Changing image on keypress

Comments

• eduard

  June 2017

  Hi James,

  Sounds like fun. Here my implementation. Let me know if it does what you want.

  import random
  
  cv = canvas() # create an empty canvas
  kb = keyboard(timeout = 20,keylist = ['a','l','return']) # create a keyboard item that allows for 3 different keys
  
  letters = [1,2,3,4,5,6,7,8] # my stimuli, I don't have your images.
  
  random.shuffle(letters) # randomize images
  
  for i in range(len(letters)-1): # loop over each comparison, I don't knwo whether this is what you had in mind, if not you can remove this for loop 
      var.selected_item = None # initliaze the item that will be selected
      while True: # stay in the loop until a selection was done
          cv.text(letters[i],x = -200) # draw one stimulus to a canvas
          cv.text(letters[i+1],x = 200) # draw the other to the canvas
          cv.show() # shwo the canvas
          if var.selected_item == True:
              cv.clear() # clear the canvas, if no selection has been made yet
          k,t=kb.get_key() # sample a key response
          if k == 'a': # if a was pressed (left stimulus)
              cv.clear() # clear the canvas and...
              cv.rect(-250,-50,100,100) # draw a rectangle around the stimulus to mark it as selected
              var.selected_item = letters[i] # store selection in variable
          elif k == 'l': # same for the right stimulus
              cv.clear()
              cv.rect(150,-50,100,100)
              var.selected_item = letters[i+1]
          elif k == 'return': # if return pressed, break the loop and clear the canvas
              cv.clear()
              break
  
  

  I made it with letters because I haven't had images, but it should be doable to adjust. Basically get the path for each image like so: path = exp.pool[u'image_in_pool.png'], and store all the paths in a list. And later draw the images with my_canvas.image(path,x=x) instead of with canvas.text(). See also here: http://osdoc.cogsci.nl/3.1/manual/python/canvas/#function-canvas46image40fname-centertrue-xnone-ynone-scalenone41

  Good luck.

  Eduard