fancylineedit.h

// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0

#pragma once

#include "completinglineedit.h"

#include <QAbstractButton>

#include <functional>

QT_BEGIN_NAMESPACE
class QEvent;
class QKeySequence;
QT_END_NAMESPACE

namespace GUI {

class FancyLineEditPrivate;

class GUI_EXPORT IconButton : public QAbstractButton
{
    Q_OBJECT
    Q_PROPERTY(float iconOpacity READ iconOpacity WRITE setIconOpacity)
    Q_PROPERTY(bool autoHide READ hasAutoHide WRITE setAutoHide)
public:
    explicit IconButton(QWidget *parent = nullptr);
    void paintEvent(QPaintEvent *event) override;
    auto iconOpacity() -> float { return m_iconOpacity; }
    void setIconOpacity(float value)
    {
        m_iconOpacity = value;
        update();
    }
    void animateShow(bool visible);

    void setAutoHide(bool hide) { m_autoHide = hide; }
    [[nodiscard]] auto hasAutoHide() const -> bool { return m_autoHide; }

    [[nodiscard]] auto sizeHint() const -> QSize override;

protected:
    void keyPressEvent(QKeyEvent *ke) override;
    void keyReleaseEvent(QKeyEvent *ke) override;

private:
    float m_iconOpacity;
    bool m_autoHide;
    QIcon m_icon;
};

class GUI_EXPORT FancyLineEdit : public CompletingLineEdit
{
    Q_OBJECT
public:
    enum Side { Left = 0, Right = 1 };
    Q_ENUM(Side)

    explicit FancyLineEdit(QWidget *parent = nullptr);
    ~FancyLineEdit() override;

    void setTextKeepingActiveCursor(const QString &text);

    [[nodiscard]] auto buttonIcon(Side side) const -> QIcon;
    void setButtonIcon(Side side, const QIcon &icon);

    [[nodiscard]] auto buttonMenu(Side side) const -> QMenu *;
    void setButtonMenu(Side side, QMenu *menu);

    void setButtonVisible(Side side, bool visible);
    [[nodiscard]] auto isButtonVisible(Side side) const -> bool;
    [[nodiscard]] auto button(Side side) const -> QAbstractButton *;

    void setButtonToolTip(Side side, const QString & /*tip*/);
    void setButtonFocusPolicy(Side side, Qt::FocusPolicy policy);

    // Set whether tabbing in will trigger the menu.
    void setMenuTabFocusTrigger(Side side, bool v);
    [[nodiscard]] auto hasMenuTabFocusTrigger(Side side) const -> bool;

    // Set if icon should be hidden when text is empty
    void setAutoHideButton(Side side, bool h);
    [[nodiscard]] auto hasAutoHideButton(Side side) const -> bool;

    // Completion

    // Enable a history completer with a history of entries.
    void setHistoryCompleter(const QString &historyKey, bool restoreLastItemFromHistory = false);
    // Sets a completer that is not a history completer.
    void setSpecialCompleter(QCompleter *completer);

    // Filtering

    // Enables filtering
    void setFiltering(bool on);

    //  Validation

    // line edit, (out)errorMessage -> valid?
    using ValidationFunction = std::function<bool(FancyLineEdit *, QString *)>;
    enum State { Invalid, DisplayingPlaceholderText, Valid };

    [[nodiscard]] auto state() const -> State;
    [[nodiscard]] auto isValid() const -> bool;
    [[nodiscard]] auto errorMessage() const -> QString;

    void setValidationFunction(const ValidationFunction &fn);
    static auto defaultValidationFunction() -> ValidationFunction;
    void validate();
    void onEditingFinished();

    static void setCamelCaseNavigationEnabled(bool enabled);
    static void setCompletionShortcut(const QKeySequence &shortcut);

protected:
    // Custom behaviour can be added here.
    virtual void handleChanged(const QString & /*unused*/) {}
    void keyPressEvent(QKeyEvent *event) override;

signals:
    void buttonClicked(FancyLineEdit::Side side);
    void leftButtonClicked();
    void rightButtonClicked();

    void filterChanged(const QString &);

    void validChanged(bool validState);
    void validReturnPressed();

protected:
    void resizeEvent(QResizeEvent *e) override;

    virtual auto fixInputString(const QString &string) -> QString;

private:
    void iconClicked(FancyLineEdit::Side /*side*/);

    static auto validateWithValidator(FancyLineEdit *edit, QString *errorMessage) -> bool;
    // Unimplemented, to force the user to make a decision on
    // whether to use setHistoryCompleter() or setSpecialCompleter().
    void setCompleter(QCompleter *);

    void updateMargins();
    void updateButtonPositions();
    auto camelCaseBackward(bool mark) -> bool;
    auto camelCaseForward(bool mark) -> bool;
    friend class FancyLineEditPrivate;

    FancyLineEditPrivate *d;
};

} // namespace GUI