Keyboard options

[Uttama_vizard]

Hi,

I am trying to build an application with radio buttons activated by keyboard instead of mouse. I am using these lines

def onKeyDown(key):
if key == 'A':
aRadio.visible(1)
aans = aRadio.get()
print aans

But, say there is another OK button
if key == 'D':
OKbutton.visible(0)
dans = OKbutton.get()
print dans

Now, I am trying, if an user presses the A and D button in succession, then I want some response.

if key == 'A':
aRadio.visible(1)
aans = aRadio.get()
print aans
if key == 'D':
OKbutton.visible(0)
dans = OKbutton.get()
print 'abcd'

But, it is not printing out 'abcd'.

Can anyone suggest where I am going wrong or is there is any better way?

Thanks in advance for the sugestion


Uttama

[Uttama_vizard]

Hi,

I have used a counter and this solves my problem.

But, I don't know, why nested if loop is not sensing.

Thanks

Uttama

[Uttama_vizard]

Hi,

Does nested if loop work in Vizard (particularly while using two buttons of keyboard or a keyboard button and a variable value)?

If somebody has some suggestion....it would be really helpful to me.

Thanks

Uttama

[farshizzo]

Python supports nested loops. Here is a sample:

for x in range(5):
    for y in range(5):
        print x,y

I'm not sure how this relates to what you are trying to do. There are many ways you can detect consecutive keyboard presses in Vizard, however using nested loops is not related to it.

[Uttama_vizard]

Hello,

I was trying by using nested if loop:

aRadio = QuestionBox.add(viz.RADIO, 0, "A. 1")
bRadio = QuestionBox.add(viz.RADIO, 0, "B. 2")
cRadio = QuestionBox.add(viz.RADIO, 0, "C. 3")
OKbutton = QuestionBox.add(viz.BUTTON, "OK")
def onKeyDown(key):
if key == 'A':
if key == 'D':
print 'abcd'
viz.callback(viz.KEYDOWN_EVENT,onKeyDown)

Here, A is my first option and D is my OK button. So, what I want is if the user presses A and subsequently D (i.e. OK button), I must print something say 'abcd'.

Are there further options available for consecutive keyboard entries?

Thanks

Uttama

[Uttama_vizard]

Hello,

The help file does not show any options for consecutive keyboard entries.

Thanks

Uttama

[Uttama_vizard]

Hi,

No suggestions? If anyone has some suggestion regarding consecutive keyboard entry, please provide.

Thanks

Uttama

[farshizzo]

I'm not sure what you mean by a 'nested if loop'. The if statement does not loop, it simply checks a condition and executes the nested code if the condition passes. The code you posted would never work because the key variable can never be equal to 'A' and 'D' at the same time.

One way to check for consecutive key presses is to save the last key press and compare it with the new one. Here is some sample code that does this. It also check how long has elapsed since the last press to make sure the keys were pressed in a short amount of time.

import viz
viz.go()

lastKey = None
lastKeyTime = 0.0
def onKeyDown(key):
	global lastKey,lastKeyTime
	
	elapsed = viz.tick() - lastKeyTime
	
	if lastKey == 'a' and key == 'd' and elapsed < 0.2:
		print 'ad pressed'
	
	lastKey = key
	lastKeyTime = viz.tick()
viz.callback(viz.KEYDOWN_EVENT,onKeyDown)

[Uttama_vizard]

Hello,

Many thanks for the code. It is working perfectly. Your suggestions are really great.

May be, my nested if loop has been interpreted wrongly. What I was trying to say was that nested loop using if statements.

def onKeyDown(key):
if key=='A':
print 'abcd'
if key=='B':
print 'pqrs'
viz.callback(viz.KEYDOWN_EVENT,onKeyDown)

When, I was using the above code and I was pressing 'A' on keyboard, I was getting a printout of 'abcd'. This implies, that the first if statement was checking the conditionality. Thus, once in the first if loop, when I was subsequently pressing the 'B' button on keyboard, I was not getting any output. Does it not imply that it was not taking the second sequential input from keyboard? or may be the 'key' was not taking in the 'B' input.

Thanks

Uttama