WindowEvent()
Syntax
Event = WindowEvent()Description
Checks if an event has occurred on any of the opened windows.
Return value
The next event from the event queue and or zero if there are no more events. Unlike WaitWindowEvent() it doesn't wait for the next event - it always returns immediately.
This makes it useful for window event loops, where other processing needs to be done without waiting for an event to happen (e.g. Network transactions) and therefore WaitWindowEvent() can't be used.
It must be handled with care though if used on a continuing basis, because unlike WaitWindowEvent(), it will not give CPU time to other programs while waiting for an event and therefore consume all CPU power. In this case, either Delay() should be used somewhere in the loop or WaitWindowEvent() with a small timeout value.
To get the window number in which the event occurred, use the EventWindow() function.
Possible Events are :#PB_Event_Menu : a menu has been selected #PB_Event_Gadget : a gadget has been pushed #PB_Event_SysTray : an icon in the systray zone was clicked #PB_Event_Timer : a timer has reached its timeout #PB_Event_CloseWindow : the window close gadget has been pushed #PB_Event_Repaint : the window content has been destroyed and must be repainted (useful for 2D graphics operations) #PB_Event_SizeWindow : the window has been resized #PB_Event_MoveWindow : the window has been moved #PB_Event_MinimizeWindow : the window has been minimized #PB_Event_MaximizeWindow : the window has been maximized #PB_Event_RestoreWindow : the window has been restored to normal size (either from a minimum or maximum size) #PB_Event_ActivateWindow : the window has been activated (got the focus) #PB_Event_DeactivateWindow: the window has been deactivated (lost the focus) #PB_Event_WindowDrop : a Drag & Drop operation was finished on a window #PB_Event_GadgetDrop : a Drag & Drop operation was finished on a gadget #PB_Event_RightClick : a right mouse button click has occurred on the window. This can be useful to display a popup menu #PB_Event_LeftClick : a left mouse button click has occurred on the window #PB_Event_LeftDoubleClick : a left mouse button double-click has occurred on the windowA basic example for event handling can be found in the WaitWindowEvent() description.
Remarks
After a #PB_Event_WindowDrop or #PB_Event_GadgetDrop Event, the event functions of the Drag & Drop library can be used to examine and read the dropped data.
Important: The window event loop should not be processed in a thread, as there is some limitation on OS X and Linux. A debugger error will be raised.
Correct way to handle an infinite WindowEvent() loop:Repeat Event = WindowEvent() If Event ; An event was in the queue so process it .... Else Delay(1) ; No event, let the others apps get some CPU time too ! EndIf Until Event = #PB_Event_CloseWindowImportant: The 'Delay' shouldn't be put after each event, because when lot of events will come (like refresh, gadgets updates etc..) the app will wait between each event. So the delay need to be put when no events are received. Other (recommened) ways is to use WaitWindowEvent() with a small timeout value, or setup a timer with AddWindowTimer()().
Supported OS
All