Windows: Added support for large icons to QFileIconProvider.

Added code using image lists to windows theme.

Initial-patch-by: Max Desyatov <max.desyatov@gmail.com>

Task-number: QTBUG-4970
Change-Id: I6e82f4edec60e456d0b1759bb1771955edb94491
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>

3 files changed, 81 insertions, 6 deletions

diff --git a/src/plugins/platforms/windows/qwindowscontext.cpp b/src/plugins/platforms/windows/qwindowscontext.cpp
index c676ca3c46..8dab1e2b1c 100644
--- a/src/plugins/platforms/windows/qwindowscontext.cpp
+++ b/src/plugins/platforms/windows/qwindowscontext.cpp
@@ -218,6 +218,7 @@ bool QWindowsUser32DLL::initTouch()
 QWindowsShell32DLL::QWindowsShell32DLL()
     : sHCreateItemFromParsingName(0)
     , sHGetStockIconInfo(0)
+    , sHGetImageList(0)
 {
 }
 
@@ -226,6 +227,7 @@ void QWindowsShell32DLL::init()
     QSystemLibrary library(QStringLiteral("shell32"));
     sHCreateItemFromParsingName = (SHCreateItemFromParsingName)(library.resolve("SHCreateItemFromParsingName"));
     sHGetStockIconInfo = (SHGetStockIconInfo)library.resolve("SHGetStockIconInfo");
+    sHGetImageList = (SHGetImageList)library.resolve("SHGetImageList");
 }
 
 QWindowsUser32DLL QWindowsContext::user32dll;
diff --git a/src/plugins/platforms/windows/qwindowscontext.h b/src/plugins/platforms/windows/qwindowscontext.h
index 0d3476e00f..173df58570 100644
--- a/src/plugins/platforms/windows/qwindowscontext.h
+++ b/src/plugins/platforms/windows/qwindowscontext.h
@@ -108,9 +108,11 @@ struct QWindowsShell32DLL
 
     typedef HRESULT (WINAPI *SHCreateItemFromParsingName)(PCWSTR, IBindCtx *, const GUID&, void **);
     typedef HRESULT (WINAPI *SHGetStockIconInfo)(int , int , _SHSTOCKICONINFO *);
+    typedef HRESULT (WINAPI *SHGetImageList)(int, REFIID , void **);
 
     SHCreateItemFromParsingName sHCreateItemFromParsingName;
     SHGetStockIconInfo sHGetStockIconInfo;
+    SHGetImageList sHGetImageList;
 };
 #endif // Q_OS_WINCE
 
diff --git a/src/plugins/platforms/windows/qwindowstheme.cpp b/src/plugins/platforms/windows/qwindowstheme.cpp
index 1710fd419a..498bd509fa 100644
--- a/src/plugins/platforms/windows/qwindowstheme.cpp
+++ b/src/plugins/platforms/windows/qwindowstheme.cpp
@@ -48,6 +48,11 @@
 #ifdef Q_OS_WINCE
 #  include "qplatformfunctions_wince.h"
 #  include "winuser.h"
+#else
+#  include <commctrl.h>
+#  include <objbase.h>
+#  include <commoncontrols.h>
+#  include <shellapi.h>
 #endif
 
 #include <QtCore/QVariant>
@@ -65,6 +70,10 @@
 
 #include <algorithm>
 
+#if defined(__IImageList_INTERFACE_DEFINED__) && defined(__IID_DEFINED__)
+#  define USE_IIMAGELIST
+#endif
+
 QT_BEGIN_NAMESPACE
 
 static inline QTextStream& operator<<(QTextStream &str, const QColor &c)
@@ -357,6 +366,11 @@ QVariant QWindowsTheme::themeHint(ThemeHint hint) const
     case IconPixmapSizes: {
         QList<int> sizes;
         sizes << 16 << 32;
+#ifdef USE_IIMAGELIST
+        sizes << 48; // sHIL_EXTRALARGE
+        if (QSysInfo::WindowsVersion >= QSysInfo::WV_VISTA)
+            sizes << 256; // SHIL_JUMBO
+#endif // USE_IIMAGELIST
         return QVariant::fromValue(sizes);
     }
     case DialogSnapToDefaultButton:
@@ -574,11 +588,24 @@ QPixmap QWindowsTheme::standardPixmap(StandardPixmap sp, const QSizeF &size) con
     return QPlatformTheme::standardPixmap(sp, size);
 }
 
-static QString dirIconPixmapCacheKey(int iIcon, int iconSize)
+enum { // Shell image list ids
+    sHIL_EXTRALARGE = 0x2, // 48x48 or user-defined
+    sHIL_JUMBO = 0x4 // 256x256 (Vista or later)
+};
+
+static QString dirIconPixmapCacheKey(int iIcon, int iconSize, int imageListSize)
 {
     QString key = QLatin1String("qt_dir_") + QString::number(iIcon);
     if (iconSize == SHGFI_LARGEICON)
         key += QLatin1Char('l');
+    switch (imageListSize) {
+    case sHIL_EXTRALARGE:
+        key += QLatin1Char('e');
+        break;
+    case sHIL_JUMBO:
+        key += QLatin1Char('j');
+        break;
+    }
     return key;
 }
 
@@ -602,6 +629,38 @@ public:
     void operator delete (void *) {}
 };
 
+// Shell image list helper functions.
+
+static QPixmap pixmapFromShellImageList(int iImageList, const SHFILEINFO &info)
+{
+    QPixmap result;
+#ifdef USE_IIMAGELIST
+    // For MinGW:
+    static const IID iID_IImageList = {0x46eb5926, 0x582e, 0x4017, {0x9f, 0xdf, 0xe8, 0x99, 0x8d, 0xaa, 0x9, 0x50}};
+
+    if (!QWindowsContext::shell32dll.sHGetImageList)
+        return result;
+    if (iImageList == sHIL_JUMBO && QSysInfo::WindowsVersion < QSysInfo::WV_VISTA)
+        return result;
+
+    IImageList *imageList = 0;
+    HRESULT hr = QWindowsContext::shell32dll.sHGetImageList(iImageList, iID_IImageList, (void **)&imageList);
+    if (hr != S_OK)
+        return result;
+    HICON hIcon;
+    hr = imageList->GetIcon(info.iIcon, ILD_TRANSPARENT, &hIcon);
+    if (hr == S_OK) {
+        result = qt_pixmapFromWinHICON(hIcon);
+        DestroyIcon(hIcon);
+    }
+    imageList->Release();
+#else
+    Q_UNUSED(iImageList)
+    Q_UNUSED(info)
+#endif // USE_IIMAGELIST
+    return result;
+}
+
 QPixmap QWindowsTheme::fileIconPixmap(const QFileInfo &fileInfo, const QSizeF &size,
                                       QPlatformTheme::IconOptions iconOptions) const
 {
@@ -617,15 +676,21 @@ QPixmap QWindowsTheme::fileIconPixmap(const QFileInfo &fileInfo, const QSizeF &s
 
     QPixmap pixmap;
     const QString filePath = QDir::toNativeSeparators(fileInfo.filePath());
-    int iconSize = size.width() > 16 ? SHGFI_LARGEICON : SHGFI_SMALLICON;
-
+    const int width = size.width();
+    const int iconSize = width > 16 ? SHGFI_LARGEICON : SHGFI_SMALLICON;
+    const int requestedImageListSize =
+#ifdef USE_IIMAGELIST
+        width > 48 ? sHIL_JUMBO : (width > 32 ? sHIL_EXTRALARGE : 0);
+#else
+        0;
+#endif // !USE_IIMAGELIST
     bool cacheableDirIcon = fileInfo.isDir() && !fileInfo.isRoot();
     if (cacheableDirIcon) {
         QMutexLocker locker(&mx);
         int iIcon = (useDefaultFolderIcon && defaultFolderIIcon) ? defaultFolderIIcon
                                                                  : **dirIconEntryCache.object(filePath);
         if (iIcon) {
-            QPixmapCache::find(dirIconPixmapCacheKey(iIcon, iconSize), pixmap);
+            QPixmapCache::find(dirIconPixmapCacheKey(iIcon, iconSize, requestedImageListSize), pixmap);
             if (pixmap.isNull()) // Let's keep both caches in sync
                 dirIconEntryCache.remove(filePath);
             else
@@ -659,7 +724,7 @@ QPixmap QWindowsTheme::fileIconPixmap(const QFileInfo &fileInfo, const QSizeF &s
                 defaultFolderIIcon = info.iIcon;
 
             //using the unique icon index provided by windows save us from duplicate keys
-            key = dirIconPixmapCacheKey(info.iIcon, iconSize);
+            key = dirIconPixmapCacheKey(info.iIcon, iconSize, requestedImageListSize);
             QPixmapCache::find(key, pixmap);
             if (!pixmap.isNull()) {
                 QMutexLocker locker(&mx);
@@ -668,7 +733,13 @@ QPixmap QWindowsTheme::fileIconPixmap(const QFileInfo &fileInfo, const QSizeF &s
         }
 
         if (pixmap.isNull()) {
-            pixmap = qt_pixmapFromWinHICON(info.hIcon);
+            if (requestedImageListSize) {
+                pixmap = pixmapFromShellImageList(requestedImageListSize, info);
+                if (pixmap.isNull() && requestedImageListSize == sHIL_JUMBO)
+                    pixmap = pixmapFromShellImageList(sHIL_EXTRALARGE, info);
+            }
+            if (pixmap.isNull())
+                pixmap = qt_pixmapFromWinHICON(info.hIcon);
             if (!pixmap.isNull()) {
                 if (cacheableDirIcon) {
                     QMutexLocker locker(&mx);