wxGUI/psmap: show more useful message when preview fails

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@55713 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/gui_core/dialogs.py

@@ -2550,3 +2550,36 @@ class TextEntryDialog(wx.Dialog):
 
     def SetValue(self, value):
         self._textCtrl.SetValue(value)
+
+
+class HyperlinkDialog(wx.Dialog):
+    """!Dialog for displaying message with hyperlink."""
+    def __init__(self, parent, title, message, hyperlink,
+                hyperlinkLabel=None, style=wx.OK):
+        """!Constructor
+
+        @param parent gui parent         
+        @param title dialog title
+        @param message message
+        @param hyperlink url
+        @param hyperlinkLabel label shown instead of url
+        @param style button style
+        """
+        wx.Dialog.__init__(self, parent=parent, id=wx.ID_ANY, title=title,
+                           style=wx.DEFAULT_DIALOG_STYLE)
+
+        sizer = wx.BoxSizer(wx.VERTICAL)
+
+        label = wx.StaticText(self, label=message)
+        sizer.Add(item=label, proportion=0, flag=wx.ALIGN_CENTRE|wx.ALL, border=10)
+        hyperlinkLabel = hyperlinkLabel if hyperlinkLabel else hyperlink
+        hyperlinkCtrl = wx.HyperlinkCtrl(self, id=wx.ID_ANY,
+                                         label=hyperlinkLabel, url=hyperlink,
+                                         style=wx.HL_ALIGN_LEFT|wx.HL_CONTEXTMENU)
+        sizer.Add(item=hyperlinkCtrl, proportion=0, flag=wx.EXPAND|wx.ALL, border=10)        
+
+        btnsizer = self.CreateSeparatedButtonSizer(style)
+        sizer.Add(item=btnsizer, proportion=1, flag=wx.EXPAND | wx.ALL, border=10)
+    
+        self.SetSizer(sizer)
+        sizer.Fit(self)

gui/wxpython/psmap/frame.py

@@ -37,6 +37,7 @@ from psmap.toolbars     import PsMapToolbar
 from core.gcmd          import RunCommand, GError, GMessage
 from core.settings      import UserSettings
 from gui_core.forms     import GUI
+from gui_core.dialogs   import HyperlinkDialog
 from psmap.menudata     import PsMapMenuData
 
 from psmap.dialogs      import *
@@ -320,11 +321,14 @@ class PsMapFrame(wx.Frame):
                     import types
                     im.load = types.MethodType(loadPSForWindows, im)
                 im.save(self.imgName, format = 'PNG')
-                
             except IOError, e:
-                GError(parent = self,
-                       message = _("Unable to generate preview. %s") % e)
                 del busy
+                dlg = HyperlinkDialog(self, title=_("Preview not available"),
+                                      message=_("Preview is not available probably due to missing Ghostscript."),
+                                      hyperlink='http://trac.osgeo.org/grass/wiki/CompileOnWindows#Ghostscript',
+                                      hyperlinkLabel=_("Please follow instructions on GRASS Trac Wiki."))
+                dlg.ShowModal()
+                dlg.Destroy()
                 return