Update Calculator keyboard for greater consistency and extensibility (#688)

src/Calculator/Views/StateTriggers/ControlSizeTrigger.cpp

@@ -0,0 +1,80 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+#include "pch.h"
+#include "ControlSizeTrigger.h"
+
+using namespace CalculatorApp::Views::StateTriggers;
+using namespace Platform;
+using namespace Windows::Foundation;
+using namespace Windows::UI::Xaml;
+
+DEPENDENCY_PROPERTY_INITIALIZATION(ControlSizeTrigger, Source);
+DEPENDENCY_PROPERTY_INITIALIZATION(ControlSizeTrigger, MinHeight);
+DEPENDENCY_PROPERTY_INITIALIZATION(ControlSizeTrigger, MinWidth);
+
+ControlSizeTrigger::ControlSizeTrigger()
+{
+    SetActive(false);
+}
+
+ControlSizeTrigger::~ControlSizeTrigger()
+{
+    UnregisterSizeChanged(Source);
+}
+
+void ControlSizeTrigger::OnSourcePropertyChanged(FrameworkElement^ oldValue, FrameworkElement^ newValue)
+{
+    UnregisterSizeChanged(oldValue);
+    RegisterSizeChanged(newValue);
+}
+
+void ControlSizeTrigger::RegisterSizeChanged(FrameworkElement^ element)
+{
+    if (element == nullptr) { return; }
+
+    if (element != Source)
+    {
+        UnregisterSizeChanged(Source);
+    }
+
+    m_sizeChangedToken =
+        element->SizeChanged += ref new SizeChangedEventHandler(this, &ControlSizeTrigger::OnSizeChanged);
+}
+
+void ControlSizeTrigger::UnregisterSizeChanged(FrameworkElement^ element)
+{
+    if ((element != nullptr) && (m_sizeChangedToken.Value != 0))
+    {
+        element->SizeChanged -= m_sizeChangedToken;
+        m_sizeChangedToken.Value = 0;
+    }
+}
+
+void ControlSizeTrigger::OnSizeChanged(Object^ sender, SizeChangedEventArgs^ e)
+{
+    UpdateIsActive(e->NewSize);
+}
+
+void ControlSizeTrigger::UpdateIsActive(Size sourceSize)
+{
+    if (Source != nullptr && MinWidth > 0 || MinHeight > 0)
+    {
+        if (MinHeight > 0 && MinWidth > 0)
+        {
+            SetActive((sourceSize.Height >= MinHeight) && (sourceSize.Width >= MinWidth));
+        }
+        else if (MinHeight > 0)
+        {
+            SetActive(sourceSize.Height >= MinHeight);
+        }
+        else
+        {
+            SetActive(sourceSize.Width >= MinWidth);
+        }
+    }
+    else
+    {
+        SetActive(false);
+    }
+}

src/Calculator/Views/StateTriggers/ControlSizeTrigger.h

@@ -0,0 +1,37 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+#pragma once
+
+#include "CalcViewModel/Common/Utils.h"
+
+namespace CalculatorApp::Views::StateTriggers
+{
+    public ref class ControlSizeTrigger sealed : public Windows::UI::Xaml::StateTriggerBase
+    {
+    public:
+        ControlSizeTrigger();
+
+        DEPENDENCY_PROPERTY_OWNER(ControlSizeTrigger);
+
+        DEPENDENCY_PROPERTY_WITH_CALLBACK(Windows::UI::Xaml::FrameworkElement^, Source);
+
+        DEPENDENCY_PROPERTY_WITH_DEFAULT(double, MinHeight, 0.0);
+
+        DEPENDENCY_PROPERTY_WITH_DEFAULT(double, MinWidth, 0.0);
+
+    private:
+        ~ControlSizeTrigger();
+
+        void OnSourcePropertyChanged(Windows::UI::Xaml::FrameworkElement^ oldValue, Windows::UI::Xaml::FrameworkElement^ newValue);
+
+        void RegisterSizeChanged(Windows::UI::Xaml::FrameworkElement^ element);
+        void UnregisterSizeChanged(Windows::UI::Xaml::FrameworkElement^ element);
+        void OnSizeChanged(Platform::Object^ sender, Windows::UI::Xaml::SizeChangedEventArgs^ e);
+
+        void UpdateIsActive(Windows::Foundation::Size sourceSize);
+
+    private:
+        Windows::Foundation::EventRegistrationToken m_sizeChangedToken;
+    };
+}