Mouse functions
class Mouse
The Mouse
class is used to collect mouse input. You generally create a
Mouse
object with the Mouse()
factory function, as described in the
section Creating a Mouse.
Example:
# Draw a 'fixation-dot mouse cursor' until a button is clicked
my_mouse = Mouse()
my_canvas = Canvas()
while True:
button, position, timestamp = my_mouse.get_click(timeout=20)
if button is not None:
break
(x,y), time = my_mouse.get_pos()
my_canvas.clear()
my_canvas.fixdot(x, y)
my_canvas.show()
Things to know
Creating a Mouse
You generally create a Mouse
with the Mouse()
factory function:
my_mouse = Mouse()
Optionally, you can pass Response keywords to
Mouse()
to set the default behavior:
my_mouse = Mouse(timeout=2000)
Coordinates
- When Uniform coordinates is set to 'yes', coordinates are relative to the center of the display. That is, (0,0) is the center. This is the default as of OpenSesame 3.0.0.
- When Uniform coordinates is set to 'no', coordinates are relative to the top-left of the display. That is, (0,0) is the top-left. This was the default in OpenSesame 2.9.X and earlier.
Button numbers
Mouse buttons are numbered as follows:
- Left button
- Middle button
- Right button
- Scroll up
- Scroll down
Touch screens
When working with a touch screen, a touch is registered as button 1 (left button).
Response keywords
Functions that accept **resp_args
take the following keyword
arguments:
timeout
specifies a timeout value in milliseconds, or is set toNone
to disable the timeout.buttonlist
specifies a list of buttons that are accepted, or is set toNone
accept all buttons.visible
indicates whether the mouse cursor becomes visible when a click is collected (True
orFalse
). To immediately change cursor visibility, use [mouse.show_cursor].
# Get a left or right button press with a timeout of 3000 ms
my_mouse = Mouse()
button, time = my_mouse.get_click(buttonlist=[1,3], timeout=3000)
Response keywords only affect the current operation (except when passed to [mouse.__init__][init]). To change the behavior for all subsequent operations, set the response properties directly:
# Get two left or right presses with a 5000 ms timeout
my_mouse = Mouse()
my_mouse.buttonlist = [1,3]
my_mouse.timeout = 5000
button1, time1 = my_mouse.get_click()
button2, time2 = my_mouse.get_click()
Or pass the response keywords to [mouse.__init__][init]:
# Get two left or right presses with a 5000 ms timeout
my_mouse = Mouse(buttonlist=[1,3], timeout=5000)
button1, time1 = my_mouse.get_click()
button2, time2 = my_mouse.get_click()
function Mouse.flush()
Clears all pending input, not limited to the mouse.
Example:
my_mouse = Mouse()
my_mouse.flush()
button, position, timestamp = my_mouse.get_click()
Returns:
True if a button had been clicked (i.e., if there was something to flush) and False otherwise.
- Type: bool
function Mouse.get_click(**resp_args)
Collects a mouse click.
Example:
my_mouse = Mouse()
button, (x, y), timestamp = my_mouse.get_click(timeout=5000)
if button is None:
print('A timeout occurred!')
Keyword dict:
**resp_args
: Optional [response keywords] that will be used for this call to [mouse.get_click]. This does not affect subsequent operations.
Returns:
A (button, position, timestamp) tuple. The button and position are None
if a timeout occurs. Position is an (x, y) tuple in screen coordinates.
- Type: tuple
function Mouse.get_click_release(**resp_args)
New in v3.2.0
Collects a mouse-click release.
Important: This function is currently not implemented for the psycho backend.
Example:
my_mouse = Mouse()
button, (x, y), timestamp = my_mouse.get_click_release(timeout=5000)
if button is None:
print('A timeout occurred!')
Keyword dict:
**resp_args
: Optional [response keywords] that will be used for this call to [mouse.get_click_release]. This does not affect subsequent operations.
Returns:
A (button, position, timestamp) tuple. The button and position are None
if a timeout occurs. Position is an (x, y) tuple in screen coordinates.
- Type: tuple
function Mouse.get_pos()
Returns the current position of the cursor.
Example:
my_mouse = Mouse()
(x, y), timestamp = my_mouse.get_pos()
print('The cursor was at (%d, %d)' % (x, y))
Returns:
A (position, timestamp) tuple.
- Type: tuple
function Mouse.get_pressed()
Returns the current state of the mouse buttons. A True value means the button is currently being pressed.
Example:
my_mouse = Mouse()
buttons = my_mouse.get_pressed()
b1, b2, b3 = buttons
print('Currently pressed mouse buttons: (%d,%d,%d)' % (b1,b2,b3))
Returns:
A (button1, button2, button3) tuple of boolean values.
- Type: tuple.
function Mouse.set_pos(pos=(0, 0))
Sets the position of the mouse cursor.
Warning: set_pos()
is unreliable and will silently fail on
some systems.
Example:
my_mouse = Mouse()
my_mouse.set_pos(pos=(0,0))
Keywords:
pos
-- An (x,y) tuple for the new mouse coordinates.- Type: tuple
- Default: (0, 0)
function Mouse.show_cursor(show=True)
Immediately changes the visibility of the mouse cursor.
Note: In most cases, you will want to use the visible
[keyword][Response keywords], which changes the visibility during
response collection, that is, while mouse.get_click()
is called.
Keywords:
show
-- Indicates whether the cursor is shown (True) or hidden (False).- Type: bool
- Default: True