SSuggestionTextBox.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "Styling/SlateColor.h"
#include "Fonts/SlateFontInfo.h"
#include "Input/Reply.h"
#include "Widgets/DeclarativeSyntaxSupport.h"
#include "Widgets/SCompoundWidget.h"
#include "Styling/SlateTypes.h"
#include "Styling/CoreStyle.h"
#include "Widgets/Input/SEditableTextBox.h"
#include "Widgets/Notifications/SErrorText.h"
#include "Widgets/Views/STableViewBase.h"
#include "Widgets/Views/STableRow.h"
 
class SMenuAnchor;
class SVerticalBox;
 
template< typename ObjectType > class TAttribute;
 
DECLARE_DELEGATE_OneParam(FOnShowingHistory, OUT TArray<FString>&)
 
 
DECLARE_DELEGATE_TwoParams(FOnShowingSuggestions, const FString&, OUT TArray<FString>&)
 
 
 
class SSuggestionTextBox
    : public SCompoundWidget
{
 
public:
 
    SLATE_BEGIN_ARGS(SSuggestionTextBox)
        : _BackgroundColor(FLinearColor::White)
        , _BackgroundImage(FCoreStyle::Get().GetBrush("SuggestionTextBox.Background"))
        , _ClearKeyboardFocusOnCommit(true)
        , _CommitOnSuggestionSelected(false)
        , _ErrorReporting()
        , _Font( FCoreStyle::Get().GetFontStyle( TEXT( "NormalFont" ) ) )
        , _ForegroundColor( FCoreStyle::Get().GetSlateColor( "InvertedForeground" ) )
        , _HintText()
        , _IsCaretMovedWhenGainFocus (true)
        , _MinDesiredWidth(0.0f)
        , _RevertTextOnEscape(false)
        , _SelectAllTextOnCommit(false)
        , _SelectAllTextWhenFocused(false)
        , _TextStyle( &FCoreStyle::Get().GetWidgetStyle<FEditableTextBoxStyle>("NormalEditableTextBox") )
        , _SuggestionTextStyle( &FCoreStyle::Get().GetWidgetStyle<FTextBlockStyle>("SuggestionTextBox.Text") )
        , _SuggestionListMaxHeight(250.0)
        , _Text()
    { }
 
        SLATE_ATTRIBUTE(FSlateColor, BackgroundColor)
 
        
        SLATE_ARGUMENT(const FSlateBrush*, BackgroundImage)
 
        
        SLATE_ATTRIBUTE(bool, ClearKeyboardFocusOnCommit)
 
        
        SLATE_ATTRIBUTE(bool, CommitOnSuggestionSelected)
 
        
        SLATE_ARGUMENT(TSharedPtr<class IErrorReportingWidget>, ErrorReporting)
 
        
        SLATE_ATTRIBUTE(FSlateFontInfo, Font)
 
        
        SLATE_ATTRIBUTE(FSlateColor, ForegroundColor)
 
        
        SLATE_ATTRIBUTE(FText, HintText)
 
        
        SLATE_ATTRIBUTE(bool, IsCaretMovedWhenGainFocus)
 
        
        SLATE_ATTRIBUTE(float, MinDesiredWidth)
 
        
        SLATE_EVENT(FOnShowingHistory, OnShowingHistory)
 
        
        SLATE_EVENT(FOnShowingSuggestions, OnShowingSuggestions)
 
        
        SLATE_EVENT(FOnTextChanged, OnTextChanged)
 
        
        SLATE_EVENT(FOnTextCommitted, OnTextCommitted)
 
        
        SLATE_ATTRIBUTE(bool, RevertTextOnEscape)
 
        
        SLATE_ATTRIBUTE(bool, SelectAllTextOnCommit)
 
        
        SLATE_ATTRIBUTE(bool, SelectAllTextWhenFocused)
 
        
        SLATE_STYLE_ARGUMENT(FEditableTextBoxStyle, TextStyle)
 
        
        SLATE_STYLE_ARGUMENT(FTextBlockStyle, SuggestionTextStyle)
 
        
        SLATE_ATTRIBUTE(float, SuggestionListMaxHeight)
 
        
        SLATE_ATTRIBUTE(FText, Text)
 
    SLATE_END_ARGS()
 
public:
 
    SLATE_API SSuggestionTextBox( );
 
public:
 
    SLATE_API void Construct( const FArguments& InArgs );
 
    FText GetText( ) const
    {
        return TextBox->GetText();
    }
 
    void SetError( const FString& InError )
    {
        TextBox->SetError(InError);
    }
 
    SLATE_API void SetText( const TAttribute< FText >& InNewText );
 
protected:
    
    SLATE_API void ClearSuggestions( );
 
    SLATE_API void FocusTextBox( );
 
    SLATE_API FString GetSelectedSuggestionString( ) const;
 
    SLATE_API void MarkActiveSuggestion( );
 
    SLATE_API void SetSuggestions( TArray<FString>& SuggestionStrings, bool InHistoryMode );
 
protected:
 
    // SWidget overrides
 
    SLATE_API virtual void OnFocusLost( const FFocusEvent& InFocusEvent ) override;
    SLATE_API virtual FReply OnKeyDown( const FGeometry& MyGeometry, const FKeyEvent& KeyEvent ) override;
    SLATE_API virtual bool SupportsKeyboardFocus( ) const override;
 
private:
 
    // Callback for generating a row widget for the suggestion list view.
    SLATE_API TSharedRef<ITableRow> HandleSuggestionListViewGenerateRow( TSharedPtr<FString> Message, const TSharedRef<STableViewBase>& OwnerTable );
 
    // Callback for changing the selected suggestion.
    SLATE_API void HandleSuggestionListViewSelectionChanged( TSharedPtr<FString> NewValue, ESelectInfo::Type SelectInfo );
 
    // Callback for getting the highlight string in a suggestion list row widget.
    SLATE_API FText HandleSuggestionListWidgetHighlightText( ) const;
 
    // Callback for changing the text box input.
    SLATE_API void HandleTextBoxTextChanged( const FText& InText );
 
    // Callback committing the text box input.
    SLATE_API void HandleTextBoxTextCommitted( const FText& InText, ETextCommit::Type CommitInfo );
 
    // Called when global focus changes so we can detect when to close the SuggestionList.
    SLATE_API void OnGlobalFocusChanging(const FFocusEvent& FocusEvent, const FWeakWidgetPath& OldFocusedWidgetPath, const TSharedPtr<SWidget>& OldFocusedWidget, const FWidgetPath& NewFocusedWidgetPath, const TSharedPtr<SWidget>& NewFocusedWidget);
 
private:
 
    // Holds a flag to prevent recursive calls in UI callbacks.
    bool IgnoreUIUpdate; 
 
    // Holds the box for history and auto-complete suggestions.
    TSharedPtr<SMenuAnchor> MenuAnchor;
 
    // Holds the current list of suggestions.
    TArray<TSharedPtr<FString> > Suggestions;
 
    // Holds the list view that displays the suggestions.
    TSharedPtr<SListView<TSharedPtr<FString> > > SuggestionListView;
 
    // Holds the index of the selected suggestion (-1 for no selection).
    int32 SelectedSuggestion;
 
    // Holds the editable text box.
    TSharedPtr<SEditableTextBox> TextBox;
 
    // The styling of the suggestion text.
    const FTextBlockStyle* SuggestionTextStyle;
 
    // The VerticalBox containing the SuggestionList.
    TSharedPtr<SVerticalBox> VerticalBox;
 
    // Trigger commit text event as soon as suggestion was selected.
    bool CommitsOnSuggestionSelected;
 
private:
 
    // Holds a delegate that is executed before the input history is shown.
    FOnShowingHistory OnShowingHistory;
 
    // Holds a delegate that is executed before the suggestions list is shown.
    FOnShowingSuggestions OnShowingSuggestions;
 
    // Holds a delegate that is executed when the text has changed.
    FOnTextChanged OnTextChanged;
 
    // Holds a delegate that is executed when the text has been committed.
    FOnTextCommitted OnTextCommitted;
};