add tool tip class to draw tool tip box for the buttons

coretk/coretk/coretoolbar.py

@@ -3,6 +3,8 @@ import tkinter as tk
 
 from coretk.images import Images
 
+# from coretk.tooltip import CreateToolTip
+
 
 class CoreToolbar(object):
     """
@@ -267,6 +269,7 @@ class CoreToolbar(object):
             command=lambda: self.draw_network_layer_options(network_layer_button),
         )
         network_layer_button.pack(side=tk.TOP, pady=1)
+        # network_layer_btt = CreateToolTip(network_layer_button, "Network-layer virtual nodes")
 
     def pick_hub(self, main_button):
         self.link_layer_option_menu.destroy()

coretk/coretk/tooltip.py

@@ -0,0 +1,38 @@
+import tkinter as tk
+
+
+class CreateToolTip(object):
+    """
+    Create tool tip for a given widget
+    """
+
+    def __init__(self, widget, text="widget info"):
+        self.widget = widget
+        self.text = text
+        self.widget.bind("<Enter>", self.enter)
+        self.widget.bind("<Leave>", self.close)
+        self.tw = None
+
+    def enter(self, event=None):
+        x = 0
+        y = 0
+        x, y, cx, cy = self.widget.bbox("insert")
+        x += self.widget.winfo_rootx()
+        y += self.widget.winfo_rooty() + 32
+
+        self.tw = tk.Toplevel(self.widget)
+        self.tw.wm_overrideredirect(True)
+        self.tw.wm_geometry("+%d+%d" % (x, y))
+        label = tk.Label(
+            self.tw,
+            text=self.text,
+            justify=tk.LEFT,
+            background="yellow",
+            relief="solid",
+            borderwidth=1,
+        )
+        label.pack(ipadx=1)
+
+    def close(self, event=None):
+        if self.tw:
+            self.tw.destroy()