Add MnemonicLabel and MnemonicAction components

Looks like i am going to do many Labels and Actions that require
mnemonics, and i do not want to setup the properties everytime.

src/CMakeLists.txt

@@ -5,13 +5,18 @@ qt_add_executable(${PROJECT_NAME}
 qt_add_qml_module(${PROJECT_NAME}
     URI Camper
     VERSION 1.0
-    DEPENDENCIES QtCore
+    DEPENDENCIES
+        QtCore
+        QtQuick
     SOURCES
         database.cpp database.h
+        mnemonicattached.cpp mnemonicattached.h
     QML_FILES
         ErrorNotification.qml
         LoginPage.qml
         Main.qml
+        MnemonicAction.qml
+        MnemonicLabel.qml
         ReservationsPage.qml
         SelectableLabel.qml
 )

src/LoginPage.qml

@@ -9,36 +9,26 @@ Page {
     title: qsTr("Login")
 
     ColumnLayout {
-        Label {
-            text: qsTr("&User:")
+        MnemonicLabel {
+            buddy: user
+            mnemonic: qsTr("&User:")
         }
 
         TextField {
             id: user
 
             focus: true
-
-            validator: RegularExpressionValidator {
-                regularExpression: /[^s].*/
         }
 
-            onAccepted: function () {
-                loginAction.trigger();
-            }
-        }
-
-        Label {
-            text: qsTr("&Password:")
+        MnemonicLabel {
+            buddy: password
+            mnemonic: qsTr("&Password:")
         }
 
         TextField {
             id: password
 
             echoMode: TextInput.Password
-
-            onAccepted: function () {
-                loginAction.trigger();
-            }
         }
 
         Button {
@@ -46,11 +36,10 @@ Page {
         }
     }
 
-    Action {
+    MnemonicAction {
         id: loginAction
 
-        enabled: user.acceptableInput
-        text: "&Login"
+        mnemonic: qsTr("Log &in")
 
         onTriggered: function () {
             Database.open(user.text, password.text);

src/MnemonicAction.qml

@@ -0,0 +1,12 @@
+import QtQuick
+import QtQuick.Controls
+
+Action {
+    id: control
+
+    required property string mnemonic
+
+    Mnemonic.label: mnemonic
+    shortcut: Mnemonic.sequence
+    text: Mnemonic.richTextLabel
+}

src/MnemonicLabel.qml

@@ -0,0 +1,21 @@
+pragma ComponentBehavior: Bound
+import QtQuick
+import QtQuick.Controls
+
+Label {
+    id: control
+
+    required property Item buddy
+    required property string mnemonic
+
+    Mnemonic.label: control.mnemonic
+    text: Mnemonic.richTextLabel
+
+    Shortcut {
+        sequence: control.Mnemonic.sequence
+
+        onActivated: function () {
+            control.buddy.forceActiveFocus();
+        }
+    }
+}

src/ReservationsPage.qml

@@ -10,13 +10,19 @@ Page {
             anchors.fill: parent
 
             ToolButton {
-                icon.name: "system-log-out"
-                text: qsTr("&Log out")
+                action: logoutAction
+            }
+        }
+    }
 
-                onClicked: function () {
+    MnemonicAction {
+        id: logoutAction
+
+        icon.name: "system-log-out"
+        mnemonic: qsTr("Log &out")
+
+        onTriggered: function () {
             Database.close();
         }
     }
 }
-    }
-}

src/database.cpp

@@ -6,7 +6,6 @@
 Database::Database(QObject *parent)
     : QObject{parent}
     , m_pool{}
-    , m_connectionName{"main"}
 {
     m_pool.setMaxThreadCount(1);
     m_pool.setExpiryTimeout(-1);
@@ -15,28 +14,36 @@ Database::Database(QObject *parent)
 QFuture<void> Database::open(const QString &user, const QString &password)
 {
     return QtConcurrent::run(&m_pool, [this, user, password]() {
-        QSqlDatabase db = QSqlDatabase::addDatabase("QPSQL", m_connectionName);
+        QString errorMessage;
+        QString connectionName;
+        {
+            QSqlDatabase db = QSqlDatabase::addDatabase("QPSQL");
             db.setConnectOptions("service=camper; options=-csearch_path=camper,public");
             if (db.open(user, password)) {
                 emit opened();
-        } else {
-            const QString errorMessage(db.lastError().text());
-            db = QSqlDatabase(); // Otherwise removeDatabase complains is still being used.
-            QSqlDatabase::removeDatabase(m_connectionName);
-            emit errorOcurred(errorMessage);
+                return;
             }
+            errorMessage = db.lastError().text();
+            connectionName = db.connectionName();
+        }
+        QSqlDatabase::removeDatabase(connectionName);
+        emit errorOcurred(errorMessage);
     });
 }
 
 QFuture<void> Database::close()
 {
     return QtConcurrent::run(&m_pool, [this]() {
-        QSqlDatabase db = QSqlDatabase::database(m_connectionName);
+        QString connectionName;
+        {
+            QSqlDatabase db = QSqlDatabase::database();
             if (!db.isValid()) {
                 return;
             }
+            connectionName = db.connectionName();
             db.close();
-        QSqlDatabase::removeDatabase(m_connectionName);
+        }
+        QSqlDatabase::removeDatabase(connectionName);
         emit closed();
     });
 }

src/database.h

@@ -25,7 +25,6 @@ signals:
 
 private:
     QThreadPool m_pool;
-    QString m_connectionName;
 };
 
 #endif // DATABASE_H

src/mnemonicattached.cpp

@@ -0,0 +1,147 @@
+#include "mnemonicattached.h"
+#include <QEvent>
+#include <QGuiApplication>
+#include <QKeyEvent>
+
+using namespace Qt::Literals::StringLiterals;
+
+class MnemonicEventFilter : public QObject
+{
+    Q_OBJECT
+
+public:
+    static MnemonicEventFilter &instance()
+    {
+        static MnemonicEventFilter s_instance;
+        return s_instance;
+    }
+
+    bool isAltPressed() const { return m_altPressed; }
+
+    bool eventFilter(QObject *watched, QEvent *event) override
+    {
+        Q_UNUSED(watched);
+
+        if (event->type() == QEvent::KeyPress) {
+            QKeyEvent *ke = static_cast<QKeyEvent *>(event);
+            if (ke->key() == Qt::Key_Alt) {
+                m_altPressed = true;
+                emit altPressed();
+            }
+        } else if (event->type() == QEvent::KeyRelease) {
+            QKeyEvent *ke = static_cast<QKeyEvent *>(event);
+            if (ke->key() == Qt::Key_Alt) {
+                m_altPressed = false;
+                emit altReleased();
+            }
+        } else if (event->type() == QEvent::ApplicationStateChange) {
+            if (m_altPressed) {
+                m_altPressed = false;
+                emit altReleased();
+            }
+        }
+
+        return false;
+    }
+
+Q_SIGNALS:
+    void altPressed();
+    void altReleased();
+
+private:
+    MnemonicEventFilter()
+        : QObject(nullptr)
+    {
+        qGuiApp->installEventFilter(this);
+    }
+
+    bool m_altPressed = false;
+};
+
+MnemonicAttached::MnemonicAttached(QObject *parent)
+    : QObject{parent}
+    , m_label{}
+    , m_richTextLabel{}
+    , m_active{MnemonicEventFilter::instance().isAltPressed()}
+{
+    connect(&MnemonicEventFilter::instance(),
+            &MnemonicEventFilter::altPressed,
+            this,
+            &MnemonicAttached::onAltPressed);
+    connect(&MnemonicEventFilter::instance(),
+            &MnemonicEventFilter::altReleased,
+            this,
+            &MnemonicAttached::onAltReleased);
+}
+
+MnemonicAttached *MnemonicAttached::qmlAttachedProperties(QObject *object)
+{
+    return new MnemonicAttached(object);
+}
+
+QString MnemonicAttached::label() const
+{
+    return m_label;
+}
+
+void MnemonicAttached::setLabel(const QString &label)
+{
+    if (m_label == label) {
+        return;
+    }
+    m_label = label;
+    emit labelChanged();
+    emit sequenceChanged();
+
+    updateRichText();
+}
+
+QString MnemonicAttached::richTextLabel() const
+{
+    return m_richTextLabel;
+}
+
+QKeySequence MnemonicAttached::sequence() const
+{
+    return QKeySequence::mnemonic(m_label);
+}
+
+void MnemonicAttached::onAltPressed()
+{
+    if (m_active) {
+        return;
+    }
+    m_active = true;
+    updateRichText();
+}
+
+void MnemonicAttached::onAltReleased()
+{
+    if (!m_active) {
+        return;
+    }
+    m_active = false;
+    updateRichText();
+}
+
+void MnemonicAttached::updateRichText()
+{
+    QString richTextLabel;
+    qsizetype pos = m_label.indexOf('&'_L1);
+    if (pos < 0 || pos + 1 == m_label.length()) {
+        richTextLabel = m_label;
+    } else if (m_active) {
+        richTextLabel = m_label.left(pos) + "<u>"_L1 + m_label.at(pos + 1) + "</u>"
+                        + m_label.mid(pos + 2);
+    } else {
+        richTextLabel = m_label.left(pos) + m_label.mid(pos + 1);
+    }
+    if (m_richTextLabel == richTextLabel) {
+        return;
+    }
+    m_richTextLabel = richTextLabel;
+    emit richTextLabelChanged();
+}
+
+#include "mnemonicattached.moc"
+#include "moc_mnemonicattached.cpp"

src/mnemonicattached.h

@@ -0,0 +1,50 @@
+#ifndef MNEMONICATTACHED_H
+#define MNEMONICATTACHED_H
+
+#include <QKeySequence>
+#include <QObject>
+#include <QString>
+#include <QtQmlIntegration>
+
+class MnemonicAttached : public QObject
+{
+    Q_OBJECT
+
+    Q_PROPERTY(QString label READ label WRITE setLabel NOTIFY labelChanged FINAL)
+    Q_PROPERTY(QString richTextLabel READ richTextLabel NOTIFY richTextLabelChanged FINAL)
+    Q_PROPERTY(QKeySequence sequence READ sequence NOTIFY sequenceChanged FINAL)
+
+    QML_NAMED_ELEMENT(Mnemonic)
+    QML_UNCREATABLE("Mnemonic is only available via attached properties")
+    QML_ATTACHED(MnemonicAttached)
+public:
+    explicit MnemonicAttached(QObject *parent = nullptr);
+
+    static MnemonicAttached *qmlAttachedProperties(QObject *object);
+
+    QString label() const;
+    void setLabel(const QString &label);
+
+    QString richTextLabel() const;
+
+    QKeySequence sequence() const;
+
+signals:
+    void enabledChanged();
+    void labelChanged();
+    void richTextLabelChanged();
+    void sequenceChanged();
+
+private slots:
+    void onAltPressed();
+    void onAltReleased();
+
+private:
+    void updateRichText();
+
+    QString m_label;
+    QString m_richTextLabel;
+    bool m_active;
+};
+
+#endif // MNEMONICATTACHED_H