I have written many posts previously on Timer in Oracle Forms like how to change images randomly with timers and how to display a clock using timer, but in this post I am simply describing to how to create a timer, stop a timer, re-start a timer and deleting a timer.
The following is the screen shot for this example showing a progress bar based on a display item:
You can also download this form from the following link Timer.fmb
Create a display item with the following properties:
Name: Prgbar
Width: 5
Bevel: Plain
Background Color: blue
Write the following code for the "Create Timer" button:
When-Button-Pressed trigger
Declare
v_timer timer;
Begin
-- find timer first if already exists.
v_timer := find_timer('PrgBarTmr');
if id_null(v_timer) then
-- Creating timer for one second... one second = 1000 millisecond
v_timer := Create_Timer('PrgBarTmr', 1000, Repeat);
else
message('already exists.');
end if;
-- will handle this timer in form level when-timer-expired trigger
End;
Write the following code for the "Stop Timer" buton:
When-Button-Pressed trigger
Declare
v_timer timer;
Begin
-- find the timer first
v_timer := find_timer('PrgBarTmr');
if not id_null(v_timer) then
-- this will stop the timer after one millisecond
Set_Timer(v_timer, 1, No_Repeat);
end if;
-- will handle this timer in form level when-timer-expired trigger
End;
Write the following code for the "Re-Start Timer" buton:
When-Button-Pressed trigger
Declare
v_timer timer;
Begin
-- find the timer first
v_timer := find_timer('prgbartmr');
if not id_null(v_timer) then
-- this will re-start the timer after one second
Set_Timer(v_timer, 1000, Repeat);
else
v_timer := create_timer('prgbartmr',1000, Repeat);
end if;
-- will handle this timer in form level when-timer-expired trigger
End;
Write the following code for the "Delete Timer" buton:
When-Button-Pressed trigger
Declare
v_timer timer;
Begin
-- find the timer first
v_timer := find_timer('PrgBarTmr');
if not id_null(v_timer) then
-- this will delete the timer
Delete_Timer(v_timer);
end if;
End;
Then finally write the code for When-Timer-Expired trigger at form level to handle the timer and to do specific task:
When-Timer-Expired trigger
Declare
v_timer_name varchar2(30);
v_width number;
Begin
-- get the timer name first.. to know which timer has expired.. if multiple timer are running
v_timer_name := get_application_property(timer_name);
-- check if the same timer with capital letters
if v_timer_name = 'PRGBARTMR' then
v_width := get_item_property('blKtmr.prgbar', width);
if v_width < 100 then
v_width := v_width + 5;
else
v_width := 0;
end if;
set_item_property('blktmr.prgbar', width, v_width);
end if;
-- will handle this timer in form level when-timer-expired trigger
End;