diff --git a/NodeGraphQt/constants.py b/NodeGraphQt/constants.py
index 9f031e81..59ef50e4 100644
--- a/NodeGraphQt/constants.py
+++ b/NodeGraphQt/constants.py
@@ -109,7 +109,7 @@
 # === ITEM CACHE MODE ===
 
 # QGraphicsItem.NoCache
-# QGraphicsItem.ItemCoordinateCache
 # QGraphicsItem.DeviceCoordinateCache
+# QGraphicsItem.ItemCoordinateCache
 
-ITEM_CACHE_MODE = QtWidgets.QGraphicsItem.ItemCoordinateCache
\ No newline at end of file
+ITEM_CACHE_MODE = QtWidgets.QGraphicsItem.DeviceCoordinateCache
\ No newline at end of file
diff --git a/NodeGraphQt/widgets/viewer.py b/NodeGraphQt/widgets/viewer.py
index a3770b24..2482bae1 100644
--- a/NodeGraphQt/widgets/viewer.py
+++ b/NodeGraphQt/widgets/viewer.py
@@ -130,7 +130,7 @@ def _set_viewer_zoom(self, value, sensitivity=None, pos=None):
         self.scale(scale, scale, pos)
 
     def _set_viewer_pan(self, pos_x, pos_y):
-        speed = self._scene_range.width() * 0.001
+        speed = self._scene_range.width() * 0.002
         x = -pos_x * speed
         y = -pos_y * speed
         self._scene_range.adjust(x, y, x, y)
diff --git a/example_auto_nodes.py b/example_auto_nodes.py
index 1874ad2c..2f50301c 100644
--- a/example_auto_nodes.py
+++ b/example_auto_nodes.py
@@ -34,17 +34,19 @@ def GetNodesFromFolder(FolderPath):
     return nodes
 
 
-def cook_node(graph,node):
+def cook_node(graph, node):
     node.cook()
 
 
-def print_functions(graph,node):
+def print_functions(graph, node):
     for func in node.module_functions:
         print(func)
 
-def toggle_auto_cook(graph,node):
+
+def toggle_auto_cook(graph, node):
     node.autoCook = not node.autoCook
 
+
 if __name__ == '__main__':
     app = QtWidgets.QApplication([])
 
diff --git a/example_auto_nodes/basic_nodes.py b/example_auto_nodes/basic_nodes.py
index f7da9e77..b731020e 100644
--- a/example_auto_nodes/basic_nodes.py
+++ b/example_auto_nodes/basic_nodes.py
@@ -1,12 +1,13 @@
 from .node_base.auto_node import AutoNode
 
+
 class FooNode(AutoNode):
     """
     A node class with 2 inputs and 2 outputs.
     """
 
     # unique node identifier.
-    __identifier__ = 'com.chantasticvfx'
+    __identifier__ = 'examples'
 
     # initial default node name.
     NODE_NAME = 'foo node'
@@ -21,7 +22,8 @@ def __init__(self):
         # create node outputs.
         self.add_output('out A')
         self.add_output('out B')
-        self.set_icon("example_auto_nodes/pear.png")
+        self.set_icon("example_auto_nodes/icons/pear.png")
+
 
 class BarNode(AutoNode):
     """
@@ -30,7 +32,7 @@ class BarNode(AutoNode):
     """
 
     # unique node identifier.
-    __identifier__ = 'com.chantasticvfx'
+    __identifier__ = 'examples'
 
     # initial default node name.
     NODE_NAME = 'bar'
diff --git a/example_auto_nodes/data_node.py b/example_auto_nodes/data_node.py
index 3e00d0a9..3af72062 100644
--- a/example_auto_nodes/data_node.py
+++ b/example_auto_nodes/data_node.py
@@ -13,22 +13,27 @@ class VectorSplit(AutoNode):
 
     def __init__(self):
         super(VectorSplit, self).__init__()
-        self.defaultValue = [0.0, 0.0, 0.0]
 
         self.add_output('x')
-        self.create_property("x", self.defaultValue[0])
+        self.create_property("x", 0.0)
         self.add_output('y')
-        self.create_property("y", self.defaultValue[1])
+        self.create_property("y", 0.0)
         self.add_output('z')
-        self.create_property("z", self.defaultValue[2])
+        self.create_property("z", 0.0)
+        self.add_output('w')
+        self.create_property("w", 0.0)
 
-        self.add_input("in vector",list)
+        self.add_input("in vector", list)
+        self.map = {0: "x", 1: "y", 2: "z", 3: "w"}
 
     def run(self):
         value = self.getInputData(0)
-        self.set_property("x", value[0])
-        self.set_property("y", value[1])
-        self.set_property("z", value[2])
+        if type(value) is not list:
+            self.error("Input data not list")
+        for index, data in enumerate(value):
+            if index > 3:
+                return
+            self.set_property(self.map[index], data)
 
 
 class VectorMaker(AutoNode):
@@ -42,17 +47,22 @@ class VectorMaker(AutoNode):
     def __init__(self):
         super(VectorMaker, self).__init__()
 
-        self.add_output('out')
-        self.create_property("out", [0, 0, 0])
-
-        self.add_input("x",float)
-        self.add_input("y",float)
-        self.add_input("z",float)
+        self.add_output('out', list)
+        self.create_property("out",None)
 
-        self.defaultValue = 0.0
+        self.add_input("x", float)
+        self.add_input("y", float)
+        self.add_input("z", float)
+        self.add_input("w", float)
 
     def run(self):
-        self.set_property("out", [self.getInputData(0), self.getInputData(1), self.getInputData(2)])
+        result = []
+        for i in range(4):
+            data = self.getInputData(i)
+            if data is not None:
+                result.append(data)
+
+        self.set_property("out", result)
 
 
 class DataConvect(AutoNode):
@@ -67,7 +77,7 @@ def __init__(self):
         super(DataConvect, self).__init__()
 
         self.add_output('out')
-        self.create_property("out",None)
+        self.create_property("out", None)
         self.add_input("in data")
 
         items = ["all to int"]
diff --git a/example_auto_nodes/icons/numpy.png b/example_auto_nodes/icons/numpy.png
new file mode 100644
index 00000000..4812a438
Binary files /dev/null and b/example_auto_nodes/icons/numpy.png differ
diff --git a/example_auto_nodes/pear.png b/example_auto_nodes/icons/pear.png
similarity index 100%
rename from example_auto_nodes/pear.png
rename to example_auto_nodes/icons/pear.png
diff --git a/example_auto_nodes/input_nodes.py b/example_auto_nodes/input_nodes.py
index 716aa931..8164188a 100644
--- a/example_auto_nodes/input_nodes.py
+++ b/example_auto_nodes/input_nodes.py
@@ -1,8 +1,7 @@
 from NodeGraphQt import QtCore
 from NodeGraphQt.constants import (NODE_PROP_VECTOR2,
                                    NODE_PROP_VECTOR3,
-                                   NODE_PROP_VECTOR4,
-                                   NODE_PROP_SLIDER)
+                                   NODE_PROP_VECTOR4)
 
 from .node_base.auto_node import AutoNode
 import os
@@ -19,7 +18,7 @@ class FloatInputNode(AutoNode):
     def __init__(self):
         super(FloatInputNode, self).__init__()
         self.output = self.add_output('out', float)
-        self.add_float_input('out', 'Float Value', value=0.0,range=(-10,10))
+        self.add_float_input('out', 'Float Value', value=0.0, range=(-10, 10))
 
 
 class IntInputNode(AutoNode):
@@ -44,7 +43,7 @@ def __init__(self):
         super(Vector2InputNode, self).__init__()
         self.output = self.add_output('out', list)
         self.create_property(
-            "out", [0, 0], widget_type=NODE_PROP_VECTOR2)
+            "out", [0.0, 0.0], widget_type=NODE_PROP_VECTOR2)
 
 
 class Vector3InputNode(AutoNode):
@@ -55,7 +54,7 @@ def __init__(self):
         super(Vector3InputNode, self).__init__()
         self.output = self.add_output('out', list)
         self.create_property(
-            "out", [0, 0, 0], widget_type=NODE_PROP_VECTOR3)
+            "out", [0.0, 0.0, 0.0], widget_type=NODE_PROP_VECTOR3)
 
 
 class Vector4InputNode(AutoNode):
@@ -66,7 +65,7 @@ def __init__(self):
         super(Vector4InputNode, self).__init__()
         self.output = self.add_output('out', list)
         self.create_property(
-            "out", [0, 0, 0, 0], widget_type=NODE_PROP_VECTOR4)
+            "out", [0.0, 0.0, 0.0, 0.0], widget_type=NODE_PROP_VECTOR4)
 
 
 class TickTimeNode(AutoNode):
@@ -106,7 +105,6 @@ def __init__(self):
         self.add_output('file content', str)
         self.create_property('file content', "")
         self.add_output('file path', str)
-
         self.add_file_input('file path', 'File Path')
 
     def run(self):
@@ -119,7 +117,7 @@ def run(self):
             except Exception as e:
                 self.error(e)
         else:
-            self.error('No existe %s' % path)
+            self.error('No exist %s' % path)
             self.set_property('file content', '')
 
 
@@ -142,3 +140,21 @@ def __init__(self):
 
         # create QLineEdit text input widget.
         self.add_text_input('out', 'Text Input')
+
+
+class BoolInputNode(AutoNode):
+    """
+    Input Bool data.
+    """
+
+    __identifier__ = 'Inputs'
+    NODE_NAME = 'Bool'
+
+    def __init__(self):
+        super(BoolInputNode, self).__init__()
+        self.add_output('out', bool)
+        self.create_property('out', True)
+        self.add_combo_menu('combo', 'Bool value', items=['True', 'False'])
+
+    def run(self):
+        self.set_property('out', eval(self.get_property('combo')))
diff --git a/example_auto_nodes/logic_nodes.py b/example_auto_nodes/logic_nodes.py
new file mode 100644
index 00000000..ee85b51a
--- /dev/null
+++ b/example_auto_nodes/logic_nodes.py
@@ -0,0 +1,77 @@
+from .basic_nodes import AutoNode
+
+
+class IfNode(AutoNode):
+    """
+    if node.
+    """
+
+    __identifier__ = 'Logics'
+    NODE_NAME = 'If'
+
+    def __init__(self):
+        super(IfNode, self).__init__()
+        self.condition = self.add_input('condition')
+        self._then = self.add_input('then')
+        self._else = self.add_input('else')
+        self.add_output('out')
+        self.create_property('out', None)
+
+    def run(self):
+        if self.getInputData(self.condition):
+            result = self.getInputData(self._then)
+        else:
+            result = self.getInputData(self._else)
+
+        self.set_property('out', result)
+
+
+class BooleanNode(AutoNode):
+    """
+    Boolean Logic funtions node.
+    """
+
+    __identifier__ = 'Logics'
+
+    NODE_NAME = 'Boolean'
+
+    logics = {'and': 'a and b',
+              'or': 'a or b',
+              'xor': '(not a and b) or (a and not b)',
+              'not': 'not a'}
+
+    def __init__(self):
+        super(BooleanNode, self).__init__()
+        self.a = self.add_input('a', bool)
+        self.b = self.add_input('b', bool)
+        self.add_output('out', bool)
+        self.create_property('out', None)
+        self.add_combo_menu('funcs',
+                            'Functions',
+                            items=list(self.logics.keys()),
+                            tab='widgets')
+
+        self.func = self.logics['and']
+        # switch math function type
+        self.view.widgets['funcs'].value_changed.connect(self.addFunction)
+
+    def addFunction(self, prop, func):
+        """
+        Create inputs based on math functions arguments.
+        """
+        self.func = self.logics[func]
+        if self.b.visible() and not 'b' in self.func:
+            self.b.set_visible(False)
+        elif not self.b.visible():
+            self.b.set_visible(True)
+        self.cook()
+
+    def run(self):
+        a = self.getInputData(self.a)
+        b = self.getInputData(self.b)
+
+        if a is None or (b is None and 'b' in self.func):
+            self.error("No inputs!")
+            return
+
+        self.set_property('out', eval(self.func))
diff --git a/example_auto_nodes/math_node.py b/example_auto_nodes/math_node.py
deleted file mode 100644
index 84b245d1..00000000
--- a/example_auto_nodes/math_node.py
+++ /dev/null
@@ -1,174 +0,0 @@
-#!/usr/bin/python
-# -*- coding: utf-8 -*-
-import math
-import inspect
-from functools import partial
-
-# add basic math functions to math library
-math.add = lambda x, y: x + y
-math.sub = lambda x, y: x - y
-math.mul = lambda x, y: x * y
-math.div = lambda x, y: x / y
-
-# Transform float to functions
-for constant in ['pi', 'e', 'tau', 'inf', 'nan']:
-    setattr(math, constant, partial(lambda x: x, getattr(math, constant)))
-
-from NodeGraphQt import BaseNode
-from .node_base.auto_node import AutoNode
-
-class MathFunctionsNode(AutoNode):
-    """
-    Math functions node.
-    """
-
-    # set a unique node identifier.
-    __identifier__ = 'Math'
-
-    # set the initial default node name.
-    NODE_NAME = 'Math Functions'
-
-    mathFuncs = [func for func in dir(math) if not func.startswith('_')]
-
-    def __init__(self):
-        super(MathFunctionsNode, self).__init__()
-        self.set_color(25, 58, 51)
-        self.add_combo_menu('funcs', 'Functions', items=self.mathFuncs,
-                            tab='widgets')
-
-        self.defaultValue = 0.0
-        # switch math function type
-        self.view.widgets['funcs'].value_changed.connect(self.addFunction)
-        self.view.widgets['funcs'].value_changed.connect(self.cook)
-        self.add_output('output')
-        self.create_property('output', None)
-
-        self.view.widgets['funcs'].widget.setCurrentIndex(2)
-
-    def addFunction(self, prop, func):
-        """
-        Create inputs based on math functions arguments.
-        """
-        self.func = getattr(math, func)
-        dataFunc = inspect.getfullargspec(self.func)
-
-        for arg in dataFunc.args:
-            if arg not in self.inputs().keys():
-                inPort = self.add_input(arg,float)
-
-        for inPort in self.input_ports():
-            if inPort.name() in dataFunc.args:
-                if not inPort.visible():
-                    inPort.set_visible(True)
-            else:
-                inPort.set_visible(False)
-
-    def run(self):
-        """
-        Evaluate all entries, pass them as arguments of the
-        chosen mathematical function.
-        """
-        args = []
-        for port in self.input_ports():
-            if not port.visible():
-                continue
-            data = self.getInputData(port)
-            if data and (type(data) is float or type(data) is int):
-                args.append(data)
-            else:
-                args.append(0)
-        try:
-            # Execute math function with arguments.
-            data = self.func(*args)
-
-            self.set_property('output', data)
-        except KeyError as error:
-            self.error("An input is missing! %s" % str(error))
-        except TypeError as error:
-            self.error("Error evaluating function: %s" % str(error))
-        except ValueError as error:
-            self.error("Error input data type: %s" % str(error))
-        except Exception as error:
-            self.error("Error : %s" % str(error))
-
-class VectorValue(AutoNode):
-    """
-    Create a basic vector data
-    """
-
-    __identifier__ = 'Math'
-    NODE_NAME = 'Vector'
-
-    def __init__(self):
-        super(VectorValue, self).__init__()
-        value = [0.0, 0.0, 0.0]
-
-        self.add_output('out',list)
-        self.create_property("out", value)
-
-        self.add_float_input('0', 'X', value=value[0], tab='widgets')
-        self.view.widgets['0'].value_changed.connect(lambda: self.updateValue(0))
-
-        self.add_float_input('1', 'Y', value=value[1], tab='widgets')
-        self.view.widgets['1'].value_changed.connect(lambda: self.updateValue(1))
-
-        self.add_float_input('2', 'Z', value=value[2], tab='widgets')
-        self.view.widgets['2'].value_changed.connect(lambda: self.updateValue(2))
-
-        self.defaultValue = value
-
-    def updateValue(self, index):
-        self.get_property("out")[index] = self.get_property(str(index))
-        self.cook()
-
-
-class VectorSplit(AutoNode):
-    """
-    Splict a vector to x,y,z
-    """
-
-    __identifier__ = 'Math'
-    NODE_NAME = 'Vector Split'
-
-    def __init__(self):
-        super(VectorSplit, self).__init__()
-        self.defaultValue = [0.0, 0.0, 0.0]
-
-        self.add_output('x')
-        self.create_property("x", self.defaultValue[0])
-        self.add_output('y')
-        self.create_property("y", self.defaultValue[1])
-        self.add_output('z')
-        self.create_property("z", self.defaultValue[2])
-
-        self.add_input("in vector",list)
-
-    def run(self):
-        value = self.getInputData(0)
-        self.set_property("x", value[0])
-        self.set_property("y", value[1])
-        self.set_property("z", value[2])
-
-
-class VectorMaker(AutoNode):
-    """
-    Create a vector by three float value
-    """
-
-    __identifier__ = 'Math'
-    NODE_NAME = 'Vector Maker'
-
-    def __init__(self):
-        super(VectorMaker, self).__init__()
-
-        self.add_output('out')
-        self.create_property("out", [0, 0, 0])
-
-        self.add_input("x",float)
-        self.add_input("y",float)
-        self.add_input("z",float)
-
-        self.defaultValue = 0.0
-
-    def run(self):
-        self.set_property("out", [self.getInputData(0), self.getInputData(1), self.getInputData(2)])
diff --git a/example_auto_nodes/module_nodes.py b/example_auto_nodes/module_nodes.py
index 915266a6..ce9994e3 100644
--- a/example_auto_nodes/module_nodes.py
+++ b/example_auto_nodes/module_nodes.py
@@ -9,11 +9,11 @@
 import numpydoc.docscrape
 import inspect
 
-import example_auto_nodes.wrappers.math as _math
-import example_auto_nodes.wrappers.list as _list
-import example_auto_nodes.wrappers.dict as _dict
-import example_auto_nodes.wrappers.str as _str
-import example_auto_nodes.wrappers.tuple as _tuple
+from .wrappers import math as _math
+from .wrappers import list as _list
+from .wrappers import dict as _dict
+from .wrappers import str as _str
+from .wrappers import tuple as _tuple
 
 
 class MathModuleNode(ModuleNode):
@@ -103,6 +103,7 @@ class numpyModuleNode(ModuleNode):
 
     def __init__(self):
         super(numpyModuleNode, self).__init__()
+        self.set_icon("example_auto_nodes/icons/numpy.png")
 
     def is_function(self, obj):
         result = super(numpyModuleNode, self).is_function(obj)
diff --git a/example_auto_nodes/node_base/auto_node.py b/example_auto_nodes/node_base/auto_node.py
index 7cf1b517..fd0aeffc 100644
--- a/example_auto_nodes/node_base/auto_node.py
+++ b/example_auto_nodes/node_base/auto_node.py
@@ -1,9 +1,11 @@
 from NodeGraphQt.base.node import BaseNode
 from NodeGraphQt.base.port import Port
 from NodeGraphQt.constants import NODE_PROP
+from NodeGraphQt import QtCore
 import random
 import copy
 
+
 def rand_color(seed_type):
     seed = id(seed_type)
     random.seed(seed + 10)
@@ -15,9 +17,12 @@ def rand_color(seed_type):
     return (r, g, b, 255)
 
 
-class AutoNode(BaseNode):
+class AutoNode(BaseNode,QtCore.QObject):
+    cooked = QtCore.Signal()
+
     def __init__(self, defaultInputType=None, defaultOutputType=None):
         super(AutoNode, self).__init__()
+        QtCore.QObject.__init__(self)
         self.needCook = True
         self._autoCook = True
         self._error = False
@@ -52,6 +57,11 @@ def cookNextNode(self):
                 n.cook()
 
     def getInputData(self, port):
+        # get input data by input Port,the type of "port" can be :
+        # int : Port index
+        # str : Port name
+        # Port : Port object
+
         if type(port) is int:
             to_port = self.input(port)
         elif type(port) is str:
@@ -99,18 +109,18 @@ def cook(self, forceCook=False):
         if self.error():
             return
 
+        self.cooked.emit()
         self.cookNextNode()
 
     def run(self):
         pass
-        # print("RUN {} Node".format(self.name()))
 
     def on_input_connected(self, to_port, from_port):
         if self.checkPortType(to_port, from_port):
             self.cook()
         else:
             self.needCook = False
-            self.graph._on_connection_changed([(from_port.view, to_port.view)], [])
+            to_port.disconnect_from(from_port)
 
     def on_input_disconnected(self, to_port, from_port):
         if not self.needCook:
@@ -124,6 +134,9 @@ def set_disabled(self, mode=False):
             self.cook()
 
     def checkPortType(self, to_port, from_port):
+        # None type port can connect with any other type port
+        # types in self.matchTypes can connect with each other
+
         if hasattr(to_port, "DataType") and hasattr(from_port, "DataType"):
             if to_port.DataType is not from_port.DataType:
                 for types in self.matchTypes:
@@ -139,7 +152,6 @@ def set_property(self, name, value):
         if name in self.model.custom_properties.keys():
             self.cook()
 
-
     def set_port_type(self, port, value_type):
         current_port = None
 
diff --git a/example_auto_nodes/node_base/module_node.py b/example_auto_nodes/node_base/module_node.py
index cca8571a..2d80aba3 100644
--- a/example_auto_nodes/node_base/module_node.py
+++ b/example_auto_nodes/node_base/module_node.py
@@ -46,7 +46,6 @@ class ModuleNode(AutoNode):
 
     def __init__(self,defaultInputType=None,defaultOutputType=None):
         super(ModuleNode, self).__init__(defaultInputType,defaultOutputType)
-        self.set_color(25, 58, 51)
         self.add_combo_menu('funcs', 'Functions', items=list(self.module_functions.keys()))
 
         # switch math function type
diff --git a/example_auto_nodes/viewer_nodes.py b/example_auto_nodes/viewer_nodes.py
index 26bbf89d..775e3172 100644
--- a/example_auto_nodes/viewer_nodes.py
+++ b/example_auto_nodes/viewer_nodes.py
@@ -1,6 +1,5 @@
 from .node_base.auto_node import AutoNode
-from NodeGraphQt.constants import NODE_PROP_QTEXTEDIT
-from NodeGraphQt.widgets.node_widgets import NodeLineEdit
+
 
 class DataViewerNode(AutoNode):
     __identifier__ = 'Viewers'
diff --git a/example_auto_nodes/widget_nodes.py b/example_auto_nodes/widget_nodes.py
index 24611c4c..ff5f90a7 100644
--- a/example_auto_nodes/widget_nodes.py
+++ b/example_auto_nodes/widget_nodes.py
@@ -1,12 +1,13 @@
 from .node_base.auto_node import AutoNode
 
+
 class DropdownMenuNode(AutoNode):
     """
     An example node with a embedded added QCombobox menu.
     """
 
     # unique node identifier.
-    __identifier__ = 'com.chantasticvfx'
+    __identifier__ = 'examples'
 
     # initial default node name.
     NODE_NAME = 'menu'
@@ -30,7 +31,7 @@ class CheckboxNode(AutoNode):
     """
 
     # set a unique node identifier.
-    __identifier__ = 'com.chantasticvfx'
+    __identifier__ = 'examples'
 
     # set the initial default node name.
     NODE_NAME = 'checkbox'