Introducing icon theme support

Added some static functions to QIcon to support desktop
themes based on the freedesktop spec. It is not intended to
replace KIcon and the intention is to use it when available to
share icon cache between applications.

Applications currently using icon themes are Assistant, Designer
and the textedit demo.

Reviewed-by: ogoffart

1 files changed, 160 insertions, 66 deletions

diff --git a/src/gui/image/qicon.cpp b/src/gui/image/qicon.cpp
index fa407c7..7a43514 100644
--- a/src/gui/image/qicon.cpp
+++ b/src/gui/image/qicon.cpp
@@ -40,9 +40,11 @@
 ****************************************************************************/
 
 #include "qicon.h"
+#include "qicon_p.h"
 #include "qiconengine.h"
 #include "qiconengineplugin.h"
 #include "private/qfactoryloader_p.h"
+#include "private/qiconloader_p.h"
 #include "qapplication.h"
 #include "qstyleoption.h"
 #include "qpainter.h"
@@ -50,6 +52,7 @@
 #include "qstyle.h"
 #include "qpixmapcache.h"
 #include "qvariant.h"
+#include "qcache.h"
 #include "qdebug.h"
 
 #ifdef Q_WS_MAC
@@ -57,6 +60,11 @@
 #include <private/qt_cocoa_helpers_mac_p.h>
 #endif
 
+#ifdef Q_WS_X11
+#include "private/qt_x11_p.h"
+#include "private/qkde_p.h"
+#endif
+
 QT_BEGIN_NAMESPACE
 
 /*!
@@ -94,73 +102,14 @@ QT_BEGIN_NAMESPACE
 
 static QBasicAtomicInt serialNumCounter = Q_BASIC_ATOMIC_INITIALIZER(1);
 
-class QIconPrivate
-{
-public:
-    QIconPrivate(): engine(0), ref(1), serialNum(serialNumCounter.fetchAndAddRelaxed(1)), detach_no(0), engine_version(2), v1RefCount(0) {}
-
-    ~QIconPrivate() {
-        if (engine_version == 1) {
-            if (!v1RefCount->deref()) {
-                delete engine;
-                delete v1RefCount;
-            }
-        } else if (engine_version == 2) {
-            delete engine;
-        }
-    }
-
-    QIconEngine *engine;
-
-    QAtomicInt ref;
-    int serialNum;
-    int detach_no;
-    int engine_version;
-
-    QAtomicInt *v1RefCount;
-};
-
-
-struct QPixmapIconEngineEntry
+QIconPrivate::QIconPrivate()
+    : engine(0), ref(1),
+    serialNum(serialNumCounter.fetchAndAddRelaxed(1)),
+    detach_no(0),
+    engine_version(2),
+    v1RefCount(0)
 {
-    QPixmapIconEngineEntry():mode(QIcon::Normal), state(QIcon::Off){}
-    QPixmapIconEngineEntry(const QPixmap &pm, QIcon::Mode m = QIcon::Normal, QIcon::State s = QIcon::Off)
-        :pixmap(pm), size(pm.size()), mode(m), state(s){}
-    QPixmapIconEngineEntry(const QString &file, const QSize &sz = QSize(), QIcon::Mode m = QIcon::Normal, QIcon::State s = QIcon::Off)
-        :fileName(file), size(sz), mode(m), state(s){}
-    QPixmap pixmap;
-    QString fileName;
-    QSize size;
-    QIcon::Mode mode;
-    QIcon::State state;
-    bool isNull() const {return (fileName.isEmpty() && pixmap.isNull()); }
-};
-
-class QPixmapIconEngine : public QIconEngineV2 {
-public:
-    QPixmapIconEngine();
-    QPixmapIconEngine(const QPixmapIconEngine &);
-    ~QPixmapIconEngine();
-    void paint(QPainter *painter, const QRect &rect, QIcon::Mode mode, QIcon::State state);
-    QPixmap pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state);
-    QPixmapIconEngineEntry *bestMatch(const QSize &size, QIcon::Mode mode, QIcon::State state, bool sizeOnly);
-    QSize actualSize(const QSize &size, QIcon::Mode mode, QIcon::State state);
-    void addPixmap(const QPixmap &pixmap, QIcon::Mode mode, QIcon::State state);
-    void addFile(const QString &fileName, const QSize &size, QIcon::Mode mode, QIcon::State state);
-
-    // v2 functions
-    QString key() const;
-    QIconEngineV2 *clone() const;
-    bool read(QDataStream &in);
-    bool write(QDataStream &out) const;
-    void virtual_hook(int id, void *data);
-
-private:
-    QPixmapIconEngineEntry *tryMatch(const QSize &size, QIcon::Mode mode, QIcon::State state);
-    QVector<QPixmapIconEngineEntry> pixmaps;
-
-    friend QDataStream &operator<<(QDataStream &s, const QIcon &icon);
-};
+}
 
 QPixmapIconEngine::QPixmapIconEngine()
 {
@@ -918,6 +867,146 @@ QList<QSize> QIcon::availableSizes(Mode mode, State state) const
     return engine->availableSizes(mode, state);
 }
 
+/*!
+    \since 4.6
+
+    Sets the search paths for icon themes.
+    \sa themeSearchPaths(), fromTheme()
+*/
+void QIcon::setThemeSearchPaths(const QStringList &paths)
+{
+    QIconLoader::instance()->setThemeSearchPath(paths);
+}
+
+/*!
+    \since 4.6
+
+    Returns the search paths for icon themes.
+
+    The default value will depend on the platform:
+
+    On X11, the search path will use the XDG_DATA_DIRS environment
+    variable if available.
+
+    On Windows the search path defaults to [Application Directory]/icons
+
+    On Mac the default search path will search in the
+    [Contents/Resources/icons] part of the application bundle.
+
+    \sa setThemeSearchPaths(), fromName()
+*/
+QStringList QIcon::themeSearchPaths()
+{
+    return QIconLoader::instance()->themeSearchPaths();
+}
+
+/*!
+    \since 4.6
+
+    Sets the current icon theme.
+
+    The name should correspond to a directory name in the
+    current \ themeSearchPath() containing an index.theme
+    file describing it's contents..
+
+*/
+void QIcon::setThemeName(const QString &path)
+{
+    QIconLoader::instance()->setThemeName(path);
+}
+
+/*!
+    \since 4.6
+
+    Returns the name of the current icon theme.
+
+    On X11, the current icon theme depends on your desktop
+    settings. On other platforms it is not set by default.
+
+    \sa themeSearchPaths(), themeIcon(), fromTheme(), hasThemeIcon()
+*/
+QString QIcon::themeName()
+{
+    return QIconLoader::instance()->themeName();
+}
+
+/*!
+    \since 4.6
+
+    Returns the QIcon corresponding to \a name in the current
+    icon theme. If no such icon is found in the current theme
+    \a fallback is return instead.
+
+    To use an icon theme on Windows or Mac, you will need to
+    bundle a compliant theme with your application and make sure
+    it is located in your themeSarchPaths.
+
+    The lastest version of the freedesktop icon specification and naming
+    spesification can be obtained here:
+    http://standards.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html
+    http://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html
+
+    To fetch an icon from the current icon theme:
+
+    \snippet doc/src/snippets/code/src_gui_image_qicon.cpp 3
+
+    Or if you want to provide a guaranteed fallback for platforms that
+    do not support theme icons, you can use the second argument:
+
+    \snippet doc/src/snippets/code/src_gui_image_qicon.cpp 4
+
+    \note By default, only X11 will support themed icons. In order to
+    use themed icons on Mac and Windows, you will have to bundle a
+    compliant theme in one of your themeSearchPaths() and set the
+    appropriate themeName().
+
+    \sa themeName(), themeSearchPaths()
+*/
+QIcon QIcon::fromTheme(const QString &name, const QIcon &fallback)
+{
+
+    static QCache <QString, QIcon> iconCache;
+
+    QIcon icon;
+
+#ifdef Q_WS_X11
+    if (X11->desktopEnvironment == DE_KDE) {
+        icon = QKde::kdeIcon(name);
+        if (!icon.isNull())
+            return icon;
+    }
+#endif
+
+    if (iconCache.contains(name)) {
+        icon = *iconCache.object(name);
+    } else {
+        QIcon *cachedIcon  = new QIcon(new QIconLoaderEngine(name));
+        iconCache.insert(name, cachedIcon);
+        icon = *cachedIcon;
+    }
+
+    if (icon.availableSizes().isEmpty())
+        return fallback;
+
+    return icon;
+}
+
+/*!
+    \since 4.6
+
+    Returns true if there is an icon available for a \a name in the current
+    icon theme, otherwise returns false.
+
+    \sa themeSearchPaths(), fromTheme()
+*/
+bool QIcon::hasThemeIcon(const QString &name)
+{
+    QIcon icon = fromTheme(name);
+
+    return !icon.isNull();
+}
+
+
 /*****************************************************************************
   QIcon stream functions
  *****************************************************************************/
@@ -989,6 +1078,11 @@ QDataStream &operator>>(QDataStream &s, QIcon &icon)
             QIconEngineV2 *engine = new QPixmapIconEngine;
             icon.d->engine = engine;
             engine->read(s);
+        } else if (key == QLatin1String("QIconLoaderEngine")) {
+            icon.d = new QIconPrivate;
+            QIconEngineV2 *engine = new QIconLoaderEngine();
+            icon.d->engine = engine;
+            engine->read(s);
 #if !defined (QT_NO_LIBRARY) && !defined(QT_NO_SETTINGS)
         } else if (QIconEngineFactoryInterfaceV2 *factory = qobject_cast<QIconEngineFactoryInterfaceV2*>(loaderV2()->instance(key))) {
             if (QIconEngineV2 *engine= factory->create()) {