Initial commit

.gitignore

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+# Created by https://www.toptal.com/developers/gitignore/api/csharp,visualstudio
+# Edit at https://www.toptal.com/developers/gitignore?templates=csharp,visualstudio
+
+### Csharp ###
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+# Microsoft Fakes
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+# GhostDoc plugin setting file
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+
+# VS Code files for those working on multiple tools
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+# User-specific files
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+
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+# Build results
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+# Visual Studio 2015/2017 cache/options directory
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+
+# Visual Studio 2017 auto generated files
+
+# MSTest test Results
+
+# NUnit
+
+# Build Results of an ATL Project
+
+# Benchmark Results
+
+# .NET Core
+
+# ASP.NET Scaffolding
+
+# StyleCop
+
+# Files built by Visual Studio
+
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+
+# Visual C++ cache files
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+
+# Visual Studio Trace Files
+
+# TFS 2012 Local Workspace
+
+# Guidance Automation Toolkit
+
+# ReSharper is a .NET coding add-in
+
+# TeamCity is a build add-in
+
+# DotCover is a Code Coverage Tool
+
+# AxoCover is a Code Coverage Tool
+
+# Coverlet is a free, cross platform Code Coverage Tool
+
+# Visual Studio code coverage results
+
+# NCrunch
+
+# MightyMoose
+
+# Web workbench (sass)
+
+# Installshield output folder
+
+# DocProject is a documentation generator add-in
+
+# Click-Once directory
+
+# Publish Web Output
+# Note: Comment the next line if you want to checkin your web deploy settings,
+# but database connection strings (with potential passwords) will be unencrypted
+
+# Microsoft Azure Web App publish settings. Comment the next line if you want to
+# checkin your Azure Web App publish settings, but sensitive information contained
+# in these scripts will be unencrypted
+
+# NuGet Packages
+# NuGet Symbol Packages
+# The packages folder can be ignored because of Package Restore
+# except build/, which is used as an MSBuild target.
+# Uncomment if necessary however generally it will be regenerated when needed
+# NuGet v3's project.json files produces more ignorable files
+
+# Microsoft Azure Build Output
+
+# Microsoft Azure Emulator
+
+# Windows Store app package directories and files
+
+# Visual Studio cache files
+# files ending in .cache can be ignored
+# but keep track of directories ending in .cache
+
+# Others
+
+# Including strong name files can present a security risk
+# (https://github.com/github/gitignore/pull/2483#issue-259490424)
+
+# Since there are multiple workflows, uncomment next line to ignore bower_components
+# (https://github.com/github/gitignore/pull/1529#issuecomment-104372622)
+
+# RIA/Silverlight projects
+
+# Backup & report files from converting an old project file
+# to a newer Visual Studio version. Backup files are not needed,
+# because we have git ;-)
+
+# SQL Server files
+
+# Business Intelligence projects
+
+# Microsoft Fakes
+
+# GhostDoc plugin setting file
+
+# Node.js Tools for Visual Studio
+
+# Visual Studio 6 build log
+
+# Visual Studio 6 workspace options file
+
+# Visual Studio 6 auto-generated workspace file (contains which files were open etc.)
+
+# Visual Studio 6 auto-generated project file (contains which files were open etc.)
+
+# Visual Studio 6 workspace and project file (working project files containing files to include in project)
+
+# Visual Studio 6 technical files
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+# Visual Studio LightSwitch build output
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+# Paket dependency manager
+
+# FAKE - F# Make
+
+# CodeRush personal settings
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+# Python Tools for Visual Studio (PTVS)
+
+# Cake - Uncomment if you are using it
+# tools/**
+# !tools/packages.config
+
+# Tabs Studio
+
+# Telerik's JustMock configuration file
+
+# BizTalk build output
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+# OpenCover UI analysis results
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+# Azure Stream Analytics local run output
+
+# MSBuild Binary and Structured Log
+
+# NVidia Nsight GPU debugger configuration file
+
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+
+# Local History for Visual Studio
+
+# Visual Studio History (VSHistory) files
+
+# BeatPulse healthcheck temp database
+
+# Backup folder for Package Reference Convert tool in Visual Studio 2017
+
+# Ionide (cross platform F# VS Code tools) working folder
+
+# Fody - auto-generated XML schema
+
+# VS Code files for those working on multiple tools
+
+# Local History for Visual Studio Code
+
+# Windows Installer files from build outputs
+
+# JetBrains Rider
+
+### VisualStudio Patch ###
+# Additional files built by Visual Studio
+
+# End of https://www.toptal.com/developers/gitignore/api/csharp,visualstudio

Shapes.sln

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+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.4.33103.184
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Shapes", "Shapes\Shapes.csproj", "{7F30E637-BAFE-42FA-A173-F42B3902ED3B}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{7F30E637-BAFE-42FA-A173-F42B3902ED3B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{7F30E637-BAFE-42FA-A173-F42B3902ED3B}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{7F30E637-BAFE-42FA-A173-F42B3902ED3B}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{7F30E637-BAFE-42FA-A173-F42B3902ED3B}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {D322E690-379C-4802-8F7E-1AC6AD090D59}
+	EndGlobalSection
+EndGlobal

Shapes/Program.cs

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+using System.Text;
+using Shapes;
+using Shapes.Shapes;
+using SimpleDrawing;
+using SimpleDrawing.Core;
+
+Console.OutputEncoding = Encoding.UTF8;
+
+const int Size = 600;
+
+var shapes = new List<Shape>();
+var generator = new ShapeGenerator(Size, Size);
+
+LeoCanvas.Init(Run, Size, Size, clickAction: HandleClick, windowTitle: "Shapes");
+
+return;
+
+void Run()
+{
+    try
+    {
+        // initial rendering
+        Redraw();
+
+        Console.WriteLine("Press any key to exit...");
+        Console.ReadKey();
+    }
+    catch (Exception ex)
+    {
+        Console.WriteLine($"An error occurred: {ex.Message}");
+    }
+}
+
+void HandleClick(ClickEvent @event)
+{
+    // TODO - handle click at location
+
+    Redraw();
+}
+
+void Redraw()
+{
+    LeoCanvas.Clear();
+    foreach (var shape in shapes)
+    {
+        if (!shape.DrawSelf())
+        {
+            Console.WriteLine($"Couldn't draw shape with id {shape.Id} 😭");
+        }
+    }
+    LeoCanvas.Render();
+}
+

Shapes/ShapeGenerator.cs

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+using System.Diagnostics;
+using Avalonia;
+using Shapes.Shapes;
+
+namespace Shapes;
+
+/// <summary>
+///     A random shape generator
+/// </summary>
+public sealed class ShapeGenerator
+{
+    private const int MinShapeIdx = 1;
+    private const int MaxShapeIdx = 4;
+    private readonly double _maxX;
+    private readonly double _maxY;
+    private readonly Random _random;
+    private int _nextShape;
+
+    /// <summary>
+    ///     Creates a new generator which will create random shapes within the canvas area
+    /// </summary>
+    /// <param name="maxX">The max x-axis value where shapes may be drawn</param>
+    /// <param name="maxY">The max y-axis value where shapes may be drawn</param>
+    public ShapeGenerator(double maxX, double maxY)
+    {
+        _maxX = maxX;
+        _maxY = maxY;
+        _nextShape = MinShapeIdx;
+        _random = Random.Shared;
+    }
+
+    /// <summary>
+    ///     Creates a new random shape at the specified location.
+    ///     A circle, rectangle, square or triangle will be created.
+    ///     The size of the shape is randomly chosen, but will not exceed the max. drawing
+    ///     boundaries - except for at most 5 pixels to allow rendering in any case.
+    ///     Shapes may overlap each other.
+    /// </summary>
+    /// <param name="atLocation">Location of the center point of the new shape</param>
+    /// <returns>The newly created shape</returns>
+    public Shape CreateNewShape(Point atLocation)
+    {
+        int shape = _nextShape++;
+        if (_nextShape > MaxShapeIdx)
+        {
+            _nextShape = MinShapeIdx;
+        }
+
+        // TODO
+        return null!;
+    }
+
+    // TODO
+}

Shapes/Shapes.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+	<PropertyGroup>
+		<OutputType>Exe</OutputType>
+		<TargetFramework>net9.0</TargetFramework>
+		<ImplicitUsings>enable</ImplicitUsings>
+		<Nullable>enable</Nullable>
+		<TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+	</PropertyGroup>
+
+	<ItemGroup>
+        <PackageReference Include="HTLLeonding.Utility.LeoAnalyzers" Version="1.0.2" />
+        <PackageReference Include="HTLLeonding.Utility.SimpleDrawing" Version="3.2.2" />
+	</ItemGroup>
+
+</Project>

readme.adoc

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+:sectnums:
+:nofooter:
+:toc: left
+:icons: font
+:data-uri:
+:source-highlighter: highlightjs
+:stem: latexmath
+
+= Inh.03 -- Shapes
+
+* This time, we are drawing colorful shapes 🤩
+* For this job you will _add a NuGet package_ yourself
+* You will be free to come up with your own application structure and inheritance hierarchy -- only the requirements are given in this document
+* A starter project and some code to help you to work with the graphics package is available
+
+NOTE: That means that neither unit tests nor a class diagram could be provided, you are on your own!
+
+== General Requirements
+
+. Display a white canvas to the user
+. When the user clicks on the canvas:
+.. If the space is empty a shape is rendered at this location -- with the click position becoming the center point of the new shape
+.. If a shape is already present at this location it gets removed
+. New shapes are created in the following, circular order:
+.. Square
+.. Circle
+.. Rectangle
+.. Triangle
+. For new shapes color and size are chosen randomly
+.. Size has to be constrained to the boundaries of the canvas (= don't draw outside)
+.. The triangle is equilateral
+.. For the rectangle both width and height are chosen randomly which can lead to a larger height than width => the rectangle is rendered in vertical orientation
+. New shapes get assigned a unique, incrementing ID
+. The final application should work like in the following sample run
+
+.Sample Run
+video::sample_run.mp4[Sample Run,width=600]
+
+== Tasks
+
+Every shape has:
+
+* Several common properties:
+.. An ID
+.. A center point (x,y)
+.. A color
+* Two common functionalities:
+.. It can _draw itself_ on the canvas
+.. It can tell you if a point (x,y) is _contained_ within the area of the shape
+
+WARNING: The provided parts of `Program` & `ShapeGenerator` assume that there is a class `Shape` => if you use different names make sure to change the provided code accordingly
+
+=== Class Diagram
+
+* Your first job is to _come up with an inheritance hierarchy_
+** Think about which features are shared and which differ between our four shapes
+** Make good choices for _visibility_
+** Ensure to properly mark classes as `abstract` or `sealed`, as required
+* Then create the appropriate class diagram
+
+=== Implementation Requirements
+
+==== Adding Graphics Package
+
+* For this assignment we will be using the https://www.nuget.org/packages/HTLLeonding.Utility.SimpleDrawing[HTLLeonding.Utility.SimpleDrawing] package
+** We already discussed why it makes a lot of sense to combine various packages (_libraries_) when creating applications -- don't reinvent the wheel all the time, but rely on _standard_ libraries when possible
+* That is a https://learn.microsoft.com/en-us/nuget/what-is-nuget[NuGet] package -- take the time to read up on what that is
+* To be able to use it in your program you have to _add_ it as a _dependency_ to the project
+* Luckily the NuGet package of the package already shows you various 'copy & paste' ways of adding the package
+** image:pics/how_to_add_nuget.png[How to add NuGet package]
+** Decide on one of the options (switch between them using the tabs)
+* On the NuGet page of the package you will also find some documentation about the package and some _sample usage_
+** Because the package was created by a _good_ developer (😎) it also comes with XML documentation your IDE will display as well as https://learn.microsoft.com/en-us/dotnet/core/diagnostics/symbols[symbols] which your IDE can use when you debug the code
+** => we always want to do our work properly and make life easier (instead of harder) for everyone!
+* Basic setup for using the package has already been done for you (in `Program`)
+** You may especially ignore `Exception` and some other things that may look unfamiliar.
+Those are just needed due to some magic going on behind the scenes -- we will learn about that later.
+** Look for the `TODO` so know where to put your own code
+
+IMPORTANT: Before adding the package successfully the starter code will _not_ compile!
+
+==== Functionality
+
+* You _have_ to use inheritance
+* Make sure to avoid code duplication wherever possible in a sensible way
+* Use the same color for both the borderline and the fill content
+* Sizes are generated in the following boundaries:
+** Rectangle: width or height 10-150
+** Triangle: side length 10-150
+** Circle: radius 5-100
+** Square: side length 10-120
+* Size may have to be reduced if the user clicked close to the border of the canvas, we don't want to draw outside the canvas
+* It is necessary to know if a point lies within the area of a shape, because we have to know _if_ and _which_ shape the user clicked (or if the click hit empty canvas)
+** image:pics/inside_outside.png[Inside or Outside]
+* If two shapes overlap the click 'hits' the one 'on top' => the one added _later_
+* Actions (adding or removing a shape) are logged to the console
+
+=== Testing
+
+* Determine which parts of your application can be tested by unit tests and which don't
+** Write down your conclusions!
+* Create unit tests for those parts which can be unit tested in a meaningful way
+
+== Implementation Hints
+
+Here are a couple hints that may help you implement the required functionality.
+
+* You can use these colors:
+
+[source,csharp]
+----
+private static readonly IBrush[] colors =
+    {
+        Brushes.Blue,
+        Brushes.Cyan,
+        Brushes.DarkGreen,
+        Brushes.Firebrick,
+        Brushes.Lime,
+        Brushes.Orange,
+        Brushes.Plum,
+        Brushes.Yellow
+    };
+----
+
+* The following function can be used to determine if a point lies on the right hand side of an edge (be careful with clockwise or counter-clockwise edge iteration):
+
+[source,csharp]
+----
+private static bool IsOnRightSideOfEdge(Point edgeStart, Point edgeEnd, Point pointToCheck)
+{
+    double d = (edgeEnd.X - edgeStart.X) * (pointToCheck.Y - edgeStart.Y)
+               - (pointToCheck.X - edgeStart.X) * (edgeEnd.Y - edgeStart.Y);
+
+    return d > 0D;
+}
+----
+
+* A (filled) triangle cannot be drawn by using three lines, because then you won't be able to fill it. Instead, you may use the `LeoCanvas.DrawPolygonByPath` method.
+