Get icons for programs that dont specify an icon resource in the registry

src/calibre/gui2/open_with.py

@@ -67,7 +67,7 @@ def entry_to_icon_text(entry, only_text=False):
 if iswindows:
     # Windows {{{
     from calibre.utils.winreg.default_programs import find_programs, friendly_app_name
-    from calibre.utils.open_with.windows import load_icon_resource
+    from calibre.utils.open_with.windows import load_icon_resource, load_icon_for_cmdline
     from win32process import CreateProcess, STARTUPINFO
     from win32event import WaitForInputIdle
     import win32con
@@ -76,9 +76,20 @@ if iswindows:
     def entry_sort_key(entry):
         return sort_key(entry.get('name') or '')
 
+    def icon_for_entry(entry, delete_icon_resource=False, as_data=False):
+        res = entry.pop('icon_resource', None) if delete_icon_resource else entry.get('icon_resource')
+        if res is None:
+            return load_icon_for_cmdline(entry['cmdline'], as_data=as_data)
+        try:
+            return load_icon_resource(res, as_data=as_data)
+        except Exception:
+            import traceback
+            traceback.print_exc()
+        return load_icon_for_cmdline(entry['cmdline'], as_data=as_data)
+
     def finalize_entry(entry):
         try:
-            data = load_icon_resource(entry.pop('icon_resource', None), as_data=True)
+            data = icon_for_entry(entry, delete_icon_resource=True, as_data=True)
         except Exception:
             data = None
             import traceback
@@ -89,7 +100,7 @@ if iswindows:
 
     def entry_to_item(entry, parent):
         try:
-            icon = load_icon_resource(entry.get('icon_resource'))
+            icon = icon_for_entry(entry)
         except Exception:
             icon = None
             import traceback

src/calibre/utils/open_with/windows.py

@@ -6,6 +6,7 @@ __license__ = 'GPL v3'
 __copyright__ = '2015, Kovid Goyal <kovid at kovidgoyal.net>'
 
 import re
+import sys
 from PyQt5.Qt import QBuffer, QByteArray, QPixmap, Qt, QtWin
 
 from calibre.constants import plugins
@@ -75,8 +76,24 @@ def load_icon_resource(icon_resource, as_data=False, size=ICON_SIZE):
     return ans
 
 
+def load_icon_for_file(path: str, as_data=False, size=ICON_SIZE):
+    try:
+        hicon = winutil.get_icon_for_file(path)
+    except Exception:
+        return
+    must_use_qt()
+    pmap = hicon_to_pixmap(hicon)
+    if not pmap.isNull():
+        if pmap.width() != size:
+            pmap = pmap.scaled(size, size, aspectRatioMode=Qt.KeepAspectRatio, transformMode=Qt.SmoothTransformation)
+        return pixmap_to_data(pmap) if as_data else pmap
+
+
+def load_icon_for_cmdline(cmdline: str):
+    return load_icon_for_cmdline(split_commandline(cmdline)[0])
+
+
 def display_image(png_data):
-    import sys
     from base64 import standard_b64encode
 
     def serialize_gr_command(cmd, payload=None):
@@ -105,6 +122,10 @@ def display_image(png_data):
 
 
 def test():
-    import sys
     png_data = load_icon_resource(sys.argv[-1], as_data=True)
     display_image(png_data)
+
+
+def test_shell():
+    png_data = load_icon_for_file(sys.argv[-1], as_data=True)
+    display_image(png_data)

src/calibre/utils/windows/winutil.cpp

@@ -14,7 +14,12 @@
 #include <combaseapi.h>
 #include <locale.h>
 #include <shlobj.h>
+#include <shlguid.h>
+#include <shellapi.h>
 #include <shlwapi.h>
+#include <commoncontrols.h>
+#include <comip.h>
+#include <comdef.h>
 #include <atlbase.h>  // for CComPtr
 #include <Python.h>
 #include <versionhelpers.h>
@@ -781,6 +786,7 @@ load_library(PyObject *self, PyObject *args) {
 	return (PyObject*)Handle_create(h, ModuleHandle, PyTuple_GET_ITEM(args, 0));
 }
 
+// Icon loading {{{
 #pragma pack( push )
 #pragma pack( 2 )
 typedef struct {
@@ -873,6 +879,41 @@ load_icons(PyObject *self, PyObject *args) {
 	return ans;
 }
 
+_COM_SMARTPTR_TYPEDEF(IImageList, __uuidof(IImageList));
+
+static HICON
+get_icon_at_index(int shilsize, int index) {
+	IImageListPtr spiml;
+	HRESULT hr = SHGetImageList(shilsize, IID_PPV_ARGS(&spiml));
+	HICON hico = NULL;
+	if (SUCCEEDED(hr)) spiml->GetIcon(index, ILD_TRANSPARENT, &hico);
+	return hico;
+}
+
+static PyObject*
+get_icon_for_file(PyObject *self, PyObject *args) {
+	wchar_raii path;
+	if (!PyArg_ParseTuple(args, "O&", py_to_wchar_no_none, &path)) return NULL;
+	scoped_com_initializer com;
+	if (!com.succeded()) { PyErr_SetString(PyExc_OSError, "Failed to initialize COM"); return NULL; }
+	SHFILEINFO fi = {0};
+	DWORD_PTR res;
+	Py_BEGIN_ALLOW_THREADS
+	res = SHGetFileInfoW(path.ptr(), 0, &fi, sizeof(fi), SHGFI_SYSICONINDEX);
+	Py_END_ALLOW_THREADS
+	if (!res) return PyErr_SetExcFromWindowsErrWithFilenameObject(PyExc_OSError, ERROR_RESOURCE_TYPE_NOT_FOUND, PyTuple_GET_ITEM(args, 0));
+	HICON icon;
+#define R(shil) { \
+	Py_BEGIN_ALLOW_THREADS \
+	icon = get_icon_at_index(SHIL_JUMBO, fi.iIcon); \
+	Py_END_ALLOW_THREADS \
+	if (icon) return (PyObject*)Handle_create(icon, IconHandle); \
+}
+	R(SHIL_JUMBO); R(SHIL_EXTRALARGE); R(SHIL_LARGE); R(SHIL_SYSSMALL); R(SHIL_SMALL);
+#undef R
+	return PyErr_SetExcFromWindowsErrWithFilenameObject(PyExc_OSError, ERROR_RESOURCE_TYPE_NOT_FOUND, PyTuple_GET_ITEM(args, 0));
+} // }}}
+
 // Boilerplate  {{{
 static const char winutil_doc[] = "Defines utility methods to interface with windows.";
 
@@ -888,6 +929,7 @@ static PyMethodDef winutil_methods[] = {
 	M(get_last_error, METH_NOARGS),
 	M(load_library, METH_VARARGS),
 	M(load_icons, METH_VARARGS),
+	M(get_icon_for_file, METH_VARARGS),
 
     {"special_folder_path", winutil_folder_path, METH_VARARGS,
     "special_folder_path(csidl_id) -> path\n\n"