juce_win32_UIASelectionProvider.h

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/*
  ==============================================================================
 
   This file is part of the JUCE library.
   Copyright (c) 2022 - Raw Material Software Limited
 
   JUCE is an open source library subject to commercial or open-source
   licensing.
 
   By using JUCE, you agree to the terms of both the JUCE 7 End-User License
   Agreement and JUCE Privacy Policy.
 
   End User License Agreement: www.juce.com/juce-7-licence
   Privacy Policy: www.juce.com/juce-privacy-policy
 
   Or: You may also use this code under the terms of the GPL v3 (see
   www.gnu.org/licenses).
 
   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.
 
  ==============================================================================
*/
 
namespace juce
{
 
JUCE_BEGIN_IGNORE_WARNINGS_GCC_LIKE ("-Wlanguage-extension-token")
 
//==============================================================================
class UIASelectionItemProvider  : public UIAProviderBase,
                                  public ComBaseClassHelper<ComTypes::ISelectionItemProvider>
{
public:
    explicit UIASelectionItemProvider (AccessibilityNativeHandle* handle)
        : UIAProviderBase (handle),
          isRadioButton (getHandler().getRole() == AccessibilityRole::radioButton)
    {
    }
 
    //==============================================================================
    JUCE_COMRESULT AddToSelection() override
    {
        if (! isElementValid())
            return (HRESULT) UIA_E_ELEMENTNOTAVAILABLE;
 
        const auto& handler = getHandler();
 
        if (isRadioButton)
        {
            handler.getActions().invoke (AccessibilityActionType::press);
            sendAccessibilityAutomationEvent (handler, ComTypes::UIA_SelectionItem_ElementSelectedEventId);
 
            return S_OK;
        }
 
        handler.getActions().invoke (AccessibilityActionType::toggle);
        handler.getActions().invoke (AccessibilityActionType::press);
 
        return S_OK;
    }
 
    JUCE_COMRESULT get_IsSelected (BOOL* pRetVal) override
    {
        return withCheckedComArgs (pRetVal, *this, [&]
        {
            const auto state = getHandler().getCurrentState();
            *pRetVal = isRadioButton ? state.isChecked() : state.isSelected();
            return S_OK;
        });
    }
 
    JUCE_COMRESULT get_SelectionContainer (IRawElementProviderSimple** pRetVal) override
    {
        return withCheckedComArgs (pRetVal, *this, [&]
        {
            if (! isRadioButton)
                if (auto* parent = getHandler().getParent())
                    parent->getNativeImplementation()->QueryInterface (IID_PPV_ARGS (pRetVal));
 
            return S_OK;
        });
    }
 
    JUCE_COMRESULT RemoveFromSelection() override
    {
        if (! isElementValid())
            return (HRESULT) UIA_E_ELEMENTNOTAVAILABLE;
 
        if (! isRadioButton)
        {
            const auto& handler = getHandler();
 
            if (handler.getCurrentState().isSelected())
                getHandler().getActions().invoke (AccessibilityActionType::toggle);
        }
 
        return S_OK;
    }
 
    JUCE_COMRESULT Select() override
    {
        if (! isElementValid())
            return (HRESULT) UIA_E_ELEMENTNOTAVAILABLE;
 
        AddToSelection();
 
        if (isElementValid() && ! isRadioButton)
        {
            const auto& handler = getHandler();
 
            if (auto* parent = handler.getParent())
                for (auto* child : parent->getChildren())
                    if (child != &handler && child->getCurrentState().isSelected())
                        child->getActions().invoke (AccessibilityActionType::toggle);
        }
 
        return S_OK;
    }
 
private:
    const bool isRadioButton;
 
    //==============================================================================
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (UIASelectionItemProvider)
};
 
//==============================================================================
class UIASelectionProvider  : public UIAProviderBase,
                              public ComBaseClassHelper<ComTypes::ISelectionProvider2>
{
public:
    using UIAProviderBase::UIAProviderBase;
 
    //==============================================================================
    JUCE_COMRESULT QueryInterface (REFIID iid, void** result) override
    {
        if (iid == __uuidof (IUnknown) || iid == __uuidof (ComTypes::ISelectionProvider))
            return castToType<ComTypes::ISelectionProvider> (result);
 
        if (iid == __uuidof (ComTypes::ISelectionProvider2))
            return castToType<ComTypes::ISelectionProvider2> (result);
 
        *result = nullptr;
        return E_NOINTERFACE;
    }
 
    //==============================================================================
    JUCE_COMRESULT get_CanSelectMultiple (BOOL* pRetVal) override
    {
        return withCheckedComArgs (pRetVal, *this, [&]
        {
            *pRetVal = isMultiSelectable();
            return S_OK;
        });
    }
 
    JUCE_COMRESULT get_IsSelectionRequired (BOOL* pRetVal) override
    {
        return withCheckedComArgs (pRetVal, *this, [&]
        {
            *pRetVal = getSelectedChildren().size() > 0 && ! isMultiSelectable();
            return S_OK;
        });
    }
 
    JUCE_COMRESULT GetSelection (SAFEARRAY** pRetVal) override
    {
        return withCheckedComArgs (pRetVal, *this, [&]
        {
            return addHandlersToArray (getSelectedChildren(), pRetVal);
        });
    }
 
    //==============================================================================
    JUCE_COMRESULT get_FirstSelectedItem (IRawElementProviderSimple** pRetVal) override
    {
        return withCheckedComArgs (pRetVal, *this, [&]
        {
            auto selectedChildren = getSelectedChildren();
 
            if (! selectedChildren.empty())
                selectedChildren.front()->getNativeImplementation()->QueryInterface (IID_PPV_ARGS (pRetVal));
 
            return S_OK;
        });
    }
 
    JUCE_COMRESULT get_LastSelectedItem (IRawElementProviderSimple** pRetVal) override
    {
        return withCheckedComArgs (pRetVal, *this, [&]
        {
            auto selectedChildren = getSelectedChildren();
 
            if (! selectedChildren.empty())
                selectedChildren.back()->getNativeImplementation()->QueryInterface (IID_PPV_ARGS (pRetVal));
 
            return S_OK;
        });
    }
 
    JUCE_COMRESULT get_CurrentSelectedItem (IRawElementProviderSimple** pRetVal) override
    {
        return withCheckedComArgs (pRetVal, *this, [&]
        {
            get_FirstSelectedItem (pRetVal);
            return S_OK;
        });
    }
 
    JUCE_COMRESULT get_ItemCount (int* pRetVal) override
    {
        return withCheckedComArgs (pRetVal, *this, [&]
        {
            *pRetVal = (int) getSelectedChildren().size();
            return S_OK;
        });
    }
 
private:
    bool isMultiSelectable() const noexcept
    {
         return getHandler().getCurrentState().isMultiSelectable();
    }
 
    std::vector<const AccessibilityHandler*> getSelectedChildren() const
    {
        std::vector<const AccessibilityHandler*> selectedHandlers;
 
        for (auto* child : getHandler().getComponent().getChildren())
            if (auto* handler = child->getAccessibilityHandler())
                if (handler->getCurrentState().isSelected())
                    selectedHandlers.push_back (handler);
 
        return selectedHandlers;
    }
 
    //==============================================================================
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (UIASelectionProvider)
};
 
JUCE_END_IGNORE_WARNINGS_GCC_LIKE
 
} // namespace juce