mnemonicattached.h

/*
*   Copyright (C) 2017 by Marco Martin <mart@kde.org>
*
*   This program is free software; you can redistribute it and/or modify
*   it under the terms of the GNU Library General Public License as
*   published by the Free Software Foundation; either version 2, or
*   (at your option) any later version.
*
*   This program is distributed in the hope that it will be useful,
*   but WITHOUT ANY WARRANTY; without even the implied warranty of
*   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*   GNU Library General Public License for more details
*
*   You should have received a copy of the GNU Library General Public
*   License along with this program; if not, write to the
*   Free Software Foundation, Inc.,
*   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/

#ifndef MNEMONICATTACHED_H
#define MNEMONICATTACHED_H

#include <QtQml>
#include <QObject>
#include <QQuickWindow>

class QQuickItem;

class MnemonicAttached : public QObject
{
    Q_OBJECT
    Q_PROPERTY(QString label READ label WRITE setLabel NOTIFY labelChanged)

    
    Q_PROPERTY(QString richTextLabel READ richTextLabel NOTIFY richTextLabelChanged)

    Q_PROPERTY(QString mnemonicLabel READ mnemonicLabel NOTIFY mnemonicLabelChanged)

    Q_PROPERTY(bool enabled READ enabled WRITE setEnabled NOTIFY enabledChanged)

    Q_PROPERTY(MnemonicAttached::ControlType controlType READ controlType WRITE setControlType NOTIFY controlTypeChanged)

    Q_PROPERTY(QKeySequence sequence READ sequence NOTIFY sequenceChanged)

public:
    enum ControlType {
        ActionElement, 
        DialogButton, 
        MenuItem, 
        FormLabel, 
        SecondaryControl 
    };
    Q_ENUM(ControlType)

    explicit MnemonicAttached(QObject *parent = nullptr);
    ~MnemonicAttached();

    void setLabel(const QString &text);
    QString label() const;

    QString richTextLabel() const;
    QString mnemonicLabel() const;

    void setEnabled(bool enabled);
    bool enabled() const;

    void setControlType(MnemonicAttached::ControlType controlType);
    ControlType controlType() const;

    QKeySequence sequence();

    //QML attached property
    static MnemonicAttached *qmlAttachedProperties(QObject *object);

protected:
    bool eventFilter(QObject *watched, QEvent *e) override;
    void updateSequence();

Q_SIGNALS:
    void labelChanged();
    void enabledChanged();
    void sequenceChanged();
    void richTextLabelChanged();
    void mnemonicLabelChanged();
    void controlTypeChanged();

private:
    void calculateWeights();

    //TODO: to have support for DIALOG_BUTTON_EXTRA_WEIGHT etc, a type enum should be exported
    enum {
        // Additional weight for first character in string
        FIRST_CHARACTER_EXTRA_WEIGHT = 50,
        // Additional weight for the beginning of a word
        WORD_BEGINNING_EXTRA_WEIGHT = 50,
        // Additional weight for a 'wanted' accelerator ie string with '&'
        WANTED_ACCEL_EXTRA_WEIGHT = 150,
        // Default weight for an 'action' widget (ie, pushbuttons)
        ACTION_ELEMENT_WEIGHT = 50,
        // Additional weight for the dialog buttons (large, we basically never want these reassigned)
        DIALOG_BUTTON_EXTRA_WEIGHT = 300,
        // Weight for FormLayout labels (low)
        FORM_LABEL_WEIGHT = 20,
        // Weight for Secondary controls which are considered less important (low)
        SECONDARY_CONTROL_WEIGHT = 10,
        // Default weight for menu items
        MENU_ITEM_WEIGHT = 250
    };

    //order word letters by weight
    int m_weight = 0;
    int m_baseWeight = 0;
    ControlType m_controlType = SecondaryControl;
    QMap<int, QChar> m_weights;

    QString m_label;
    QString m_actualRichTextLabel;
    QString m_richTextLabel;
    QString m_mnemonicLabel;
    QKeySequence m_sequence;
    bool m_enabled = true;

    QPointer<QQuickWindow> m_window;

    //global mapping of mnemonics
    //TODO: map by QWindow
    static QHash<QKeySequence, MnemonicAttached *> s_sequenceToObject;
};

QML_DECLARE_TYPEINFO(MnemonicAttached, QML_HAS_ATTACHED_PROPERTIES)

#endif // MnemonicATTACHED_H