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There are at least three ways to handle event notifications in Flex:

  • Registering an event handler in mxml
  • Creating an inline event handler in the mxml definition
  • Registering an event listener through ActionScript

The XML code in Listing 3 uses the inline approach.

The inline approach

The advantage of using the inline approach, (at least insofar as my Introduction to XML , students are concerned) , is that it doesn't require you to create a Script element within the mxmlor to create a separate ActionScript file.

Handling the slider's change event

Now consider the code that begins with the word change in Listing 3. The code within the quotation marks can be a little hard to explain, but I will give it atry. (The code in quotation marks is actually an ActionScript code fragment.)

Think of it this way

There is a Flex/ActionScript class named Event . The reference to event in Listing 3 is a reference to an object of the Event class that comes into being each time the slider fires a change event .

The Event object encapsulates a property named currentTarget , which is described in the Flex 3 documentation as follows:

"The object that is actively processing the Event object with an event listener. For example, if a user clicks an OK button, the current target couldbe the node containing that button or one of its ancestors that has registered an event listener for that event."

The currentTarget is the slider

In this application, the value of currentTarget points to the slider which is firing change events as the user moves the thumb.

The value property of an HSlider object

The slider is an object of the HSlider class, which has a property named value . The value property contains the current position of the thumb and is a number between the minimum and maximum property values.

Get the current value of the thumb

Therefore, each time the slider fires a change event, the code on the right side of the assignment operator within the highlighted quotation marks inListing 3 gets the numeric value that indicates the current position of the thumb.

Cause the image to be resized

This value is assigned to the height property of the image, causing the overall size of the image to be adjusted, if necessary, to match the currentposition of the slider's thumb. (I could go into more detail as to the sequence of events that causes the size of the image to change, but I will leavethat as an exercise for the student.)

The liveDragging property

That leaves one more attribute or property for us to discuss in Listing 3: liveDragging . This one is much easier to understand.

The Flex 3 documentation has this to say about the liveDragging property:

"Specifies whether live dragging is enabled for the slider. If false, Flex sets the value and values properties and dispatches the change event whenthe user stops dragging the slider thumb. If true, Flex sets the value and values properties and dispatches the change event continuously as the usermoves the thumb. The default value is false."

If liveDragging is false...

If you were to modify the code in Listing 3 to cause the value of the liveDragging property to be false (or simply not set the attribute value to true) , the slider would only fire change events each time the thumb stops moving (as opposed to firing a stream of events while the thumb is moving) . This, in turn, would cause the size of the image to change only when the thumb stops moving instead of changing continuously while the thumb is moving.

Questions & Answers

can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
Commplementary angles
Idrissa Reply
hello
Sherica
im all ears I need to learn
Sherica
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Tamia
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Kim
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Al
y=10×
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
is it 3×y ?
Joan Reply
J, combine like terms 7x-4y
Bridget Reply
im not good at math so would this help me
Rachael Reply
yes
Asali
I'm not good at math so would you help me
Samantha
what is the problem that i will help you to self with?
Asali
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Introduction to xml. OpenStax CNX. Dec 02, 2014 Download for free at https://legacy.cnx.org/content/col11207/1.18
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