- Handling key and mouse events on Cocos2d

Author: SteveClement

handling_events.py

@@ -0,0 +1,138 @@
+#!/usr/bin/env python3
+# Source: https://github.com/los-cocos/cocos/blob/master/samples/handling_events.py
+from __future__ import division, print_function, unicode_literals
+
+# This code is so you can run the samples without installing the package
+import sys
+import os
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))
+#
+
+import cocos
+from cocos.director import director
+
+import pyglet
+
+# Our main KeyDisplay Class
+class KeyDisplay(cocos.layer.Layer):
+
+    # If you want your layer to receive director.window events
+    # you have to set this variable to 'True'
+    is_event_handler = True     #: enable pyglet's events
+
+    def __init__(self):
+
+        super(KeyDisplay, self).__init__()
+
+        self.text = cocos.text.Label("", x=100, y=280)
+
+        # To keep track of which keys are pressed:
+        self.keys_pressed = set()
+        self.update_text()
+        self.add(self.text)
+
+    # This method of the class updates the text
+    def update_text(self):
+        key_names = [pyglet.window.key.symbol_string(k) for k in self.keys_pressed]
+        text = 'Keys: ' + ','.join(key_names)
+        # Update self.text
+        self.text.element.text = text
+
+    def on_key_press(self, key, modifiers):
+        """This function is called when a key is pressed.
+
+        'key' is a constant indicating which key was pressed.
+        'modifiers' is a bitwise or of several constants indicating which
+           modifiers are active at the time of the press (ctrl, shift, capslock, etc.)
+
+        See also on_key_release situations when a key press does not fire an
+         'on_key_press' event.
+        """
+        self.keys_pressed.add(key)
+        self.update_text()
+
+    def on_key_release(self, key, modifiers):
+        """This function is called when a key is released.
+
+        'key' is a constant indicating which key was pressed.
+        'modifiers' is a bitwise or of several constants indicating which
+           modifiers are active at the time of the press (ctrl, shift, capslock, etc.)
+
+        Constants are the ones from pyglet.window.key
+
+        Sometimes a key release can arrive without a previous 'press' event, so discard
+        is used instead of remove.
+
+        This can happen in Windows by example when you 'press ALT, release ALT, press B,
+        release B'; the events received are 'pressed ALT, released ALT, released B'.
+
+        This may depend on the pyglet version, here pyglet from repo at may 2014 was used.
+        """
+        self.keys_pressed.discard(key)
+        self.update_text()
+
+
+class MouseDisplay(cocos.layer.Layer):
+
+    # If you want that your layer receives events
+    # you must set this variable to 'True',
+    # otherwise it won't receive any event.
+    is_event_handler = True
+
+    def __init__(self):
+        super(MouseDisplay, self).__init__()
+
+        self.posx = 100
+        self.posy = 240
+        self.text = cocos.text.Label('No mouse events yet', font_size=18, x=self.posx, y=self.posy)
+        self.add(self.text)
+
+    def update_text(self, x, y):
+        text = 'Mouse @ %d,%d' % (x, y)
+        self.text.element.text = text
+        self.text.element.x = self.posx
+        self.text.element.y = self.posy
+
+    def on_mouse_motion(self, x, y, dx, dy):
+        """Called when the mouse moves over the app window with no button pressed
+
+        (x, y) are the physical coordinates of the mouse
+        (dx, dy) is the distance vector covered by the mouse pointer since the
+          last call.
+        """
+        self.update_text(x, y)
+
+    def on_mouse_drag(self, x, y, dx, dy, buttons, modifiers):
+        """Called when the mouse moves over the app window with some button(s) pressed
+
+        (x, y) are the physical coordinates of the mouse
+        (dx, dy) is the distance vector covered by the mouse pointer since the
+          last call.
+        'buttons' is a bitwise or of pyglet.window.mouse constants LEFT, MIDDLE, RIGHT
+        'modifiers' is a bitwise or of pyglet.window.key modifier constants
+           (values like 'SHIFT', 'OPTION', 'ALT')
+        """
+        self.update_text(x, y)
+
+    def on_mouse_press(self, x, y, buttons, modifiers):
+        """This function is called when any mouse button is pressed
+
+        (x, y) are the physical coordinates of the mouse
+        'buttons' is a bitwise or of pyglet.window.mouse constants LEFT, MIDDLE, RIGHT
+        'modifiers' is a bitwise or of pyglet.window.key modifier constants
+           (values like 'SHIFT', 'OPTION', 'ALT')
+
+        cocos has 2 coordinates systems, a physical one and a virtual one.
+        pyglet sends physical coordinates, as we want to map it in a virtual context,
+        director.get_virtual_coordinates(x, y) does the correct mapping for us
+        doing it with self.posx, self.posy = x,y will work too but as soon
+        as we change the window size the mapping is off-set
+        """
+        self.posx, self.posy = director.get_virtual_coordinates(x, y)
+        self.update_text(x, y)
+
+
+if __name__ == "__main__":
+    director.init(resizable=True)
+    # Run a scene with our event displayers:
+    director.run(cocos.scene.Scene(KeyDisplay(), MouseDisplay()))