ITextInputMethodSystem.h

Go to the documentation of this file.

// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreTypes.h"
#include "GenericPlatform/GenericWindow.h"
 
class ITextInputMethodContext
{
public:
    enum class ECaretPosition
    {
        Beginning,
        Ending
    };
 
public:
    virtual ~ITextInputMethodContext() {}
 
    virtual bool IsComposing() = 0;
 
    virtual bool IsReadOnly() = 0;
 
    virtual uint32 GetTextLength() = 0;
 
    virtual void GetSelectionRange(uint32& OutBeginIndex, uint32& OutLength, ECaretPosition& OutCaretPosition) = 0;
 
    virtual void SetSelectionRange(const uint32 InBeginIndex, const uint32 InLength, const ECaretPosition InCaretPosition) = 0;
 
    virtual void GetTextInRange(const uint32 InBeginIndex, const uint32 InLength, FString& OutString) = 0;
 
    virtual void SetTextInRange(const uint32 InBeginIndex, const uint32 InLength, const FString& InString) = 0;
 
    virtual int32 GetCharacterIndexFromPoint(const FVector2D& InPoint) = 0;
    
    virtual bool GetTextBounds(const uint32 InBeginIndex, const uint32 InLength, FVector2D& OutPosition, FVector2D& OutSize) = 0;
 
    virtual void GetScreenBounds(FVector2D& OutPosition, FVector2D& OutSize) = 0;
 
    virtual TSharedPtr<FGenericWindow> GetWindow() = 0;
 
    virtual void BeginComposition() = 0;
 
    virtual void UpdateCompositionRange(const int32 InBeginIndex, const uint32 InLength) = 0;
 
    virtual void EndComposition() = 0;
};
 
class ITextInputMethodChangeNotifier
{
public:
    enum class ELayoutChangeType
    {
        Created,
        Changed,
        Destroyed
    };
 
public:
    virtual ~ITextInputMethodChangeNotifier() {}
 
    virtual void NotifyLayoutChanged(const ELayoutChangeType ChangeType) = 0;
    virtual void NotifySelectionChanged() = 0;
    virtual void NotifyTextChanged(const uint32 BeginIndex, const uint32 OldLength, const uint32 NewLength) = 0;
    virtual void CancelComposition() = 0;
};
 
class ITextInputMethodSystem
{
public:
    virtual ~ITextInputMethodSystem() {}
 
    virtual void ApplyDefaults(const TSharedRef<FGenericWindow>& InWindow) = 0;
 
    virtual TSharedPtr<ITextInputMethodChangeNotifier> RegisterContext(const TSharedRef<ITextInputMethodContext>& Context) = 0;
 
    virtual void UnregisterContext(const TSharedRef<ITextInputMethodContext>& Context) = 0;
 
    virtual void ActivateContext(const TSharedRef<ITextInputMethodContext>& Context) = 0;
 
    virtual void DeactivateContext(const TSharedRef<ITextInputMethodContext>& Context) = 0;
 
    virtual bool IsActiveContext(const TSharedRef<ITextInputMethodContext>& Context) const = 0;
};