Add overlay classes

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/Phoenix/trunk@71497 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/overlay/overlay.py

@@ -0,0 +1,88 @@
+"""
+A simple sample of using a wx.Overlay to draw a rubberband effect
+"""
+
+import wx
+print wx.version()
+
+class TestPanel(wx.Panel):
+    def __init__(self, *args, **kw):
+        wx.Panel.__init__(self, *args, **kw)
+
+        self.Bind(wx.EVT_PAINT, self.OnPaint)
+        self.Bind(wx.EVT_LEFT_DOWN, self.OnLeftDown)
+        self.Bind(wx.EVT_LEFT_UP, self.OnLeftUp)
+        self.Bind(wx.EVT_MOTION, self.OnMouseMove)
+
+        self.startPos = None
+        self.overlay = wx.Overlay()
+
+        wx.TextCtrl(self, pos=(140,20))
+        
+
+    def OnPaint(self, evt):
+        # Just some simple stuff to paint in the window for an example
+        dc = wx.PaintDC(self)
+        dc.SetBackground(wx.Brush("sky blue"))
+        dc.Clear() 
+        dc.DrawLabel("Drag the mouse across this window to see \n"
+                     "a rubber-band effect using wx.Overlay",
+                     (140, 50, -1, -1))
+
+        coords = ((40,40),(200,220),(210,120),(120,300))
+        dc = wx.GCDC(dc)
+        dc.SetPen(wx.Pen("red", 2))
+        dc.SetBrush(wx.CYAN_BRUSH)
+        dc.DrawPolygon(coords)
+        
+
+    def OnLeftDown(self, evt):
+        # Capture the mouse and save the starting position for the
+        # rubber-band
+        self.CaptureMouse()
+        self.startPos = evt.GetPosition()
+
+
+    def OnMouseMove(self, evt):
+        if evt.Dragging() and evt.LeftIsDown():
+            rect = wx.Rect(topLeft=self.startPos, bottomRight=evt.GetPosition())
+            
+            # Draw the rubber-band rectangle using an overlay so it
+            # will manage keeping the rectangle and the former window
+            # contents separate.
+            dc = wx.ClientDC(self)
+            odc = wx.DCOverlay(self.overlay, dc)
+            odc.Clear()
+
+            # Mac's DC is already the same as a GCDC, and it causes
+            # problems with the overlay if we try to use an actual
+            # wx.GCDC so don't try it.
+            if 'wxMac' not in wx.PlatformInfo:
+                dc = wx.GCDC(dc)
+            
+            dc.SetPen(wx.Pen("black", 2))
+            dc.SetBrush(wx.Brush(wx.Colour(0xC0, 0xC0, 0xC0, 0x80)))
+            dc.DrawRectangle(rect)
+
+
+    def OnLeftUp(self, evt):
+        if self.HasCapture():
+            self.ReleaseMouse()
+        self.startPos = None
+
+        # When the mouse is released we reset the overlay and it
+        # restores the former content to the window.
+        dc = wx.ClientDC(self)
+        odc = wx.DCOverlay(self.overlay, dc)
+        odc.Clear()
+        del odc
+        self.overlay.Reset()
+
+            
+
+app = wx.App(redirect=False)
+frm = wx.Frame(None, title="wx.Overlay Test", size=(450,450))
+#frm.SetDoubleBuffered(True)
+pnl = TestPanel(frm)
+frm.Show()
+app.MainLoop()