Added wxScrolledPanel from Wil Sadkin

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_4_BRANCH@19768 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

wxPython/wxPython/lib/scrolledpanel.py

@@ -0,0 +1,85 @@
+#----------------------------------------------------------------------------
+# Name:         wxScrolledPanel.py
+# Author:       Will Sadkin
+# Created:      03/21/2003
+# Copyright:    (c) 2003 by Will Sadkin
+# RCS-ID:       $Id$
+# License:      wxWindows license
+#----------------------------------------------------------------------------
+#
+
+from wxPython.wx import *
+
+
+class wxScrolledPanel( wxScrolledWindow ):
+    """
+wxScrolledPanel fills a "hole" in the implementation of wxScrolledWindow,
+providing automatic scrollbar and scrolling behavior and the tab traversal
+mangement that wxScrolledWindow lacks.  This code was based on the original
+demo code showing how to do this, but is now available for general use
+as a proper class (and the demo is now converted to just use it.)
+"""
+    def __init__(self, parent, id=-1,
+                 pos = wxDefaultPosition, size = wxDefaultSize,
+                 style = wxTAB_TRAVERSAL, name = "scrolledpanel"):
+
+        wxScrolledWindow.__init__(self, parent, -1,
+                                  pos=pos, size=size,
+                                  style=style, name=name)
+
+
+    def SetupScrolling(self, scroll_x=True, scroll_y=True, rate_x=1, rate_y=1):
+        """
+        This function sets up the event handling necessary to handle
+        scrolling properly. It should be called within the __init__
+        function of any class that is derived from wxScrolledPanel,
+        once the controls on the panel have been constructed and
+        thus the size of the scrolling area can be determined.
+
+        """
+        # The following is all that is needed to integrate the sizer and the
+        # scrolled window.
+        if not scroll_x: rate_x = 0
+        if not scroll_y: rate_y = 0
+
+        self.SetScrollRate(rate_x, rate_y)
+
+        self.GetSizer().SetVirtualSizeHints(self)
+        EVT_CHILD_FOCUS(self, self.OnChildFocus)
+        wxCallAfter(self.Scroll, 0, 0) # scroll back to top after initial events
+
+
+    def OnChildFocus(self, evt):
+        # If the child window that gets the focus is not visible,
+        # this handler will try to scroll enough to see it.
+        evt.Skip()
+        child = evt.GetWindow()
+
+        sppu_x, sppu_y = self.GetScrollPixelsPerUnit()
+        vs_x, vs_y   = self.GetViewStart()
+        cpos = child.GetPosition()
+        csz  = child.GetSize()
+        new_vs_x, new_vs_y = -1, -1
+
+        # is it before the left edge?
+        if cpos.x < 0 and sppu_x > 0:
+                new_vs_x = cpos.x / sppu_x
+
+        # is it above the top?
+        if cpos.y < 0 and sppu_y > 0:
+            new_vs_y = cpos.y / sppu_y
+
+
+        # is it past the right edge ?
+        if cpos.x + csz.width > self.GetClientSize().width and sppu_x > 0:
+            diff = (cpos.x + csz.width - self.GetClientSize().width) / sppu_x
+            new_vs_x = vs_x + diff + 1
+
+        # is it below the bottom ?
+        if cpos.y + csz.height > self.GetClientSize().height and sppu_y > 0:
+            diff = (cpos.y + csz.height - self.GetClientSize().height) / sppu_y
+            new_vs_y = vs_y + diff + 1
+
+        # if we need to adjust
+        if new_vs_x != -1 or new_vs_y != -1:
+            self.Scroll(new_vs_x, new_vs_y)