Check for task dialog availability even under Vista and later.

Task dialogs are not always available under Vista and later Windows versions
because we might not be using the right (i.e. 6+) version of comctl32.dll.

Improve the check for task dialog availability and fall back to the classic
message box if we can't use it.

Closes #12553.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65816 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

diff --git a/include/wx/msw/msgdlg.h b/include/wx/msw/msgdlg.h
index 3a91076877efab302b66541e16d282a7be4b0d32..784d339b61364e19e150095ce6fa3f5e80baa4c6 100644 (file)
--- a/include/wx/msw/msgdlg.h
+++ b/include/wx/msw/msgdlg.h
@@ -59,8 +59,6 @@ private:
     // aren't available.
     int ShowMessageBox();
 
     // aren't available.
     int ShowMessageBox();
 

-    // used by ShowModal() to display a task dialog.
-    int ShowTaskDialog();

 
     WXHANDLE m_hook; // HHOOK used to position the message box
 
 
     WXHANDLE m_hook; // HHOOK used to position the message box
 

diff --git a/src/msw/msgdlg.cpp b/src/msw/msgdlg.cpp
index ce8d4eafe56d4c85d1e418321cf64d2ca44d8ccc..f6057f73611fd8eda54650ed064c79db47fade9e 100644 (file)
--- a/src/msw/msgdlg.cpp
+++ b/src/msw/msgdlg.cpp
@@ -573,39 +573,29 @@ int wxMessageDialog::ShowMessageBox()
     return MSWTranslateReturnCode(msAns);
 }
 
     return MSWTranslateReturnCode(msAns);
 }
 

-int wxMessageDialog::ShowTaskDialog()
+int wxMessageDialog::ShowModal()

 {
 #ifdef wxHAS_MSW_TASKDIALOG
 {
 #ifdef wxHAS_MSW_TASKDIALOG

-    TaskDialogIndirect_t taskDialogIndirect = GetTaskDialogIndirectFunc();
-    if ( !taskDialogIndirect )
-        return wxID_CANCEL;
-
-    WinStruct<TASKDIALOGCONFIG> tdc;
-    wxMSWTaskDialogConfig wxTdc( *this );
-    wxTdc.MSWCommonTaskDialogInit( tdc );
-
-    int msAns;
-    HRESULT hr = taskDialogIndirect( &tdc, &msAns, NULL, NULL );
-    if ( FAILED(hr) )
+    if ( HasNativeTaskDialog() )

     {
     {

-        wxLogApiError( "TaskDialogIndirect", hr );
-        return wxID_CANCEL;
-    }
-
-    return MSWTranslateReturnCode( msAns );
-#else
-    wxFAIL_MSG( "Task dialogs are unavailable." );
-
-    return wxID_CANCEL;
-#endif // wxHAS_MSW_TASKDIALOG
-}
+        TaskDialogIndirect_t taskDialogIndirect = GetTaskDialogIndirectFunc();
+        wxCHECK_MSG( taskDialogIndirect, wxID_CANCEL, wxS("no task dialog?") );

 
 

+        WinStruct<TASKDIALOGCONFIG> tdc;
+        wxMSWTaskDialogConfig wxTdc( *this );
+        wxTdc.MSWCommonTaskDialogInit( tdc );

 
 

+        int msAns;
+        HRESULT hr = taskDialogIndirect( &tdc, &msAns, NULL, NULL );
+        if ( FAILED(hr) )
+        {
+            wxLogApiError( "TaskDialogIndirect", hr );
+            return wxID_CANCEL;
+        }

 
 

-int wxMessageDialog::ShowModal()
-{
-    if ( HasNativeTaskDialog() )
-        return ShowTaskDialog();
+        return MSWTranslateReturnCode( msAns );
+    }
+#endif // wxHAS_MSW_TASKDIALOG

 
     return ShowMessageBox();
 }
 
     return ShowMessageBox();
 }


@@ -758,19 +748,20 @@ wxCRIT_SECT_DECLARE(gs_csTaskDialogIndirect);
 
 TaskDialogIndirect_t wxMSWMessageDialog::GetTaskDialogIndirectFunc()
 {
 
 TaskDialogIndirect_t wxMSWMessageDialog::GetTaskDialogIndirectFunc()
 {

-    static TaskDialogIndirect_t s_TaskDialogIndirect = NULL;
+    // Initialize the function pointer to an invalid value different from NULL
+    // to avoid reloading comctl32.dll and trying to resolve it every time
+    // we're called if task dialog is not available (notice that this may
+    // happen even under Vista+ if we don't use comctl32.dll v6).
+    static const TaskDialogIndirect_t
+        INVALID_TASKDIALOG_FUNC = reinterpret_cast<TaskDialogIndirect_t>(-1);
+    static TaskDialogIndirect_t s_TaskDialogIndirect = INVALID_TASKDIALOG_FUNC;

 
     wxCRIT_SECT_LOCKER(lock, gs_csTaskDialogIndirect);
 
 
     wxCRIT_SECT_LOCKER(lock, gs_csTaskDialogIndirect);
 

-    if ( !s_TaskDialogIndirect )
+    if ( s_TaskDialogIndirect == INVALID_TASKDIALOG_FUNC )

     {
         wxLoadedDLL dllComCtl32("comctl32.dll");
         wxDL_INIT_FUNC(s_, TaskDialogIndirect, dllComCtl32);
     {
         wxLoadedDLL dllComCtl32("comctl32.dll");
         wxDL_INIT_FUNC(s_, TaskDialogIndirect, dllComCtl32);

-
-        // We must always succeed as this code is only executed under Vista and
-        // later which must have task dialog support.
-        wxASSERT_MSG( s_TaskDialogIndirect,
-                      "Task dialog support unexpectedly not available" );

     }
 
     return s_TaskDialogIndirect;
     }
 
     return s_TaskDialogIndirect;


@@ -781,10 +772,14 @@ TaskDialogIndirect_t wxMSWMessageDialog::GetTaskDialogIndirectFunc()
 bool wxMSWMessageDialog::HasNativeTaskDialog()
 {
 #ifdef wxHAS_MSW_TASKDIALOG
 bool wxMSWMessageDialog::HasNativeTaskDialog()
 {
 #ifdef wxHAS_MSW_TASKDIALOG

-    return wxGetWinVersion() >= wxWinVersion_6;
-#else
+    if ( wxGetWinVersion() >= wxWinVersion_6 )
+    {
+        if ( wxMSWMessageDialog::GetTaskDialogIndirectFunc() )
+            return true;
+    }
+#endif // wxHAS_MSW_TASKDIALOG
+

     return false;
     return false;

-#endif

 }
 
 int wxMSWMessageDialog::MSWTranslateReturnCode(int msAns)
 }
 
 int wxMSWMessageDialog::MSWTranslateReturnCode(int msAns)