Advanced Programming - Chapter 6.ppt

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Chapter Six

GUI

1



GUI• Graphical User Interface ("Goo-ee")

• Pictoral interface to a program – Distinctie "loo!" an "feel"

• Different applications #ith consistent GUIsimproe pro$ctiit%

• &xample' – etscape Comm$nicator

– en$ *ar+ text fiel+ la*el

• GUIs *$ilt from components• Component' o*,ect #ith #hich $ser interacts

• &xamples' a*els+ .ext fiels+ /$ttons+Chec!*oxes

0



GUI

• .he graphical $ser interface allo#s $s tointeract #ith o$r programs thro$gh mo$semoements+ *$tton clic!s+ !e% presses+

an so on

• 2o$r 3ino#s or acintosh operating

s%stem proies %o$ #ith a GUI so %o$on4t hae to remem*er all sorts ofinstr$ctions to t%pe at the comman line

5



GUI

• .here are three *asic things that are necessar%

to eelop a graphical $ser interface

– The GUI components sets

• form the interface• *$ttons+ la*els+ chec! *oxes+ etc

– Component arrangement

• the scheme #here*% the UI components are arrange to

create the interface

– Response to user requests

• the act of associating actions to $ser re6$ests+ !no#n as

4eents4

7



Implementing GUIs in 8aa• .he 8aa 9o$nation Classes (89C)

&ncompass a gro$p of feat$res forconstr$cting graphical $ser interfaces (GUI)

• encompassing the follo#ing :PIs'

– Abstract Window Toolkit (AWT)' natie GUIcomponents

– wing' light#eight GUI components

– !"' renering t#o-imensional shapes+ text+ animages

– Accessibilit#' allo#ing compati*ilit% #ith+ for

example+ screen reaers an screen magnifiers;



Abstract Window Toolkit

(AWT)• Proies *asic UI components'

– /$ttons+ lists+ men$s+ textfiels+ etc

– &ent hanling mechanism

– Clip*oar an ata transfer

– Image manip$lation

– 9ont manip$lation

– Graphics

• Platform inepenence is achiee

thro$gh peers+ or natie GUI components

<



Using :3. Components• :3. is 8aa=s original set of classes for *$iling

GUIs – Uses peer components of the >S? hea%#eight

– ot tr$l% porta*le' loo!s ifferent an la%s o$t

inconsistentl% on ifferent >Ss

• D$e to >S=s $nerl%ing ispla% management s%stem

• &er% GUI component is a s$*class of the :3.

Component class (except for men$s)

•Controls allo# simple $ser inp$t• a*els ispla% text

• Containers arrange other components

• Use Canases for c$stom components@



Components and Containers• .he :3. set is str$ct$re in a class

hierarch%• eer% UI component is a escenant of

the Component class

• .his contains the er% *asic f$nctionalit%common to all components

A



:3. Components

primitiecontainer

B



Peers an Platform Inepenence• .h$s an :3. men$ on the Solaris platform+

for example+ act$all% creates a otif men$o*,ect as its peer

• UI components that hae peers are calle

heavyweight because – they are rendered in their own (opaque) windows

and thus are expensive to use,

– they must be rectangular and cannot havetransparent backgrounds, and

– they are not amenable to being subclassed

1



Using Peers

• : 8aa program creates an ispla%s an :3. component+

• #hich creates an ispla%s a natiecomponent+ or peer

• /% $sing peers• Platform controls component appearance

• Inconsistencies in implementations – -

JavaPr ogram

JavaAWT

NativeWindowSystemPeers

11



ight#eight Components• :3. 11 intro$ce the notion of lightweight

components #hich' – are containe #ithin a hea%#eight component4s #ino#

– o not hae peers

– are renere in their container4s #ino# rather than one

of their o#n – o not inc$r performance penalties an can hae

transparent *ac!gro$ns

• :lmost all S#ing components are light#eight onesthat exten either

• java.awt.Component or java.awt.Container

10



3hat is S#ing

• is 8aa4s graphical $ser interface li*rar%• :*stract 3ino# .ool!it (:3.) E0• 1F P$re 8aa

– e6$ires 8DH 110 or higher • Part of 89C – Components – e# high-leel components – Pl$gga*le oo! 9eel

• 2o$ US. import the follo#ing pac!ages'

import java.awt.*;import javax.swing.*;

15



S#ing Philosoph%

• icher Component Set

– eplaces :3. Component Set

– :s more complex components

• S#ing Components 8aa-/ase

– If pro*lems+ same pro*lems eer%#here

17



.he S#ing Containment Jierarch%

• t%picall% has at least'

– a top$le%el container& the root container thathols eer%thing together eg 8:pplet+89rame+ 3ino#

– an intermediate container& a container tosimplif% the positioning of atomic componentseg 8Panel+ 8ScrollPane

– an atomic component& a self-s$fficientcomponent not holing other components eg8/$tton+ 8a*el

1;



• a Container is a special t%pe of component

• %o$ can a other components &xample+

89rame+ 8:pplet+ 8Panel etc

• :ll containers hae methos to a an

remoe components

Components and Containers

1<



GUI Class Jierarch% (S#ing)

Dimension

Font

FontMetrics

Component

Graphics

Object Color

Container

Panel Applet

Frame

Dialog

Window

JComponent

JApplet

JFrame

JDialog

Swing Components

in te java!"swing pac#age

$igtweigt

%eavyweigt

Classes in te java"awt pac#age

&

LayoutManager

'

1@



Description of Classes

• >*,ect' :ll classes $ltimatel% erie from >*,ect+

th$s this class is at the top of the tree

• Component' represents an o*,ect that has a

is$al representation that can *e sho#n on-

screen an that can interact #ith $sers .his class

efines some *asic methos that are aaila*le to

all S#ing classes

1A




(Cont=)

• Container' *$ils on the *asic is$al capa*ilities

of the Component class *% aing the a*ilit% to

hol other containers

• 3ino#' a specialiKe t%pe of container o*,ect

that has a *orer+ a title *ar+ *$ttons that

minimiKe+ maximiKe+ an close the #ino#+ an

that can *e repositione an possi*l% eenresiKe *% the $ser

1B




(Cont=)

• 9rame' a t%pe of 3ino# that seres as the *asis

for 8aa GUI applications 9rame is an :3. class

that has *een improe $pon *% the 89rame

class

• 89rame' the S#ing ersion of the oler 9rame

class ost of the S#ing applications incl$e at

least one 89rame o*,ect• 8Component' is the *asis for all other S#ing

components except for frames

0




(Cont=)

• 8Panel' $se to organiKe an control the

la%o$t of other components s$ch as la*els+

*$ttons+ text fiels+ etc In most S#ing

applications+ one or more panels are ae

to a frame .hen+ #hen the frame is

ispla%e+ the components that #ere ae

to its panels are mae isi*le• 8a*el' creates a la*el that ispla%s a simple

text al$e

01



:3. s S#ing• S#ing oes not replace the :3.? it is *$ilt on

top of it• :ll 1 :3. components are heavyweight;

corresponding Swing components are

lightweight • Swing component names begin with ``J!

– Component ("#$) vs% JComponent (Swing)

– Button ("#$) vs% JButton (Swing)

• "lways use Swing components; however,

since Swing is built on top o& "#$, you will

need to know some "#$ methods00



.ransitioning from :3.• 9or most components+ a 8 *efore

name – 'utton → J'utton+ "pplet → J"pplet + L

• 3or! from Components o$t to

Containers – :ing to top-leel containers ifferent M

elegate

05



9rames

• 9rame is a #ino# that is not containeinsie another #ino# 9rame is the *asis

to contain other $ser interface components

in 8aa GUI applications• .he 89rame class can *e $se to create

#ino#s

• 9or S#ing GUI programs+ $se 89rame class

to create #io#s

07



89rame

• JFrame is the application #ino# class

• It is special? it ra#s the #ino# an

interacts #ith the operating s%stem

• 3hen a JFrame is create+ an inner

container calle the contentPane is

a$tomaticall% create

• 3e on4t ra# graphics irectl% on

JFrame; #e ra# on the contentPane

0;



:natom% of a 89rame

title bar

minimie

maximie

close

$he contentPane holds your

content; created automatically

when a Jrame is created

0<



&xample' &mpt% 9rame

package swinglab;

import java.awt.*;import javax.swing.*;// extends keyword makes Calc a JFrame

public class Calc extends JFrame{ public Calc! { // get t"e content#ane and assign it to cp Container cp $ getContent#ane!; // exit program w"en user closes t"e window set%e&aultClose'peration()+,'-,C'(!; // sets t"e layout; will be covered in later slide

cp.setayoutnew Flowayout!!; // sets title to 01y Funky Calculator0

set+itle01y Funky Calculator0!; seti2e34445644!; // Frame "as 4 de&ault si2e

7 0@



&xample contin$e

. . .

public static void main tring89 args!{

Calc trial $ new Calc!;

// Frame is invisible by de&ault

trial.set:isibletrue!;

// main met"od exits but user inter&ace// stays alive

7

7

0A



Using the 8Panel Class

• : panel is a t%pe of container that4s esigne to hol

a gro$p of components so the% can *e ispla%e on

a frame .he normal #a% to ispla% a gro$p of

controls s$ch as text fiels+ la*els+ *$ttons+ an otherGUI #igets is to a those controls to a panel+ an

then a the panel to the frame

•2o$ can *%pass the panel an a the controlsirectl% to the frame if %o$ #ant+ *$t $sing a separate

panel to hol the frames control is almost al#a%s a

goo iea

0B



Usef$l 8Panel Constr$ctors

an ethos (Cont=)

'ethod "escriptionvoid add Component c! :s the specifie

component to thepanel

void remove Componentc!

void setayoutayout1anager layout!

emoes the specifiecomponent from the

panelSets the la%o$t manager $se tocontrol ho# components arearrange #hen the panel isispla%e .he efa$lt is the

9Io#a%o$t manager 51

Usef$l 8Panel Constr$ctors an



Usef$l 8Panel Constr$ctors an

ethos (Cont=)

'ethod "escriptionvoid setocation intx5 int y!

void seti2e int widt"5 int "eig"t!

void set+ool+ip+exttring text!

Sets the x an % positionof the frame-screen .hetop-left corner of the

screen is + Sets the siKe of the frame tothe specifie #ith anheightSets the tooltip text that4sispla%e if the $ser reststhe mo$se oer an empt%

part of the panel 50



&xample' package swinglab;


public class Calc extends JFrame{ private J#anel entry#anel;

private J#anel answer#anel; public Calc! {Container cp $ getContent#ane!;

set%e&aultClose'peration()+,'-,C'(!;cp.setackgroundColor.w"ite!;

set+itle01y Funky Calculator0!;seti2e34445644!;

entry#anel $ new J#anel!; entry#anel.setackgroundColor.orange!; answer#anel $ new J#anel!;

answer#anel.setackgroundColor.yellow!;

// . . . 55



&xample'

cp.addentry#anel!; cp.addanswer#anel!;

7 public static void main tring89 args!{ Calc trial $ new Calc!; trial.set:isibletrue!; 77

57



Colors

• .here are 15 preefine colors

• 2o$ can access them $sing Color.x #here

x is – orange+ pin!+ c%an+ magenta+ %ello#+ *lac!+ *l$e+

#hite+ gra%+ lightGra%+ ar!Gra%+ re+ green

• 2o$ can efine %o$r o#n colors

Color ugly $ new Color<45=453>4!;

//?@redAgreenAblue!; values between 4A>BB;

5;



9rames+ Panes an Panels

5<



JComponents• JComponent: .he *ase class for all S#ing components

except top-leel containers

• JComponents o not exten their :3. co$nterparts' – 9or example+ the JButton class is not a s$*class (irect or

inirect) of Button

• ote that JComponents are containers

• Jo#eer+ some S#ing components are notJComponents – 9or example+ some S#ing containers are irect s$*classes of

their :3. co$nterparts

• Its s$*classes present information or interact #ith the

$ser – &xamples'la*els(JLabels)+ *$ttons(JButtons)+textfiels(JTextField)

- Containers are some 8Components that are esigne to holother components (no interaction #ith the $ser)

- &xamples' JPanel, JScrollPane5@



Using a*els

• : la*el is a component that simpl% ispla%s

text a*els are $se for a ariet% of

p$rposes' to ispla% captions for other

controls s$ch as text fiels or com*o *oxes+

to ispla% informational messages+ or to

sho# the res$lts of a calc$lation or a

ata*ase loo!$p

5A



Using a*els

• : la*el can also ispla% an image+ or it can

ispla% *oth an image an some text :n

%o$ hae complete control oer the

appearance of the text

• 2o$ can specif% the font+ siKe+ #hether the

text is *ol+ italic+ or $nerline+ #hat color

the text is ispla%e as+ an so on

5B

Usef$l 8a*els Constr$ctors an



Usef$l 8a*els Constr$ctors an

ethosConstructor "escription

Jabel ! Creates a ne# la*el #ith noinitial text

'ethod "escription

tring get+ext ! et$rns the text ispla%e*% the la*el

void set+ext tringtext!void set+ool+ip+exttring text!

Sets the text ispla%e *%

the la*elSets the tooltip text that4sispla%e if the $ser reststhe mo$se oer the la*el

for a fe# moments 7

S#ing &xample



S#ing &xample


public class 1y+est extends JFrame { Jabel myabel $ new Jabel0ello5 DorldE0!; public 1y+est! {

super01y+est0!; seti2e<B45 344!; getContent#ane!.addmyabel!;

set%e&aultClose'peration()+,'-,C'(!;set:isibletrue!;

7

public static void main tring args89! { 1y+est m $ new 1y+est!; 7

7 71



Simple S#ing :pplication

70



Creating /$ttons

• ext to la*els+ the S#ing component $se

most is the 8/$tton component #hich

creates a *$tton the $ser can clic!

• .he constr$ctors of the 8/$tton class are

similar to the constr$ctors for the 8a*el

class 2o$ can either create an empt%

*$tton or a *$tton #ith text

75

U f l 8/ tt C t t



Usef$l 8/$tton Constr$ctors

an ethos

Constructor "escriptionJutton ! Creates a ne# *$tton

#ith no initial textJutton tring text!

tring get+ext !

Creates a ne# *$tton#ith the specifie textet$rns the textispla%e *% the*$tton

77

Usef l 8/ tton Constr ctors an



Usef$l 8/$tton Constr$ctors an

ethos (Cont=)'ethod "escriptionvoidset?ollover(nabledboolean value!

&na*les or isa*les therolloer effect+ #hich

ca$ses the *orer to getthic!er #hen the mo$semoes oer the *$tton.he efa$lt setting is tr$e

(rolloer effect ena*le)

void set(nabledboolean value!

&na*les or isa*les the*$tton .he efa$lt setting is

tr$e (ena*le)7;





an ethos (Cont=)

'ethod "escription

void set+exttring text!

Sets the text ispla%e *% the*$tton

void set+ool+ip+exttring text!

Sets the tooltip text that4sispla%e if the $ser lets themo$se rest oer the *$tton

void set:isibleboolean value! Sho#s or hies the *$tton

.he efa$lt setting is tr$e (the*$tton is isi*le)

7<



8.ext9iel - 8Pass3or9iel

• .he% are single-line areas in #hich text can *eentere *% the $ser from the !e%*oar or text cansimpl% *e ispla%e

• *onstructors – 8.ext9iel(int col$mns)

• Creates an empt% text fiel #ith the specifie n$m*er ofcol$mns

– 8.ext9iel(String text)

– Creates a text fiel initialiKe #ith the specifie text

– 8.ext9iel(String text+ int col$mns) – Creates a text fiel initialiKe #ith the specifie text an the

col$mn siKe

– 8.ext9iel (String+ int maxim$m$m*erCharaters)7@



• +ethods – int getColomns(int col)? – oi setColo$mns(int col)? – get.ext()

• et$rns the string from the text fiel – set.ext(String text)

• P$ts the gien string in the text fiel

– set&ita*le(*oolean eita*le)• &na*les or isa*les the text fiel to *e eite /% efa$lt+

eita*le is tr$e – setCol$mns(int)

• Sets the n$m*er of col$mns in this text fiel .he length ofthe text fiel is changea*le

7A



• 3hen the $ser t%pes ata into them an presses

the Enter !e%+ an action eent occ$rs If the

program registers an eent listener+ the listener

processes the eent an can $se the ata in thetext fiel at the time of the eent in the program

– JTextField textField1 = new JTextField("This is the

initial text");

– JTextField textField2 = new JTextField("Initial text",columns);

– textField.setText(“hi);

7B



assword*ield class extens 8.ext9iel class• +ethods

– CharN O getPass#or()? MM.o o*tain the pass#orTe+tArea' a component $se to accept m$ltiple

line text

*onstructors

– 8.ext:rea( )• Defa$lt constr$ctor - Create an empt% text area

• 8.ext:rea(int ro#s+ int col$mns) – Creates a text area #ith the specifie n$m*er of

ro#s an col$mns

• 8.ext:rea(String s+ int ro#s+ int col$mns) – Creates a text area #ith the initial text an

the n$m*er of ro#s an col$mns specifie

;

,th C t



,ther Components

• Combo-o+ – rop-o#n list of items from #hich the $ser can

ma!es selection *% clic!ing an item or possi*l%*% t%ping into the *ox

– *onstructor • 8Com*o/ox(String strNO)?

– ethos• getSelecteItem()?MMret$rns the selecte item

• getSelecteInex()?• setaxim$mo#Co$nt(int n) - maxim$m of n items

#ill *e ispla%e if there are more items asscroll*ar

;1

import java.awt.*;



import javax.swing.*;import java.util.*;

public class Calc extends JFrame{

private Jabel letabel;

private Jabel answerabel; private J+extField num3; private J+extField num>;

private JComboox operation; private Jutton calculate; private Jutton uit; private J#anel entry#anel; private J#anel answer#anel;

static &inal tring G%%,'# $ 0G%%+'-0; static &inal tring H,'# $ 0H+?GC+'-0; static &inal tring 1H,'# $ 01H+#CG+'-0; static &inal tring %:,'# $ 0%:'-0;

;0

i t t ti &i l i t )I( 3444



private static &inal int )I( $ 3444; private static &inal int I( $ 644;

public Calc! {

Container cp $ getContent#ane!; set%e&aultClose'peration()+,'-,C'(!; cp.setayoutnew Flowayout!!; cp.setackgroundColor.D+(!; set+itle01y Funky Calculator0!;

seti2e)I(5I(!;

entry#anel $ new J#anel!;entry#anel.setackgroundColor.'?G-@(!;

answer#anel $ new J#anel!; answer#anel.setackgroundColor.('D!;

letabel $ new Jabel0etKs CalculateE0!; entry#anel.addletabel!; letabel.setForegroundColor.@?((-!; ;5

num3 $ new J+extField03st -umber0 34!;



num3 $ new J+extField03st -umber05 34!; entry#anel.addnum3!; num3.setackgroundColor. @+,@?G!;

num>$ new J+extField0>nd -umber05 34!; entry#anel.addnum>!; num>.setackgroundColor.@+,@?G!;

operation $ new JComboox!;

operation.addtemG%%,'#!; operation.addtemH,'#!; operation.addtem1H,'#!; operation.addtem%:,'#!;

entry#anel.addoperation!;

operation.setackgroundColor.H(!; answerabel $ new Jabel0Gnswer0!;

;7

entry#anel.addanswerabel!;



answerabel.setForegroundColor.red!;calculate $ new Jutton0Calculate0!;

calculate.setackgroundColor.pink!; answer#anel.addcalculate!;

uit $ new Jutton0Luit0!; answer#anel.adduit!; Color uitter $ new ColorB453445B4!; uit.setackgrounduitter!;

cp.addentry#anel!;

cp.addanswer#anel!;

7

public static void maintring89 args!{ Calc trial $ new Calc!; trial.set:isibletrue!; 7

7;;



;<



a%o$t anagers

• :ssociate #ith containers

• :$tomate the la%o$t of elements

– 3hen elements are ae to the container

– 3hen the #ino# is resiKe• a$tomaticall% a,$st the positions an siKes of the elements

• a%o$t managers control'

– 3here components appear

– 3hat siKes the% are

– Jo# the% react #hen the% are resiKe

;@



Jierarch% of a%o$t anagers

;A



/orera%o$t

• It $ses fie areas to hol components'

north+ south+ east+ west+ an center

• :ll extra space is place in the center

area

;B



9lo#a%o$t

• It simpl% la%s o$t components from left to

right+ starting ne# ro#s if necessar%

<



Cara%o$t

• Use the Cara%o$t class #hen %o$ hae

an area that can contain ifferent

components at ifferent times

<1



Gria%o$t

• Gria%o$ts simpl% ma!e a *$nch of

Components hae e6$al siKe+ ispla%ing

them in the re6$este n$m*er of ro#s an

col$mns

<0



Using a%o$t anagers

/orera%o$t

Mnameo&containerN.setayoutnew orderayout!!;

3hen aing components to the container'

Mnameo&containerN.addMnameo&componentN5orderayout.?(@'-!;

#here &GI> is either >.J+ S>U.J+ 3&S.+

C&.& > &:S.J#anel panel $ new J#anel!; // de&ault

// Flowayout

panel.setayoutnew orderayout!!;

panel.addbutton5orderayout.-'?+!;<5



Using a%o$t anagers

9lo#a%o$t<nameocontainer!.setLa"out#ne$ Flo$La"out#%%;

3hen aing components to the container'<nameocontainer!.add#<nameocomponent!%;

JPanel panel & ne$ JPanel#%; '' deault

'' Flo$La"out

''ollo$in( line is redundant

panel.setLa"out#ne$ Flo$La"out#%%;

Advanced Programming - Chapter 6.ppt

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