I am trying to understand the difference between interval and delay in cocos2d's scheduler.
If delay is the time between 2 selectors get executed. What is interval really?
Comments in cocos2D CCNode.h file, may be useful.
Schedules a custom selector with an interval time in seconds
/**
repeat will execute the action repeat + 1 times, for a continues action use kCCRepeatForever
delay is the amount of time the action will wait before execution
*/
If the selector is already scheduled, then the interval parameter will be updated without scheduling it again.
-(void) schedule:(SEL)selector interval:(ccTime)interval repeat: (uint) repeat delay:(ccTime) delay;
Related
I want to set a timer for a user that counts every hour and minute from when they start the timer (logging in / submitting a button) to when they stop the timer (log out). I'm thinking I could use my dynamodb user table to keep the current hour from timer start and the current hour from timer end and write my own logic on it to tally up the hours. I feel this method is inefficient.
I wanted to program an interval-timer which you can use for training. So there have to be a stack widget were the user can input the times for the training- and the rest-rounds and the repetitions followed by a press on a start button which changes the page and starts the first round-countdown shown in a display.
So if the user enter 20 seconds for training, 10 seconds for rest and 3 repetitions the numbers
20 to 0, 10 to 0, 20 to 0, 10 to 0 and 20 to 0
should be displayed one after another.
The problem I ran in:
I tried QTimer and a QThread with a 1 sec-sleep-function and a signal-slot to the gui, but in both options the gui froze.
The use of a QTimer will not block the main window. This is the purpose of timers.
Moreover, you don't need to use threads at all, you only have to start a timer with the desired interval (for example, a tick every 10ms) and connect the timeout() signal to a slot that will process your application behaviour.
In this slot, you just have to handle the countdown and the state change (working time to break time if the number of repetitions is not reached, break time to working time and the finished state).
I have created such an application and it worked well. Maybe I will later make it available on github. If I do it, I would made an edit to my answer to provide the link.
I hope it helps.
I think you have designed the solution in a very complicated way. With no code it's impossible to tell you what went wrong.
If I had to develop a solution for this, it'd be in the form of interconnecting blocks, which can be delay blocks or flow control blocks (child classes of the block parent).
Each block has a next one and a trigger function. A delay block also has a time. A flow control block may have different functionalities, like pointing to a previous block only for x repetitions. You can use a global QTimer when a new delay block is triggered to trigger the next block (connect the timeout signal of the timer to the trigger function of the next block, then start the timer with the current block's time).
For instance, if you wanted to do 3 times 30s exercise, 10s rest, you'd connect two delay blocks with a repeat block.
Qt 5.7 32-bit on windows 10 64-bit
long period timer
the interval of a QTimer is given in msecs as a signed integer, so the maximum interval which can be set is a little bit more than 24 days (2^31 / (1000*3600*24) = 24.85)
I need a timer with intervals going far beyond this limit.
So my question is, which alternative do you recommend? std::chrono (C++11) seems not to be suitable as it does not have an event handler?
Alain
You could always create your own class which uses multiple QTimer's for the duration they are valid and just count how many have elapsed.
Pretty simple problem. If you can only count to 10 and you need to count to 100 - just count to 10 ten times.
I would implement this in the following way:
Upon timer start, note the current time in milliseconds like this:
m_timerStartTime = QDateTime::currentMSecsSinceEpoch()
The, I would start a timer at some large interval, such as 10 hours, and attach a handler function to the timer that simply compared the time since it started to see if we are due:
if(QDateTime::currentMSecsSinceEpoch() - m_timerStartTime > WANTED_DELAY_TIME){
// Execute the timer payload
// Stop interval timer
}
This simple approach could be improved in several ways. For example, to keep the timer running even if application is stopped/restarted, simply save the timer start time in a setting or other persistent storage, and read it back in at application start up.
And to improve precision, simply change the interval from the timer handler function in the last iteration so that it tracks the initial end time perfectly (instead of overshooting by up to 10 minutes).
I try to start timer at specific time like 02:30. Every day it starts at 02.30.
Is it possible? Do you have any idea?
Thank a lot.
QTimer doesn't handle specific times of day natively, but you could use it in conjunction with QDateTime to get what you want. That is, use QDateTime objects to figure out how many seconds are between (right now) and 2:30 (QDateTime::msecsTo() looks particularly appropriate here), then set your QTimer to go off after that many seconds. Repeat as necessary.
Depending on the required resolution, you could use an ordinary QTimer that fires let's say every minute.
In the timerEvent, you could check if you are on the right time (using QDateTime), and trigger the necessary event.
The solution of Jeremy is indeed elegant, but it doesn't take into account the daylight savings time.
To guard against that, you should fire a timer event every hour and check the wall clock.
Calculate the delta to the target, like Jeremy proposes, and if it falls within the coming hour, set a timer to fire, and disable the hourly timer.
If not, just wait for the hourly timer to fire again.
Pseudo code:
Get wall clock time
Calculate difference between target time and wall clock
If difference < 1 hour:
Set timer to fire after difference secs
If this is a repeating event, restart the hourly timer
Else:
Start watch timer to do this calculation again after one hour
I have am creating a game.Then game has a timer 100 sec ,which move to zero like 99,98,97...
Now when we lose the game we retry ...but this time the timer decrements of2...lieke 98,96,94
if we lose again and retry this time the difference is of 3...
i noticed that when we lose and retry the timer function is called twice so it make decrement of 2...similarly if we retry for the 3rd time the timer is called three times and so on?
what is this issue?please urgent help required
Perhaps your timer is being started each time you retry. The first time, you have one timer running. Then the second time, you have two timers, and the third time three... You may need to stop the previous timer before retrying so that you only have one timer running.