/*
 * Copyright 2002-2006, project beam (http://sourceforge.net/projects/beam).
 * All rights reserved. Distributed under the terms of the MIT License.
 *
 * Authors:
 *              Oliver Tappe <beam@hirschkaefer.de>
 */
#ifndef _AUTO_COMPLETER_H
#define _AUTO_COMPLETER_H

#include <MessageFilter.h>

#include <Rect.h>
#include <String.h>

class BAutoCompleter {
public:
        class Choice {
        public:
                                                                Choice(const BString& choiceText,
                                                                        const BString& displayText, int32 matchPos,
                                                                        int32 matchLen)
                                                                        :
                                                                        fText(choiceText),
                                                                        fDisplayText(displayText),
                                                                        fMatchPos(matchPos),
                                                                        fMatchLen(matchLen)
                                                                {
                                                                }
                virtual                                 ~Choice() {}
                                const BString&  Text() const { return fText; }
                                const BString&  DisplayText() const { return fDisplayText; }
                                int32                   MatchPos() const { return fMatchPos; }
                                int32                   MatchLen() const { return fMatchLen; }

        private:
                                BString                 fText;
                                BString                 fDisplayText;
                                int32                   fMatchPos;
                                int32                   fMatchLen;
        };

        class EditView {
        public:
                virtual                                 ~EditView()     {}

                virtual BRect                   GetAdjustmentFrame() = 0;
                virtual void                    GetEditViewState(BString& text,
                                                                        int32* caretPos) = 0;
                virtual void                    SetEditViewState(const BString& text,
                                                                        int32 caretPos,
                                                                        int32 selectionLength = 0) = 0;
        };

        class PatternSelector {
        public:
                virtual                                 ~PatternSelector() {}
                
                virtual void                    SelectPatternBounds(const BString& text,
                                                                        int32 caretPos, int32* start,
                                                                        int32* length) = 0;
        };

        class ChoiceModel {
        public:
        
                virtual                                 ~ChoiceModel() {}
                
                virtual void                    FetchChoicesFor(const BString& pattern) = 0;

                virtual int32                   CountChoices() const = 0;
                virtual const Choice*   ChoiceAt(int32 index) const = 0;
        };
        
        class CompletionStyle;
        class ChoiceView {
        public:
                virtual                                 ~ChoiceView() {}

                virtual void                    SelectChoiceAt(int32 index) = 0;
                virtual void                    ShowChoices(
                                                                        BAutoCompleter::CompletionStyle* completer)
                                                                        = 0;
                virtual void                    HideChoices() = 0;
                virtual bool                    ChoicesAreShown() = 0;
                virtual int32                   CountVisibleChoices() const = 0;
        };

        class CompletionStyle {
        public:
                                                                CompletionStyle(EditView* editView,
                                                                        ChoiceModel* choiceModel,
                                                                        ChoiceView* choiceView,
                                                                        PatternSelector* patternSelector);
                virtual                                 ~CompletionStyle();

                virtual bool                    Select(int32 index) = 0;
                virtual bool                    SelectNext(bool wrap = false) = 0;
                virtual bool                    SelectPrevious(bool wrap = false) = 0;
                virtual bool                    IsChoiceSelected() const = 0;
                virtual int32                   SelectedChoiceIndex() const = 0;

                virtual void                    ApplyChoice(bool hideChoices = true) = 0;
                virtual void                    CancelChoice() = 0;

                virtual void                    EditViewStateChanged(bool updateChoices) = 0;

                                void                    SetEditView(EditView* view);
                                void                    SetPatternSelector(PatternSelector* selector);
                                void                    SetChoiceModel(ChoiceModel* model);
                                void                    SetChoiceView(ChoiceView* view);

                                EditView*               GetEditView() { return fEditView; }
                                PatternSelector* GetPatternSelector()
                                                                        { return fPatternSelector; }
                                ChoiceModel*    GetChoiceModel() { return fChoiceModel; }
                                ChoiceView*             GetChoiceView() { return fChoiceView; }

        protected:
                                EditView*               fEditView;
                                PatternSelector* fPatternSelector;
                                ChoiceModel*    fChoiceModel;
                                ChoiceView*             fChoiceView;
        };

protected:
                                                                BAutoCompleter(
                                                                        CompletionStyle* completionStyle = NULL);
                                                                BAutoCompleter(EditView* editView,
                                                                        ChoiceModel* choiceModel,
                                                                        ChoiceView* choiceView,
                                                                        PatternSelector* patternSelector);
        virtual                                         ~BAutoCompleter();
        
                        void                            EditViewStateChanged(
                                                                        bool updateChoices = true);
                
                        bool                            Select(int32 index);
                        bool                            SelectNext(bool wrap = false);
                        bool                            SelectPrevious(bool wrap = false);
                        bool                            IsChoiceSelected() const;
                        int32                           CountChoices() const;
                        int32                           CountVisibleChoices() const;
                        int32                           SelectedChoiceIndex() const;
                
                        void                            ApplyChoice(bool hideChoices = true);
                        void                            CancelChoice();
                        
                        void                            SetEditView(EditView* view);
                        void                            SetPatternSelector(PatternSelector* selector);
                        void                            SetChoiceModel(ChoiceModel* model);
                        void                            SetChoiceView(ChoiceView* view);
                
                        void                            SetCompletionStyle(CompletionStyle* style);
        
private:
                        CompletionStyle*        fCompletionStyle;
};


#endif // _AUTO_COMPLETER_H