Make wxAppProgressIndicator actually usable.

First of all, do define it under non-MSW platforms.

Second, don't crash in it when running under XP where wxTaskBarButton is not
available.

Also add IsAvailable() method to check for its availability explicitly and add
a demonstration of this class to the dialogs sample.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77706 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/appprogress.h

@@ -17,6 +17,9 @@ class WXDLLIMPEXP_CORE wxAppProgressIndicatorBase
 public:
     wxAppProgressIndicatorBase() {}
     virtual ~wxAppProgressIndicatorBase() {}
+
+    virtual bool IsAvailable() const = 0;
+
     virtual void SetValue(int value) = 0;
     virtual void SetRange(int range) = 0;
     virtual void Pulse() = 0;
@@ -28,6 +31,22 @@ private:
 
 #if defined(__WXMSW__)
     #include "wx/msw/appprogress.h"
+#else
+    class wxAppProgressIndicator : public wxAppProgressIndicatorBase
+    {
+    public:
+        wxAppProgressIndicator(wxWindow* WXUNUSED(parent) = NULL,
+                               int WXUNUSED(maxValue) = 100)
+        {
+        }
+
+        virtual bool IsAvailable() const wxOVERRIDE { return false; }
+
+        virtual void SetValue(int WXUNUSED(value)) wxOVERRIDE { }
+        virtual void SetRange(int WXUNUSED(range)) wxOVERRIDE { }
+        virtual void Pulse() wxOVERRIDE { }
+        virtual void Reset() wxOVERRIDE { }
+    };
 #endif
 
 #endif  // _WX_APPPROG_H_

include/wx/msw/appprogress.h

@@ -21,6 +21,8 @@ public:
     wxAppProgressIndicator(wxWindow* parent = NULL, int maxValue = 100);
     virtual ~wxAppProgressIndicator();
 
+    virtual bool IsAvailable() const wxOVERRIDE;
+
     virtual void SetValue(int value) wxOVERRIDE;
     virtual void SetRange(int range) wxOVERRIDE;
     virtual void Pulse() wxOVERRIDE;

interface/wx/appprogress.h

@@ -40,6 +40,17 @@ public:
     */
     virtual ~wxAppProgressIndicator();
 
+    /**
+        Check if the application progress display is available.
+
+        Currently this only returns @true when using wxMSW and running under
+        Vista or later system, which provide task bar button API.
+
+        If this method returns @false, no other methods of this class do
+        anything, but they may still be called without any ill effects.
+     */
+    bool IsAvailable() const;
+
     /**
         Set the progress value in taskbar button of parent window.
 

samples/dialogs/dialogs.cpp

@@ -60,6 +60,8 @@
     #include "wx/progdlg.h"
 #endif // wxUSE_PROGRESSDLG
 
+#include "wx/appprogress.h"
+
 #if wxUSE_ABOUTDLG
     #include "wx/aboutdlg.h"
 
@@ -220,6 +222,8 @@ wxBEGIN_EVENT_TABLE(MyFrame, wxFrame)
     EVT_MENU(DIALOGS_PROGRESS,                      MyFrame::ShowProgress)
 #endif // wxUSE_PROGRESSDLG
 
+    EVT_MENU(DIALOGS_APP_PROGRESS,                  MyFrame::ShowAppProgress)
+
 #if wxUSE_ABOUTDLG
     EVT_MENU(DIALOGS_ABOUTDLG_SIMPLE,               MyFrame::ShowSimpleAboutDialog)
     EVT_MENU(DIALOGS_ABOUTDLG_FANCY,                MyFrame::ShowFancyAboutDialog)
@@ -466,6 +470,8 @@ bool MyApp::OnInit()
         info_menu->Append(DIALOGS_PROGRESS, wxT("Pro&gress dialog\tCtrl-G"));
     #endif // wxUSE_PROGRESSDLG
 
+        info_menu->Append(DIALOGS_APP_PROGRESS, wxT("&App progress\tShift-Ctrl-G"));
+
     #if wxUSE_BUSYINFO
        info_menu->Append(DIALOGS_BUSYINFO, wxT("&Busy info dialog\tCtrl-B"));
     #endif // wxUSE_BUSYINFO
@@ -2268,6 +2274,29 @@ void MyFrame::ShowProgress( wxCommandEvent& WXUNUSED(event) )
 
 #endif // wxUSE_PROGRESSDLG
 
+void MyFrame::ShowAppProgress( wxCommandEvent& WXUNUSED(event) )
+{
+    wxAppProgressIndicator progress(this);
+    if ( !progress.IsAvailable() )
+    {
+        wxLogStatus("Progress indicator not available under this platform.");
+        return;
+    }
+
+    wxLogStatus("Using application progress indicator...");
+
+    const int range = 10;
+    progress.SetRange(range);
+    for ( int i = 0; i < range; i++ )
+    {
+        progress.SetValue(i);
+
+        wxMilliSleep(500);
+    }
+
+    wxLogStatus("Progress finished");
+}
+
 #if wxUSE_ABOUTDLG
 
 static void InitAboutInfoMinimal(wxAboutDialogInfo& info)

samples/dialogs/dialogs.h

@@ -430,6 +430,7 @@ public:
 #if wxUSE_PROGRESSDLG
     void ShowProgress(wxCommandEvent& event);
 #endif // wxUSE_PROGRESSDLG
+    void ShowAppProgress(wxCommandEvent& event);
 
 #if wxUSE_ABOUTDLG
     void ShowSimpleAboutDialog(wxCommandEvent& event);
@@ -570,6 +571,7 @@ enum
     DIALOGS_ONTOP,
     DIALOGS_MODELESS_BTN,
     DIALOGS_PROGRESS,
+    DIALOGS_APP_PROGRESS,
     DIALOGS_ABOUTDLG_SIMPLE,
     DIALOGS_ABOUTDLG_FANCY,
     DIALOGS_ABOUTDLG_FULL,

src/msw/appprogress.cpp

@@ -62,6 +62,11 @@ wxAppProgressIndicator::~wxAppProgressIndicator()
 #endif  // wxUSE_TASKBARBUTTON
 }
 
+bool wxAppProgressIndicator::IsAvailable() const
+{
+    return !m_taskBarButtons.empty();
+}
+
 void wxAppProgressIndicator::SetValue(int value)
 {
     wxASSERT_MSG( value <= m_maxValue, wxT("invalid progress value") );

src/msw/taskbarbutton.cpp

@@ -696,32 +696,46 @@ bool wxThumbBarButton::UpdateParentTaskBarButton()
 // ----------------------------------------------------------------------------
 // wxTaskBarButtonImpl Implementation.
 // ----------------------------------------------------------------------------
-wxTaskBarButtonImpl::wxTaskBarButtonImpl(wxWindow* parent)
-    : m_hwnd(parent->GetHandle()),
-      m_taskbarList(NULL),
-      m_progressRange(0),
-      m_hasInitThumbnailToolbar(false)
+
+/* static */
+wxTaskBarButton* wxTaskBarButton::New(wxWindow* parent)
 {
+    wxITaskbarList3* taskbarList = NULL;
+
     HRESULT hr = CoCreateInstance
                  (
                     wxCLSID_TaskbarList,
                     NULL,
                     CLSCTX_INPROC_SERVER,
                     wxIID_ITaskbarList3,
-                    reinterpret_cast<void **>(&m_taskbarList)
+                    reinterpret_cast<void **>(&taskbarList)
                  );
     if ( FAILED(hr) )
     {
-        wxLogApiError(wxT("CoCreateInstance(wxCLSID_TaskbarList)"), hr);
-        return;
+        // Don't log this error, it may be normal when running under XP.
+        return NULL;
     }
 
-    hr = m_taskbarList->HrInit();
+    hr = taskbarList->HrInit();
     if ( FAILED(hr) )
     {
+        // This is however unexpected.
         wxLogApiError(wxT("ITaskbarList3::Init"), hr);
-        return;
+
+        taskbarList->Release();
+        return NULL;
     }
+
+    return new wxTaskBarButtonImpl(taskbarList, parent);
+}
+
+wxTaskBarButtonImpl::wxTaskBarButtonImpl(wxITaskbarList3* taskbarList,
+                                         wxWindow* parent)
+    : m_hwnd(parent->GetHandle()),
+      m_taskbarList(taskbarList),
+      m_progressRange(0),
+      m_hasInitThumbnailToolbar(false)
+{
 }
 
 wxTaskBarButtonImpl::~wxTaskBarButtonImpl()