////////////////////////////////////////////////////////////////////////////////////////////////////
// NoesisGUI - http://www.noesisengine.com
// Copyright (c) 2013 Noesis Technologies S.L. All Rights Reserved.
////////////////////////////////////////////////////////////////////////////////////////////////////


#ifndef __GUI_COMMANDBINDING_H__
#define __GUI_COMMANDBINDING_H__


#include <NsCore/Noesis.h>
#include <NsCore/BaseComponent.h>
#include <NsCore/ReflectionDeclare.h>
#include <NsCore/Delegate.h>
#include <NsGui/CoreApi.h>
#include <NsGui/IUITreeNode.h>
#include <NsGui/RoutedEvent.h>


namespace Noesis
{

NS_INTERFACE ICommand;

////////////////////////////////////////////////////////////////////////////////////////////////////
/// Provides data for the CanExecute and PreviewCanExecute routed events.
////////////////////////////////////////////////////////////////////////////////////////////////////
struct CanExecuteRoutedEventArgs: public RoutedEventArgs
{
    /// The command associated with this event
    const ICommand* command;

    /// The command specific data
    Ptr<BaseComponent> parameter;

    /// Indicates whether the RoutedCommand associated with this event can be executed on the target
    mutable bool canExecute = false;

    /// Determines whether the input routed event that invoked the command should continue to route
    /// through the element tree
    mutable bool continueRouting = false;

    CanExecuteRoutedEventArgs(BaseComponent* source, const RoutedEvent* event,
        const ICommand* command, BaseComponent* parameter);
};

typedef Delegate<void (BaseComponent*, const CanExecuteRoutedEventArgs&)> CanExecuteRoutedEventHandler;

////////////////////////////////////////////////////////////////////////////////////////////////////
/// Provides data for the Executed and PreviewExecuted routed events.
////////////////////////////////////////////////////////////////////////////////////////////////////
struct ExecutedRoutedEventArgs: public RoutedEventArgs
{
    /// The command associated with this event
    const ICommand* command;

    /// The command specific data
    Ptr<BaseComponent> parameter;

    ExecutedRoutedEventArgs(BaseComponent* source, const RoutedEvent* event,
        const ICommand* command, BaseComponent* parameter);
};

typedef Delegate<void (BaseComponent*, const ExecutedRoutedEventArgs&)> ExecutedRoutedEventHandler;

NS_WARNING_PUSH
NS_MSVC_WARNING_DISABLE(4251 4275)

////////////////////////////////////////////////////////////////////////////////////////////////////
/// Binds a RoutedCommand to the event handlers that implement the command.
///
/// http://msdn.microsoft.com/en-us/library/system.windows.input.commandbinding.aspx
////////////////////////////////////////////////////////////////////////////////////////////////////
class NS_GUI_CORE_API CommandBinding: public BaseComponent, public IUITreeNode
{
public:
    CommandBinding();
    CommandBinding(ICommand* command);
    CommandBinding(ICommand* command, const CanExecuteRoutedEventHandler& canExecuteHandler);
    CommandBinding(ICommand* command, const ExecutedRoutedEventHandler& executedHandler);
    CommandBinding(ICommand* command, const CanExecuteRoutedEventHandler& canExecuteHandler,
        const ExecutedRoutedEventHandler& executedHandler);

    ~CommandBinding();

    /// Gets or sets the ICommand associated with this CommandBinding
    //@{
    ICommand* GetCommand() const;
    void SetCommand(ICommand* command);
    //@}

    /// Occurs when the command associated with this CommandBinding initiates a check to determine 
    /// whether the command can be executed on the current command target
    DelegateEvent_<CanExecuteRoutedEventHandler> PreviewCanExecute();

    /// Occurs when the command associated with this CommandBinding initiates a check to determine
    /// whether the command can be executed on the command target
    DelegateEvent_<CanExecuteRoutedEventHandler> CanExecute();

    /// Occurs when the command associated with this CommandBinding executes
    DelegateEvent_<ExecutedRoutedEventHandler> PreviewExecuted();

    /// Occurs when the command associated with this CommandBinding executes
    DelegateEvent_<ExecutedRoutedEventHandler> Executed();

    // From IUITreeNode
    //@{
    IUITreeNode* GetNodeParent() const override;
    void SetNodeParent(IUITreeNode* parent) override;
    BaseComponent* FindNodeResource(const char* key, bool fullElementSearch) const override;
    ObjectWithNameScope FindNodeName(const char* name) const override;
    //@}

    NS_IMPLEMENT_INTERFACE_FIXUP

private:
    friend struct CommandManager;

    /// Raises specified event
    //@{
    void RaisePreviewCanExecute(BaseComponent* sender,
        const CanExecuteRoutedEventArgs& args) const;
    void RaiseCanExecute(BaseComponent* sender, const CanExecuteRoutedEventArgs& args) const;
    void RaisePreviewExecuted(BaseComponent* sender,
        const ExecutedRoutedEventArgs& args) const;
    void RaiseExecuted(BaseComponent* sender, const ExecutedRoutedEventArgs& args) const;
    //@}

    bool CheckCanExecute(BaseComponent* sender, const ExecutedRoutedEventArgs& args) const;

private:
    Ptr<ICommand> mCommand;
    IUITreeNode* mOwner;

    CanExecuteRoutedEventHandler mPreviewCanExecute;
    CanExecuteRoutedEventHandler mCanExecute;
    ExecutedRoutedEventHandler mPreviewExecuted;
    ExecutedRoutedEventHandler mExecuted;

    NS_DECLARE_REFLECTION(CommandBinding, BaseComponent)
};

NS_WARNING_POP

}

#include <NsGui/CommandBinding.inl>

#endif