Added wx.lib.ticker.Ticker class from Chris Mellon.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@28998 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

wxPython/wx/lib/ticker.py

@@ -0,0 +1,211 @@
+#----------------------------------------------------------------------
+# Name:        wx.lib.ticker
+# Purpose:     A news-ticker style scrolling text control
+#
+# Author:      Chris Mellon
+#
+# Created:     29-Aug-2004
+# RCS-ID:      $Id$
+# Copyright:   (c) 2004 by Chris Mellon
+# Licence:     wxWindows license
+#----------------------------------------------------------------------
+
+"""News-ticker style scrolling text control
+
+    Can scroll from right to left or left to right.
+    Speed of the ticking is controlled by two parameters:
+        Frames per Second(FPS): How many times per second the ticker updates
+        Pixels per Frame(PPF): How many pixels the text moves each update
+    Low FPS with high PPF will result in "jumpy" text, lower PPF with higher FPS
+    is smoother (but blurrier and more CPU intensive) text.
+"""
+
+import wx
+
+#----------------------------------------------------------------------
+
+class Ticker(wx.PyControl):
+    def __init__(self, 
+            parent, 
+            id=-1, 
+            text=wx.EmptyString,        #text in the ticker
+            fgcolor = wx.BLACK,         #text/foreground color
+            bgcolor = wx.WHITE,         #background color
+            start=True,                 #if True, the ticker starts immediately
+            ppf=2,                      #pixels per frame
+            fps=20,                     #frames per second
+            direction="rtl",            #direction of ticking, rtl or ltr
+            pos=wx.DefaultPosition, size=wx.DefaultSize, style=wx.NO_BORDER, 
+            name="Ticker"
+        ):
+        wx.PyControl.__init__(self, parent, id=id, pos=pos, size=size, style=style, name=name)
+        self.timer = wx.Timer(owner=self)
+        self._extent = (-1, -1)  #cache value for the GetTextExtent call
+        self._offset = 0
+        self._fps = fps  #frames per second
+        self._ppf = ppf  #pixels per frame
+        self.SetDirection(direction)
+        self.SetText(text)
+        self.SetBestFittingSize(size)
+        self.SetForegroundColour(fgcolor)
+        self.SetBackgroundColour(bgcolor)
+        wx.EVT_TIMER(self, -1, self.OnTick)
+        wx.EVT_PAINT(self, self.OnPaint)
+        wx.EVT_ERASE_BACKGROUND(self, self.OnErase)
+        if start:
+            self.Start()
+
+            
+    def Stop(self):
+        """Stop moving the text"""
+        self.timer.Stop()
+
+        
+    def Start(self):
+        """Starts the text moving"""
+        if not self.timer.IsRunning():
+            self.timer.Start(1000 / self._fps)
+
+    
+    def IsTicking(self):
+        """Is the ticker ticking? ie, is the text moving?"""
+        return self.timer.IsRunning()
+
+        
+    def SetFPS(self, fps):
+        """Adjust the update speed of the ticker"""
+        self._fps = fps
+        self.Stop()
+        self.Start()
+
+        
+    def GetFPS(self):
+        """Update speed of the ticker"""
+        return self._fps
+
+        
+    def SetPPF(self, ppf):
+        """Set the number of pixels per frame the ticker moves - ie, how "jumpy" it is"""
+        self._ppf = ppf
+
+        
+    def GetPPF(self):
+        """Pixels per frame"""
+        return self._ppf
+
+        
+    def SetFont(self, font):
+        self._extent = (-1, -1)
+        wx.Control.SetFont(self, font)
+
+        
+    def SetDirection(self, dir):
+        """Sets the direction of the ticker: right to left(rtl) or left to right (ltr)"""
+        if dir == "ltr" or dir == "rtl":
+            if self._offset <> 0:
+                #Change the offset so it's correct for the new direction
+                self._offset = self._extent[0] + self.GetSize()[0] - self._offset
+            self._dir = dir
+        else:
+            raise TypeError
+
+            
+    def GetDirection(self):
+        return self._dir
+
+        
+    def SetText(self, text):
+        """Set the ticker text."""
+        self._text = text
+        self._extent = (-1, -1)
+        if not self._text:
+            self.Refresh() #Refresh here to clear away the old text.
+            
+            
+    def GetText(self):
+        return self._text
+
+        
+    def UpdateExtent(self, dc):
+        """Updates the cached text extent if needed"""
+        if not self._text:
+            self._extent = (-1, -1)
+            return
+        if self._extent == (-1, -1):
+            self._extent = dc.GetTextExtent(self.GetText())
+            
+            
+    def DrawText(self, dc):
+        """Draws the ticker text at the current offset using the provided DC"""
+        dc.SetTextForeground(self.GetForegroundColour())
+        dc.SetFont(self.GetFont())
+        self.UpdateExtent(dc)
+        if self._dir == "ltr":
+            offx = self._offset - self._extent[0]
+        else:
+            offx = self.GetSize()[0] - self._offset
+        offy = (self.GetSize()[1] - self._extent[1]) / 2 #centered vertically
+        dc.DrawText(self._text, offx, offy)
+        
+        
+    def OnTick(self, evt):
+        self._offset += self._ppf
+        w1 = self.GetSize()[0]
+        w2 = self._extent[0]
+        if self._offset >= w1+w2:
+            self._offset = 0
+        self.Refresh()
+        
+        
+    def OnPaint(self, evt):
+        dc = wx.BufferedPaintDC(self)
+        brush = wx.Brush(self.GetBackgroundColour())
+        dc.SetBackground(brush)
+        dc.Clear()
+        self.DrawText(dc)
+        
+        
+    def OnErase(self, evt):
+        """Noop because of double buffering"""
+        pass
+        
+
+    def AcceptsFocus(self):
+        """Non-interactive, so don't accept focus"""
+        return False
+
+        
+    def DoGetBestSize(self):
+        """Width we don't care about, height is either -1, or the character
+        height of our text with a little extra padding
+        """
+        if self._extent == (-1, -1):
+            if not self._text:
+                h = self.GetCharHeight()
+            else:
+                h = self.GetTextExtent(self.GetText())[1]
+        else:
+            h = self._extent[1]
+        return (100, h+5)
+
+
+    def ShouldInheritColours(self): 
+        """Don't get colours from our parent..."""
+        return False
+        
+
+
+#testcase/demo
+if __name__ == '__main__':
+    app = wx.PySimpleApp()
+    f = wx.Frame(None)
+    p = wx.Panel(f)
+    t = Ticker(p, text="Some sample ticker text")   
+    #set ticker properties here if you want
+    s = wx.BoxSizer(wx.VERTICAL)
+    s.Add(t, flag=wx.GROW, proportion=0)
+    p.SetSizer(s)
+    f.Show()
+    app.MainLoop()
+    
+