xcb: implement and deprecate QWidget::setWindowIconText()

This is a little-used feature which only affects how minimized icons
are displayed on certain older window managers, and is not necessary
even then.  It has not been implemented in Qt 5 until now.

Task-number: QTBUG-44659
Change-Id: Ie6ead7a6f922878b349a096d905bf7f675dc2f31
Reviewed-by: Jørgen Lind <jorgen.lind@theqtcompany.com>

src/corelib/kernel/qcoreevent.cpp

@@ -150,7 +150,7 @@ QT_BEGIN_NAMESPACE
     \value HoverLeave                       The mouse cursor leaves a hover widget (QHoverEvent).
     \value HoverMove                        The mouse cursor moves inside a hover widget (QHoverEvent).
     \value IconDrag                         The main icon of a window has been dragged away (QIconDragEvent).
-    \value IconTextChange                   Widget's icon text has been changed.
+    \value IconTextChange                   Widget's icon text has been changed. (Deprecated)
     \value InputMethod                      An input method is being used (QInputMethodEvent).
     \value InputMethodQuery                 A input method query event (QInputMethodQueryEvent)
     \value KeyboardLayoutChange             The keyboard layout has changed.

src/corelib/kernel/qcoreevent.h

@@ -133,7 +133,7 @@ public:
         EnabledChange = 98,                     // enabled state has changed
         ActivationChange = 99,                  // window activation has changed
         StyleChange = 100,                      // style has changed
-        IconTextChange = 101,                   // icon text has changed
+        IconTextChange = 101,                   // icon text has changed.  Deprecated.
         ModifiedChange = 102,                   // modified state has changed
         MouseTrackingChange = 109,              // mouse tracking state has changed
 

src/platformheaders/xcbfunctions/qxcbwindowfunctions.h

@@ -69,6 +69,13 @@ public:
         return QXcbFunctionsHelper::callPlatformFunction<void, SetWmWindowType, QWindow *, WmWindowType>(setWmWindowTypeIdentifier(), window, type);
     }
 
+    typedef void (*SetWmWindowIconText)(QWindow *window, const QString &text);
+    static const QByteArray setWmWindowIconTextIdentifier() { return QByteArrayLiteral("XcbSetWmWindowIconText"); }
+    static void setWmWindowIconText(QWindow *window, const QString &text)
+    {
+        return QXcbFunctionsHelper::callPlatformFunction<void, SetWmWindowIconText, QWindow *, const QString &>(setWmWindowIconTextIdentifier(), window, text);
+    }
+
     typedef void (*SetParentRelativeBackPixmap)(const QWindow *window);
     static const QByteArray setParentRelativeBackPixmapIdentifier() { return QByteArrayLiteral("XcbSetParentRelativeBackPixmap"); }
     static void setParentRelativeBackPixmap(const QWindow *window)

src/plugins/platforms/xcb/qxcbnativeinterface.cpp

@@ -331,6 +331,9 @@ QFunctionPointer QXcbNativeInterface::platformFunction(const QByteArray &functio
     if (function == QXcbWindowFunctions::setWmWindowTypeIdentifier())
         return QFunctionPointer(QXcbWindowFunctions::SetWmWindowType(QXcbWindow::setWmWindowTypeStatic));
 
+    if (function == QXcbWindowFunctions::setWmWindowIconTextIdentifier())
+        return QFunctionPointer(QXcbWindowFunctions::SetWmWindowIconText(QXcbWindow::setWindowIconTextStatic));
+
     if (function == QXcbWindowFunctions::setParentRelativeBackPixmapIdentifier())
         return QFunctionPointer(QXcbWindowFunctions::SetParentRelativeBackPixmap(QXcbWindow::setParentRelativeBackPixmapStatic));
 

src/plugins/platforms/xcb/qxcbwindow.cpp

@@ -1393,10 +1393,22 @@ void QXcbWindow::setWindowTitle(const QString &title)
     xcb_flush(xcb_connection());
 }
 
+void QXcbWindow::setWindowIconText(const QString &title)
+{
+    const QByteArray ba = title.toUtf8();
+    Q_XCB_CALL(xcb_change_property(xcb_connection(),
+                                   XCB_PROP_MODE_REPLACE,
+                                   m_window,
+                                   atom(QXcbAtom::_NET_WM_ICON_NAME),
+                                   atom(QXcbAtom::UTF8_STRING),
+                                   8,
+                                   ba.length(),
+                                   ba.constData()));
+}
+
 void QXcbWindow::setWindowIcon(const QIcon &icon)
 {
     QVector<quint32> icon_data;
-
     if (!icon.isNull()) {
         QList<QSize> availableSizes = icon.availableSizes();
         if (availableSizes.isEmpty()) {
@@ -1561,6 +1573,12 @@ void QXcbWindow::setWmWindowTypeStatic(QWindow *window, QXcbWindowFunctions::WmW
         window->setProperty(wm_window_type_property_id, QVariant::fromValue(static_cast<int>(windowTypes)));
 }
 
+void QXcbWindow::setWindowIconTextStatic(QWindow *window, const QString &text)
+{
+    if (window->handle())
+        static_cast<QXcbWindow *>(window->handle())->setWindowIconText(text);
+}
+
 QXcbWindowFunctions::WmWindowTypes QXcbWindow::wmWindowTypes() const
 {
     QXcbWindowFunctions::WmWindowTypes result(0);

src/plugins/platforms/xcb/qxcbwindow.h

@@ -86,6 +86,7 @@ public:
     QPoint mapFromGlobal(const QPoint &pos) const Q_DECL_OVERRIDE;
 
     void setWindowTitle(const QString &title) Q_DECL_OVERRIDE;
+    void setWindowIconText(const QString &title);
     void setWindowIcon(const QIcon &icon) Q_DECL_OVERRIDE;
     void raise() Q_DECL_OVERRIDE;
     void lower() Q_DECL_OVERRIDE;
@@ -142,6 +143,8 @@ public:
     QXcbWindowFunctions::WmWindowTypes wmWindowTypes() const;
     void setWmWindowType(QXcbWindowFunctions::WmWindowTypes types);
 
+    static void setWindowIconTextStatic(QWindow *window, const QString &text);
+
     static void setParentRelativeBackPixmapStatic(QWindow *window);
     void setParentRelativeBackPixmap();
 

src/widgets/kernel/qwidget.cpp

@@ -100,6 +100,7 @@
 
 #include "qwindowcontainer_p.h"
 
+#include <QtPlatformHeaders/qxcbwindowfunctions.h>
 
 // widget/widget data creation count
 //#define QWIDGET_EXTRA_DEBUG
@@ -704,7 +705,7 @@ void QWidget::setAutoFillBackground(bool enabled)
         close().
 
     \row \li Top-level windows \li
-        \l windowModified, \l windowTitle, \l windowIcon, \l windowIconText,
+        \l windowModified, \l windowTitle, \l windowIcon,
         \l isActiveWindow, activateWindow(), \l minimized, showMinimized(),
         \l maximized, showMaximized(), \l fullScreen, showFullScreen(),
         showNormal().
@@ -5934,7 +5935,7 @@ void QWidget::unsetLocale()
     window title, if set. This is done by the QPA plugin, so it is shown to the
     user, but isn't part of the windowTitle string.
 
-    \sa windowIcon, windowIconText, windowModified, windowFilePath
+    \sa windowIcon, windowModified, windowFilePath
 */
 QString QWidget::windowTitle() const
 {
@@ -6029,7 +6030,11 @@ void QWidgetPrivate::setWindowIconText_helper(const QString &title)
 
 void QWidgetPrivate::setWindowIconText_sys(const QString &iconText)
 {
-    Q_UNUSED(iconText);
+    Q_Q(QWidget);
+    // ### The QWidget property is deprecated, but the XCB window function is not.
+    // It should remain available for the rare application that needs it.
+    if (QWindow *window = q->windowHandle())
+        QXcbWindowFunctions::setWmWindowIconText(window, iconText);
 }
 
 /*!
@@ -6039,6 +6044,9 @@ void QWidgetPrivate::setWindowIconText_sys(const QString &iconText)
     new \a iconText as an argument.
 
     \since 5.2
+    \obsolete
+
+    This signal is deprecated.
 */
 
 void QWidget::setWindowIconText(const QString &iconText)
@@ -6089,7 +6097,7 @@ void QWidget::setWindowTitle(const QString &title)
     has been set, windowIcon() returns the application icon
     (QApplication::windowIcon()).
 
-    \sa windowIconText, windowTitle
+    \sa windowTitle
 */
 QIcon QWidget::windowIcon() const
 {
@@ -6149,10 +6157,15 @@ void QWidgetPrivate::setWindowIcon_sys()
 
 /*!
     \property QWidget::windowIconText
-    \brief the widget's icon text
+    \brief the text to be displayed on the icon of a minimized window
 
     This property only makes sense for windows. If no icon
-    text has been set, this functions returns an empty string.
+    text has been set, this accessor returns an empty string.
+    It is only implemented on the X11 platform, and only certain
+    window managers use this window property.
+
+    \obsolete
+    This property is deprecated.
 
     \sa windowIcon, windowTitle
 */

src/widgets/kernel/qwidget.h

@@ -165,7 +165,7 @@ class Q_WIDGETS_EXPORT QWidget : public QObject, public QPaintDevice
     Q_PROPERTY(bool acceptDrops READ acceptDrops WRITE setAcceptDrops)
     Q_PROPERTY(QString windowTitle READ windowTitle WRITE setWindowTitle NOTIFY windowTitleChanged DESIGNABLE isWindow)
     Q_PROPERTY(QIcon windowIcon READ windowIcon WRITE setWindowIcon NOTIFY windowIconChanged DESIGNABLE isWindow)
-    Q_PROPERTY(QString windowIconText READ windowIconText WRITE setWindowIconText NOTIFY windowIconTextChanged DESIGNABLE isWindow)
+    Q_PROPERTY(QString windowIconText READ windowIconText WRITE setWindowIconText NOTIFY windowIconTextChanged DESIGNABLE isWindow) // deprecated
     Q_PROPERTY(double windowOpacity READ windowOpacity WRITE setWindowOpacity DESIGNABLE isWindow)
     Q_PROPERTY(bool windowModified READ isWindowModified WRITE setWindowModified DESIGNABLE isWindow)
 #ifndef QT_NO_TOOLTIP

tests/manual/qscreen/propertywatcher.cpp

@@ -50,6 +50,8 @@ PropertyWatcher::PropertyWatcher(QObject *subject, QString annotation, QWidget *
         if (prop.isReadable()) {
             PropertyField* field = new PropertyField(m_subject, prop);
             m_layout->addRow(prop.name(), field);
+            if (!qstrcmp(prop.name(), "name"))
+                setWindowIconText(prop.read(subject).toString());
         }
     }
     QPushButton *updateButton = new QPushButton("update");