QIcon: add theme icon constants

Add a list of constant string literals for a subset of icons from the
freedesktop specification. Those are icons we document to support today,
and that users might have written themes for.

Omit icons that are mime types (we have Q(Abstract)FileIconProvider
and QPlatformTheme::fileIcon for that), the "flag-aa" icon (where 'aa'
is an ISO 3166 country code, and Face* icons. Flags and Face icons can
be added as supported QIcon constants, but should then be rendered as
emojis from the respective font (they are not provided by any of the
native icon libraries or icon fonts).

We use string constants instead of an enum so that we have the same code
path for icon constants, user-defined icons, and native icons. I.e. in
addition to QIcon::fromTheme(QIcon::ThemeIcon::EditCopy), code can
request the icon for "trash.circle.fill" on Apple platforms, or
or for U"\ue5cd" on platforms where the engine is font-based; or an app
can define their own icon name and provide the assets through a theme-
description, as before.

The downside is that we cannot use arrays for looking up the native icon
for an enum-value in the engine implementations, but given that icons
are cached this is an acceptable trade-off.

To make the list of icon contants more manageable, have them in a
separate header file. Since we want those constants to live in the QIcon
"namespace", we then include that header in a declaration of a nested
struct, "ThemeIcon", resulting in e.g. QIcon::ThemeIcon::EditCopy.

Change-Id: Ic20e36ab321e6c4b20806ec0b400bba13fffc983
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

4 files changed, 279 insertions, 1 deletions

diff --git a/src/gui/CMakeLists.txt b/src/gui/CMakeLists.txt
index 0b2bc18f94..b86dbd2ae2 100644
--- a/src/gui/CMakeLists.txt
+++ b/src/gui/CMakeLists.txt
@@ -61,7 +61,7 @@ qt_internal_add_module(Gui
         image/qabstractfileiconprovider.cpp image/qabstractfileiconprovider.h image/qabstractfileiconprovider_p.h
         image/qbitmap.cpp image/qbitmap.h
         image/qbmphandler.cpp image/qbmphandler_p.h
-        image/qicon.cpp image/qicon.h image/qicon_p.h
+        image/qicon.cpp image/qicon.h image/qicon_p.h image/qiconconstants_impl.h
         image/qiconengine.cpp image/qiconengine.h image/qiconengine_p.h
         image/qiconengineplugin.cpp image/qiconengineplugin.h
         image/qiconloader.cpp image/qiconloader_p.h
diff --git a/src/gui/image/qicon.h b/src/gui/image/qicon.h
index 22f63b1ecb..ee421bf732 100644
--- a/src/gui/image/qicon.h
+++ b/src/gui/image/qicon.h
@@ -22,6 +22,10 @@ public:
     enum Mode { Normal, Disabled, Active, Selected };
     enum State { On, Off };
 
+    struct ThemeIcon {
+#include <QtGui/qiconconstants_impl.h>
+    };
+
     QIcon() noexcept;
     QIcon(const QPixmap &pixmap);
     QIcon(const QIcon &other);
diff --git a/src/gui/image/qiconconstants_impl.h b/src/gui/image/qiconconstants_impl.h
new file mode 100644
index 0000000000..e2e3437263
--- /dev/null
+++ b/src/gui/image/qiconconstants_impl.h
@@ -0,0 +1,268 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#ifndef QICONCONSTANTS_IMPL_H
+#define QICONCONSTANTS_IMPL_H
+
+#ifndef QICON_H
+#error Do not include qiconconstants_impl.h directly
+#endif
+
+#if 0
+#pragma qt_sync_skip_header_check
+#pragma qt_sync_stop_processing
+#endif
+
+#define QT_THEME_ICON(Constant, string) \
+static constexpr auto Constant = QLatin1StringView(string)
+
+QT_THEME_ICON(AddressBookNew, "address-book-new");
+QT_THEME_ICON(ApplicationExit, "application-exit");
+QT_THEME_ICON(AppointmentNew, "appointment-new");
+QT_THEME_ICON(CallStart, "call-start");
+QT_THEME_ICON(CallStop, "call-stop");
+QT_THEME_ICON(ContactNew, "contact-new");
+QT_THEME_ICON(DocumentNew, "document-new");
+QT_THEME_ICON(DocumentOpen, "document-open");
+QT_THEME_ICON(DocumentOpenRecent, "document-open-recent");
+QT_THEME_ICON(DocumentPageSetup, "document-page-setup");
+QT_THEME_ICON(DocumentPrint, "document-print");
+QT_THEME_ICON(DocumentPrintPreview, "document-print-preview");
+QT_THEME_ICON(DocumentProperties, "document-properties");
+QT_THEME_ICON(DocumentRevert, "document-revert");
+QT_THEME_ICON(DocumentSave, "document-save");
+QT_THEME_ICON(DocumentSaveAs, "document-save-as");
+QT_THEME_ICON(DocumentSend, "document-send");
+QT_THEME_ICON(EditClear, "edit-clear");
+QT_THEME_ICON(EditCopy, "edit-copy");
+QT_THEME_ICON(EditCut, "edit-cut");
+QT_THEME_ICON(EditDelete, "edit-delete");
+QT_THEME_ICON(EditFind, "edit-find");
+QT_THEME_ICON(EditFindReplace, "edit-find-replace");
+QT_THEME_ICON(EditPaste, "edit-paste");
+QT_THEME_ICON(EditRedo, "edit-redo");
+QT_THEME_ICON(EditSelectAll, "edit-select-all");
+QT_THEME_ICON(EditUndo, "edit-undo");
+QT_THEME_ICON(FolderNew, "folder-new");
+QT_THEME_ICON(FormatIndentLess, "format-indent-less");
+QT_THEME_ICON(FormatIndentMore, "format-indent-more");
+QT_THEME_ICON(FormatJustifyCenter, "format-justify-center");
+QT_THEME_ICON(FormatJustifyFill, "format-justify-fill");
+QT_THEME_ICON(FormatJustifyLeft, "format-justify-left");
+QT_THEME_ICON(FormatJustifyRight, "format-justify-right");
+QT_THEME_ICON(FormatTextDirectionLtr, "format-text-direction-ltr");
+QT_THEME_ICON(FormatTextDirectionRtl, "format-text-direction-rtl");
+QT_THEME_ICON(FormatTextBold, "format-text-bold");
+QT_THEME_ICON(FormatTextItalic, "format-text-italic");
+QT_THEME_ICON(FormatTextUnderline, "format-text-underline");
+QT_THEME_ICON(FormatTextStrikethrough, "format-text-strikethrough");
+QT_THEME_ICON(GoBottom, "go-bottom");
+QT_THEME_ICON(GoDown, "go-down");
+QT_THEME_ICON(GoFirst, "go-first");
+QT_THEME_ICON(GoHome, "go-home");
+QT_THEME_ICON(GoJump, "go-jump");
+QT_THEME_ICON(GoLast, "go-last");
+QT_THEME_ICON(GoNext, "go-next");
+QT_THEME_ICON(GoPrevious, "go-previous");
+QT_THEME_ICON(GoTop, "go-top");
+QT_THEME_ICON(GoUp, "go-up");
+QT_THEME_ICON(HelpAbout, "help-about");
+QT_THEME_ICON(HelpContents, "help-contents");
+QT_THEME_ICON(HelpFaq, "help-faq");
+QT_THEME_ICON(InsertImage, "insert-image");
+QT_THEME_ICON(InsertLink, "insert-link");
+QT_THEME_ICON(InsertObject, "insert-object");
+QT_THEME_ICON(InsertText, "insert-text");
+QT_THEME_ICON(ListAdd, "list-add");
+QT_THEME_ICON(ListRemove, "list-remove");
+QT_THEME_ICON(MailForward, "mail-forward");
+QT_THEME_ICON(MailMarkImportant, "mail-mark-important");
+QT_THEME_ICON(MailMarkJunk, "mail-mark-junk");
+QT_THEME_ICON(MailMarkNotjunk, "mail-mark-notjunk");
+QT_THEME_ICON(MailMarkRead, "mail-mark-read");
+QT_THEME_ICON(MailMarkUnread, "mail-mark-unread");
+QT_THEME_ICON(MailMessageNew, "mail-message-new");
+QT_THEME_ICON(MailReplyAll, "mail-reply-all");
+QT_THEME_ICON(MailReplySender, "mail-reply-sender");
+QT_THEME_ICON(MailSend, "mail-send");
+QT_THEME_ICON(MailSendReceive, "mail-send-receive");
+QT_THEME_ICON(MediaEject, "media-eject");
+QT_THEME_ICON(MediaPlaybackPause, "media-playback-pause");
+QT_THEME_ICON(MediaPlaybackStart, "media-playback-start");
+QT_THEME_ICON(MediaPlaybackStop, "media-playback-stop");
+QT_THEME_ICON(MediaRecord, "media-record");
+QT_THEME_ICON(MediaSeekBackward, "media-seek-backward");
+QT_THEME_ICON(MediaSeekForward, "media-seek-forward");
+QT_THEME_ICON(MediaSkipBackward, "media-skip-backward");
+QT_THEME_ICON(MediaSkipForward, "media-skip-forward");
+QT_THEME_ICON(ObjectFlipHorizontal, "object-flip-horizontal");
+QT_THEME_ICON(ObjectFlipVertical, "object-flip-vertical");
+QT_THEME_ICON(ObjectRotateLeft, "object-rotate-left");
+QT_THEME_ICON(ObjectRotateRight, "object-rotate-right");
+QT_THEME_ICON(ProcessStop, "process-stop");
+QT_THEME_ICON(SystemLockScreen, "system-lock-screen");
+QT_THEME_ICON(SystemLogOut, "system-log-out");
+QT_THEME_ICON(SystemRun, "system-run");
+QT_THEME_ICON(SystemSearch, "system-search");
+QT_THEME_ICON(SystemReboot, "system-reboot");
+QT_THEME_ICON(SystemShutdown, "system-shutdown");
+QT_THEME_ICON(ToolsCheckSpelling, "tools-check-spelling");
+QT_THEME_ICON(ViewFullscreen, "view-fullscreen");
+QT_THEME_ICON(ViewRefresh, "view-refresh");
+QT_THEME_ICON(ViewRestore, "view-restore");
+QT_THEME_ICON(ViewSortAscending, "view-sort-ascending");
+QT_THEME_ICON(ViewSortDescending, "view-sort-descending");
+QT_THEME_ICON(WindowClose, "window-close");
+QT_THEME_ICON(WindowNew, "window-new");
+QT_THEME_ICON(ZoomFitBest, "zoom-fit-best");
+QT_THEME_ICON(ZoomIn, "zoom-in");
+QT_THEME_ICON(ZoomOriginal, "zoom-original");
+QT_THEME_ICON(ZoomOut, "zoom-out");
+
+QT_THEME_ICON(ProcessWorking, "process-working");
+
+QT_THEME_ICON(AccessoriesCalculator, "accessories-calculator");
+QT_THEME_ICON(AccessoriesCharacterMap, "accessories-character-map");
+QT_THEME_ICON(AccessoriesDictionary, "accessories-dictionary");
+QT_THEME_ICON(AccessoriesTextEditor, "accessories-text-editor");
+QT_THEME_ICON(HelpBrowser, "help-browser");
+QT_THEME_ICON(MultimediaVolumeControl, "multimedia-volume-control");
+QT_THEME_ICON(PreferencesDesktopAccessibility, "preferences-desktop-accessibility");
+QT_THEME_ICON(PreferencesDesktopFont, "preferences-desktop-font");
+QT_THEME_ICON(PreferencesDesktopKeyboard, "preferences-desktop-keyboard");
+QT_THEME_ICON(PreferencesDesktopLocale, "preferences-desktop-locale");
+QT_THEME_ICON(PreferencesDesktopMultimedia, "preferences-desktop-multimedia");
+QT_THEME_ICON(PreferencesDesktopScreensaver, "preferences-desktop-screensaver");
+QT_THEME_ICON(PreferencesDesktopTheme, "preferences-desktop-theme");
+QT_THEME_ICON(PreferencesDesktopWallpaper, "preferences-desktop-wallpaper");
+QT_THEME_ICON(SystemFileManager, "system-file-manager");
+QT_THEME_ICON(SystemSoftwareInstall, "system-software-install");
+QT_THEME_ICON(SystemSoftwareUpdate, "system-software-update");
+QT_THEME_ICON(UtilitiesSystemMonitor, "utilities-system-monitor");
+QT_THEME_ICON(UtilitiesTerminal, "utilities-terminal");
+
+QT_THEME_ICON(ApplicationsAccessories, "applications-accessories");
+QT_THEME_ICON(ApplicationsDevelopment, "applications-development");
+QT_THEME_ICON(ApplicationsEngineering, "applications-engineering");
+QT_THEME_ICON(ApplicationsGames, "applications-games");
+QT_THEME_ICON(ApplicationsGraphics, "applications-graphics");
+QT_THEME_ICON(ApplicationsInternet, "applications-internet");
+QT_THEME_ICON(ApplicationsMultimedia, "applications-multimedia");
+QT_THEME_ICON(ApplicationsOffice, "applications-office");
+QT_THEME_ICON(ApplicationsOther, "applications-other");
+QT_THEME_ICON(ApplicationsScience, "applications-science");
+QT_THEME_ICON(ApplicationsSystem, "applications-system");
+QT_THEME_ICON(ApplicationsUtilities, "applications-utilities");
+QT_THEME_ICON(PreferencesDesktop, "preferences-desktop");
+QT_THEME_ICON(PreferencesDesktopPeripherals, "preferences-desktop-peripherals");
+QT_THEME_ICON(PreferencesDesktopPersonal, "preferences-desktop-personal");
+QT_THEME_ICON(PreferencesOther, "preferences-other");
+QT_THEME_ICON(PreferencesSystem, "preferences-system");
+QT_THEME_ICON(PreferencesSystemNetwork, "preferences-system-network");
+QT_THEME_ICON(SystemHelp, "system-help");
+
+QT_THEME_ICON(AudioCard, "audio-card");
+QT_THEME_ICON(AudioInputMicrophone, "audio-input-microphone");
+QT_THEME_ICON(Battery, "battery");
+QT_THEME_ICON(CameraPhoto, "camera-photo");
+QT_THEME_ICON(CameraVideo, "camera-video");
+QT_THEME_ICON(CameraWeb, "camera-web");
+QT_THEME_ICON(Computer, "computer");
+QT_THEME_ICON(DriveHarddisk, "drive-harddisk");
+QT_THEME_ICON(DriveOptical, "drive-optical");
+QT_THEME_ICON(DriveRemovableMedia, "drive-removable-media");
+QT_THEME_ICON(InputGaming, "input-gaming");
+QT_THEME_ICON(InputKeyboard, "input-keyboard");
+QT_THEME_ICON(InputMouse, "input-mouse");
+QT_THEME_ICON(InputTablet, "input-tablet");
+QT_THEME_ICON(MediaFlash, "media-flash");
+QT_THEME_ICON(MediaFloppy, "media-floppy");
+QT_THEME_ICON(MediaOptical, "media-optical");
+QT_THEME_ICON(MediaTape, "media-tape");
+QT_THEME_ICON(Modem, "modem");
+QT_THEME_ICON(MultimediaPlayer, "multimedia-player");
+QT_THEME_ICON(NetworkWired, "network-wired");
+QT_THEME_ICON(NetworkWireless, "network-wireless");
+QT_THEME_ICON(Pda, "pda");
+QT_THEME_ICON(Phone, "phone");
+QT_THEME_ICON(Printer, "printer");
+QT_THEME_ICON(Scanner, "scanner");
+QT_THEME_ICON(VideoDisplay, "video-display");
+
+QT_THEME_ICON(EmblemDefault, "emblem-default");
+QT_THEME_ICON(EmblemDocuments, "emblem-documents");
+QT_THEME_ICON(EmblemDownloads, "emblem-downloads");
+QT_THEME_ICON(EmblemFavorite, "emblem-favorite");
+QT_THEME_ICON(EmblemImportant, "emblem-important");
+QT_THEME_ICON(EmblemMail, "emblem-mail");
+QT_THEME_ICON(EmblemPhotos, "emblem-photos");
+QT_THEME_ICON(EmblemReadonly, "emblem-readonly");
+QT_THEME_ICON(EmblemShared, "emblem-shared");
+QT_THEME_ICON(EmblemSymbolicLink, "emblem-symbolic-link");
+QT_THEME_ICON(EmblemSynchronized, "emblem-synchronized");
+QT_THEME_ICON(EmblemSystem, "emblem-system");
+QT_THEME_ICON(EmblemUnreadable, "emblem-unreadable");
+
+QT_THEME_ICON(AppointmentMissed, "appointment-missed");
+QT_THEME_ICON(AppointmentSoon, "appointment-soon");
+QT_THEME_ICON(AudioVolumeHigh, "audio-volume-high");
+QT_THEME_ICON(AudioVolumeLow, "audio-volume-low");
+QT_THEME_ICON(AudioVolumeMedium, "audio-volume-medium");
+QT_THEME_ICON(AudioVolumeMuted, "audio-volume-muted");
+QT_THEME_ICON(BatteryCaution, "battery-caution");
+QT_THEME_ICON(BatteryLow, "battery-low");
+QT_THEME_ICON(DialogError, "dialog-error");
+QT_THEME_ICON(DialogInformation, "dialog-information");
+QT_THEME_ICON(DialogPassword, "dialog-password");
+QT_THEME_ICON(DialogQuestion, "dialog-question");
+QT_THEME_ICON(DialogWarning, "dialog-warning");
+QT_THEME_ICON(FolderDragAccept, "folder-drag-accept");
+QT_THEME_ICON(FolderOpen, "folder-open");
+QT_THEME_ICON(FolderVisiting, "folder-visiting");
+QT_THEME_ICON(ImageLoading, "image-loading");
+QT_THEME_ICON(ImageMissing, "image-missing");
+QT_THEME_ICON(MailAttachment, "mail-attachment");
+QT_THEME_ICON(MailUnread, "mail-unread");
+QT_THEME_ICON(MailRead, "mail-read");
+QT_THEME_ICON(MailReplied, "mail-replied");
+QT_THEME_ICON(MailSigned, "mail-signed");
+QT_THEME_ICON(MailSignedVerified, "mail-signed-verified");
+QT_THEME_ICON(MediaPlaylistRepeat, "media-playlist-repeat");
+QT_THEME_ICON(MediaPlaylistShuffle, "media-playlist-shuffle");
+QT_THEME_ICON(NetworkError, "network-error");
+QT_THEME_ICON(NetworkIdle, "network-idle");
+QT_THEME_ICON(NetworkOffline, "network-offline");
+QT_THEME_ICON(NetworkReceive, "network-receive");
+QT_THEME_ICON(NetworkTransmit, "network-transmit");
+QT_THEME_ICON(NetworkTransmitReceive, "network-transmit-receive");
+QT_THEME_ICON(PrinterError, "printer-error");
+QT_THEME_ICON(PrinterPrinting, "printer-printing");
+QT_THEME_ICON(SecurityHigh, "security-high");
+QT_THEME_ICON(SecurityMedium, "security-medium");
+QT_THEME_ICON(SecurityLow, "security-low");
+QT_THEME_ICON(SoftwareUpdateAvailable, "software-update-available");
+QT_THEME_ICON(SoftwareUpdateUrgent, "software-update-urgent");
+QT_THEME_ICON(SyncError, "sync-error");
+QT_THEME_ICON(SyncSynchronizing, "sync-synchronizing");
+QT_THEME_ICON(TaskDue, "task-due");
+QT_THEME_ICON(TaskPastDue, "task-past-due");
+QT_THEME_ICON(UserAvailable, "user-available");
+QT_THEME_ICON(UserAway, "user-away");
+QT_THEME_ICON(UserIdle, "user-idle");
+QT_THEME_ICON(UserOffline, "user-offline");
+QT_THEME_ICON(UserTrashFull, "user-trash-full");
+QT_THEME_ICON(WeatherClear, "weather-clear");
+QT_THEME_ICON(WeatherClearNight, "weather-clear-night");
+QT_THEME_ICON(WeatherFewClouds, "weather-few-clouds");
+QT_THEME_ICON(WeatherFewCloudsNight, "weather-few-clouds-night");
+QT_THEME_ICON(WeatherFog, "weather-fog");
+QT_THEME_ICON(WeatherOvercast, "weather-overcast");
+QT_THEME_ICON(WeatherSevereAlert, "weather-severe-alert");
+QT_THEME_ICON(WeatherShowers, "weather-showers");
+QT_THEME_ICON(WeatherShowersScattered, "weather-showers-scattered");
+QT_THEME_ICON(WeatherSnow, "weather-snow");
+QT_THEME_ICON(WeatherStorm, "weather-storm");
+
+#undef QT_THEME_ICON
+
+#endif // QICONCONSTANTS_IMPL_H
diff --git a/tests/auto/gui/image/qicon/tst_qicon.cpp b/tests/auto/gui/image/qicon/tst_qicon.cpp
index f479a33625..38a48c38c5 100644
--- a/tests/auto/gui/image/qicon/tst_qicon.cpp
+++ b/tests/auto/gui/image/qicon/tst_qicon.cpp
@@ -41,6 +41,7 @@ private slots:
     void streamAvailableSizes();
     void fromTheme();
     void fromThemeCache();
+    void fromThemeConstant();
 
 #ifndef QT_NO_WIDGETS
     void task184901_badCache();
@@ -848,6 +849,11 @@ void tst_QIcon::fromThemeCache()
     QVERIFY(QIcon::fromTheme("notexist-fallback").isNull());
 }
 
+void tst_QIcon::fromThemeConstant()
+{
+    const QIcon icon = QIcon::fromTheme(QIcon::ThemeIcon::EditCut);
+}
+
 void tst_QIcon::task223279_inconsistentAddFile()
 {
     QIcon icon1;