<< Chapter < Page Chapter >> Page >

Will explain the code in fragments

I will explain the code for this Flex application in fragments. A complete listing of the application is provided in Listing 6 near the end of thelesson.

Beginning of XML code for SliderChangeEvent01

The primary purpose of this application is to illustrate the use of inline event handling for Flex 3 slider change events.

The application begins in Listing 2 which shows the beginning of the Application element and the two complete Label elements shown at the top of Figure 1.

Beginning of xml code for sliderchangeevent01.

<?xml version="1.0" encoding="utf-8"?><mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"><mx:Label text="Put your name here" fontSize="16" fontWeight="bold"/><mx:Label text="Image Height in Pixels" fontWeight="bold" fontSize="14"/>

Make it easy - drag and drop

The two Label elements were created by dragging Label controls from the Components tab shown in Figure 4 onto the Design tab shown in Figure 5. Then the attribute values were set using the Flex Properties tab shown in Figure 6.

The attributes shown in Listing 2 represent common properties of a text label and shouldn't require further explanation.

Create and condition the slider

Listing 3 adds a horizontal slider (HSlider) control to the application and sets the attributes that control both its appearance and itsbehavior.

Create and condition the slider.

<mx:HSlider minimum="100" maximum="250" value="250" toolTip="Height"change="myimg.height=event.currentTarget.value" liveDragging="true" />

The slider is a little more complicated than a label and deserves a more thorough explanation.

The numeric properties

Recall that a slider represents a range of numeric values. The position of the thumb at any instant in time selects a value from that range. Thefollowing three attributes shown in Listing 3 deal with the slider and its numeric range:

  • minimum - the numeric value represented by the left end of a horizontal slider.
  • maximum - the value represented by the right end of a horizontal slider.
  • value - the value that specifies the initial position of the thumb when the slider is constructed and first presented in the application'swindow.

The toolTip property

As you have probably already guessed, the value of the toolTip property specifies the text that appears in the tool tip when it is visible as shown in Figure 2.

The change property

This is where thing get a little more interesting. As the user moves the thumb to the left or right, the slider fires a continuous stream of change events. You might think of this as the slider yelling out "Hey, the position of my thumb has been changed." over and over as the thumb is being moved. (Also see the discussion of the liveDragging property later.)

An event handler

The value that is assigned to the change attribute in Listing 3 is often referred to as an event handler . This value specifies what the application will do each time the slider fires a change event.

Three ways to handle events in Flex

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Introduction to xml. OpenStax CNX. Dec 02, 2014 Download for free at https://legacy.cnx.org/content/col11207/1.18
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Introduction to xml' conversation and receive update notifications?