helpers/killer: Modernize UI

This overhauls the kill prompt UI to make it more modern and more
easily to grasp.

* Reduce the amount of text and redundancy.
  Give the window a title and drop the "app is not responding" heading.
  Try to remove the application name from the displayed window title.
  Also use the bold emphasis used in other places like deleting files.

* Use the application icon if available with a warning overlay.
  This makes it easier to grasp which application it's talking about.

* Move technical information (like PID and hostname) into an
  expandable "Details" section.

KGuiAddons has been implicitly pulled in by KConfigWidgets already.

CMakeLists.txt

@@ -83,6 +83,7 @@ find_package(KF6 ${KF6_MIN_VERSION} REQUIRED COMPONENTS
     Crash
     DBusAddons
     GlobalAccel
+    GuiAddons
     I18n
     IdleTime
     Package

src/helpers/killer/CMakeLists.txt

@@ -8,7 +8,9 @@ qt6_generate_wayland_protocol_client_sources(kwin_killer_helper FILES ${WaylandP
 
 target_link_libraries(kwin_killer_helper
     KF6::AuthCore
+    KF6::GuiAddons
     KF6::I18n
+    KF6::Service
     KF6::WidgetsAddons
     Qt::GuiPrivate
     Qt::WaylandClient

src/helpers/killer/killer.cpp

@@ -7,9 +7,11 @@
 */
 
 #include <KAuth/Action>
+#include <KIconUtils>
 #include <KLocalizedString>
 #include <KMessageBox>
 #include <KMessageDialog>
+#include <KService>
 
 #include <QApplication>
 #include <QCommandLineParser>
@@ -65,7 +67,7 @@ int main(int argc, char *argv[])
 {
     KLocalizedString::setApplicationDomain(QByteArrayLiteral("kwin"));
     QApplication app(argc, argv);
-    QApplication::setWindowIcon(QIcon::fromTheme(QStringLiteral("dialog-warning")));
+    QApplication::setWindowIcon(QIcon::fromTheme(QStringLiteral("tools-report-bug")));
     QCoreApplication::setApplicationName(QStringLiteral("kwin_killer_helper"));
     QCoreApplication::setOrganizationDomain(QStringLiteral("kde.org"));
     QApplication::setApplicationDisplayName(i18n("Window Manager"));
@@ -126,23 +128,32 @@ int main(int argc, char *argv[])
     }
     bool isLocal = hostname == QStringLiteral("localhost");
 
+    const auto service = KService::serviceByDesktopName(appname);
+    if (service) {
+        appname = service->name();
+        QApplication::setApplicationDisplayName(appname);
+    }
+
+    // Drop redundant application name, cf. QXcbWindow::setWindowTitle.
+    const QString titleSeparator = QString::fromUtf8(" \xe2\x80\x94 "); // // U+2014, EM DASH
+    caption.remove(titleSeparator + appname);
+    caption.remove(QStringLiteral(" – ") + appname); // EN dash (Firefox)
+    caption.remove(QStringLiteral(" - ") + appname); // classic minus :-)
+
     caption = caption.toHtmlEscaped();
     appname = appname.toHtmlEscaped();
     hostname = hostname.toHtmlEscaped();
     QString pidString = QString::number(pid); // format pid ourself as it does not make sense to format an ID according to locale settings
 
-    QString question = i18nc("@info", "<b>Application \"%1\" is not responding</b>", appname);
+    QString question = (caption == appname) ? xi18nc("@info", "<para><application>%1</application> is not responding. Do you want to terminate this application?</para>",
-    question += isLocal
+                                                     appname)
-        ? xi18nc("@info", "<para>You tried to close window \"%1\" from application \"%2\" (Process ID: %3) but the application is not responding.</para>",
+                                            : xi18nc("@info \"window title\" of application name is not responding.", "<para>\"%1\" of <application>%2</application> is not responding. Do you want to terminate this application?</para>",
-                 caption, appname, pidString)
+                                                     caption, appname);
-        : xi18nc("@info", "<para>You tried to close window \"%1\" from application \"%2\" (Process ID: %3), running on host \"%4\", but the application is not responding.</para>",
-                 caption, appname, pidString, hostname);
     question += xi18nc("@info",
-                       "<para>Do you want to terminate this application?</para>"
+                       "<para><emphasis strong='true'>Terminating this application will close all of its windows. Any unsaved data will be lost.</emphasis></para>");
-                       "<para><warning>Terminating the application will close all of its child windows. Any unsaved data will be lost.</warning></para>");
 
-    KGuiItem continueButton = KGuiItem(i18n("&Terminate Application %1", appname), QStringLiteral("edit-bomb"));
+    KGuiItem continueButton = KGuiItem(i18nc("@action:button Terminate app", "&Terminate %1", appname), QStringLiteral("application-exit"));
-    KGuiItem cancelButton = KGuiItem(i18n("Wait Longer"), QStringLiteral("chronometer"));
+    KGuiItem cancelButton = KGuiItem(i18nc("@action:button Wait for frozen app to maybe respond again", "&Wait Longer"), QStringLiteral("chronometer"));
 
     if (isX11) {
         QX11Info::setAppUserTime(timestamp);
@@ -150,9 +161,27 @@ int main(int argc, char *argv[])
 
     auto *dialog = new KMessageDialog(KMessageDialog::WarningContinueCancel, question);
     dialog->setAttribute(Qt::WA_DeleteOnClose);
-    dialog->setCaption(QString()); // use default caption.
+    dialog->setCaption(i18nc("@title:window", "Not Responding"));
-    dialog->setIcon(QIcon()); // use default warning icon.
+
+    QIcon icon;
+    if (service) {
+        const QIcon appIcon = QIcon::fromTheme(service->icon());
+        if (!appIcon.isNull()) {
+            // emblem-warning is non-standard, fall back to emblem-important if necessary.
+            const QIcon warningBadge = QIcon::fromTheme(QStringLiteral("emblem-warning"), QIcon::fromTheme(QStringLiteral("emblem-important")));
+
+            icon = KIconUtils::addOverlay(appIcon, warningBadge, qApp->isRightToLeft() ? Qt::BottomLeftCorner : Qt::BottomRightCorner);
+        }
+    }
+    dialog->setIcon(icon); // null icon will result in default warning icon.
     dialog->setButtons(continueButton, KGuiItem(), cancelButton);
+
+    QStringList details{
+        i18nc("@info", "Process ID: %1", pidString)};
+    if (!isLocal) {
+        details << i18nc("@info", "Host name: %1", hostname);
+    }
+    dialog->setDetails(details.join(QLatin1Char('\n')));
     dialog->winId();
 
     std::unique_ptr<XdgImporter> xdgImporter;