AutoCompleteLineEdit.h

// Author: Kang Lin <kl222@126.com>
 
#pragma once
 
#include <QLineEdit>
#include <QStringList>
#include <QKeyEvent>
#include <QFocusEvent>
#include <QTimer>
 
class CAutoCompleteLineEdit : public QLineEdit
{
    Q_OBJECT
public:
    explicit CAutoCompleteLineEdit(QWidget *parent = nullptr);
    explicit CAutoCompleteLineEdit(const QString &contents, QWidget *parent = nullptr);
 
    void setCompletions(const QStringList &completions);
 
    QColor GetSuggestionColor() const;
    void SetSuggestionColor(const QColor &newSuggestionColor);
    QColor GetSuggestionBackground() const;
    void SetSuggestionBackground(const QColor &newSuggestionBackground);
 
protected:
    void keyPressEvent(QKeyEvent *event) override;
    void focusInEvent(QFocusEvent *event) override;
    void focusOutEvent(QFocusEvent *event) override;
    virtual void paintEvent(QPaintEvent *event) override;
 
private slots:
    void updateCompletion();
 
private:
    QStringList m_completions;
    QString m_currentSuggestion;
 
    QColor m_suggestionColor;
    QColor m_suggestionBackground;
 
    QTimer m_updateTimer;
 
    void initTimer();
    void showSuggestion();
    void hideSuggestion();
    void acceptSuggestion();
    QString findBestMatch(const QString &input) const;
};