Modify how narrator names the first and last bits of a number in Bit Flip (#675)

* Replace 0th by "least significant bit"

* Add support of Most Significant Bit

* Fix issue with narrator not updating text of some bits

src/Calculator/Resources/en-US/Resources.resw

@@ -805,9 +805,9 @@
     <value>1st</value>
     <comment>Sub-string used in automation name for 1 bit in bit flip</comment>
   </data>
-  <data name="0" xml:space="preserve">
+  <data name="LeastSignificantBit" xml:space="preserve">
-    <value>0th</value>
+    <value>least significant bit</value>
-    <comment>Sub-string used in automation name for 0 bit in bit flip</comment>
+    <comment>Used to describe the first bit of a binary number. Used in bit flip</comment>
   </data>
   <data name="MemoryButton_Open" xml:space="preserve">
     <value>Open memory flyout</value>
@@ -3427,4 +3427,8 @@
     <value>Calculation failed</value>
     <comment>Text displayed when the application is not able to do a calculation</comment>
   </data>
+  <data name="MostSignificantBit" xml:space="preserve">
+    <value>most significant bit</value>
+    <comment>Used to describe the last bit of a binary number. Used in bit flip</comment>
+  </data>
 </root>

src/Calculator/Views/CalculatorProgrammerBitFlipPanel.xaml.cpp

@@ -50,6 +50,7 @@ void CalculatorProgrammerBitFlipPanel::SubscribePropertyChanged()
     if (Model != nullptr)
     {
         m_propertyChangedToken = Model->PropertyChanged += ref new PropertyChangedEventHandler(this, &CalculatorProgrammerBitFlipPanel::OnPropertyChanged);
+        m_currentValueBitLength = Model->ValueBitLength;
         UpdateCheckedStates(true);
     }
 }
@@ -68,8 +69,10 @@ void CalculatorProgrammerBitFlipPanel::OnPropertyChanged(Object ^ sender, Proper
     if (e->PropertyName == StandardCalculatorViewModel::BinaryDigitsPropertyName)
     {
         UpdateCheckedStates(false);
+        m_currentValueBitLength = Model->ValueBitLength;
     }
-    else if (e->PropertyName == StandardCalculatorViewModel::IsBitFlipCheckedPropertyName
+    else if (
+        e->PropertyName == StandardCalculatorViewModel::IsBitFlipCheckedPropertyName
         || e->PropertyName == StandardCalculatorViewModel::IsProgrammerPropertyName)
     {
         if (Model->IsBitFlipChecked && Model->IsProgrammer)
@@ -190,14 +193,20 @@ void CalculatorProgrammerBitFlipPanel::UpdateCheckedStates(bool updateAutomation
     m_updatingCheckedStates = true;
     auto it = m_flipButtons.begin();
     int index = 0;
+    bool mustUpdateTextOfMostSignificantDigits = m_currentValueBitLength != Model->ValueBitLength;
+    int previousMSDPosition = GetIndexOfLastBit(m_currentValueBitLength);
+    int newMSDPosition = GetIndexOfLastBit(Model->ValueBitLength);
     for (bool val : Model->BinaryDigits)
     {
         FlipButtons ^ flipButton = *it;
-        if (updateAutomationPropertiesNames)
+        bool hasValueChanged = flipButton->IsChecked->Value != val;
-        {
-            flipButton->SetValue(AutomationProperties::NameProperty, GenerateAutomationPropertiesName(index, flipButton->IsChecked->Value));
-        }
         flipButton->IsChecked = val;
+        if (updateAutomationPropertiesNames
+            || hasValueChanged
+            || (mustUpdateTextOfMostSignificantDigits && (index == previousMSDPosition || index == newMSDPosition)))
+        {
+            flipButton->SetValue(AutomationProperties::NameProperty, GenerateAutomationPropertiesName(index, val));
+        }
         ++it;
         ++index;
     }
@@ -215,29 +224,53 @@ void CalculatorProgrammerBitFlipPanel::UpdateAutomationPropertiesNames()
 }
 
 bool CalculatorProgrammerBitFlipPanel::ShouldEnableBit(BitLength length, int index)
+{
+    return index <= GetIndexOfLastBit(length);
+}
+
+int CalculatorProgrammerBitFlipPanel::GetIndexOfLastBit(BitLength length) const
 {
     switch (length)
     {
     case BitLength::BitLengthQWord:
-        return index <= 63;
+        return 63;
     case BitLength::BitLengthDWord:
-        return index <= 31;
+        return 31;
     case BitLength::BitLengthWord:
-        return index <= 15;
+        return 15;
     case BitLength::BitLengthByte:
-        return index <= 7;
+        return 7;
     }
-    return false;
+    return -1;
 }
 
-String ^ CalculatorProgrammerBitFlipPanel::GenerateAutomationPropertiesName(int position, bool value) const
+String ^ CalculatorProgrammerBitFlipPanel::GenerateAutomationPropertiesName(int position, bool value)
 {
     auto resourceLoader = AppResourceProvider::GetInstance();
-
-    String ^ indexName = resourceLoader.GetResourceString(ref new Platform::String(to_wstring(position).c_str()));
     String ^ automationNameTemplate = resourceLoader.GetResourceString(L"BitFlipItemAutomationName");
-    String ^ bitPositionTemplate = resourceLoader.GetResourceString(L"BitPosition");
+    wstring bitPosition;
+    if (position == 0)
+    {
+        bitPosition = wstring(resourceLoader.GetResourceString(L"LeastSignificantBit")->Data());
+    }
+    else
+    {
+        int lastPosition = -1;
+        if (Model != nullptr)
+        {
+            lastPosition = GetIndexOfLastBit(Model->ValueBitLength);
+        }
 
-    wstring bitPosition = LocalizationStringUtil::GetLocalizedString(bitPositionTemplate->Data(), indexName->Data());
+        if (position == lastPosition)
+        {
+            bitPosition = wstring(resourceLoader.GetResourceString(L"MostSignificantBit")->Data());
+        }
+        else
+        {
+            String ^ indexName = resourceLoader.GetResourceString(ref new Platform::String(to_wstring(position).c_str()));
+            String ^ bitPositionTemplate = resourceLoader.GetResourceString(L"BitPosition");
+            bitPosition = LocalizationStringUtil::GetLocalizedString(bitPositionTemplate->Data(), indexName->Data());
+        }
+    }
     return ref new String(LocalizationStringUtil::GetLocalizedString(automationNameTemplate->Data(), bitPosition.c_str(), value ? L"1" : L"0").c_str());
 }

src/Calculator/Views/CalculatorProgrammerBitFlipPanel.xaml.h

@@ -37,12 +37,14 @@ namespace CalculatorApp
 
     private:
         Windows::Foundation::EventRegistrationToken m_propertyChangedToken;
-        Platform::String ^ GenerateAutomationPropertiesName(int position, bool value) const;
+        Platform::String ^ GenerateAutomationPropertiesName(int position, bool value);
         void UpdateCheckedStates(bool updateAutomationPropertiesNames);
         void UpdateAutomationPropertiesNames();
+        int GetIndexOfLastBit(CalculatorApp::Common::BitLength length) const;
 
         static const unsigned int s_numBits = 64;
         std::array<CalculatorApp::Controls::FlipButtons ^, s_numBits> m_flipButtons;
         bool m_updatingCheckedStates;
+        CalculatorApp::Common::BitLength m_currentValueBitLength;
     };
 }