Programming languages provide the ultimate flexibility for parameterizing user interfaces and graphical output in general. But they lack the instant feedback that markup languages and visual editors provide. This drawback is not set in stone. With some effort and tool support, it is possible to visualize code-generated drawings in realtime as you type.

using CrossUI;

[assembly: DrawingBackend(typeof(CrossUI.SharpDX.DrawingBackend))]

namespace MyDrawings
{
	public class RoundedRectangleTest
	{
		[BitmapDrawingTest(Width = 80, Height = 40)]
		public void RoundedRect(IDrawingTarget target)
		{
			target.RoundedRectangle(0, 0, 80, 40, 8);
		}
	}
}

There are a number of reasons for CrossUI.

• Markup languages and APIs are not portable. Modern user interface APIs like .NET WPF, WinRT, iOS, Mac OS X, and Android are all different and make porting an application's user interface very time consuming. CrossUI could provide an API and testing frontend for all drawings and user interface components.
• Some of the user interface APIs lack the most basic features, like rendering UI controls into a background bitmap or composing geometries. CrossUI could provide implementations that use alternative APIs (like Direct2D for WinRT).
• For graphical editors, regression testing and visualizing different drawing states side by side is not a primary focus. CrossUI's testrunner can already be used to visualize different states of the same drawing and will soon support visual diffs.
• Like Test Driven Development puts your implementation code into shape, Test Driven Visualizations could do the same for user interfaces. All the major platforms' user interface APIs feel bloated and are a pain to work with. CrossUI's instant testing feedback could be basis for user interface APIs that are simple, light and extensible.

The most import Projects in the CrossUI solutions are:

• CrossUI.Portable: The portable C# based drawing abstraction that is inspired by processing.org.
• CrossUI.TestRunner.Portable: The (internal) test backend which need to be referenced by your test code.

• CrossUI.Runner.WPF: A WPF based graphical test runner that automatically reruns tests and presents them when DLLs are changed. Here is a screenshot of the test runner in action.
• CrossUI.Runner.WPF.x86: The WPF runner to test DLLs that require a 32 bit execution.

• CrossUI.SharpDX.WinRT: CrossUI's SharpDX based WinRT backend.
• CrossUI.SharpDX: The SharpDX desktop backend.

• Download and extract the ZIP file or clone the repository.
• Open CrossUI.sln in Visual Studio
• Build the solution
• Start CrossUI.Runner.WPF
• Press "Add Test.."
• Select "CrossUI.Tests.DrawingContext/bin/Debug/CrossUI.Tests.DrawingContext.dll"

The WPF Testrunner should now show some drawings. These drawings are test results of the tests in CrossUI.Tests.DrawingContext.dll.

• For trying the instant feedback, open a source file in the project CrossUI.Tests.DrawingContext and change the code that produces the test results. If you got .NET Demon installed, changes should appear as you type.

• Reference CrossUI.Portable from your project.
• Reference one of the Backends (for example CrossUI.SharpDX).

... and somewhere in your code:

using (var backend = new DrawingBackend())
using (var surface = backend.CreateBitmapDrawingSurface(Width, Height))
{
	using (var target = surface.BeginDraw())
	{
		// draw here against target
	}

	// Returns the alpha-premultiplied (ARGB) bitmap.
	var bitmap = surface.ExtractRawBitmap();
}

• Complete the drawing API
  • Add bitmap loading and drawing
• Port the Drawing Backend to more platforms
  • Android via MonoDroid
  • iOS via MonoTouch
  • Mac OS X via MonoMac
  • ? GDI via System.Drawing
  • ? Cairo via Mono.Cairo
  • ? XAML
  • ? SVG
  • ? CrossGraphics
• Implement visual diffs

• Create an API and test-runner for user interface components, animations and gesture recognizers which are instant testable.

For non-trivial contributations, please use the issue tracker to align your changes with the roadmap.

Copyright (c) 2012, Armin Sander All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
• Neither the name of Armin Sander nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

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