bits Bitmap:
    var hBitmap = loadImageCached(imageDartLogoPath);
    // Get the Bitmap dimensions:
    var imgDimension = getBitmapDimension(hBitmap);

    // Valid Bitmap:
    if (imgDimension != null) {
      var imgW = imgDimension.width;
      var imgH = imgDimension.height;
      
      // Center image horizontally:
      final x = (dimensionWidth - imgW) ~/ 2;
      final y = 10;

      // Draws the Bitmap copying its bytes to this Window.
      drawImage(hdc, hBitmap, x, y, imgW, imgH);
    }
  }
}

Features and bugs #

Please file feature requests and bugs at the issue tracker.

Contribution #

Your assistance and involvement within the open-source community is not only valued but vital. Here's how you can contribute:

• Found an issue?
  • Please fill a bug report with details.
• Wish a feature?
  • Open a feature request with use cases.
• Are you using and liking the project?
  • Advocate for the project: craft an article, share a post, or offer a donation.
• Are you a developer?
  • Fix a bug and send a pull request.
  • Implement a new feature.
  • Improve the Unit Tests.
• Already offered your support?
  • Sincere gratitude from myself, fellow contributors, and all beneficiaries of this project!

By donating one hour of your time, you can make a significant contribution, as others will also join in doing the same. Just be a part of it and begin with your one hour.

Author #

Graciliano M. Passos: gmpassos@GitHub.

License #

Apache License - Version 2.0