Use Windows native file icons as a fallback in icon display

jlu5 · May 22, 2017 · 4479f8d · 4479f8d
1 parent 1b1761b
commit 4479f8d
Show file tree

Hide file tree

Showing 3 changed files with 26 additions and 5 deletions.
diff --git a/fileinsight.cpp b/fileinsight.cpp
@@ -254,13 +254,13 @@ void FileInsight::openFile(QString filename, bool overwrite)
     QString mimetype = this->getMimeType(filename);
     currentTab->ui->mimeOutput->setPlainText(mimetype);
 
-    QIcon icon = this->getIcon(mimetype);
+    QIcon icon = this->getIcon(mimetype, filename);
 
     // TODO: consider scaling the icon display based on the window size
     currentTab->ui->iconDisplay->setPixmap(icon.pixmap(128,128));
 }
 
-QIcon FileInsight::getIcon(QString mimetype) {
+QIcon FileInsight::getIcon(QString mimetype, QString filename) {
     /* Fetch an icon based on the MIME type string given. This uses freedesktop.org
      * comptible icon themes, which are native to Linux but can be ported to Windows
      * by bundling a theme.
@@ -294,12 +294,27 @@ QIcon FileInsight::getIcon(QString mimetype) {
         /* Otherwise, fall back to the following in order:
          * 1) The icon for the generic type (e.g. a "video" icon for .mp4 files)
          * 2) The "unknown file type" icon in the icon theme used.
-         * 3) Qt's (small and out of place) generic file icon.
+         * 3) IF on Windows, the shell file type icon for the given file.
+         * 4) Qt's (small and out of place) generic file icon.
          */
         if (QIcon::hasThemeIcon(generic_type)) {
             icon = QIcon::fromTheme(generic_type);
         } else {
-            icon = QIcon::fromTheme("unknown", this->iconprovider.icon(QFileIconProvider::File));
+            #ifdef Q_OS_WIN
+                // Fetch the Windows icon using shell32.SHGetFileInfo:
+                // https://msdn.microsoft.com/en-us/library/windows/desktop/bb762179(v=vs.85).aspx
+                SHFILEINFOW shellfileinfo;
+                SHGetFileInfo((LPCTSTR) filename.utf16(),
+                              FILE_ATTRIBUTE_NORMAL, &shellfileinfo, sizeof(shellfileinfo),
+                              SHGFI_ICON | SHGFI_LARGEICON | SHGFI_SYSICONINDEX | SHGFI_USEFILEATTRIBUTES);
+                // Then, convert it into a QIcon.
+                QPixmap pixmap = QtWin::fromHICON(shellfileinfo.hIcon);
+                icon = QIcon(pixmap);
+            #endif
+
+            if (icon.isNull()) {
+                icon = QIcon::fromTheme("unknown", this->iconprovider.icon(QFileIconProvider::File));
+            }
         }
     }
     return icon;

diff --git a/fileinsight.h b/fileinsight.h
@@ -24,6 +24,11 @@
 #include <QList>
 #include <QDebug>
 
+#ifdef Q_OS_WIN
+#include <windows.h>
+#include <QtWinExtras>
+#endif
+
 enum FileInsightBackend { BACKEND_MAGIC, BACKEND_TRID, BACKEND_QT, BACKEND_QT_FILEONLY};
 
 namespace Ui {
@@ -40,7 +45,7 @@ class FileInsight : public QMainWindow
     void chooseFile();
     FileInsightBackend getBackend();
     FileInsightSubdialog * getCurrentTab();
-    QIcon getIcon(QString mimetype);
+    QIcon getIcon(QString mimetype, QString filename);
     QString getMagicInfo(QString filename);
     QString getMimeType(QString filename);
     QString getTridInfo(QString filename);

diff --git a/fileinsight.pro b/fileinsight.pro
@@ -24,6 +24,7 @@ FORMS    += fileinsight.ui \
 win32:INCLUDEPATH += $$PWD\thirdparty\include
 win32:LIBPATH += $$PWD\thirdparty\bin
 win32:LIBPATH += $$PWD\thirdparty\lib
+win32:QT += winextras
 
 # Link to libmagic for file type detection
 LIBS += -lmagic