Using WComp beans

This documentation page presents the most usual ways of creating applications and converting event types using basic beans. Events are noted ^eventName and methods are noted methodName(argument types).

Windows forms only provide events with no argument (void). A textbox does not directly provide a string event for example. Below is a list of mostly used widgets and events.

  • ^Click: emitted when the button is clicked. Generally used to trigger void methods on other beans, like starting threads or triggering the sending of one argument events in the PrimitiveValueEmitter bean.
  • ^CheckedChanged: emitted when the state of the checkbox is changed (checked or unchecked). The boolean information of this status is provided by the get_Checked() property getter.
  • set_Checked(boolean): method allowing to change the checked state of the checkbox.

Labels are generally only used to display information, not as a source of event.

  • set_Text(string): method allowing to change the text inside the label.
  • ^TextChanged: emitted when the text changes in the textbox, at each change, so when text is typed in the textbox, each character change will result in a new event. The string information of the text is provided by the get_Text() property getter.
  • ^Leave: emitted when the focus is lost by the textbox, i.e. when the mouse is clicked outside the textbox. This event can be used to mark the end of the text edition in the textbox. It has the advantage of being sent only once, contrary to the ^TextChanged event which is sent on each character change. The string information of the text is provided by the get_Text() property getter.

This bean allows to generate boolean events from void events, quite similar to the PrimitiveValueEmitter, but more simply. The default value of the output boolean is false, and this value can be changed either using the State property and thus the set_State(boolean) method, or using the two following void methods:

  • set_TrueEvent(): changes the emitted boolean value to true.
  • set_FalseEvent(): changes the emitted boolean value to false.

A simple method is then used to trigger the boolean event:

  • FireBool(): method triggering the sending of the boolean event.
  • ^BooleanCreated: the boolean event emitted by the BooleanFactory bean.

This bean is used to propagate a boolean event only when its value is either true or false, but not both. The filtered value of the boolean event can be parametrized by the Filter property of the bean. When the received event value matches the Filter property value, the BoolFilter can send two events, a void and an integer event:

  • ^EventFiltered: the void event sent by the bean when the incoming event matches the property value.
  • ^IntValEmitted: the integer event sent by the bean when the incoming event matches the property value. The value of the integer is parametrized by the SendValue bean property.
  • SetLevel(boolean): the input method of the bean, that will trigger the filtering and consequent event sending.

This integer counter increments its internal value when the Increment() input method is called. It sends a void event indicating that its value has changed, and provides an integer property (Value) and thus the get_Value() property getter method to retrieve the value of the internal counter.

Moreover, it has the ability to apply a modulo to the incrementing internal counter. This can be useful to make binary counters (modulo = 2) for example. In this case, when the counter comes back to 0, the Carry event is raised, allowing to cascade the counters when a modulo is used, and create a multi-bit counter for example. The value of the modulo is parametrized by the Modulo property.

  • Increment(): input method, incrementing the internal counter value.
  • ^ValueChanged: void notification of incrementation. Use the get_Value() property getter as callback value to complete integer method calls.
  • ^Carry: void notification of reset of the counter value because of modulo value reaching.
  • Reset(): resets the counter, setting 0 for the internal value and sending the ValueChanged event (introduced in version 870).

The EventFilter bean acts as an electric relay on a flow of void events. It has a boolean property indicating if it is closed or open, and an input method relayed to an output event.

  • FireEvent(): input method of the event flow.
  • ^EventOut: output event of the event flow.
  • set_Propagate(boolean): the setter method of the Propagate property, indicating if the event flow is relayed (true) or not (false).

This bean allows to create alternating event calls from a single event stream. It receives a void event and sends alternatively the ^EventOut0 and ^EventOut1 void events. It also sends a boolean event alternating between true and false values.

  • FireEvent(): the input method that triggers the sending of one of the two EventOut[0|1] events in an alternate way. Also emits the EventOut boolean event.
  • ^EventOut: the boolean event sent alternatively with a true and a false value.

The PrimitiveValueEmitter is probably the most useful bean, since it can convert a void event to any primitive type of events, like string, integer, boolean, double and so on. All the available types can be seen in the property panel. The value of the primitive type event you want to send has to be configured using these properties too, and all events are triggered by the same method:

  • FireValueEvent(): this method triggers the sending of all primitive type events of the bean.
  • ^EmitTypeValue: an event of a primitive type Type, sent when FireValueEvent() is invoked, and using the value set in the property TypeValue of the bean.
  • set_TypeValue(Type): a method allowing to remotely set the value that the bean will send (property setter method).

This bean allows to filter a string event flow containing decimal numbers according to a minimal or maximal value of the decimal number. For example, it can allow events to be relayed only when the value in the string is higher than “17.2”.

  • set_Value(string): input method of the bean, receiving the string containing the decimal number.
  • ^CeilledValue: the string: event emitted when the input value (of set_Value()) was higher than the threshold, or lower if the bean is inverted (Inverted property set to true).
  • ^ThresholdReachedBool: a boolean event sent when the input values cross the threshold level, up or down. The value of the event is true when the value is above and false when value is below the threshold. This behavior is inverted when the bean is inverted (Inverted property set to true).
  • The ThresholdValue property parametrizes the value of the threshold that evaluates incoming events.

This bean allows to convert a primitive type event to a string. This is nearly the opposite of the PrimitiveValueEmitter, since the ValueFormatter has as many inputs as handled types and only one (string) output.

  • Format(Type): input method, existing for many type arguments.
  • ^StringValueChanged: the string output event, sent when the above method is invoked.

More than allowing to convert primitive types to a string, the ValueFormatter allows to modify the format of the output string, for example to add the unit of an integer value. The ValueFormat property of the bean allows to change the output format of the string. The format of the ValueFormat property is the standard C# formatting syntax (doc page).

Example: a “{0} ms” ValueFormat value will emit a “12 ms” string for a Format(12) method invocation.

The timer bean allows an event to be sent periodically. It creates a single thread that manages the loop. A sleep is done before each event sending, for the time defined by the Period property. It means that if the methods called by the event sending (if the event is linked to methods of other beans) take one second to execute, the actual time between two events will be 1s+Period. The ActiveTimer bean fixes this issue.

  • ^TimerTick: the void event that is sent periodically.
  • Start(): this method is used to start the timer's loop once it has been created. It is also used to restart the loop once it has been stopped.
  • Stop(): stops the loop and thus event sending.

This timer has the same goal than the Timer bean, but creates a new thread on each event sending. The main difference with Timer is thus that the time between two events is not affected by what's executed by the event in other beans. It has the same interface than Timer.

This bean acts as a simple event delayer. It is a generic bean, meaning that it can handle any type of event in input and methods in output. When its Input() method is called, it will wait for a delay configured by the DelayMillisec property, and send the ^Output event with the same arguments than the Input. The method and event of this bean, and all other generic beans, won't appear in the compatible list when creating a link. It has to be searched in the incompatible list of methods.

  • beansdoc.txt
  • Last modified: 2011/06/21 18:08
  • by hourdin