From d5a14f9a1f161c45943136700013a3246a868c76 Mon Sep 17 00:00:00 2001
From: Mike Griese <migrie@microsoft.com>
Date: Wed, 14 Jul 2021 09:19:51 -0500
Subject: [PATCH 1/8] Fix a bug where error/warning -> indeterminate would not
 update the progress value correctly

---
 src/cascadia/WindowsTerminal/IslandWindow.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/cascadia/WindowsTerminal/IslandWindow.cpp b/src/cascadia/WindowsTerminal/IslandWindow.cpp
index 33b250c3da6..5d0e8f8229f 100644
--- a/src/cascadia/WindowsTerminal/IslandWindow.cpp
+++ b/src/cascadia/WindowsTerminal/IslandWindow.cpp
@@ -702,7 +702,12 @@ void IslandWindow::SetTaskbarProgress(const size_t state, const size_t progress)
             _taskbar->SetProgressValue(_window.get(), progress, 100);
             break;
         case 3:
-            // sets the progress indicator to an indeterminate state
+            // sets the progress indicator to an indeterminate state.
+            // FIRST, set the progress to "no progress". That'll clear out any
+            // progress value from the previous state. Otherwise, a transition
+            // from (error,x%) or (warning,x%) to indeterminate will leave the
+            // progress value unchanged, and not show the spinner.
+            _taskbar->SetProgressState(_window.get(), TBPF_NOPROGRESS);
             _taskbar->SetProgressState(_window.get(), TBPF_INDETERMINATE);
             break;
         case 4:

From 95a26f09cc5a5ffbc155759525b42442fd57a83f Mon Sep 17 00:00:00 2001
From: Mike Griese <migrie@microsoft.com>
Date: Wed, 14 Jul 2021 09:21:22 -0500
Subject: [PATCH 2/8] This is a janky way of compining multiple pane's TB state
 in the icon at once. Not sure I love it.

---
 src/cascadia/TerminalApp/Pane.cpp        | 44 ++++++++++++++++++++++++
 src/cascadia/TerminalApp/Pane.h          | 15 ++++++++
 src/cascadia/TerminalApp/TerminalTab.cpp | 12 +++++--
 3 files changed, 68 insertions(+), 3 deletions(-)

diff --git a/src/cascadia/TerminalApp/Pane.cpp b/src/cascadia/TerminalApp/Pane.cpp
index cb8f4278a76..06fe62298c8 100644
--- a/src/cascadia/TerminalApp/Pane.cpp
+++ b/src/cascadia/TerminalApp/Pane.cpp
@@ -2133,6 +2133,50 @@ bool Pane::ContainsReadOnly() const
     return _IsLeaf() ? _control.ReadOnly() : (_firstChild->ContainsReadOnly() || _secondChild->ContainsReadOnly());
 }
 
+TaskbarState::TaskbarState(const uint64_t dispatchTypesState, const uint64_t progressParam) :
+    state{ dispatchTypesState },
+    progress{ progressParam } {}
+
+uint64_t TaskbarState::_getPriority() const
+{
+    // This seemingly nonsensical ordering is from
+    // https://docs.microsoft.com/en-us/windows/win32/api/shobjidl_core/nf-shobjidl_core-itaskbarlist3-setprogressstate#how-the-taskbar-button-chooses-the-progress-indicator-for-a-group
+    switch (state)
+    {
+    case 0: // Clear = 0,
+        return 5;
+    case 1: // Set = 1,
+        return 3;
+    case 2: // Error = 2,
+        return 1;
+    case 3: // Indeterminate = 3,
+        return 4;
+    case 4: // Paused = 4
+        return 2;
+    }
+    // Here, return 6, to definitely be greater than all the other valid values.
+    // This should never really happen.
+    return 6;
+}
+
+int TaskbarState::ComparePriority(const TaskbarState& lhs, const TaskbarState& rhs)
+{
+    return lhs._getPriority() < rhs._getPriority();
+}
+
+void Pane::CollectTaskbarStates(std::vector<TaskbarState>& states)
+{
+    if (_IsLeaf())
+    {
+        states.emplace_back(_control.TaskbarState(), _control.TaskbarProgress());
+    }
+    else
+    {
+        _firstChild->CollectTaskbarStates(states);
+        _secondChild->CollectTaskbarStates(states);
+    }
+}
+
 DEFINE_EVENT(Pane, GotFocus, _GotFocusHandlers, winrt::delegate<std::shared_ptr<Pane>>);
 DEFINE_EVENT(Pane, LostFocus, _LostFocusHandlers, winrt::delegate<std::shared_ptr<Pane>>);
 DEFINE_EVENT(Pane, PaneRaiseBell, _PaneRaiseBellHandlers, winrt::Windows::Foundation::EventHandler<bool>);
diff --git a/src/cascadia/TerminalApp/Pane.h b/src/cascadia/TerminalApp/Pane.h
index 6e7f801b787..1f831f6d39b 100644
--- a/src/cascadia/TerminalApp/Pane.h
+++ b/src/cascadia/TerminalApp/Pane.h
@@ -32,6 +32,19 @@ enum class Borders : int
 };
 DEFINE_ENUM_FLAG_OPERATORS(Borders);
 
+class TaskbarState
+{
+public:
+    TaskbarState(const uint64_t dispatchTypesState, const uint64_t progress);
+    static int ComparePriority(const TaskbarState& lhs, const TaskbarState& rhs);
+
+    uint64_t state{ 0 };
+    uint64_t progress{ 0 };
+
+private:
+    uint64_t _getPriority() const;
+};
+
 class Pane : public std::enable_shared_from_this<Pane>
 {
 public:
@@ -82,6 +95,8 @@ class Pane : public std::enable_shared_from_this<Pane>
 
     bool ContainsReadOnly() const;
 
+    void CollectTaskbarStates(std::vector<TaskbarState>& states);
+
     WINRT_CALLBACK(Closed, winrt::Windows::Foundation::EventHandler<winrt::Windows::Foundation::IInspectable>);
     DECLARE_EVENT(GotFocus, _GotFocusHandlers, winrt::delegate<std::shared_ptr<Pane>>);
     DECLARE_EVENT(LostFocus, _LostFocusHandlers, winrt::delegate<std::shared_ptr<Pane>>);
diff --git a/src/cascadia/TerminalApp/TerminalTab.cpp b/src/cascadia/TerminalApp/TerminalTab.cpp
index 4a09839407a..7e65aa41883 100644
--- a/src/cascadia/TerminalApp/TerminalTab.cpp
+++ b/src/cascadia/TerminalApp/TerminalTab.cpp
@@ -645,9 +645,15 @@ namespace winrt::TerminalApp::implementation
     // - <none>
     void TerminalTab::_UpdateProgressState()
     {
-        if (const auto& activeControl{ GetActiveTerminalControl() })
+        std::vector<TaskbarState> states;
+        _rootPane->CollectTaskbarStates(states);
+        std::sort(states.begin(), states.end(), TaskbarState::ComparePriority);
+        if (!states.empty())
         {
-            const auto taskbarState = activeControl.TaskbarState();
+            const auto& state{ states[0] };
+            // if (const auto& activeControl{ GetActiveTerminalControl() })
+            // {
+            const auto taskbarState = state.state;
             // The progress of the control changed, but not necessarily the progress of the tab.
             // Set the tab's progress ring to the active pane's progress
             if (taskbarState > 0)
@@ -662,7 +668,7 @@ namespace winrt::TerminalApp::implementation
                     // any non-indeterminate state has a value, set the progress ring as such
                     _tabStatus.IsProgressRingIndeterminate(false);
 
-                    const auto progressValue = gsl::narrow<uint32_t>(activeControl.TaskbarProgress());
+                    const auto progressValue = gsl::narrow<uint32_t>(state.progress);
                     _tabStatus.ProgressValue(progressValue);
                 }
                 // Hide the tab icon (the progress ring is placed over it)

From 2dccf0fade3f8a48b25503908da9ae4998c76ea0 Mon Sep 17 00:00:00 2001
From: Mike Griese <migrie@microsoft.com>
Date: Wed, 14 Jul 2021 10:10:25 -0500
Subject: [PATCH 3/8] Not in love with this.

---
 src/cascadia/TerminalApp/Pane.cpp         |  4 ++
 src/cascadia/TerminalApp/Pane.h           |  1 +
 src/cascadia/TerminalApp/TerminalPage.cpp |  8 +--
 src/cascadia/TerminalApp/TerminalTab.cpp  | 67 ++++++++++++-----------
 src/cascadia/TerminalApp/TerminalTab.h    |  1 +
 5 files changed, 45 insertions(+), 36 deletions(-)

diff --git a/src/cascadia/TerminalApp/Pane.cpp b/src/cascadia/TerminalApp/Pane.cpp
index 06fe62298c8..a834552f165 100644
--- a/src/cascadia/TerminalApp/Pane.cpp
+++ b/src/cascadia/TerminalApp/Pane.cpp
@@ -2133,6 +2133,10 @@ bool Pane::ContainsReadOnly() const
     return _IsLeaf() ? _control.ReadOnly() : (_firstChild->ContainsReadOnly() || _secondChild->ContainsReadOnly());
 }
 
+// Default to unset, 0%.
+TaskbarState::TaskbarState() :
+    TaskbarState(0, 0){};
+
 TaskbarState::TaskbarState(const uint64_t dispatchTypesState, const uint64_t progressParam) :
     state{ dispatchTypesState },
     progress{ progressParam } {}
diff --git a/src/cascadia/TerminalApp/Pane.h b/src/cascadia/TerminalApp/Pane.h
index 1f831f6d39b..bfb31cf51fc 100644
--- a/src/cascadia/TerminalApp/Pane.h
+++ b/src/cascadia/TerminalApp/Pane.h
@@ -35,6 +35,7 @@ DEFINE_ENUM_FLAG_OPERATORS(Borders);
 class TaskbarState
 {
 public:
+    TaskbarState();
     TaskbarState(const uint64_t dispatchTypesState, const uint64_t progress);
     static int ComparePriority(const TaskbarState& lhs, const TaskbarState& rhs);
 
diff --git a/src/cascadia/TerminalApp/TerminalPage.cpp b/src/cascadia/TerminalApp/TerminalPage.cpp
index a5eb4c5ddf7..56ad3da7290 100644
--- a/src/cascadia/TerminalApp/TerminalPage.cpp
+++ b/src/cascadia/TerminalApp/TerminalPage.cpp
@@ -2022,9 +2022,9 @@ namespace winrt::TerminalApp::implementation
     // - The taskbar state of the last active control
     size_t TerminalPage::GetLastActiveControlTaskbarState()
     {
-        if (auto control{ _GetActiveControl() })
+        if (auto tab{ _GetFocusedTabImpl() })
         {
-            return gsl::narrow_cast<size_t>(control.TaskbarState());
+            return gsl::narrow_cast<size_t>(tab->GetCombinedTaskbarState().state);
         }
         return {};
     }
@@ -2035,9 +2035,9 @@ namespace winrt::TerminalApp::implementation
     // - The taskbar progress of the last active control
     size_t TerminalPage::GetLastActiveControlTaskbarProgress()
     {
-        if (auto control{ _GetActiveControl() })
+        if (auto tab{ _GetFocusedTabImpl() })
         {
-            return gsl::narrow_cast<size_t>(control.TaskbarProgress());
+            return gsl::narrow_cast<size_t>(tab->GetCombinedTaskbarState().progress);
         }
         return {};
     }
diff --git a/src/cascadia/TerminalApp/TerminalTab.cpp b/src/cascadia/TerminalApp/TerminalTab.cpp
index 7e65aa41883..f19e334f1f7 100644
--- a/src/cascadia/TerminalApp/TerminalTab.cpp
+++ b/src/cascadia/TerminalApp/TerminalTab.cpp
@@ -177,10 +177,9 @@ namespace winrt::TerminalApp::implementation
             {
                 lastFocusedControl.Focus(_focusState);
 
-                // Update our own progress state, and fire an event signaling
+                // Update our own progress state. This will fire an event signaling
                 // that our taskbar progress changed.
                 _UpdateProgressState();
-                _TaskbarProgressChangedHandlers(lastFocusedControl, nullptr);
             }
             // When we gain focus, remove the bell indicator if it is active
             if (_tabStatus.BellIndicator())
@@ -630,6 +629,14 @@ namespace winrt::TerminalApp::implementation
         });
     }
 
+    TaskbarState TerminalTab::GetCombinedTaskbarState() const
+    {
+        std::vector<TaskbarState> states;
+        _rootPane->CollectTaskbarStates(states);
+        std::sort(states.begin(), states.end(), TaskbarState::ComparePriority);
+        return states.empty() ? TaskbarState{} : states[0];
+    }
+
     // Method Description:
     // - This should be called on the UI thread. If you don't, then it might
     //   silently do nothing.
@@ -645,43 +652,39 @@ namespace winrt::TerminalApp::implementation
     // - <none>
     void TerminalTab::_UpdateProgressState()
     {
-        std::vector<TaskbarState> states;
-        _rootPane->CollectTaskbarStates(states);
-        std::sort(states.begin(), states.end(), TaskbarState::ComparePriority);
-        if (!states.empty())
+        const auto state{ GetCombinedTaskbarState() };
+
+        const auto taskbarState = state.state;
+        // The progress of the control changed, but not necessarily the progress of the tab.
+        // Set the tab's progress ring to the active pane's progress
+        if (taskbarState > 0)
         {
-            const auto& state{ states[0] };
-            // if (const auto& activeControl{ GetActiveTerminalControl() })
-            // {
-            const auto taskbarState = state.state;
-            // The progress of the control changed, but not necessarily the progress of the tab.
-            // Set the tab's progress ring to the active pane's progress
-            if (taskbarState > 0)
+            if (taskbarState == 3)
             {
-                if (taskbarState == 3)
-                {
-                    // 3 is the indeterminate state, set the progress ring as such
-                    _tabStatus.IsProgressRingIndeterminate(true);
-                }
-                else
-                {
-                    // any non-indeterminate state has a value, set the progress ring as such
-                    _tabStatus.IsProgressRingIndeterminate(false);
-
-                    const auto progressValue = gsl::narrow<uint32_t>(state.progress);
-                    _tabStatus.ProgressValue(progressValue);
-                }
-                // Hide the tab icon (the progress ring is placed over it)
-                HideIcon(true);
-                _tabStatus.IsProgressRingActive(true);
+                // 3 is the indeterminate state, set the progress ring as such
+                _tabStatus.IsProgressRingIndeterminate(true);
             }
             else
             {
-                // Show the tab icon
-                HideIcon(false);
-                _tabStatus.IsProgressRingActive(false);
+                // any non-indeterminate state has a value, set the progress ring as such
+                _tabStatus.IsProgressRingIndeterminate(false);
+
+                const auto progressValue = gsl::narrow<uint32_t>(state.progress);
+                _tabStatus.ProgressValue(progressValue);
             }
+            // Hide the tab icon (the progress ring is placed over it)
+            HideIcon(true);
+            _tabStatus.IsProgressRingActive(true);
         }
+        else
+        {
+            // Show the tab icon
+            HideIcon(false);
+            _tabStatus.IsProgressRingActive(false);
+        }
+
+        // fire an event signaling that our taskbar progress changed.
+        _TaskbarProgressChangedHandlers(nullptr, nullptr);
     }
 
     // Method Description:
diff --git a/src/cascadia/TerminalApp/TerminalTab.h b/src/cascadia/TerminalApp/TerminalTab.h
index 7167f74a67c..eb83bac3e63 100644
--- a/src/cascadia/TerminalApp/TerminalTab.h
+++ b/src/cascadia/TerminalApp/TerminalTab.h
@@ -81,6 +81,7 @@ namespace winrt::TerminalApp::implementation
 
         void TogglePaneReadOnly();
         std::shared_ptr<Pane> GetActivePane() const;
+        TaskbarState GetCombinedTaskbarState() const;
 
         winrt::TerminalApp::TerminalTabStatus TabStatus()
         {

From 8c0a7db88b42e704819cd01aa61ea7f35c84c44d Mon Sep 17 00:00:00 2001
From: Mike Griese <migrie@microsoft.com>
Date: Wed, 21 Jul 2021 14:04:21 -0500
Subject: [PATCH 4/8] Move TaskbarState to be a WinRT class. We'll need this
 for the next part...

---
 src/cascadia/TerminalApp/Pane.cpp             | 41 ++------------
 src/cascadia/TerminalApp/Pane.h               | 17 +-----
 src/cascadia/TerminalApp/TaskbarState.cpp     | 54 +++++++++++++++++++
 src/cascadia/TerminalApp/TaskbarState.h       | 34 ++++++++++++
 src/cascadia/TerminalApp/TaskbarState.idl     | 15 ++++++
 .../TerminalApp/TerminalAppLib.vcxproj        |  7 +++
 src/cascadia/TerminalApp/TerminalPage.cpp     |  4 +-
 src/cascadia/TerminalApp/TerminalTab.cpp      | 12 ++---
 src/cascadia/TerminalApp/TerminalTab.h        |  2 +-
 9 files changed, 125 insertions(+), 61 deletions(-)
 create mode 100644 src/cascadia/TerminalApp/TaskbarState.cpp
 create mode 100644 src/cascadia/TerminalApp/TaskbarState.h
 create mode 100644 src/cascadia/TerminalApp/TaskbarState.idl

diff --git a/src/cascadia/TerminalApp/Pane.cpp b/src/cascadia/TerminalApp/Pane.cpp
index 983adadef90..71c62339146 100644
--- a/src/cascadia/TerminalApp/Pane.cpp
+++ b/src/cascadia/TerminalApp/Pane.cpp
@@ -2132,46 +2132,13 @@ bool Pane::ContainsReadOnly() const
     return _IsLeaf() ? _control.ReadOnly() : (_firstChild->ContainsReadOnly() || _secondChild->ContainsReadOnly());
 }
 
-// Default to unset, 0%.
-TaskbarState::TaskbarState() :
-    TaskbarState(0, 0){};
-
-TaskbarState::TaskbarState(const uint64_t dispatchTypesState, const uint64_t progressParam) :
-    state{ dispatchTypesState },
-    progress{ progressParam } {}
-
-uint64_t TaskbarState::_getPriority() const
-{
-    // This seemingly nonsensical ordering is from
-    // https://docs.microsoft.com/en-us/windows/win32/api/shobjidl_core/nf-shobjidl_core-itaskbarlist3-setprogressstate#how-the-taskbar-button-chooses-the-progress-indicator-for-a-group
-    switch (state)
-    {
-    case 0: // Clear = 0,
-        return 5;
-    case 1: // Set = 1,
-        return 3;
-    case 2: // Error = 2,
-        return 1;
-    case 3: // Indeterminate = 3,
-        return 4;
-    case 4: // Paused = 4
-        return 2;
-    }
-    // Here, return 6, to definitely be greater than all the other valid values.
-    // This should never really happen.
-    return 6;
-}
-
-int TaskbarState::ComparePriority(const TaskbarState& lhs, const TaskbarState& rhs)
-{
-    return lhs._getPriority() < rhs._getPriority();
-}
-
-void Pane::CollectTaskbarStates(std::vector<TaskbarState>& states)
+void Pane::CollectTaskbarStates(std::vector<winrt::TerminalApp::TaskbarState>& states)
 {
     if (_IsLeaf())
     {
-        states.emplace_back(_control.TaskbarState(), _control.TaskbarProgress());
+        auto tbState{ winrt::make<winrt::TerminalApp::implementation::TaskbarState>(_control.TaskbarState(),
+                                                                                    _control.TaskbarProgress()) };
+        states.push_back(tbState);
     }
     else
     {
diff --git a/src/cascadia/TerminalApp/Pane.h b/src/cascadia/TerminalApp/Pane.h
index bfb31cf51fc..a38f0842de5 100644
--- a/src/cascadia/TerminalApp/Pane.h
+++ b/src/cascadia/TerminalApp/Pane.h
@@ -21,6 +21,7 @@
 #pragma once
 
 #include "../../cascadia/inc/cppwinrt_utils.h"
+#include "TaskbarState.h"
 
 enum class Borders : int
 {
@@ -32,20 +33,6 @@ enum class Borders : int
 };
 DEFINE_ENUM_FLAG_OPERATORS(Borders);
 
-class TaskbarState
-{
-public:
-    TaskbarState();
-    TaskbarState(const uint64_t dispatchTypesState, const uint64_t progress);
-    static int ComparePriority(const TaskbarState& lhs, const TaskbarState& rhs);
-
-    uint64_t state{ 0 };
-    uint64_t progress{ 0 };
-
-private:
-    uint64_t _getPriority() const;
-};
-
 class Pane : public std::enable_shared_from_this<Pane>
 {
 public:
@@ -96,7 +83,7 @@ class Pane : public std::enable_shared_from_this<Pane>
 
     bool ContainsReadOnly() const;
 
-    void CollectTaskbarStates(std::vector<TaskbarState>& states);
+    void CollectTaskbarStates(std::vector<winrt::TerminalApp::TaskbarState>& states);
 
     WINRT_CALLBACK(Closed, winrt::Windows::Foundation::EventHandler<winrt::Windows::Foundation::IInspectable>);
     DECLARE_EVENT(GotFocus, _GotFocusHandlers, winrt::delegate<std::shared_ptr<Pane>>);
diff --git a/src/cascadia/TerminalApp/TaskbarState.cpp b/src/cascadia/TerminalApp/TaskbarState.cpp
new file mode 100644
index 00000000000..9402182de8a
--- /dev/null
+++ b/src/cascadia/TerminalApp/TaskbarState.cpp
@@ -0,0 +1,54 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#include "pch.h"
+#include <LibraryResources.h>
+#include "TaskbarState.h"
+#include "TaskbarState.g.cpp"
+
+using namespace winrt;
+
+namespace winrt
+{
+    namespace MUX = Microsoft::UI::Xaml;
+    namespace WUX = Windows::UI::Xaml;
+}
+
+namespace winrt::TerminalApp::implementation
+{
+    // Default to unset, 0%.
+    TaskbarState::TaskbarState() :
+        TaskbarState(0, 0){};
+
+    TaskbarState::TaskbarState(const uint64_t dispatchTypesState, const uint64_t progressParam) :
+        _State{ dispatchTypesState },
+        _Progress{ progressParam } {}
+
+    uint64_t TaskbarState::Priority() const
+    {
+        // This seemingly nonsensical ordering is from
+        // https://docs.microsoft.com/en-us/windows/win32/api/shobjidl_core/nf-shobjidl_core-itaskbarlist3-setprogressstate#how-the-taskbar-button-chooses-the-progress-indicator-for-a-group
+        switch (_State)
+        {
+        case 0: // Clear = 0,
+            return 5;
+        case 1: // Set = 1,
+            return 3;
+        case 2: // Error = 2,
+            return 1;
+        case 3: // Indeterminate = 3,
+            return 4;
+        case 4: // Paused = 4
+            return 2;
+        }
+        // Here, return 6, to definitely be greater than all the other valid values.
+        // This should never really happen.
+        return 6;
+    }
+
+    int TaskbarState::ComparePriority(const winrt::TerminalApp::TaskbarState& lhs, const winrt::TerminalApp::TaskbarState& rhs)
+    {
+        return lhs.Priority() < rhs.Priority();
+    }
+
+}
diff --git a/src/cascadia/TerminalApp/TaskbarState.h b/src/cascadia/TerminalApp/TaskbarState.h
new file mode 100644
index 00000000000..e36b4440cc9
--- /dev/null
+++ b/src/cascadia/TerminalApp/TaskbarState.h
@@ -0,0 +1,34 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#pragma once
+#include "inc/cppwinrt_utils.h"
+#include "TaskbarState.g.h"
+
+// fwdecl unittest classes
+namespace TerminalAppLocalTests
+{
+    class TabTests;
+};
+
+namespace winrt::TerminalApp::implementation
+{
+    struct TaskbarState : TaskbarStateT<TaskbarState>
+    {
+    public:
+        TaskbarState();
+        TaskbarState(const uint64_t dispatchTypesState, const uint64_t progress);
+
+        static int ComparePriority(const winrt::TerminalApp::TaskbarState& lhs, const winrt::TerminalApp::TaskbarState& rhs);
+
+        uint64_t Priority() const;
+
+        WINRT_PROPERTY(uint64_t, State, 0);
+        WINRT_PROPERTY(uint64_t, Progress, 0);
+    };
+}
+
+namespace winrt::TerminalApp::factory_implementation
+{
+    BASIC_FACTORY(TaskbarState);
+}
diff --git a/src/cascadia/TerminalApp/TaskbarState.idl b/src/cascadia/TerminalApp/TaskbarState.idl
new file mode 100644
index 00000000000..159242a17b2
--- /dev/null
+++ b/src/cascadia/TerminalApp/TaskbarState.idl
@@ -0,0 +1,15 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+namespace TerminalApp
+{
+    [default_interface] runtimeclass TaskbarState
+    {
+        TaskbarState();
+        TaskbarState(UInt64 dispatchTypesState, UInt64 progress);
+
+        UInt64 State{ get; };
+        UInt64 Progress{ get; };
+        UInt64 Priority { get; };
+    }
+}
diff --git a/src/cascadia/TerminalApp/TerminalAppLib.vcxproj b/src/cascadia/TerminalApp/TerminalAppLib.vcxproj
index 67317f4e482..95e49e2008b 100644
--- a/src/cascadia/TerminalApp/TerminalAppLib.vcxproj
+++ b/src/cascadia/TerminalApp/TerminalAppLib.vcxproj
@@ -89,6 +89,9 @@
       <DependentUpon>TabBase.idl</DependentUpon>
     </ClInclude>
     <ClInclude Include="TabPaletteItem.h" />
+    <ClInclude Include="TaskbarState.h">
+      <DependentUpon>TaskbarState.idl</DependentUpon>
+    </ClInclude>
     <ClInclude Include="TerminalTab.h">
       <DependentUpon>TerminalTab.idl</DependentUpon>
     </ClInclude>
@@ -164,6 +167,9 @@
       <DependentUpon>TabBase.idl</DependentUpon>
     </ClCompile>
     <ClCompile Include="TabPaletteItem.cpp" />
+    <ClCompile Include="TaskbarState.cpp">
+      <DependentUpon>TaskbarState.idl</DependentUpon>
+    </ClCompile>
     <ClCompile Include="TerminalTab.cpp">
       <DependentUpon>TerminalTab.idl</DependentUpon>
     </ClCompile>
@@ -256,6 +262,7 @@
     </Midl>
     <Midl Include="TabBase.idl" />
     <Midl Include="TabPaletteItem.idl" />
+    <Midl Include="TaskbarState.idl" />
     <Midl Include="TerminalTab.idl" />
     <Midl Include="TerminalPage.idl">
       <DependentUpon>TerminalPage.xaml</DependentUpon>
diff --git a/src/cascadia/TerminalApp/TerminalPage.cpp b/src/cascadia/TerminalApp/TerminalPage.cpp
index ebca8a87954..ba723c26a47 100644
--- a/src/cascadia/TerminalApp/TerminalPage.cpp
+++ b/src/cascadia/TerminalApp/TerminalPage.cpp
@@ -2046,7 +2046,7 @@ namespace winrt::TerminalApp::implementation
     {
         if (auto tab{ _GetFocusedTabImpl() })
         {
-            return tab->GetCombinedTaskbarState().state;
+            return tab->GetCombinedTaskbarState().State();
         }
         return {};
     }
@@ -2059,7 +2059,7 @@ namespace winrt::TerminalApp::implementation
     {
         if (auto tab{ _GetFocusedTabImpl() })
         {
-            return tab->GetCombinedTaskbarState().progress;
+            return tab->GetCombinedTaskbarState().Progress();
         }
         return {};
     }
diff --git a/src/cascadia/TerminalApp/TerminalTab.cpp b/src/cascadia/TerminalApp/TerminalTab.cpp
index f19e334f1f7..cc8058f50b0 100644
--- a/src/cascadia/TerminalApp/TerminalTab.cpp
+++ b/src/cascadia/TerminalApp/TerminalTab.cpp
@@ -629,12 +629,12 @@ namespace winrt::TerminalApp::implementation
         });
     }
 
-    TaskbarState TerminalTab::GetCombinedTaskbarState() const
+    winrt::TerminalApp::TaskbarState TerminalTab::GetCombinedTaskbarState() const
     {
-        std::vector<TaskbarState> states;
+        std::vector<winrt::TerminalApp::TaskbarState> states;
         _rootPane->CollectTaskbarStates(states);
-        std::sort(states.begin(), states.end(), TaskbarState::ComparePriority);
-        return states.empty() ? TaskbarState{} : states[0];
+        std::sort(states.begin(), states.end(), TerminalApp::implementation::TaskbarState::ComparePriority);
+        return states.empty() ? winrt::make<winrt::TerminalApp::implementation::TaskbarState>() : states[0];
     }
 
     // Method Description:
@@ -654,7 +654,7 @@ namespace winrt::TerminalApp::implementation
     {
         const auto state{ GetCombinedTaskbarState() };
 
-        const auto taskbarState = state.state;
+        const auto taskbarState = state.State();
         // The progress of the control changed, but not necessarily the progress of the tab.
         // Set the tab's progress ring to the active pane's progress
         if (taskbarState > 0)
@@ -669,7 +669,7 @@ namespace winrt::TerminalApp::implementation
                 // any non-indeterminate state has a value, set the progress ring as such
                 _tabStatus.IsProgressRingIndeterminate(false);
 
-                const auto progressValue = gsl::narrow<uint32_t>(state.progress);
+                const auto progressValue = gsl::narrow<uint32_t>(state.Progress());
                 _tabStatus.ProgressValue(progressValue);
             }
             // Hide the tab icon (the progress ring is placed over it)
diff --git a/src/cascadia/TerminalApp/TerminalTab.h b/src/cascadia/TerminalApp/TerminalTab.h
index eb83bac3e63..4f135a327e9 100644
--- a/src/cascadia/TerminalApp/TerminalTab.h
+++ b/src/cascadia/TerminalApp/TerminalTab.h
@@ -81,7 +81,7 @@ namespace winrt::TerminalApp::implementation
 
         void TogglePaneReadOnly();
         std::shared_ptr<Pane> GetActivePane() const;
-        TaskbarState GetCombinedTaskbarState() const;
+        winrt::TerminalApp::TaskbarState GetCombinedTaskbarState() const;
 
         winrt::TerminalApp::TerminalTabStatus TabStatus()
         {

From cbbdd385385e4b1f04632975c88d50a9080abb3e Mon Sep 17 00:00:00 2001
From: Mike Griese <migrie@microsoft.com>
Date: Wed, 21 Jul 2021 14:42:54 -0500
Subject: [PATCH 5/8] yay it works

---
 src/cascadia/TerminalApp/AppLogic.cpp     | 32 ++++++------
 src/cascadia/TerminalApp/AppLogic.h       |  5 +-
 src/cascadia/TerminalApp/AppLogic.idl     |  5 +-
 src/cascadia/TerminalApp/TerminalPage.cpp | 60 +++++++++++++++--------
 src/cascadia/TerminalApp/TerminalPage.h   |  5 +-
 src/cascadia/TerminalApp/TerminalPage.idl |  6 ++-
 src/cascadia/WindowsTerminal/AppHost.cpp  | 11 +++--
 7 files changed, 73 insertions(+), 51 deletions(-)

diff --git a/src/cascadia/TerminalApp/AppLogic.cpp b/src/cascadia/TerminalApp/AppLogic.cpp
index 441fbd4deff..301aadc2ef0 100644
--- a/src/cascadia/TerminalApp/AppLogic.cpp
+++ b/src/cascadia/TerminalApp/AppLogic.cpp
@@ -1125,31 +1125,27 @@ namespace winrt::TerminalApp::implementation
         }
     }
 
-    // Method Description:
-    // - Gets the taskbar state value from the last active control
-    // Return Value:
-    // - The taskbar state of the last active control
-    uint64_t AppLogic::GetLastActiveControlTaskbarState()
+    winrt::TerminalApp::TaskbarState AppLogic::TaskbarState()
     {
         if (_root)
         {
-            return _root->GetLastActiveControlTaskbarState();
+            return _root->TaskbarState();
         }
         return {};
     }
 
-    // Method Description:
-    // - Gets the taskbar progress value from the last active control
-    // Return Value:
-    // - The taskbar progress of the last active control
-    uint64_t AppLogic::GetLastActiveControlTaskbarProgress()
-    {
-        if (_root)
-        {
-            return _root->GetLastActiveControlTaskbarProgress();
-        }
-        return {};
-    }
+    // // Method Description:
+    // // - Gets the taskbar progress value from the last active control
+    // // Return Value:
+    // // - The taskbar progress of the last active control
+    // uint64_t AppLogic::GetLastActiveControlTaskbarProgress()
+    // {
+    //     if (_root)
+    //     {
+    //         return _root->GetLastActiveControlTaskbarProgress();
+    //     }
+    //     return {};
+    // }
 
     // Method Description:
     // - Sets the initial commandline to process on startup, and attempts to
diff --git a/src/cascadia/TerminalApp/AppLogic.h b/src/cascadia/TerminalApp/AppLogic.h
index 3d778203921..5661134becb 100644
--- a/src/cascadia/TerminalApp/AppLogic.h
+++ b/src/cascadia/TerminalApp/AppLogic.h
@@ -89,8 +89,9 @@ namespace winrt::TerminalApp::implementation
 
         void WindowCloseButtonClicked();
 
-        uint64_t GetLastActiveControlTaskbarState();
-        uint64_t GetLastActiveControlTaskbarProgress();
+        // uint64_t GetLastActiveControlTaskbarState();
+        // uint64_t GetLastActiveControlTaskbarProgress();
+        winrt::TerminalApp::TaskbarState TaskbarState();
 
         winrt::Windows::Foundation::IAsyncOperation<winrt::Windows::UI::Xaml::Controls::ContentDialogResult> ShowDialog(winrt::Windows::UI::Xaml::Controls::ContentDialog dialog);
 
diff --git a/src/cascadia/TerminalApp/AppLogic.idl b/src/cascadia/TerminalApp/AppLogic.idl
index bb334d26f47..389dffe3579 100644
--- a/src/cascadia/TerminalApp/AppLogic.idl
+++ b/src/cascadia/TerminalApp/AppLogic.idl
@@ -68,8 +68,9 @@ namespace TerminalApp
         void TitlebarClicked();
         void WindowCloseButtonClicked();
 
-        UInt64 GetLastActiveControlTaskbarState();
-        UInt64 GetLastActiveControlTaskbarProgress();
+        // UInt64 GetLastActiveControlTaskbarState();
+        // UInt64 GetLastActiveControlTaskbarProgress();
+        TaskbarState TaskbarState{ get; };
 
         FindTargetWindowResult FindTargetWindow(String[] args);
 
diff --git a/src/cascadia/TerminalApp/TerminalPage.cpp b/src/cascadia/TerminalApp/TerminalPage.cpp
index ba723c26a47..ecadb69b8b2 100644
--- a/src/cascadia/TerminalApp/TerminalPage.cpp
+++ b/src/cascadia/TerminalApp/TerminalPage.cpp
@@ -2038,31 +2038,49 @@ namespace winrt::TerminalApp::implementation
         _dialogPresenter = dialogPresenter;
     }
 
-    // Method Description:
-    // - Gets the taskbar state value from the last active control
-    // Return Value:
-    // - The taskbar state of the last active control
-    uint64_t TerminalPage::GetLastActiveControlTaskbarState()
+    winrt::TerminalApp::TaskbarState TerminalPage::TaskbarState() const
     {
-        if (auto tab{ _GetFocusedTabImpl() })
-        {
-            return tab->GetCombinedTaskbarState().State();
-        }
-        return {};
-    }
+        std::vector<winrt::TerminalApp::TaskbarState> states;
 
-    // Method Description:
-    // - Gets the taskbar progress value from the last active control
-    // Return Value:
-    // - The taskbar progress of the last active control
-    uint64_t TerminalPage::GetLastActiveControlTaskbarProgress()
-    {
-        if (auto tab{ _GetFocusedTabImpl() })
+        for (const auto& tab : _tabs)
         {
-            return tab->GetCombinedTaskbarState().Progress();
+            if (auto tabImpl{ _GetTerminalTabImpl(tab) })
+            {
+                auto tabState{ tabImpl->GetCombinedTaskbarState() };
+                states.push_back(tabState);
+            }
         }
-        return {};
-    }
+
+        std::sort(states.begin(), states.end(), TerminalApp::implementation::TaskbarState::ComparePriority);
+
+        return states.empty() ? winrt::make<winrt::TerminalApp::implementation::TaskbarState>() : states[0];
+    }
+
+    // // Method Description:
+    // // - Gets the taskbar state value from the last active control
+    // // Return Value:
+    // // - The taskbar state of the last active control
+    // uint64_t TerminalPage::GetLastActiveControlTaskbarState()
+    // {
+    //     if (auto tab{ _GetFocusedTabImpl() })
+    //     {
+    //         return tab->GetCombinedTaskbarState().State();
+    //     }
+    //     return {};
+    // }
+
+    // // Method Description:
+    // // - Gets the taskbar progress value from the last active control
+    // // Return Value:
+    // // - The taskbar progress of the last active control
+    // uint64_t TerminalPage::GetLastActiveControlTaskbarProgress()
+    // {
+    //     if (auto tab{ _GetFocusedTabImpl() })
+    //     {
+    //         return tab->GetCombinedTaskbarState().Progress();
+    //     }
+    //     return {};
+    // }
 
     // Method Description:
     // - This is the method that App will call when the titlebar
diff --git a/src/cascadia/TerminalApp/TerminalPage.h b/src/cascadia/TerminalApp/TerminalPage.h
index 6d7370b9acd..1812be1652c 100644
--- a/src/cascadia/TerminalApp/TerminalPage.h
+++ b/src/cascadia/TerminalApp/TerminalPage.h
@@ -85,8 +85,9 @@ namespace winrt::TerminalApp::implementation
         winrt::TerminalApp::IDialogPresenter DialogPresenter() const;
         void DialogPresenter(winrt::TerminalApp::IDialogPresenter dialogPresenter);
 
-        uint64_t GetLastActiveControlTaskbarState();
-        uint64_t GetLastActiveControlTaskbarProgress();
+        // uint64_t GetLastActiveControlTaskbarState();
+        // uint64_t GetLastActiveControlTaskbarProgress();
+        winrt::TerminalApp::TaskbarState TaskbarState() const;
 
         void ShowKeyboardServiceWarning();
         winrt::hstring KeyboardServiceDisabledText();
diff --git a/src/cascadia/TerminalApp/TerminalPage.idl b/src/cascadia/TerminalApp/TerminalPage.idl
index 0d055782268..db93f02bfbf 100644
--- a/src/cascadia/TerminalApp/TerminalPage.idl
+++ b/src/cascadia/TerminalApp/TerminalPage.idl
@@ -1,5 +1,6 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT license.
+import "TaskbarState.idl";
 
 namespace TerminalApp
 {
@@ -42,8 +43,9 @@ namespace TerminalApp
         void ShowKeyboardServiceWarning();
         String KeyboardServiceDisabledText { get; };
 
-        UInt64 GetLastActiveControlTaskbarState();
-        UInt64 GetLastActiveControlTaskbarProgress();
+        // UInt64 GetLastActiveControlTaskbarState();
+        // UInt64 GetLastActiveControlTaskbarProgress();
+        TaskbarState TaskbarState{ get; };
 
         event Windows.Foundation.TypedEventHandler<Object, String> TitleChanged;
         event Windows.Foundation.TypedEventHandler<Object, LastTabClosedEventArgs> LastTabClosed;
diff --git a/src/cascadia/WindowsTerminal/AppHost.cpp b/src/cascadia/WindowsTerminal/AppHost.cpp
index 53e21ccdd38..070cb2c9be2 100644
--- a/src/cascadia/WindowsTerminal/AppHost.cpp
+++ b/src/cascadia/WindowsTerminal/AppHost.cpp
@@ -126,13 +126,16 @@ bool AppHost::OnDirectKeyEvent(const uint32_t vkey, const uint8_t scanCode, cons
 // Arguments:
 // - sender: not used
 // - args: not used
-void AppHost::SetTaskbarProgress(const winrt::Windows::Foundation::IInspectable& /*sender*/, const winrt::Windows::Foundation::IInspectable& /*args*/)
+void AppHost::SetTaskbarProgress(const winrt::Windows::Foundation::IInspectable& /*sender*/,
+                                 const winrt::Windows::Foundation::IInspectable& /*args*/)
 {
     if (_logic)
     {
-        const auto state = gsl::narrow_cast<size_t>(_logic.GetLastActiveControlTaskbarState());
-        const auto progress = gsl::narrow_cast<size_t>(_logic.GetLastActiveControlTaskbarProgress());
-        _window->SetTaskbarProgress(state, progress);
+        const auto state = _logic.TaskbarState();
+        // const auto state = gsl::narrow_cast<size_t>(_logic.GetLastActiveControlTaskbarState());
+        // const auto progress = gsl::narrow_cast<size_t>(_logic.GetLastActiveControlTaskbarProgress());
+        _window->SetTaskbarProgress(gsl::narrow_cast<size_t>(state.State()),
+                                    gsl::narrow_cast<size_t>(state.Progress()));
     }
 }
 

From 2703447e1c10deabeb6eebde93ae1ba333dab959 Mon Sep 17 00:00:00 2001
From: Mike Griese <migrie@microsoft.com>
Date: Thu, 22 Jul 2021 08:55:53 -0500
Subject: [PATCH 6/8] cleanup

---
 src/cascadia/TerminalApp/AppLogic.cpp     | 13 --------
 src/cascadia/TerminalApp/AppLogic.h       |  2 --
 src/cascadia/TerminalApp/AppLogic.idl     |  2 --
 src/cascadia/TerminalApp/Pane.cpp         |  8 +++++
 src/cascadia/TerminalApp/TerminalPage.cpp | 38 +++++++----------------
 src/cascadia/TerminalApp/TerminalPage.h   |  2 --
 src/cascadia/TerminalApp/TerminalPage.idl |  2 --
 src/cascadia/TerminalApp/TerminalTab.cpp  | 12 +++++++
 src/cascadia/WindowsTerminal/AppHost.cpp  |  2 --
 9 files changed, 32 insertions(+), 49 deletions(-)

diff --git a/src/cascadia/TerminalApp/AppLogic.cpp b/src/cascadia/TerminalApp/AppLogic.cpp
index 301aadc2ef0..4b029905d35 100644
--- a/src/cascadia/TerminalApp/AppLogic.cpp
+++ b/src/cascadia/TerminalApp/AppLogic.cpp
@@ -1134,19 +1134,6 @@ namespace winrt::TerminalApp::implementation
         return {};
     }
 
-    // // Method Description:
-    // // - Gets the taskbar progress value from the last active control
-    // // Return Value:
-    // // - The taskbar progress of the last active control
-    // uint64_t AppLogic::GetLastActiveControlTaskbarProgress()
-    // {
-    //     if (_root)
-    //     {
-    //         return _root->GetLastActiveControlTaskbarProgress();
-    //     }
-    //     return {};
-    // }
-
     // Method Description:
     // - Sets the initial commandline to process on startup, and attempts to
     //   parse it. Commands will be parsed into a list of ShortcutActions that
diff --git a/src/cascadia/TerminalApp/AppLogic.h b/src/cascadia/TerminalApp/AppLogic.h
index 5661134becb..0f97f47e58b 100644
--- a/src/cascadia/TerminalApp/AppLogic.h
+++ b/src/cascadia/TerminalApp/AppLogic.h
@@ -89,8 +89,6 @@ namespace winrt::TerminalApp::implementation
 
         void WindowCloseButtonClicked();
 
-        // uint64_t GetLastActiveControlTaskbarState();
-        // uint64_t GetLastActiveControlTaskbarProgress();
         winrt::TerminalApp::TaskbarState TaskbarState();
 
         winrt::Windows::Foundation::IAsyncOperation<winrt::Windows::UI::Xaml::Controls::ContentDialogResult> ShowDialog(winrt::Windows::UI::Xaml::Controls::ContentDialog dialog);
diff --git a/src/cascadia/TerminalApp/AppLogic.idl b/src/cascadia/TerminalApp/AppLogic.idl
index 389dffe3579..0b889103899 100644
--- a/src/cascadia/TerminalApp/AppLogic.idl
+++ b/src/cascadia/TerminalApp/AppLogic.idl
@@ -68,8 +68,6 @@ namespace TerminalApp
         void TitlebarClicked();
         void WindowCloseButtonClicked();
 
-        // UInt64 GetLastActiveControlTaskbarState();
-        // UInt64 GetLastActiveControlTaskbarProgress();
         TaskbarState TaskbarState{ get; };
 
         FindTargetWindowResult FindTargetWindow(String[] args);
diff --git a/src/cascadia/TerminalApp/Pane.cpp b/src/cascadia/TerminalApp/Pane.cpp
index 71c62339146..e937fb31342 100644
--- a/src/cascadia/TerminalApp/Pane.cpp
+++ b/src/cascadia/TerminalApp/Pane.cpp
@@ -2132,6 +2132,14 @@ bool Pane::ContainsReadOnly() const
     return _IsLeaf() ? _control.ReadOnly() : (_firstChild->ContainsReadOnly() || _secondChild->ContainsReadOnly());
 }
 
+// Method Description:
+// - If we're a parent, place the taskbar state for all our leaves into the
+//   provided vector.
+// - If we're a leaf, place our own state into the vector.
+// Arguments:
+// - states: a vector that will receive all the states of all leaves in the tree
+// Return Value:
+// - <none>
 void Pane::CollectTaskbarStates(std::vector<winrt::TerminalApp::TaskbarState>& states)
 {
     if (_IsLeaf())
diff --git a/src/cascadia/TerminalApp/TerminalPage.cpp b/src/cascadia/TerminalApp/TerminalPage.cpp
index ecadb69b8b2..8113b2b9614 100644
--- a/src/cascadia/TerminalApp/TerminalPage.cpp
+++ b/src/cascadia/TerminalApp/TerminalPage.cpp
@@ -2038,6 +2038,18 @@ namespace winrt::TerminalApp::implementation
         _dialogPresenter = dialogPresenter;
     }
 
+    // Method Description:
+    // - Get the combined taskbar state for the page. This is the combination of
+    //   all the states of all the tabs, which are themselves a combination of
+    //   all their panes. Taskbar states are given a priority based on the rules
+    //   in:
+    //   https://docs.microsoft.com/en-us/windows/win32/api/shobjidl_core/nf-shobjidl_core-itaskbarlist3-setprogressstate
+    //   under "How the Taskbar Button Chooses the Progress Indicator for a Group"
+    // Arguments:
+    // - <none>
+    // Return Value:
+    // - A TaskbarState object representing the combined taskbar state and
+    //   progress precentage of all our tabs.
     winrt::TerminalApp::TaskbarState TerminalPage::TaskbarState() const
     {
         std::vector<winrt::TerminalApp::TaskbarState> states;
@@ -2056,32 +2068,6 @@ namespace winrt::TerminalApp::implementation
         return states.empty() ? winrt::make<winrt::TerminalApp::implementation::TaskbarState>() : states[0];
     }
 
-    // // Method Description:
-    // // - Gets the taskbar state value from the last active control
-    // // Return Value:
-    // // - The taskbar state of the last active control
-    // uint64_t TerminalPage::GetLastActiveControlTaskbarState()
-    // {
-    //     if (auto tab{ _GetFocusedTabImpl() })
-    //     {
-    //         return tab->GetCombinedTaskbarState().State();
-    //     }
-    //     return {};
-    // }
-
-    // // Method Description:
-    // // - Gets the taskbar progress value from the last active control
-    // // Return Value:
-    // // - The taskbar progress of the last active control
-    // uint64_t TerminalPage::GetLastActiveControlTaskbarProgress()
-    // {
-    //     if (auto tab{ _GetFocusedTabImpl() })
-    //     {
-    //         return tab->GetCombinedTaskbarState().Progress();
-    //     }
-    //     return {};
-    // }
-
     // Method Description:
     // - This is the method that App will call when the titlebar
     //   has been clicked. It dismisses any open flyouts.
diff --git a/src/cascadia/TerminalApp/TerminalPage.h b/src/cascadia/TerminalApp/TerminalPage.h
index 1812be1652c..91178c92002 100644
--- a/src/cascadia/TerminalApp/TerminalPage.h
+++ b/src/cascadia/TerminalApp/TerminalPage.h
@@ -85,8 +85,6 @@ namespace winrt::TerminalApp::implementation
         winrt::TerminalApp::IDialogPresenter DialogPresenter() const;
         void DialogPresenter(winrt::TerminalApp::IDialogPresenter dialogPresenter);
 
-        // uint64_t GetLastActiveControlTaskbarState();
-        // uint64_t GetLastActiveControlTaskbarProgress();
         winrt::TerminalApp::TaskbarState TaskbarState() const;
 
         void ShowKeyboardServiceWarning();
diff --git a/src/cascadia/TerminalApp/TerminalPage.idl b/src/cascadia/TerminalApp/TerminalPage.idl
index db93f02bfbf..7d4c580e9f3 100644
--- a/src/cascadia/TerminalApp/TerminalPage.idl
+++ b/src/cascadia/TerminalApp/TerminalPage.idl
@@ -43,8 +43,6 @@ namespace TerminalApp
         void ShowKeyboardServiceWarning();
         String KeyboardServiceDisabledText { get; };
 
-        // UInt64 GetLastActiveControlTaskbarState();
-        // UInt64 GetLastActiveControlTaskbarProgress();
         TaskbarState TaskbarState{ get; };
 
         event Windows.Foundation.TypedEventHandler<Object, String> TitleChanged;
diff --git a/src/cascadia/TerminalApp/TerminalTab.cpp b/src/cascadia/TerminalApp/TerminalTab.cpp
index cc8058f50b0..4242fce2b6c 100644
--- a/src/cascadia/TerminalApp/TerminalTab.cpp
+++ b/src/cascadia/TerminalApp/TerminalTab.cpp
@@ -629,6 +629,18 @@ namespace winrt::TerminalApp::implementation
         });
     }
 
+    // Method Description:
+    // - Get the combined taskbar state for the tab. This is the combination of
+    //   all the states of all our panes. Taskbar states are given a priority
+    //   based on the rules in:
+    //   https://docs.microsoft.com/en-us/windows/win32/api/shobjidl_core/nf-shobjidl_core-itaskbarlist3-setprogressstate
+    //   under "How the Taskbar Button Chooses the Progress Indicator for a
+    //   Group"
+    // Arguments:
+    // - <none>
+    // Return Value:
+    // - A TaskbarState object representing the combined taskbar state and
+    //   progress precentage of all our panes.
     winrt::TerminalApp::TaskbarState TerminalTab::GetCombinedTaskbarState() const
     {
         std::vector<winrt::TerminalApp::TaskbarState> states;
diff --git a/src/cascadia/WindowsTerminal/AppHost.cpp b/src/cascadia/WindowsTerminal/AppHost.cpp
index 070cb2c9be2..e59c3ec5f62 100644
--- a/src/cascadia/WindowsTerminal/AppHost.cpp
+++ b/src/cascadia/WindowsTerminal/AppHost.cpp
@@ -132,8 +132,6 @@ void AppHost::SetTaskbarProgress(const winrt::Windows::Foundation::IInspectable&
     if (_logic)
     {
         const auto state = _logic.TaskbarState();
-        // const auto state = gsl::narrow_cast<size_t>(_logic.GetLastActiveControlTaskbarState());
-        // const auto progress = gsl::narrow_cast<size_t>(_logic.GetLastActiveControlTaskbarProgress());
         _window->SetTaskbarProgress(gsl::narrow_cast<size_t>(state.State()),
                                     gsl::narrow_cast<size_t>(state.Progress()));
     }

From 15f03b34610b08912f7f90111833c719adac6b3a Mon Sep 17 00:00:00 2001
From: Mike Griese <migrie@microsoft.com>
Date: Thu, 22 Jul 2021 09:07:05 -0500
Subject: [PATCH 7/8] percentage

---
 src/cascadia/TerminalApp/TerminalPage.cpp | 2 +-
 src/cascadia/TerminalApp/TerminalTab.cpp  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/cascadia/TerminalApp/TerminalPage.cpp b/src/cascadia/TerminalApp/TerminalPage.cpp
index 8113b2b9614..446c184e9a2 100644
--- a/src/cascadia/TerminalApp/TerminalPage.cpp
+++ b/src/cascadia/TerminalApp/TerminalPage.cpp
@@ -2049,7 +2049,7 @@ namespace winrt::TerminalApp::implementation
     // - <none>
     // Return Value:
     // - A TaskbarState object representing the combined taskbar state and
-    //   progress precentage of all our tabs.
+    //   progress percentage of all our tabs.
     winrt::TerminalApp::TaskbarState TerminalPage::TaskbarState() const
     {
         std::vector<winrt::TerminalApp::TaskbarState> states;
diff --git a/src/cascadia/TerminalApp/TerminalTab.cpp b/src/cascadia/TerminalApp/TerminalTab.cpp
index 4242fce2b6c..0e3b369c399 100644
--- a/src/cascadia/TerminalApp/TerminalTab.cpp
+++ b/src/cascadia/TerminalApp/TerminalTab.cpp
@@ -640,7 +640,7 @@ namespace winrt::TerminalApp::implementation
     // - <none>
     // Return Value:
     // - A TaskbarState object representing the combined taskbar state and
-    //   progress precentage of all our panes.
+    //   progress percentage of all our panes.
     winrt::TerminalApp::TaskbarState TerminalTab::GetCombinedTaskbarState() const
     {
         std::vector<winrt::TerminalApp::TaskbarState> states;

From 75f8ff2390dd1229ced5a2df1aebc5caa5e2a30b Mon Sep 17 00:00:00 2001
From: Mike Griese <migrie@microsoft.com>
Date: Mon, 9 Aug 2021 13:44:44 -0500
Subject: [PATCH 8/8] some really clever suggestions from carlos

---
 src/cascadia/TerminalApp/TaskbarState.cpp |  9 ---------
 src/cascadia/TerminalApp/TerminalPage.cpp | 12 +++++++-----
 src/cascadia/TerminalApp/TerminalTab.cpp  |  4 ++--
 3 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/src/cascadia/TerminalApp/TaskbarState.cpp b/src/cascadia/TerminalApp/TaskbarState.cpp
index 9402182de8a..183460556cc 100644
--- a/src/cascadia/TerminalApp/TaskbarState.cpp
+++ b/src/cascadia/TerminalApp/TaskbarState.cpp
@@ -2,18 +2,9 @@
 // Licensed under the MIT license.
 
 #include "pch.h"
-#include <LibraryResources.h>
 #include "TaskbarState.h"
 #include "TaskbarState.g.cpp"
 
-using namespace winrt;
-
-namespace winrt
-{
-    namespace MUX = Microsoft::UI::Xaml;
-    namespace WUX = Windows::UI::Xaml;
-}
-
 namespace winrt::TerminalApp::implementation
 {
     // Default to unset, 0%.
diff --git a/src/cascadia/TerminalApp/TerminalPage.cpp b/src/cascadia/TerminalApp/TerminalPage.cpp
index 9dbbff532da..4d49779ade9 100644
--- a/src/cascadia/TerminalApp/TerminalPage.cpp
+++ b/src/cascadia/TerminalApp/TerminalPage.cpp
@@ -2090,20 +2090,22 @@ namespace winrt::TerminalApp::implementation
     //   progress percentage of all our tabs.
     winrt::TerminalApp::TaskbarState TerminalPage::TaskbarState() const
     {
-        std::vector<winrt::TerminalApp::TaskbarState> states;
+        auto state{ winrt::make<winrt::TerminalApp::implementation::TaskbarState>() };
 
         for (const auto& tab : _tabs)
         {
             if (auto tabImpl{ _GetTerminalTabImpl(tab) })
             {
                 auto tabState{ tabImpl->GetCombinedTaskbarState() };
-                states.push_back(tabState);
+                // lowest priority wins
+                if (tabState.Priority() < state.Priority())
+                {
+                    state = tabState;
+                }
             }
         }
 
-        std::sort(states.begin(), states.end(), TerminalApp::implementation::TaskbarState::ComparePriority);
-
-        return states.empty() ? winrt::make<winrt::TerminalApp::implementation::TaskbarState>() : states[0];
+        return state;
     }
 
     // Method Description:
diff --git a/src/cascadia/TerminalApp/TerminalTab.cpp b/src/cascadia/TerminalApp/TerminalTab.cpp
index e3559c1556d..48cf05d3347 100644
--- a/src/cascadia/TerminalApp/TerminalTab.cpp
+++ b/src/cascadia/TerminalApp/TerminalTab.cpp
@@ -690,8 +690,8 @@ namespace winrt::TerminalApp::implementation
     {
         std::vector<winrt::TerminalApp::TaskbarState> states;
         _rootPane->CollectTaskbarStates(states);
-        std::sort(states.begin(), states.end(), TerminalApp::implementation::TaskbarState::ComparePriority);
-        return states.empty() ? winrt::make<winrt::TerminalApp::implementation::TaskbarState>() : states[0];
+        return states.empty() ? winrt::make<winrt::TerminalApp::implementation::TaskbarState>() :
+                                *std::min_element(states.begin(), states.end(), TerminalApp::implementation::TaskbarState::ComparePriority);
     }
 
     // Method Description: