Matt's examples
diff --git a/Demo/tkinter/matt/canvas-mult-item-sel.py b/Demo/tkinter/matt/canvas-mult-item-sel.py
new file mode 100644
index 0000000..1e49ba6
--- /dev/null
+++ b/Demo/tkinter/matt/canvas-mult-item-sel.py
@@ -0,0 +1,85 @@
+from Tkinter import *
+
+# allows moving dots with multiple selection.
+
+SELECTED_COLOR = "red"
+UNSELECTED_COLOR = "blue"
+
+class Test(Frame):
+ ###################################################################
+ ###### Event callbacks for THE CANVAS (not the stuff drawn on it)
+ ###################################################################
+ def mouseDown(self, event):
+ # see if we're inside a dot. If we are, it
+ # gets tagged as "current" for free by tk.
+
+ if not event.widget.find_withtag("current"):
+ # we clicked outside of all dots on the canvas. unselect all.
+
+ # re-color everything back to an unselected color
+ self.draw.itemconfig("selected", {"fill" : UNSELECTED_COLOR})
+ # unselect everything
+ self.draw.dtag("selected")
+ else:
+ # mark as "selected" the thing the cursor is under
+ self.draw.addtag("selected", "withtag", "current")
+ # color it as selected
+ self.draw.itemconfig("selected", {"fill": SELECTED_COLOR})
+
+ self.lastx = event.x
+ self.lasty = event.y
+
+
+ def mouseMove(self, event):
+ self.draw.move("selected", event.x - self.lastx, event.y - self.lasty)
+ self.lastx = event.x
+ self.lasty = event.y
+
+ def makeNewDot(self):
+ # create a dot, and mark it as current
+ fred = self.draw.create_oval(0, 0, 20, 20,
+ {"fill" : SELECTED_COLOR, "tag" : "current"})
+ # and make it selected
+ self.draw.addtag("selected", "withtag", "current")
+
+ def createWidgets(self):
+ self.QUIT = Button(self, {'text': 'QUIT',
+ 'fg': 'red',
+ 'command': self.quit})
+
+ ################
+ # make the canvas and bind some behavior to it
+ ################
+ self.draw = Canvas(self, {"width" : "5i", "height" : "5i"})
+ Widget.bind(self.draw, "<1>", self.mouseDown)
+ Widget.bind(self.draw, "<B1-Motion>", self.mouseMove)
+
+
+ # and other things.....
+ self.button = Button(self, {"text" : "make a new dot",
+ "command" : self.makeNewDot,
+ "fg" : "blue"})
+
+ self.label = Message(self,
+ {"width" : "5i",
+ "text" : SELECTED_COLOR + " dots are selected and can be dragged.\n" +
+ UNSELECTED_COLOR + " are not selected.\n" +
+ "Click in a dot to select it.\n" +
+ "Click on empty space to deselect all dots." })
+
+ self.QUIT.pack({'side': 'bottom', 'fill': 'both'})
+ self.label.pack({"side" : "bottom", "fill" : "x", "expand" : 1})
+ self.button.pack({"side" : "bottom", "fill" : "x"})
+ self.draw.pack({'side': 'left'})
+
+
+ def __init__(self, master=None):
+ Frame.__init__(self, master)
+ Pack.config(self)
+ self.createWidgets()
+
+test = Test()
+test.mainloop()
+
+
+