Add a Monarch/Peasant sample app (microsoft#8171)

This PR adds a sample monarch/peasant application. This is a type of
application where a single "Monarch" can coordinate the actions of multiple
other "Peasant" processes, as described by the specs in microsoft#7240 and microsoft#8135.

This project is intended to be a standalone sample of how the architecture would
work, without involving the entirety of the Windows Terminal build. Eventually,
this architecture will be incorporated into `wt.exe` itself, to enable scenarios
like:
* Run `wt` in the current window (microsoft#4472)
* Single Instance Mode (microsoft#2227)

For an example of this sample running, see the below GIF:

![monarch-peasant-sample-001](https://user-images.githubusercontent.com/18356694/98262202-f39b1500-1f4a-11eb-9220-4af4d922339f.gif)

This sample operates largely by printing to the console, to help the reader
understand how it's working through its logic.

I'm doing this mostly so we can have a _committed_ sample of this type of application, kinda like how VtPipeTerm is a sample ConPTY application. It's a lot easier to understand (& build on) when there aren't any window shenanigans, settings loading, Island instantiation, or anything else that the whole of `WindowsTerminal.exe` needs

* [x] I work here
* [x] This is sample code, so I'm not shipping tests for it.
* [x] Go see the doc over in microsoft#8135

.github/actions/spell-check/dictionary/apis.txt

@@ -40,6 +40,7 @@ ITab
 ITaskbar
 LCID
 llabs
+llu
 localtime
 lround
 LSHIFT
@@ -61,6 +62,7 @@ PAGESCROLL
 REGCLS
 pmr
 RETURNCMD
+REGCLS
 rfind
 roundf
 RSHIFT

consolegit2gitfilters.json

@@ -21,7 +21,8 @@
     "/res/terminal/",
     "/doc/specs/",
     "/doc/cascadia/",
-    "/doc/user-docs/"
+    "/doc/user-docs/",
+    "/src/tools/MonarchPeasantSample/",
   ],
   "SuffixFilters": [
     ".dbb",
@@ -38,5 +39,5 @@
     ".rec",
     ".err",
     ".xlsx"
-  ]    
+  ]
 }

src/tools/MonarchPeasantPackage/MonarchPeasantPackage.wapproj

@@ -0,0 +1,88 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="15.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '' or '$(VisualStudioVersion)' &lt; '15.0'">
+    <VisualStudioVersion>15.0</VisualStudioVersion>
+  </PropertyGroup>
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|x86">
+      <Configuration>Debug</Configuration>
+      <Platform>x86</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|x86">
+      <Configuration>Release</Configuration>
+      <Platform>x86</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|x64">
+      <Configuration>Debug</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|x64">
+      <Configuration>Release</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|ARM">
+      <Configuration>Debug</Configuration>
+      <Platform>ARM</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|ARM">
+      <Configuration>Release</Configuration>
+      <Platform>ARM</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|ARM64">
+      <Configuration>Debug</Configuration>
+      <Platform>ARM64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|ARM64">
+      <Configuration>Release</Configuration>
+      <Platform>ARM64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|AnyCPU">
+      <Configuration>Debug</Configuration>
+      <Platform>AnyCPU</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|AnyCPU">
+      <Configuration>Release</Configuration>
+      <Platform>AnyCPU</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <PropertyGroup>
+    <WapProjPath Condition="'$(WapProjPath)'==''">$(MSBuildExtensionsPath)\Microsoft\DesktopBridge\</WapProjPath>
+  </PropertyGroup>
+  <Import Project="$(WapProjPath)\Microsoft.DesktopBridge.props" />
+  <PropertyGroup>
+    <ProjectGuid>f75e29d0-d288-478b-8d83-2c190f321a3f</ProjectGuid>
+    <TargetPlatformVersion>10.0.18362.0</TargetPlatformVersion>
+    <TargetPlatformMinVersion>10.0.17763.0</TargetPlatformMinVersion>
+    <DefaultLanguage>en-US</DefaultLanguage>
+    <AppxPackageSigningEnabled>false</AppxPackageSigningEnabled>
+    <EntryPointProjectUniqueName>..\MonarchPeasantSample\MonarchPeasantSample.vcxproj</EntryPointProjectUniqueName>
+  </PropertyGroup>
+  <ItemGroup>
+    <AppxManifest Include="Package.appxmanifest">
+      <SubType>Designer</SubType>
+    </AppxManifest>
+  </ItemGroup>
+  <ItemGroup>
+    <Content Include="Images\SplashScreen.scale-200.png" />
+    <Content Include="Images\LockScreenLogo.scale-200.png" />
+    <Content Include="Images\Square150x150Logo.scale-200.png" />
+    <Content Include="Images\Square44x44Logo.scale-200.png" />
+    <Content Include="Images\Square44x44Logo.targetsize-24_altform-unplated.png" />
+    <Content Include="Images\StoreLogo.png" />
+    <Content Include="Images\Wide310x150Logo.scale-200.png" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\MonarchPeasantSample\MonarchPeasantSample.vcxproj" >
+      <!--
+      THESE PROPERTIES ARE LOAD BEARING!
+
+      We need them so the MonarchPeasantSample.winmd will be placed in the
+      package root. If it's not there, then we won't be able to activate our
+      WinRT classes!
+      -->
+      <Private>true</Private>
+      <CopyLocalSatelliteAssemblies>true</CopyLocalSatelliteAssemblies>
+    </ProjectReference>
+  </ItemGroup>
+  <Import Project="$(WapProjPath)\Microsoft.DesktopBridge.targets" />
+</Project>

src/tools/MonarchPeasantPackage/Package.appxmanifest

@@ -0,0 +1,62 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<Package
+  xmlns="http://schemas.microsoft.com/appx/manifest/foundation/windows10"
+  xmlns:uap="http://schemas.microsoft.com/appx/manifest/uap/windows10"
+  xmlns:rescap="http://schemas.microsoft.com/appx/manifest/foundation/windows10/restrictedcapabilities"
+  xmlns:uap3="http://schemas.microsoft.com/appx/manifest/uap/windows10/3"
+  xmlns:uap5="http://schemas.microsoft.com/appx/manifest/uap/windows10/5"
+  xmlns:desktop="http://schemas.microsoft.com/appx/manifest/desktop/windows10"
+  IgnorableNamespaces="uap rescap">
+
+  <Identity
+    Name="5d4b020d-14a7-4a1a-a359-3f468e23bae3"
+    Publisher="CN=migrie"
+    Version="1.0.0.0" />
+
+  <Properties>
+    <DisplayName>MonarchPeasantPackage</DisplayName>
+    <PublisherDisplayName>migrie</PublisherDisplayName>
+    <Logo>Images\StoreLogo.png</Logo>
+  </Properties>
+
+  <Dependencies>
+    <TargetDeviceFamily Name="Windows.Universal" MinVersion="10.0.0.0" MaxVersionTested="10.0.0.0" />
+    <TargetDeviceFamily Name="Windows.Desktop" MinVersion="10.0.14393.0" MaxVersionTested="10.0.14393.0" />
+  </Dependencies>
+
+  <Resources>
+    <Resource Language="x-generate"/>
+  </Resources>
+
+  <Applications>
+    <Application Id="App"
+      Executable="$targetnametoken$.exe"
+      EntryPoint="$targetentrypoint$">
+      <uap:VisualElements
+        DisplayName="MonarchPeasantPackage"
+        Description="MonarchPeasantPackage"
+        BackgroundColor="transparent"
+        Square150x150Logo="Images\Square150x150Logo.png"
+        Square44x44Logo="Images\Square44x44Logo.png">
+        <uap:DefaultTile Wide310x150Logo="Images\Wide310x150Logo.png" />
+        <uap:SplashScreen Image="Images\SplashScreen.png" />
+      </uap:VisualElements>
+
+      <Extensions>
+        <uap3:Extension Category="windows.appExecutionAlias" Executable="MonarchPeasantSample\MonarchPeasantSample.exe" EntryPoint="Windows.FullTrustApplication">
+          <uap3:AppExecutionAlias>
+            <desktop:ExecutionAlias Alias="MonarchPeasantSample.exe" />
+          </uap3:AppExecutionAlias>
+        </uap3:Extension>
+
+      </Extensions>
+
+    </Application>
+  </Applications>
+
+  <Capabilities>
+    <Capability Name="internetClient" />
+    <rescap:Capability Name="runFullTrust" />
+  </Capabilities>
+</Package>

src/tools/MonarchPeasantSample/AppState.cpp

@@ -0,0 +1,119 @@
+#include "pch.h"
+#include "AppState.h"
+#include "../../types/inc/utils.hpp"
+
+using namespace winrt;
+using namespace winrt::Windows::Foundation;
+using namespace ::Microsoft::Console;
+
+void AppState::_setupConsole()
+{
+    hOutput = GetStdHandle(STD_OUTPUT_HANDLE);
+    hInput = GetStdHandle(STD_INPUT_HANDLE);
+    DWORD dwMode = 0;
+    GetConsoleMode(hOutput, &dwMode);
+    dwMode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
+    SetConsoleMode(hOutput, dwMode);
+}
+
+void AppState::initializeState()
+{
+    // Initialize the console handles
+    _setupConsole();
+
+    // Set up WinRT
+    init_apartment();
+}
+
+bool AppState::areWeTheKing(const bool logPIDs)
+{
+    auto kingPID = monarch.GetPID();
+    auto ourPID = GetCurrentProcessId();
+    if (logPIDs)
+    {
+        if (ourPID == kingPID)
+        {
+            printf(fmt::format("We're the\x1b[33m king\x1b[m - our PID is {}\n", ourPID).c_str());
+        }
+        else
+        {
+            printf(fmt::format("We're a lowly peasant - the king is {}\n", kingPID).c_str());
+        }
+    }
+    return (ourPID == kingPID);
+}
+
+void AppState::remindKingWhoTheyAre(const winrt::MonarchPeasantSample::IPeasant& iPeasant)
+{
+    winrt::com_ptr<MonarchPeasantSample::implementation::Monarch> monarchImpl;
+    monarchImpl.copy_from(winrt::get_self<MonarchPeasantSample::implementation::Monarch>(monarch));
+    if (monarchImpl)
+    {
+        auto ourID = iPeasant.GetID();
+        monarchImpl->SetSelfID(ourID);
+        monarchImpl->AddPeasant(iPeasant);
+        printf("The king is peasant #%lld\n", ourID);
+    }
+    else
+    {
+        printf("Shoot, we wanted to be able to get the monarchImpl here but couldnt\n");
+    }
+}
+
+winrt::MonarchPeasantSample::Monarch AppState::instantiateMonarch()
+{
+    // Heads up! This only works because we're using
+    // "metadata-based-marshalling" for our WinRT types. THat means the OS is
+    // using the .winmd file we generate to figure out the proxy/stub
+    // definitions for our types automatically. This only works in the following
+    // cases:
+    //
+    // * If we're running unpackaged: the .winmd but be a sibling of the .exe
+    // * If we're running packaged: the .winmd must be in the package root
+    auto monarch = create_instance<winrt::MonarchPeasantSample::Monarch>(Monarch_clsid,
+                                                                         CLSCTX_LOCAL_SERVER);
+    return monarch;
+}
+
+MonarchPeasantSample::IPeasant AppState::_createOurPeasant()
+{
+    auto peasant = winrt::make_self<MonarchPeasantSample::implementation::Peasant>();
+    auto ourID = monarch.AddPeasant(*peasant);
+    printf("The monarch assigned us the ID %llu\n", ourID);
+
+    if (areWeTheKing())
+    {
+        remindKingWhoTheyAre(*peasant);
+    }
+
+    return *peasant;
+}
+
+void AppState::createMonarch()
+{
+    monarch = AppState::instantiateMonarch();
+}
+
+// return true to exit early, false if we should continue into the main loop
+bool AppState::processCommandline()
+{
+    const bool isKing = areWeTheKing(false);
+    // If we're the king, we _definitely_ want to process the arguments, we were
+    // launched with them!
+    //
+    // Otherwise, the King will tell us if we should make a new window
+    const bool createNewWindow = isKing || monarch.ProposeCommandline({ args }, { L"placeholder CWD" });
+
+    if (createNewWindow)
+    {
+        peasant = _createOurPeasant();
+        peasant.ExecuteCommandline({ args }, { L"placeholder CWD" });
+        return false;
+    }
+    else
+    {
+        printf("The Monarch instructed us to not create a new window. We'll be exiting now.\n");
+    }
+
+    return true;
+}

src/tools/MonarchPeasantSample/AppState.h

@@ -0,0 +1,32 @@
+#pragma once
+#include "SampleMonarch.h"
+#include "SamplePeasant.h"
+#include "../../types/inc/utils.hpp"
+
+class AppState
+{
+public:
+    bool areWeTheKing(const bool logPIDs = false);
+    void initializeState();
+
+    static winrt::MonarchPeasantSample::Monarch instantiateMonarch();
+
+    void createMonarch();
+    bool processCommandline();
+    void remindKingWhoTheyAre(const winrt::MonarchPeasantSample::IPeasant& peasant);
+
+    HANDLE hInput{ INVALID_HANDLE_VALUE };
+    HANDLE hOutput{ INVALID_HANDLE_VALUE };
+    winrt::MonarchPeasantSample::IPeasant peasant{ nullptr };
+    winrt::MonarchPeasantSample::Monarch monarch{ nullptr };
+    std::vector<winrt::hstring> args;
+
+private:
+    void _setupConsole();
+    int _appLoop();
+
+    winrt::MonarchPeasantSample::IPeasant _createOurPeasant();
+};
+
+bool monarchAppLoop(AppState& state); // Defined in MonarchMain.cpp
+bool peasantAppLoop(AppState& state); // Defined in PeasantMain.cpp

src/tools/MonarchPeasantSample/MonarchMain.cpp

@@ -0,0 +1,38 @@
+#include "pch.h"
+#include "AppState.h"
+#include "../../types/inc/utils.hpp"
+
+void printPeasants(const winrt::MonarchPeasantSample::Monarch& /*monarch*/)
+{
+    printf("This is unimplemented\n");
+}
+
+bool monarchAppLoop(AppState& state)
+{
+    bool exitRequested = false;
+    printf("Press `l` to list peasants, 'm' to change modes `q` to quit\n");
+
+    winrt::com_ptr<winrt::MonarchPeasantSample::implementation::Monarch> monarchImpl;
+    monarchImpl.copy_from(winrt::get_self<winrt::MonarchPeasantSample::implementation::Monarch>(state.monarch));
+
+    while (!exitRequested)
+    {
+        const auto ch = _getch();
+        if (ch == 'l')
+        {
+            printPeasants(state.monarch);
+        }
+        else if (ch == 'q')
+        {
+            exitRequested = true;
+        }
+        else if (ch == 'm')
+        {
+            if (monarchImpl)
+            {
+                monarchImpl->ToggleWindowingBehavior();
+            }
+        }
+    }
+    return true;
+}