GAMBAS BOOK 3.19.1

The class Timer (gb) implements a Timer object. A Timer object is to be understood as a clock that triggers events with each clock pulse. The time between each clock pulse is determined by the value of the Delay property (clock pulse time in milliseconds).

The Timer class has only two properties:

Table 20.3.0.1.1 : Properties of the Timer class

The Timer class has three methods, the description of which can be found in the following table:

Table 20.3.0.2.1 : Methods of the class Timer

There is exactly one event for the class Timer → Timer_Timer(). This event is triggered every time the cycle time specified via Timer.Delay has elapsed.

Note that the cycle time is at least Timer.Delay. There is generally no guarantee - depending on the hardware used and and the operating system and its configuration - that the event handler will be executed “close in time”.

The following is a compilation of selected fields of application for Timer objects from various demonstration projects in the online book:

• Clocks (analogue, digital, binary),
• stopwatches,
• stopwatches,
• count-down counters (date or time),
• TimeOut for time-critical routines,
• Triggering of actions once, several times (asynchronous) or periodically → measured values, status acquisition, automatic storage,
• Repeat functions for button,
• flashing displays of text or of symbols (single or multi-coloured) with adjustable frequency.

This concept has proven successful when using a timer:

• Determining whether the use of a timer allows the specified goal to be achieved.
• Determine clock time and set the Timer.Delay property with a suitable start value.
• Determine in which procedures the timer is started and stopped.
• Specify whether the 1st timer event should be triggered immediately after the timer start with the Timer.Trigger() method or only after the 1st clock pulse.
• Define exactly what should happen when the Timer_Timer() event is triggered.

The timer function Timer() - which is unrelated to the class Timer - specifies the number of seconds that have elapsed since the programme start. The function value is of the float data type. The function uses the system clock.

With the following source code excerpt

Dim fZeitdifferenz as Float

fZeitdifferenz = Timer
Print "Sekunden seit Programm-Start = ";;fZeitdifferenz;;" Sekunden"

… the number of seconds elapsed since the programme start is displayed in the console of the Gambas IDE:

Zeit seit Programm-Start =  17,8296689987183  Sekunden

The function can be used, for example, to measure runtime when comparing search or sort algorithms or for selected, time-intensive procedures.