Added wxHelpEvent, wxContextHelp (MSW only so far), modified help sample

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@8271 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/helpbase.cpp

@@ -26,8 +26,196 @@
 
 #include "wx/helpbase.h"
 
+#ifdef __WXMSW__
+#include "wx/msw/private.h"
+#endif
+
 #if wxUSE_HELP
 
 IMPLEMENT_CLASS(wxHelpControllerBase, wxObject)
 
+/*
+ * Invokes context-sensitive help
+ */
+
+IMPLEMENT_DYNAMIC_CLASS(wxContextHelp, wxObject)
+
+wxContextHelp::wxContextHelp(wxWindow* win, bool beginHelp)
+{
+    m_inHelp = FALSE;
+
+    if (beginHelp)
+        BeginContextHelp(win);
+}
+
+wxContextHelp::~wxContextHelp()
+{
+    if (m_inHelp)
+        EndContextHelp();
+}
+
+bool wxContextHelp::BeginContextHelp(wxWindow* win)
+{
+    if (!win)
+        win = wxTheApp->GetTopWindow();
+    if (!win)
+        return FALSE;
+
+    wxCursor cursor(wxCURSOR_QUESTION_ARROW);
+    wxSetCursor(cursor);
+
+    win->CaptureMouse();
+
+    EventLoop(cursor, win);
+
+    win->ReleaseMouse();
+
+    return TRUE;
+}
+
+bool wxContextHelp::EndContextHelp()
+{
+    m_inHelp = FALSE;
+
+    return TRUE;
+}
+
+bool wxContextHelp::EventLoop(const wxCursor& cursor, wxWindow* win)
+{
+#ifdef __WXMSW__
+    m_inHelp = TRUE;
+    while ( m_inHelp )
+    {
+        MSG msg;
+        if (::PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE))
+        {
+            if (!ProcessHelpMessage((WXMSG*) & msg, cursor, win))
+            {
+                m_inHelp = FALSE;
+            }
+        }
+        else
+        {
+            wxTheApp->ProcessIdle();
+        }
+    }
+    return TRUE;
+#else
+    return FALSE;
+#endif
+}
+
+#ifdef __WXMSW__
+bool wxContextHelp::ProcessHelpMessage(WXMSG* wxmsg, const wxCursor& cursor, wxWindow* winInQuestion)
+{
+    MSG& msg = * (MSG*) wxmsg;
+
+    if (msg.message == WM_KEYDOWN || msg.wParam == VK_ESCAPE)
+    {
+        PeekMessage(&msg, NULL, msg.message, msg.message, PM_REMOVE);
+        return FALSE;
+    }
+
+    if (msg.message == WM_CAPTURECHANGED)
+    {
+        PeekMessage(&msg, NULL, msg.message, msg.message, PM_REMOVE);
+        return FALSE;
+    }
+
+    if (msg.message == WM_ACTIVATE)
+    {
+        PeekMessage(&msg, NULL, msg.message, msg.message, PM_REMOVE);
+        return FALSE;
+    }
+
+	if ((msg.message >= WM_MOUSEFIRST && msg.message <= WM_MOUSELAST))
+//        || (msg.message >= WM_NCMOUSEFIRST && msg.message <= WM_NCMOUSELAST))
+	{
+        wxSetCursor(cursor);
+
+        HWND hWndHit = ::WindowFromPoint(msg.pt);
+
+        wxWindow* win = wxFindWinFromHandle((WXHWND) hWndHit) ;
+        HWND hWnd = hWndHit;
+
+        // Try to find a window with a wxWindow associated with it
+        while (!win && (hWnd != 0))
+        {
+            hWnd = ::GetParent(hWnd);
+            win = wxFindWinFromHandle((WXHWND) hWnd) ;
+        }
+
+        if (win)
+        {
+            // It's a wxWindows window
+			if (msg.message != WM_LBUTTONDOWN)
+			{
+				// Hit one of our owned windows -- eat the message.
+				PeekMessage(&msg, NULL, msg.message, msg.message, PM_REMOVE);
+				return TRUE;
+            }
+			int iHit = (int)::SendMessage(hWndHit, WM_NCHITTEST, 0,
+				MAKELONG(msg.pt.x, msg.pt.y));
+			if (iHit == HTMENU || iHit == HTSYSMENU)
+			{
+                // Eat this message, send the event and return
+				PeekMessage(&msg, NULL, msg.message, msg.message, PM_REMOVE);
+                DispatchEvent(win, wxPoint(msg.pt.x, msg.pt.y));
+                return FALSE;
+			}
+			else if (iHit == HTCLIENT)
+			{
+				PeekMessage(&msg, NULL, msg.message, msg.message, PM_REMOVE);
+                DispatchEvent(win, wxPoint(msg.pt.x, msg.pt.y));
+				return FALSE;
+			}
+			else
+			{
+				PeekMessage(&msg, NULL, msg.message, msg.message, PM_REMOVE);
+				return FALSE;
+			}
+        }
+        else
+        {
+            // Someone else's message
+		    if (PeekMessage(&msg, NULL, msg.message, msg.message, PM_REMOVE))
+            {
+                ::TranslateMessage(&msg);
+                ::DispatchMessage(&msg);
+            }
+            return TRUE;
+        }
+    }
+    else
+    {
+        // allow all other messages to go through (capture still set)
+        if (PeekMessage(&msg, NULL, msg.message, msg.message, PM_REMOVE))
+            DispatchMessage(&msg);
+        return TRUE;
+
+    }
+    return TRUE;
+}
+#endif
+
+// Dispatch the help event to the relevant window
+bool wxContextHelp::DispatchEvent(wxWindow* win, const wxPoint& pt)
+{
+    wxWindow* subjectOfHelp = win;
+    bool eventProcessed = FALSE;
+    while (subjectOfHelp && !eventProcessed)
+    {
+        wxHelpEvent helpEvent(wxEVT_HELP, subjectOfHelp->GetId(), pt) ;
+        helpEvent.SetEventObject(this);
+        eventProcessed = win->GetEventHandler()->ProcessEvent(helpEvent);
+        
+        // Go up the window hierarchy until the event is handled (or not).
+        // I.e. keep submitting ancestor windows until one is recognised
+        // by the app code that processes the ids and displays help.
+        subjectOfHelp = subjectOfHelp->GetParent();
+    }
+    return eventProcessed;
+}
+
+
 #endif // wxUSE_HELP