PowerToys/src/modules/keyboardmanager/ui/KeyDropDownControl.h

#pragma once
#include <keyboardmanager/common/KeyboardManagerState.h>

// Wrapper class for the key drop down menu
class KeyDropDownControl
{
private:
    // Stores the drop down combo box
    ComboBox dropDown;
    // Stores the previous layout
    HKL previousLayout = 0;
    // Stores the key code list
    std::vector<DWORD> keyCodeList;

    // Function to set properties apart from the SelectionChanged event handler
    void SetDefaultProperties(bool isShortcut);

    // Function to check if the layout has changed and accordingly update the drop down list
    void CheckAndUpdateKeyboardLayout(ComboBox currentDropDown, bool isShortcut);

public:
    // Pointer to the keyboard manager state
    static KeyboardManagerState* keyboardManagerState;

    // Constructor for single key drop down
    KeyDropDownControl(size_t rowIndex, size_t colIndex, std::vector<std::vector<DWORD>>& singleKeyRemapBuffer)
    {
        SetDefaultProperties(false);
        dropDown.SelectionChanged([&, rowIndex, colIndex](IInspectable const& sender, SelectionChangedEventArgs const& args) {
            ComboBox currentDropDown = sender.as<ComboBox>();
            int selectedKeyIndex = currentDropDown.SelectedIndex();

            // Check if the element was not found or the index exceeds the known keys
            if (selectedKeyIndex != -1 && keyCodeList.size() > selectedKeyIndex)
            {
                singleKeyRemapBuffer[rowIndex][colIndex] = keyCodeList[selectedKeyIndex];
            }
            else
            {
                // Reset to null if the key is not found
                singleKeyRemapBuffer[rowIndex][colIndex] = NULL;
            }
        });
    }

    // Constructor for shortcut drop down
    KeyDropDownControl(size_t rowIndex, size_t colIndex, std::vector<std::vector<Shortcut>>& shortcutRemapBuffer, std::vector<std::unique_ptr<KeyDropDownControl>>& keyDropDownControlObjects, StackPanel parent)
    {
        SetDefaultProperties(true);
        Flyout warningFlyout;
        TextBlock warningMessage;
        warningFlyout.Content(warningMessage);
        dropDown.ContextFlyout().SetAttachedFlyout((FrameworkElement)dropDown, warningFlyout);

        // drop down selection handler
        dropDown.SelectionChanged([&, rowIndex, colIndex, parent, warningMessage](IInspectable const& sender, SelectionChangedEventArgs const&) {
            ComboBox currentDropDown = sender.as<ComboBox>();
            int selectedKeyIndex = currentDropDown.SelectedIndex();
            uint32_t dropDownIndex = -1;
            bool dropDownFound = parent.Children().IndexOf(currentDropDown, dropDownIndex);

            if (selectedKeyIndex != -1 && keyCodeList.size() > selectedKeyIndex && dropDownFound)
            {
                // If only 1 drop down and action key is chosen: Warn that a modifier must be chosen
                if (parent.Children().Size() == 1 && !IsModifierKey(keyCodeList[selectedKeyIndex]))
                {
                    // warn and reset the drop down
                    SetDropDownError(currentDropDown, warningMessage, L"Shortcut must start with a modifier key");
                }
                // If it is the last drop down
                else if (dropDownIndex == parent.Children().Size() - 1)
                {
                    // If last drop down and a modifier is selected: add a new drop down (max of 5 drop downs should be enforced)
                    if (IsModifierKey(keyCodeList[selectedKeyIndex]) && parent.Children().Size() < 5)
                    {
                        // If it matched any of the previous modifiers then reset that drop down
                        if (CheckRepeatedModifier(parent, dropDownIndex, selectedKeyIndex, keyCodeList))
                        {
                            // warn and reset the drop down
                            SetDropDownError(currentDropDown, warningMessage, L"Shortcut cannot contain a repeated modifier");
                        }
                        // If not, add a new drop down
                        else
                        {
                            AddDropDown(parent, rowIndex, colIndex, shortcutRemapBuffer, keyDropDownControlObjects);
                        }
                    }
                    // If last drop down and a modifier is selected but there are already 5 drop downs: warn the user
                    else if (IsModifierKey(keyCodeList[selectedKeyIndex]) && parent.Children().Size() >= 5)
                    {
                        // warn and reset the drop down
                        SetDropDownError(currentDropDown, warningMessage, L"Shortcut must contain an action key");
                    }
                    // If None is selected but it's the last index: warn
                    else if (keyCodeList[selectedKeyIndex] == 0)
                    {
                        // warn and reset the drop down
                        SetDropDownError(currentDropDown, warningMessage, L"Shortcut must contain an action key");
                    }
                    // If none of the above, then the action key will be set
                }
                // If it is the not the last drop down
                else
                {
                    if (IsModifierKey(keyCodeList[selectedKeyIndex]))
                    {
                        // If it matched any of the previous modifiers then reset that drop down
                        if (CheckRepeatedModifier(parent, dropDownIndex, selectedKeyIndex, keyCodeList))
                        {
                            // warn and reset the drop down
                            SetDropDownError(currentDropDown, warningMessage, L"Shortcut cannot contain a repeated modifier");
                        }
                        // If not, the modifier key will be set
                    }
                    // If None is selected and there are more than 2 drop downs
                    else if (keyCodeList[selectedKeyIndex] == 0 && parent.Children().Size() > 2)
                    {
                        // delete drop down
                        parent.Children().RemoveAt(dropDownIndex);
                        // delete drop down control object from the vector so that it can be destructed
                        keyDropDownControlObjects.erase(keyDropDownControlObjects.begin() + dropDownIndex);
                        parent.UpdateLayout();
                    }
                    else if (keyCodeList[selectedKeyIndex] == 0 && parent.Children().Size() <= 2)
                    {
                        // warn and reset the drop down
                        SetDropDownError(currentDropDown, warningMessage, L"Shortcut must have atleast 2 keys");
                    }
                    // If the user tries to set an action key check if all drop down menus after this are empty if it is not the first key
                    else if (dropDownIndex != 0)
                    {
                        bool isClear = true;
                        for (int i = dropDownIndex + 1; i < (int)parent.Children().Size(); i++)
                        {
                            ComboBox currentDropDown = parent.Children().GetAt(i).as<ComboBox>();
                            if (currentDropDown.SelectedIndex() != -1)
                            {
                                isClear = false;
                                break;
                            }
                        }

                        if (isClear)
                        {
                            // remove all the drop down
                            int elementsToBeRemoved = parent.Children().Size() - dropDownIndex - 1;
                            for (int i = 0; i < elementsToBeRemoved; i++)
                            {
                                parent.Children().RemoveAtEnd();
                            }
                            parent.UpdateLayout();
                        }
                        else
                        {
                            // warn and reset the drop down
                            SetDropDownError(currentDropDown, warningMessage, L"Shortcut cannot have more than one action key");
                        }
                    }
                    // If there an action key is chosen on the first drop down and there are more than one drop down menus
                    else
                    {
                        // warn and reset the drop down
                        SetDropDownError(currentDropDown, warningMessage, L"Shortcut must start with a modifier key");
                    }
                }
            }

            // Reset the buffer based on the new selected drop down items
            shortcutRemapBuffer[rowIndex][colIndex].SetKeyCodes(GetKeysFromStackPanel(parent));
        });
    }

    // Function to set the selected index of the drop down
    void SetSelectedIndex(int32_t index);

    // Function to return the combo box element of the drop down
    ComboBox GetComboBox();

    // Function to add a drop down to the shortcut stack panel
    static void AddDropDown(StackPanel parent, const size_t rowIndex, const size_t colIndex, std::vector<std::vector<Shortcut>>& shortcutRemapBuffer, std::vector<std::unique_ptr<KeyDropDownControl>>& keyDropDownControlObjects);

    // Function to get the list of key codes from the shortcut combo box stack panel
    std::vector<DWORD> GetKeysFromStackPanel(StackPanel parent);

    // Function to check if a modifier has been repeated in the previous drop downs
    bool CheckRepeatedModifier(StackPanel parent, uint32_t dropDownIndex, int selectedKeyIndex, const std::vector<DWORD>& keyCodeList);

    // Function to set the flyout warning message
    void SetDropDownError(ComboBox dropDown, TextBlock messageBlock, hstring message);
};