Bug 345922: Implement option to use notifications to display alarms

Add an option to the alarm edit dialog to display an alarm as a
notification instead of in a window.

CMakeLists.txt

@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 3.5)
 set(PIM_VERSION "5.15.40")
 set(PIM_VERSION ${PIM_VERSION})
 set(RELEASE_SERVICE_VERSION "20.11.80")
-set(KALARM_VERSION "3.0.2")
+set(KALARM_VERSION "3.1.0")
 
 project(kalarm VERSION ${KALARM_VERSION})
 

Changelog

 KAlarm Change Log
 
+=== Version 3.1.0 (KDE Applications 20.12) --- 11 September 2020 ===
++ Add option to show alarm message as a notification instead of in a window [KDE Bug 345922]
+
 === Version 3.0.2 (KDE Applications 20.08.2) --- 10 September 2020 ===
 + If command generating text for display alarm fails, only display error message,
   not the display alarm, and don't redisplay the alarm on every restart.

src/CMakeLists.txt

@@ -96,6 +96,7 @@ set(kalarm_bin_SRCS ${libkalarm_SRCS} ${resources_SRCS}
     mainwindow.cpp
     messagedisplay.cpp
     messagedisplayhelper.cpp
+    messagenotification.cpp
     messagewindow.cpp
     preferences.cpp
     prefdlg.cpp
@@ -208,6 +209,7 @@ install(FILES data/org.kde.kalarm.appdata.xml DESTINATION ${KDE_INSTALL_METAINFO
 install(FILES data/kalarmconfig.kcfg DESTINATION ${KDE_INSTALL_KCFGDIR})
 install(FILES data/kalarmui.rc DESTINATION ${KDE_INSTALL_KXMLGUI5DIR}/kalarm)
 install(FILES data/org.kde.kalarm.kalarm.xml DESTINATION ${KDE_INSTALL_DBUSINTERFACEDIR})
+install(FILES data/kalarm.notifyrc DESTINATION ${KDE_INSTALL_KNOTIFY5RCDIR})
 
 ########### KAuth helper ###############
 

src/data/kalarm.notifyrc

+[Global]
+IconName=kalarm
+DesktopEntry=org.kde.kalarm
+Comment=KAlarm
+
+[Event/Message]
+Name=Alarm message
+Action=Popup
+
+[Event/MessageError]
+Name=Alarm error message
+Action=Popup|Sound
+Sound=Oxygen-Sys-App-Error.ogg

src/data/kalarmconfig.kcfg

 <?xml version="1.0" encoding="UTF-8"?>
-<!-- Author: David Jarvie <djarvie@kde.org> -->
+<!--
+SPDX-FileCopyrightText: 2007-2020 David Jarvie <djarvie@kde.org>
+SPDX-License-Identifier: GPL-2.0-or-later
+-->
 <kcfg xmlns="http://www.kde.org/standards/kcfg/1.0"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.kde.org/standards/kcfg/1.0
@@ -259,6 +262,15 @@
     </entry>
   </group>
   <group name="Defaults">
+    <entry name="DefaultDisplayMethod" key="DisplayMethod" type="Enum">
+      <label context="@label">Alarm message display method</label>
+      <whatsthis context="@info:whatsthis">Default setting in the alarm edit dialog for "display method", to determine whether to display alarm messages in windows or in system notifications.</whatsthis>
+      <choices name="DisplayMethod" prefix="Display_">
+        <choice name="Window"/>
+        <choice name="Notification"/>
+      </choices>
+      <default>Window</default>
+    </entry>
     <entry name="DefaultLateCancel" key="LateCancel" type="Int">
       <label context="@label">Cancel if late (minutes)</label>
       <whatsthis context="@info:whatsthis">Default value in the alarm edit dialog for late cancellation time (in minutes). 0 for no late cancellation, >0 how many minutes before cancelling.</whatsthis>

src/editdlgtypes.cpp

@@ -61,6 +61,7 @@ using namespace KCalendarCore;
 using namespace KAlarmCal;
 
 enum { tTEXT, tFILE, tCOMMAND };  // order of mTypeCombo items
+enum { dWINDOW, dNOTIFY };        // order of mDisplayMethodCombo items
 
 
 /*=============================================================================
@@ -86,9 +87,11 @@ class PickLogFileRadio : public PickFileRadio
 = Dialog to edit display alarms.
 =============================================================================*/
 
+QString EditDisplayAlarmDlg::i18n_lbl_DisplayMethod() { return i18nc("@label:listbox", "Display method:"); }
+QString EditDisplayAlarmDlg::i18n_combo_Window()      { return i18nc("@item:inlistbox", "Window"); }
+QString EditDisplayAlarmDlg::i18n_combo_Notify()      { return i18nc("@item:inlistbox", "Notification"); }
 QString EditDisplayAlarmDlg::i18n_chk_ConfirmAck()    { return i18nc("@option:check", "Confirm acknowledgment"); }
 
-
 /******************************************************************************
 * Constructor.
 * Parameters:
@@ -135,9 +138,9 @@ void EditDisplayAlarmDlg::type_init(QWidget* parent, QVBoxLayout* frameLayout)
     label->setFixedSize(label->sizeHint());
     mTypeCombo = new ComboBox(box);
     boxHLayout->addWidget(mTypeCombo);
-    QString textItem    = i18nc("@item:inlistbox", "Text message");
-    QString fileItem    = i18nc("@item:inlistbox", "File contents");
-    QString commandItem = i18nc("@item:inlistbox", "Command output");
+    const QString textItem    = i18nc("@item:inlistbox", "Text message");
+    const QString fileItem    = i18nc("@item:inlistbox", "File contents");
+    const QString commandItem = i18nc("@item:inlistbox", "Command output");
     mTypeCombo->addItem(textItem);     // index = tTEXT
     mTypeCombo->addItem(fileItem);     // index = tFILE
     mTypeCombo->addItem(commandItem);  // index = tCOMMAND
@@ -220,13 +223,38 @@ void EditDisplayAlarmDlg::type_init(QWidget* parent, QVBoxLayout* frameLayout)
     connect(mFontColourButton, &FontColourButton::selected, this, &EditDisplayAlarmDlg::setColours);
     connect(mFontColourButton, &FontColourButton::selected, this, &EditDisplayAlarmDlg::contentsChanged);
 
+    // Display method selector
+    hlayout = new QHBoxLayout();
+    hlayout->setContentsMargins(0, 0, 0, 0);
+    frameLayout->addLayout(hlayout);
+    mDisplayMethodBox = new QWidget(parent);    // to group widgets for QWhatsThis text
+    boxHLayout = new QHBoxLayout(mDisplayMethodBox);
+    boxHLayout->setContentsMargins(0, 0, 0, 0);
+    label = new QLabel(i18n_lbl_DisplayMethod(), mDisplayMethodBox);
+    boxHLayout->addWidget(label);
+    label->setFixedSize(label->sizeHint());
+    mDisplayMethodCombo = new ComboBox(mDisplayMethodBox);
+    boxHLayout->addWidget(mDisplayMethodCombo);
+    const QString windowItem = i18n_combo_Window();
+    const QString notifyItem = i18n_combo_Notify();
+    mDisplayMethodCombo->addItem(windowItem);     // index = dWINDOW
+    mDisplayMethodCombo->addItem(notifyItem);     // index = dNOTIFY
+    mDisplayMethodCombo->setFixedSize(mDisplayMethodCombo->sizeHint());
+    connect(mDisplayMethodCombo, static_cast<void (ComboBox::*)(int)>(&ComboBox::currentIndexChanged), this, &EditDisplayAlarmDlg::slotDisplayMethodChanged);
+    connect(mDisplayMethodCombo, static_cast<void (ComboBox::*)(int)>(&ComboBox::currentIndexChanged), this, &EditDisplayAlarmDlg::contentsChanged);
+    label->setBuddy(mDisplayMethodCombo);
+    mDisplayMethodBox->setWhatsThis(i18nc("@info:whatsthis", "Select whether to display the alarm in a window or by the notification system."));
+    hlayout->addWidget(mDisplayMethodBox);
+    hlayout->addSpacing(2 * style()->pixelMetric(QStyle::PM_LayoutHorizontalSpacing));
+    hlayout->addStretch();
+
     if (ShellProcess::authorised())    // don't display if shell commands not allowed (e.g. kiosk mode)
     {
         // Special actions button
         mSpecialActionsButton = new SpecialActionsButton(false, parent);
         mSpecialActionsButton->setFixedSize(mSpecialActionsButton->sizeHint());
         connect(mSpecialActionsButton, &SpecialActionsButton::selected, this, &EditDisplayAlarmDlg::contentsChanged);
-        frameLayout->addWidget(mSpecialActionsButton, 0, Qt::AlignRight);
+        hlayout->addWidget(mSpecialActionsButton);
     }
 
     // Top-adjust the controls
@@ -279,6 +307,7 @@ void EditDisplayAlarmDlg::type_initValues(const KAEvent* event)
         mFontColourButton->setBgColour(event->bgColour());
         mFontColourButton->setFgColour(event->fgColour());
         setColours(event->fgColour(), event->bgColour());
+        mDisplayMethodCombo->setCurrentIndex(event->notify() ? dNOTIFY : dWINDOW);
         mConfirmAck->setChecked(event->confirmAck());
         bool recurs = event->recurs();
         int reminderMins = event->reminderMinutes();
@@ -324,6 +353,7 @@ void EditDisplayAlarmDlg::type_initValues(const KAEvent* event)
         mFontColourButton->setBgColour(Preferences::defaultBgColour());
         mFontColourButton->setFgColour(Preferences::defaultFgColour());
         setColours(Preferences::defaultFgColour(), Preferences::defaultBgColour());
+        mDisplayMethodCombo->setCurrentIndex(Preferences::defaultDisplayMethod() == Preferences::Display_Window ? dWINDOW : dNOTIFY);
         mConfirmAck->setChecked(Preferences::defaultConfirmAck());
         reminder()->setMinutes(0, false);
         reminder()->enableOnceOnly(isTimedRecurrence());   // must be called after mRecurrenceEdit is set up
@@ -352,9 +382,15 @@ void EditDisplayAlarmDlg::type_showOptions(bool more)
     if (mSpecialActionsButton)
     {
         if (more)
+        {
+            mDisplayMethodBox->show();
             mSpecialActionsButton->show();
+        }
         else
+        {
+            mDisplayMethodBox->hide();
             mSpecialActionsButton->hide();
+        }
     }
 }
 
@@ -449,6 +485,7 @@ void EditDisplayAlarmDlg::setReadOnly(bool readOnly)
     mCmdEdit->setReadOnly(readOnly);
     mFontColourButton->setReadOnly(readOnly);
     mSoundPicker->setReadOnly(readOnly);
+    mDisplayMethodCombo->setReadOnly(readOnly);
     mConfirmAck->setReadOnly(readOnly);
     reminder()->setReadOnly(readOnly);
     if (mSpecialActionsButton)
@@ -466,19 +503,20 @@ void EditDisplayAlarmDlg::setReadOnly(bool readOnly)
 void EditDisplayAlarmDlg::saveState(const KAEvent* event)
 {
     EditAlarmDlg::saveState(event);
-    mSavedType        = mTypeCombo->currentIndex();
-    mSavedCmdScript   = mCmdEdit->isScript();
-    mSavedSoundType   = mSoundPicker->sound();
-    mSavedSoundFile   = mSoundPicker->file();
-    mSavedSoundVolume = mSoundPicker->volume(mSavedSoundFadeVolume, mSavedSoundFadeSeconds);
-    mSavedRepeatPause = mSoundPicker->repeatPause();
-    mSavedConfirmAck  = mConfirmAck->isChecked();
-    mSavedFont        = mFontColourButton->font();
-    mSavedFgColour    = mFontColourButton->fgColour();
-    mSavedBgColour    = mFontColourButton->bgColour();
-    mSavedReminder    = reminder()->minutes();
-    mSavedOnceOnly    = reminder()->isOnceOnly();
-    mSavedAutoClose   = lateCancel()->isAutoClose();
+    mSavedType          = mTypeCombo->currentIndex();
+    mSavedCmdScript     = mCmdEdit->isScript();
+    mSavedSoundType     = mSoundPicker->sound();
+    mSavedSoundFile     = mSoundPicker->file();
+    mSavedSoundVolume   = mSoundPicker->volume(mSavedSoundFadeVolume, mSavedSoundFadeSeconds);
+    mSavedRepeatPause   = mSoundPicker->repeatPause();
+    mSavedDisplayMethod = mDisplayMethodCombo->currentIndex();
+    mSavedConfirmAck    = mConfirmAck->isChecked();
+    mSavedFont          = mFontColourButton->font();
+    mSavedFgColour      = mFontColourButton->fgColour();
+    mSavedBgColour      = mFontColourButton->bgColour();
+    mSavedReminder      = reminder()->minutes();
+    mSavedOnceOnly      = reminder()->isOnceOnly();
+    mSavedAutoClose     = lateCancel()->isAutoClose();
     if (mSpecialActionsButton)
     {
         mSavedPreAction        = mSpecialActionsButton->preAction();
@@ -495,17 +533,22 @@ void EditDisplayAlarmDlg::saveState(const KAEvent* event)
 */
 bool EditDisplayAlarmDlg::type_stateChanged() const
 {
-    if (mSavedType       != mTypeCombo->currentIndex()
-    ||  mSavedCmdScript  != mCmdEdit->isScript()
-    ||  mSavedSoundType  != mSoundPicker->sound()
-    ||  mSavedConfirmAck != mConfirmAck->isChecked()
-    ||  mSavedFont       != mFontColourButton->font()
-    ||  mSavedFgColour   != mFontColourButton->fgColour()
-    ||  mSavedBgColour   != mFontColourButton->bgColour()
-    ||  mSavedReminder   != reminder()->minutes()
-    ||  mSavedOnceOnly   != reminder()->isOnceOnly()
-    ||  mSavedAutoClose  != lateCancel()->isAutoClose())
+    if (mSavedType          != mTypeCombo->currentIndex()
+    ||  mSavedCmdScript     != mCmdEdit->isScript()
+    ||  mSavedSoundType     != mSoundPicker->sound()
+    ||  mSavedDisplayMethod != mDisplayMethodCombo->currentIndex()
+    ||  mSavedReminder      != reminder()->minutes()
+    ||  mSavedOnceOnly      != reminder()->isOnceOnly()
+    ||  mSavedAutoClose     != lateCancel()->isAutoClose())
         return true;
+    if (mDisplayMethodCombo->currentIndex() == dWINDOW)
+    {
+        if (mSavedConfirmAck    != mConfirmAck->isChecked()
+        ||  mSavedFont          != mFontColourButton->font()
+        ||  mSavedFgColour      != mFontColourButton->fgColour()
+        ||  mSavedBgColour      != mFontColourButton->bgColour())
+            return true;
+    }
     if (mSpecialActionsButton)
     {
         if (mSavedPreAction        != mSpecialActionsButton->preAction()
@@ -579,12 +622,13 @@ KAEvent::Flags EditDisplayAlarmDlg::getAlarmFlags() const
     if (mFontColourButton->defaultFont())                  flags |= KAEvent::DEFAULT_FONT;
     if (cmd)                                               flags |= KAEvent::DISPLAY_COMMAND;
     if (cmd && mCmdEdit->isScript())                       flags |= KAEvent::SCRIPT;
+    if (mDisplayMethodCombo->currentIndex() == dNOTIFY)    flags |= KAEvent::NOTIFY;
     return flags;
 }
 
 /******************************************************************************
-* Called when one of the alarm display type combo box is changed, to display
-* the appropriate set of controls for that action type.
+* Called when the alarm display type combo box is changed, to display the
+* appropriate set of controls for that action type.
 */
 void EditDisplayAlarmDlg::slotAlarmTypeChanged(int index)
 {
@@ -624,6 +668,17 @@ void EditDisplayAlarmDlg::slotAlarmTypeChanged(int index)
         focus->setFocus();
 }
 
+/******************************************************************************
+* Called when the display method combo box is changed, to enable/disable the
+* appropriate set of controls for that display method.
+*/
+void EditDisplayAlarmDlg::slotDisplayMethodChanged(int index)
+{
+    const bool enable = (index == dWINDOW);
+    mConfirmAck->setEnabled(enable);
+    mFontColourButton->setEnabled(enable);
+}
+
 /******************************************************************************
 * Called when the file browse button is pressed to select a file to display.
 */

src/kalarmapp.cpp

@@ -17,6 +17,7 @@
 #include "kamail.h"
 #include "mainwindow.h"
 #include "messagewindow.h"
+#include "messagenotification.h"
 #include "migratekde4files.h"
 #include "preferences.h"
 #include "prefdlg.h"
@@ -287,6 +288,8 @@ bool KAlarmApp::restoreSession()
         }
     }
 
+    MessageNotification::sessionRestore();
+
     // Try to display the system tray icon if it is configured to be shown
     if (trayParent  ||  wantShowInSystemTray())
     {
@@ -2177,10 +2180,10 @@ void* KAlarmApp::execAlarm(KAEvent& event, const KAAlarm& alarm, ExecAlarmFlags
             if (!disp)
             {
                 // There isn't already a message for this event
-                const int mdFlags = (flags & Reschedule ? 0 : MessageDisplay::NO_RESCHEDULE)
-                                  | (flags & AllowDefer ? 0 : MessageDisplay::NO_DEFER)
+                const int mdFlags = (flags & Reschedule ? 0 : MessageDisplay::NoReschedule)
+                                  | (flags & AllowDefer ? 0 : MessageDisplay::NoDefer)
                                   | (flags & NoRecordCmdError ? MessageDisplay::NoRecordCmdError : 0);
-                (new MessageWindow(&event, alarm, mdFlags))->show();
+                MessageDisplay::create(event, alarm, mdFlags)->showDisplay();
             }
             else if (replaceReminder)
             {
@@ -2237,8 +2240,8 @@ void* KAlarmApp::execAlarm(KAEvent& event, const KAAlarm& alarm, ExecAlarmFlags
             if (!disp)
             {
                 // There isn't already a message for this event.
-                const int mdFlags = (flags & Reschedule ? 0 : MessageDisplay::NO_RESCHEDULE) | MessageDisplay::ALWAYS_HIDE;
-                disp = new MessageWindow(&event, alarm, mdFlags);
+                const int mdFlags = (flags & Reschedule ? 0 : MessageDisplay::NoReschedule) | MessageDisplay::AlwaysHide;
+                disp = MessageDisplay::create(event, alarm, mdFlags);
             }
             else
             {
@@ -2263,7 +2266,7 @@ void KAlarmApp::emailSent(KAMail::JobData& data, const QStringList& errmsgs, boo
         // Some error occurred, although the email may have been sent successfully
         if (errmsgs.count() > 1)
             qCDebug(KALARM_LOG) << "KAlarmApp::emailSent:" << (copyerr ? "Copy error:" : "Failed:") << errmsgs[1];
-        MessageWindow::showError(data.event, data.alarm.dateTime(), errmsgs);
+        MessageDisplay::showError(data.event, data.alarm.dateTime(), errmsgs);
     }
     else if (data.queued)
         Q_EMIT execAlarmSuccess();
@@ -2312,10 +2315,12 @@ ShellProcess* KAlarmApp::execCommandAlarm(const KAEvent& event, const KAAlarm& a
 * To connect to the exited signal of the process, specify the name of a method
 * to be called by supplying 'receiver' and 'methodExited' parameters.
 * To connect to the output ready signals of the process, specify a slot to be
-* called by supplying 'receiver' and 'slot' parameters.
+* called by supplying 'receiver' and 'slotOutput' parameters.
 *
 * Note that if shell access is not authorised, the attempt to run the command
 * will be errored.
+*
+* Reply = process which has been started, or null if a process couldn't be started.
 */
 ShellProcess* KAlarmApp::doShellCommand(const QString& command, const KAEvent& event, const KAAlarm* alarm, int flags, QObject* receiver, const char* slotOutput, const char* methodExited)
 {
@@ -2484,7 +2489,7 @@ QString KAlarmApp::createTempScriptFile(const QString& command, bool insertShell
     }
 
     const QStringList errmsgs(i18nc("@info", "Error creating temporary script file"));
-    MessageWindow::showError(event, alarm.dateTime(), errmsgs, QStringLiteral("Script"));
+    MessageDisplay::showError(event, alarm.dateTime(), errmsgs, QStringLiteral("Script"));
     return QString();
 }
 
@@ -2611,7 +2616,7 @@ void KAlarmApp::commandErrorMsg(const ShellProcess* proc, const KAEvent& event,
                 errmsgs += proc->command();
             dontShowAgain += QString::number(proc->status());
         }
-        MessageWindow::showError(event, (alarm ? alarm->dateTime() : DateTime()), errmsgs, dontShowAgain);
+        MessageDisplay::showError(event, (alarm ? alarm->dateTime() : DateTime()), errmsgs, dontShowAgain);
     }
 }
 
@@ -2741,9 +2746,7 @@ KAlarmApp::ProcData::ProcData(ShellProcess* p, KAEvent* e, KAAlarm* a, int f)
     : process(p)
     , event(e)
     , alarm(a)
-    , messageBoxParent(nullptr)
     , flags(f)
-    , eventDeleted(false)
 { }
 
 KAlarmApp::ProcData::~ProcData()

src/messagedisplay.cpp

@@ -8,12 +8,17 @@
 
 #include "messagedisplayhelper.h"
 #include "messagewindow.h"
-//#include "messagenotification.h"
+#include "messagenotification.h"
 
+#include "deferdlg.h"
 #include "displaycalendar.h"
+#include "functions.h"
 #include "kalarmapp.h"
 #include "resourcescalendar.h"
 #include "resources/resources.h"
+#include "lib/messagebox.h"
+
+#include <KLocalizedString>
 
 using namespace KAlarmCal;
 using namespace KCalendarCore;
@@ -21,24 +26,60 @@ using namespace KCalendarCore;
 
 bool MessageDisplay::mRedisplayed = false;
 
-MessageDisplay::MessageDisplay(const QString& displayType)
-    : mDisplayType(displayType)
-    , mHelper(new MessageDisplayHelper(this))
+/******************************************************************************
+* Create a new instance of a MessageDisplay, the derived class being dependent
+* on 'event.notify()'.
+*/
+MessageDisplay* MessageDisplay::create(const KAEvent& event, const KAAlarm& alarm, int flags)
 {
+    if (event.notify())
+        return new MessageNotification(event, alarm, flags);
+    else
+        return new MessageWindow(event, alarm, flags);
 }
 
-MessageDisplay::MessageDisplay(const QString& displayType, const KAEvent* event, const KAAlarm& alarm, int flags)
-    : mDisplayType(displayType)
-    , mHelper(new MessageDisplayHelper(this, event, alarm, flags))
+/******************************************************************************
+* Show an error message about the execution of an alarm.
+* If 'dontShowAgain' is non-null, a "Don't show again" option is displayed. Note
+* that the option is specific to 'event'.
+*/
+void MessageDisplay::showError(const KAEvent& event, const DateTime& alarmDateTime,
+                               const QStringList& errmsgs, const QString& dontShowAgain)
 {
+    if (MessageDisplayHelper::shouldShowError(event, errmsgs, dontShowAgain))
+    {
+        MessageDisplay* disp;
+        if (event.notify())
+            disp = new MessageNotification(event, alarmDateTime, errmsgs, dontShowAgain);
+        else
+            disp = new MessageWindow(event, alarmDateTime, errmsgs, dontShowAgain);
+        disp->showDisplay();
+    }
 }
 
-MessageDisplay::MessageDisplay(const QString& displayType, const KAEvent* event,
-                               const DateTime& alarmDateTime,
+/******************************************************************************
+* Constructors.
+*/
+MessageDisplay::MessageDisplay()
+    : mHelper(new MessageDisplayHelper(this))
+{
+}
+
+MessageDisplay::MessageDisplay(const KAEvent& event, const KAAlarm& alarm, int flags)
+    : mHelper(new MessageDisplayHelper(this, event, alarm, flags))
+{
+}
+
+MessageDisplay::MessageDisplay(const KAEvent& event, const DateTime& alarmDateTime,
                                const QStringList& errmsgs, const QString& dontShowAgain)
-    : mDisplayType(displayType)
-    , mHelper(new MessageDisplayHelper(this, event, alarmDateTime, errmsgs, dontShowAgain))
+    : mHelper(new MessageDisplayHelper(this, event, alarmDateTime, errmsgs, dontShowAgain))
+{
+}
+
+MessageDisplay::MessageDisplay(MessageDisplayHelper* helper)
+    : mHelper(helper)
 {
+    mHelper->setParent(this);
 }
 
 MessageDisplay::~MessageDisplay()
@@ -83,8 +124,8 @@ void MessageDisplay::redisplayAlarms()
                 }
                 qCDebug(KALARM_LOG) << "MessageDisplay::redisplayAlarms:" << eventId;
                 const bool login = alarm.repeatAtLogin();
-                const int flags = NO_RESCHEDULE | (login ? NO_DEFER : 0) | NO_INIT_VIEW;
-                MessageDisplay* d = new MessageWindow(&event, alarm, flags);
+                const int flags = NoReschedule | (login ? NoDefer : 0) | NoInitView;
+                MessageDisplay* d = create(event, alarm, flags);
                 MessageDisplayHelper* h = d->mHelper;
                 h->mResource = resource;
                 const bool rw = resource.isWritable(event.category());
@@ -102,9 +143,9 @@ void MessageDisplay::redisplayAlarms()
 * or if not found there, from the archive calendar. 'resource' is set to the
 * resource which originally contained the event, or invalid if not known.
 */
-bool MessageDisplay::retrieveEvent(KAEvent& event, Resource& resource, bool& showEdit, bool& showDefer)
+bool MessageDisplay::retrieveEvent(const EventId& evntId, KAEvent& event, Resource& resource, bool& showEdit, bool& showDefer)
 {
-    const QString eventId = mHelper->mEventId.eventId();
+    const QString eventId = evntId.eventId();
     const Event::Ptr kcalEvent = DisplayCalendar::kcalEvent(CalEvent::uid(eventId, CalEvent::DISPLAYING));
     if (!reinstateFromDisplaying(kcalEvent, event, resource, showEdit, showDefer))
     {
@@ -147,4 +188,120 @@ bool MessageDisplay::reinstateFromDisplaying(const Event::Ptr& kcalEvent, KAEven
     return true;
 }
 
+/******************************************************************************
+* Display the main window, with the appropriate alarm selected.
+*/
+void MessageDisplay::displayMainWindow()
+{
+    KAlarm::displayMainWindowSelected(mEventId().eventId());
+}
+
+MessageDisplay::DeferDlgData::~DeferDlgData()
+{
+    delete dlg;
+}
+
+/******************************************************************************
+* Create a defer message dialog.
+*/
+MessageDisplay::DeferDlgData* MessageDisplay::createDeferDlg(bool displayClosing)
+{
+    DeferAlarmDlg* dlg = new DeferAlarmDlg(KADateTime::currentDateTime(Preferences::timeSpec()).addSecs(60), mDateTime().isDateOnly(), false, displayParent());
+    dlg->setObjectName(QStringLiteral("DeferDlg"));    // used by LikeBack
+    dlg->setDeferMinutes(mDefaultDeferMinutes() > 0 ? mDefaultDeferMinutes() : Preferences::defaultDeferTime());
+    dlg->setLimit(mEvent());
+    DeferDlgData* data = new DeferDlgData(dlg);
+    data->eventId      = mEventId();
+    data->alarmType    = mAlarmType();
+    data->commandError = mCommandError();
+    data->displayOpen  = !displayClosing;
+    return data;
+}
+
+/******************************************************************************
+* Display a defer message dialog.
+*/
+void MessageDisplay::executeDeferDlg(DeferDlgData* data)
+{
+    if (data->dlg->exec() == QDialog::Accepted)
+    {
+        const DateTime dateTime  = data->dlg->getDateTime();
+        const int      delayMins = data->dlg->deferMinutes();
+        // Fetch the up-to-date alarm from the calendar. Note that it could have
+        // changed since it was displayed.
+        KAEvent event;
+        if (!data->eventId.isEmpty())
+            event = ResourcesCalendar::event(data->eventId);
+        if (event.isValid())
+        {
+            // The event still exists in the active calendar
+            qCDebug(KALARM_LOG) << "MessageDisplay::executeDeferDlg: Deferring event" << data->eventId;
+            KAEvent newev(event);
+            newev.defer(dateTime, (data->alarmType & KAAlarm::REMINDER_ALARM), true);
+            newev.setDeferDefaultMinutes(delayMins);
+            KAlarm::updateEvent(newev, data->dlg, true);
+            if (data->displayOpen)
+            {
+                if (newev.deferred())
+                    mNoPostAction() = true;
+            }
+        }
+        else
+        {
+            // Try to retrieve the event from the displaying or archive calendars
+            Resource resource;   // receives the event's original resource, if known
+            KAEvent event2;
+            bool showEdit, showDefer;
+            if (!retrieveEvent(data->eventId, event2, resource, showEdit, showDefer))
+            {
+                // The event doesn't exist any more !?!, so recurrence data,
+                // flags, and more, have been lost.
+                KAMessageBox::error(displayParent(), xi18nc("@info", "<para>Cannot defer alarm:</para><para>Alarm not found.</para>"));
+                if (data->displayOpen)
+                {
+                    raiseDisplay();
+                    enableDeferButton(false);
+                    enableEditButton(false);
+                }
+                delete data;
+                return;
+            }
+            qCDebug(KALARM_LOG) << "MessageDisplay::executeDeferDlg: Deferring retrieved event" << data->eventId;
+            event2.defer(dateTime, (data->alarmType & KAAlarm::REMINDER_ALARM), true);
+            event2.setDeferDefaultMinutes(delayMins);
+            event2.setCommandError(data->commandError);
+            // Add the event back into the calendar file, retaining its ID
+            // and not updating KOrganizer.
+            KAlarm::addEvent(event2, resource, data->dlg, KAlarm::USE_EVENT_ID);
+            if (data->displayOpen)
+            {
+                if (event2.deferred())
+                    mNoPostAction() = true;
+            }
+            // Finally delete it from the archived calendar now that it has
+            // been reactivated.
+            event2.setCategory(CalEvent::ARCHIVED);
+            Resource res;
+            KAlarm::deleteEvent(event2, res, false);
+        }
+        if (theApp()->wantShowInSystemTray())
+        {
+            // Alarms are to be displayed only if the system tray icon is running,
+            // so start it if necessary so that the deferred alarm will be shown.
+            theApp()->displayTrayIcon(true);
+        }
+        if (data->displayOpen)
+        {
+            mHelper->mNoCloseConfirm = true;   // allow window to close without confirmation prompt
+            closeDisplay();
+        }
+    }
+    else
+    {
+        if (data->displayOpen)
+            raiseDisplay();
+    }
+    delete data;
+}