Qt Basics GKO 2010

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Qt basics

Tarmo Aidantausta, Digia Plc

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2 © 2010 Digia Plc

Qt basics: About me

• I'm a Noia !erti"ied Qt De#elo$er%

• I &a#e around ear o" e($erience )it& it%

• I can read, co$, $aste and mae lists%

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* © 2010 Digia Plc

Qt basics: +#er#ie)

• Presentation co#ers onl basics o" Qt and sim$lecom$onent and gra$&ics $rogramming%

• &at is Qt-

• &at can ou do )it& it-• !an I do console a$$lications-

• !an I do gra$&ical user inter"aces-

• & )ould I )ant to use it-

• &at do I need to no) to use it-

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Qt basics: +#er#ie)

• &at are t&e "undamentals o" Qt-

• /o) do I do I a$$lications )it& it-• /o) do I do /ello orld-

• /o) do I do e#ents-

• /o) do I do com$onents-

• 3ost o" t&e in"ormation &as been gat&ered and somee#en 4ust 5uoted as is "rom &tt$:665t%noia%com6doc6 %

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7 © 2010 Digia Plc

&at is Qt-

• Qt is a cross8$lat"orm a$$licationand I "rame)or%

• sing Qt, ou can )ritea$$lications once and de$lot&em across desto$, mobile and

embedded o$erating sstems)it&out re)riting t&e source code%

• Qt is $artl !99 and $artl nati#ecode de$ending on $lat"orm%

• Qt I APIs )ra$ nati#e I

com$onents%

HW

Windows Kernel Mac Kernel

Win32 GDI Carbon / Cocoa

Qt/Windows Qt/Mac

Linux Kernel

X11

Qt/nix

Qt

Qt !"Is

!##lication 1 !##lication 2 !##lication 3

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&at is Qt-

• +""icial su$$ort• ;mbedded

• indo)s

• 11

• indo)s !;

•

=0• 3eeo

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&at is Qt-

• According to ii$edia@ &tt$:66en%)ii$edia%org6)ii6Qt@toolitB B t&ere's bindings to Qt "rom:

• Pt&on• P=ide @

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&at can ou do )it& it-

• ou can do ant&ing )it& it%

• T&ere's $lent o" stu""%

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!an I do console a$$lications-

• es, ou can%

• Qt!ore &tt$:665t%noia%com6doc65tcore%&tml• T&e Qt!ore module contains core non8I "unctionalit%

• Q!oreA$$lication 8 ;#ent loo$ "or console Qt a$$lications

• &tt$:66doc%trolltec&%com65corea$$lication%&tml

• QtNet)or &tt$:665t%noia%com6doc65tnet)or%&tml• T&e QtNet)or module o""ers classes t&at allo) ou to

)rite T!P6IP clients and ser#ers%

http://qt.nokia.com/doc/qtcore.htmlhttp://doc.trolltech.com/qcoreapplication.htmlhttp://qt.nokia.com/doc/qtnetwork.htmlhttp://qt.nokia.com/doc/qtnetwork.htmlhttp://doc.trolltech.com/qcoreapplication.htmlhttp://qt.nokia.com/doc/qtcore.html

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10 © 2010 Digia Plc

!an I do console a$$lications-

• Qt>ml &tt$:665t%noia%com6doc65t(ml%&tml• T&e Qt>ml module $ro#ides a stream reader and )riter

"or >3< documents, and !99 im$lementations o" =A>and D+3%

•

Qt>3

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!an I do gra$&ical user inter"aces-

• +" course ou can%

• %%%multi$le )as

• ou can use all t&e $re#iousl mentioned non8I modules%

• T&ese are some o" t&e )idgets "rom t&e Qtui module:•

&tt$:665t%noia%com6doc6galler%&tml• /ere are all t&e classes under Qtui module:

• &tt$:665t%noia%com6doc65tgui%&tml

• ou can e#en do *D gra$&ics )it& it:• Qt+$en< &tt$:665t%noia%com6doc65to$engl%&tml

• T&e Qt+$en< module o""ers classes t&at mae it eas to use+$en< in Qt a$$lications%

• ;(am$les can be "ound "rom: &tt$:665t%noia%com6doc6e(am$les%&tmlEo$engl

http://qt.nokia.com/doc/gallery.htmlhttp://qt.nokia.com/doc/qtgui.htmlhttp://qt.nokia.com/doc/qtopengl.htmlhttp://qt.nokia.com/doc/examples.htmlhttp://qt.nokia.com/doc/examples.htmlhttp://qt.nokia.com/doc/examples.htmlhttp://qt.nokia.com/doc/examples.htmlhttp://qt.nokia.com/doc/qtopengl.htmlhttp://qt.nokia.com/doc/qtgui.htmlhttp://qt.nokia.com/doc/gallery.html

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!an I do gra$&ical user inter"aces

• T&ere's e#en a )eb bro)ser ou can embed into oura$$lication:

• Qtebit &tt$:665t%noia%com6doc65t)ebit%&tml

• QtebKit $ro#ides a )eb bro)ser engine t&at maes iteas to embed content "rom t&e orld ide eb intoour Qt a$$lication%

• &tt$:665t%noia%com6doc6e(am$les%&tmlE)ebit

• Qt=#g &tt$:665t%noia%com6doc65ts#g%&tml• T&e Qt=#g module $ro#ides classes "or dis$laing t&e

contents o" =L "iles%

http://qt.nokia.com/doc/qtwebkit.htmlhttp://qt.nokia.com/doc/examples.htmlhttp://qt.nokia.com/doc/qtsvg.htmlhttp://qt.nokia.com/doc/qtsvg.htmlhttp://qt.nokia.com/doc/qtsvg.htmlhttp://qt.nokia.com/doc/examples.htmlhttp://qt.nokia.com/doc/examples.htmlhttp://qt.nokia.com/doc/qtwebkit.htmlhttp://qt.nokia.com/doc/qtwebkit.html

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& )ould I )ant to use it-

• ou are a NERD and )ant to s&o) o"" our gra$&ical$rogramming sills-

• Qt &as a 5uite good $enetration on di""erent $lat"orms%

• It's "airl straig&t8"or)ard to $ort our a$$lication to

$lat"orms )&ere Qt is su$$orted%• Qt &as been around "or a long time, so it &as matured as a

"rame)or%

• It adds some)&at automatic memor management on to$ o"!99 t&roug& di""erent means%

• T&ere's $lent o" com$onents%• Mecause Noia is using it

• obs-

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&at do I need to no) to use it-

• As mentioned be"ore Qt &as bindings "or di""erentlanguages, but best su$$ort is "or !99%

• I t&in t&at le#el "or learning Qt is 4ust basics o"$rogramming and !99%

•

I &ad onl done some !99 be"ore started, but $lento" $rogramming @mostl )it& a#aB%

• Kno)ing about !99 &el$s%• Pointers• Fe"erences•

3acros• Tem$lates• All t&at )eird stu""

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&at are t&e "undamentals o" Qt-

• =ource: &tt$:665t%noia%com6doc6ob4ect%&tml

• 3ostl automatic memor management t&roug&di""erent means

• &ierarc&ical and 5uerable ob4ect trees t&at organiOe

ob4ect o)ners&i$• &tt$:665t%noia%com6doc6ob4ecttrees%&tml

• Im$lemented )it& Q+b4ects

• im$licitl s&ared classes• &tt$:66doc%trolltec&%com6s&ared%&tml

• #ariet o" di""erent smart $ointers

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1 © 2010 Digia Plc

&at are t&e "undamentals o" Qt

• ob4ect communication met&od called signals and slots• &tt$:665t%noia%com6doc6signalsandslots%&tml

• Im$lemented t&roug& 3+!&tt$:665t%noia%com6doc6moc%&tmlEmoc

• e#ents and e#ent "ilters• &tt$:665t%noia%com6doc6e#entsand"ilters%&tml

• 5uerable and designable ob4ect $ro$erties• &tt$:665t%noia%com6doc6$ro$erties%&tml

• Im$lemented t&roug& 3+!

&tt$:665t%noia%com6doc6moc%&tmlEmoc

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&at are t&e "undamentals o" Qt

• conte(tual string translation "or internationaliOation• &tt$:665t%noia%com6doc6i1Hn%&tml

• =im$l use Q+b4ect::tr@Te(tB

• inter#al dri#en timers

• &tt$:665t%noia%com6doc6timers%&tml• ell lea#e t&ese out, but its good to mention t&em%

• Q+b4ects accom$anied )it& moc are mostl t&esource o" magic in Qt

• T&e enable some o" t&e cool "unctionalit based on

in&eritance "rom Q+b4ect and code generation%

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&at are "undamentals o" Qt-

• T&e 3eta8+b4ect !om$iler, moc, is t&e $rogram t&at&andles Qt's !99 e(tensions%

• &tt$:665t%noia%com6doc6moc%&tmlEmoc

• Pro#ides us t&e Qts 3eta8+b4ect =stem• &tt$:665t%noia%com6doc6metaob4ects%&tml

http://qt.nokia.com/doc/moc.htmlhttp://qt.nokia.com/doc/moc.html

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/ierarc&ical and 5uerable ob4ect trees

• =ource: &tt$:665t%noia%com6doc6ob4ecttrees%&tml

• Q+b4ects organiOe t&emsel#es in ob4ect trees%

• &en ou create a Q+b4ect )it& anot&er ob4ect as$arent%

• It's added to t&e $arent's c&ildren@B list%• It is deleted )&en t&e $arent is%

• A Q=&ortcut @eboard s&ortcutB is a c&ild o" t&erele#ant )indo)%

•

=o )&en t&e user closes t&at )indo), t&e s&orcut isdeleted too%

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!onstruction6Destruction +rder o"Q+b4ects

• ou can construct a tree o" Q+b4ects in an order ou )ant%• +" course ou &a#e to create t&e Q+b4ect be"ore ou can use it

as a $arent%

• A"ter t&e ob4ect tree &as been created, it can be destroedin an order%

• &en an Q+b4ect in t&e tree is deleted• i" t&e ob4ect &as a $arent

• t&e destructor automaticall remo#es t&e ob4ect "rom its $arent

• i" t&e ob4ect &as c&ildren• t&e destructor automaticall deletes eac& c&ild

• No Q+b4ect is deleted t)ice, regardless o" t&e order o"destruction%

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!onstruction6Destruction order o"Q+b4ects

• It loos somet&ing liet&is: $arent

c&ild c&ild c&ild

c&ild

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/ierarc&ical and 5uerable ob4ecttrees

• e do a delete on onec&ild: $arent

c&ild c&ild c&ild

c&ild

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/ierarc&ical and 5uerable ob4ecttrees

• e get:

$arent

c&ild c&ild

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&at is t&e stac-

• =tac is somet&ing lie:

• Image source:&tt$:66)))%a$artmentt&era$%com6uimages6n6.81?8stac8dra)ers81%4$g

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&at is t&e stac-

• =ource: &tt$:66en%)ii$edia%org6)ii6!allstac

• A call stac is a stac data structure• stores in"ormation about t&e acti#e subroutines

• T&is ind o" stac is also no)n as

• an e(ecution stac• control stac• "unction stac• run8time stac• t&e stac

• &en memor allocation &a$$ens to t&e stac• It )ill be automaticall released a"ter it goes out o"

sco$e%

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&at is t&e &ea$-

• =ource:&tt$:66en%)ii$edia%org6)ii6Dnamicmemorallocation

• dnamic memor allocation• also no)n as &ea$8based memor allocation

• is t&e allocation o" memor storage "or use during t&e runtime

• Dnamicall allocated memor e(ists until it is released• e($licitl b t&e $rogrammer

• lie in !99

• b t&e garbage collector• lie in a#a and !E

• T&is is in contrast to static memor allocation, )&ic& &as a "i(edduration% It is said t&at an ob4ect so allocated &as a dnamicli"etime @as in stacB%

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Im$licitl s&ared classes

• =ource: &tt$:66doc%trolltec&%com6s&ared%&tml

• &en ou see stac allocated ob4ect• t&e mig&t not al)as be storing all t&e data in t&e stac

• Mut data mig&t be in t&e &ea$• t&e stac is onl used "or automatic dere"erencing

• =tac ob4ects $oint to a &ea$ allocated s&ared data%

• A s&ared class consists o":• a $ointer to a s&ared data bloc t&at contains:

• a re"erence count• t&e data%

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Im$licitl s&aredclass

re"erence count data

stac

&ea$

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• &en a s&ared ob4ect is created• it sets t&e re"erence count to 1

• t&e re"erence count is incremented )&ene#er a ne)ob4ect re"erences t&e s&ared data

• and decremented )&en t&e ob4ect dere"erences t&es&ared data

• T&e s&ared data is deleted )&en t&e re"erence countbecomes Oero

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• =o )&en ou see somet&ing lie:• Q=tring "oo R S"ooS

• Q=tring "oo is in t&e stac• MT it &as a re"erence to a data bloc )&ic& &as

• a re"erence count• 1

• and t&e data• S"oo

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• =o )&en ou do Q=tring bar R "oo• Q=tring class no) does a s&allo) co$ @to t&e stacB

• t&e "oo and bar no) actuall $oint to t&e =A3; data bloc

• onl t&e re"erence count )as increased• 2

• I" ou no) do bar%a$$end@SbarSB• No) t&e Q=tring class does a dee$ co$ "or bar%

• T&e data "rom "oo )as co$ied%• SbarS )as a$$ended to it%

• re"erence count is no) 1

• "oos re"erence count is no) 1%

• =im$le, isnt it

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Di""erent smart $ointers

• =ource: &tt$:66labs%trolltec&%com6blogs6200J60H6276count8)it&8me8&o)8man8smart8$ointer8classes8

does85t8&a#e6

Q=&aredDataPointer 6

Q;($licitl=&aredDataPointer

Im$lements s&aring o" data@not o" $ointersB, im$licitl ande($licitl, res$ecti#el% T&eQ=&aredDataPointer classre$resents a $ointer to anim$licitl s&ared ob4ect%

Q=&aredPointer Im$lements re"erence8countedstrong s&aring o" $ointers%Q=&aredPointer )ill delete t&e

$ointer it is &olding )&en itgoes out o" sco$e, $ro#ided noot&er Q=&aredPointer ob4ectsare re"erencing it%

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Di""erent smart $ointers

QeaPointer Im$lements re"erence8counted )ea

s&aring o" $ointers% T&e QeaPointer isan automatic )ea re"erence to a$ointer in !99% It cannot be used todere"erence t&e $ointer directl, but itcan be used to #eri" i" t&e $ointer &asbeen deleted or not in anot&er conte(t%

QeaPointer ob4ects can onl becreated b assignment "rom aQ=&aredPointer%

Q=co$edPointer 6Q=co$edArraPointer

Im$lements non8re"erence8countedstrong $ointer )ra$$er

@Q=&aredPointers little brot&erB% T&eQ=co$edPointer class stores a $ointer toa dnamicall allocated ob4ect, anddeletes it u$on destruction%

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Qt ob4ect model: =ignals and slots

• =ource: &tt$:665t%noia%com6doc6signalsandslots%&tml

• It's a )a "or Q+b4ects to communicate )it&outno)ing eac& ot&er%

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=ignals and slots

• =ignals are emited%• =lots recei#e signals%

• =ignals and slots are connected t&roug&Q+b4ect::connect

• 3an slots can be connected to a signal%• =ignals can be connected to signals%

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* © 2010 Digia Plc

=ignals and slots

QObject* sender = new QObject;

QObject* receiver = new QObject;

/* This will connect the signal for senders destruction

* to receivers deleteLater. It will result to a situation

* where if sender is deleted, the signal destroyed()

* will be sent ust before destruction and it will trigger* the receivers deleteLater which will result the receiver

* being deleted as well. */

QObject!!connect(sender, SIGNAL(destroyed()),

receiver, SLOT(deleteLater()));

sender"#deleteLater();

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;#ents and e#ent "ilters

• =ource: &tt$:66doc%trolltec&%com6e#entsand"ilters%&tml

• In Qt, e#ents are ob4ects, deri#ed "rom t&e abstractQ;#ent class%

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/o) e#ents are deli#ered-

• =ource:&tt$:665t%noia%com6doc6e#entsand"ilters%&tmlE&o)8e#ents8are8deli#ered

• As e#ent occurs•

Qt creates an e#ent ob4ect to re$resent it• b constructing an instance o" t&e a$$ro$riate Q;#ent

subclass• &tt$:66doc%trolltec&%com65e#ent%&tml

• ie% Q3ouse;#ent, QKe;#ent, QPaint;#ent

• deli#ers it to a $articular instance o" Q+b4ect @or one o"

its subclassesB b calling its e#ent@B "unction

http://doc.trolltech.com/qevent.htmlhttp://doc.trolltech.com/qevent.html

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/o) e#ents are deli#ered-

• e#ent@B "unction does not &andle t&e e#ent itsel" • but based on t&e t$e o" e#ent deli#ered

• it calls an e#ent &andler "or t&at s$eci"ic t$e o" e#ent

• sends a res$onse based on )&et&er t&e e#ent )as acce$tedor ignored

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;#ent t$es

• =ource:&tt$:665t%noia%com6doc6e#entsand"ilters%&tmlEe#ent8t$es

• 3ost e#ent t$es &a#e s$ecial classes

• As said earlier, t&e are descents o" Q;#ent• &tt$:665t%noia%com6doc65e#ent%&tml

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;#ent t$es

• common ones are:• QFesiOe;#ent &tt$:665t%noia%com6doc65resiOee#ent%&tml

• FesiOe e#ents

• QPaint;#ent &tt$:665t%noia%com6doc65$ainte#ent%&tml• Paint e#ents

• Q3ouse;#ent&tt$:665t%noia%com6doc65mousee#ent%&tml

• 3ouse e#ents

• QKe;#ent &tt$:665t%noia%com6doc65ee#ent%&tml• Ke e#ents

• Q!lose;#ent &tt$:665t%noia%com6doc65closee#ent%&tml• !lose e#ents @lie )indo), dialog, a$$licationB

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;#ent &andlers

• =ource:&tt$:665t%noia%com6doc6e#entsand"ilters%&tmlEe#ent8&andlers

• suall t&ere's a #irtual "unction in a base class%•

lie Qidget• /andling an e#ent &a$$ens so t&at:

• ou in&erit t&e class and im$lement t&e #irtual "unction%

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;#ent "ilters

• =ource:&tt$:665t%noia%com6doc6e#entsand"ilters%&tmlEe#ent8"ilters

• It is $ossible to )rite e#ent "ilters•

;#ent "ilters can loo or e#en interce$t t&e e#ents• In&erit Q+b4ect

• Im$lement bool Q+b4ect::e#entGilter@Q+b4ect Uob4ect,Q;#ent Ue#entB

• T&e )or $er Q+b4ect basis• ou set an e#ent "ilter to a Q+b4ect )it&

• Q+b4ect::install;#entGilter@B&tt$:665t%noia%com6doc65ob4ect%&tmlEinstall;#entGilter

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Querable and designable ob4ect$ro$erties

• =ource: &tt$:665t%noia%com6doc6$ro$erties%&tml

• A $ro$ert be&a#es lie a class data member%

• It &as additional "eatures accessible t&roug& t&e 3eta8+b4ect =stem%

• It is im$lemented t&roug& moc %• Needs Q+M;!T in t&e class &eader declaration%

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Querable and designable ob4ect$ro$erties

• ou can do somet&ing lie:$ %&''T+(bool enabled - isnabled IT setnabled)

• bool re"ers to t&e t$e o" t&e $ro$ert

• enabled is t&e $ro$ert name

• F;AD ob#iousl re"ers to t&e reading

• is;nabled is t&e "unction called "or reading• it &as to &a#e a $ublic im$lementation

• FIT;, again ob#iousl, re"ers to )riting

• set;nabled is t&e "unction to be called )&en )riting• it &as to &a#e a $ublic im$lementation

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. © 2010 Digia Plc

3oc and meta8ob4ect model

• =ource: &tt$:665t%noia%com6doc6moc%&tmlEmoc

• T&e 3eta8+b4ect !om$iler, moc, is t&e $rogram t&at&andles Qt's !99 e(tensions%

• Pro#ides us t&e Qts 3eta8+b4ect =stem

• 3agic &a$$ens t&roug& macros lie:• Q+M;!T

• QPF+P;FT

• Q;N3=

• signals:

• $ublic slots:

• $ri#ate slots:

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3oc and meta8ob4ect model

• T&is moc tool reads our &eader "ile

• Tries to "ind t&e Q+M;!T macro

• enerates meta8ob4ect code "or t&ose classes• code "or signals and slots

• )&ere signals, $ublic slots or $ri#ate slots are used• code "or $ro$erties

• )&ere QPF+P;FT is used

• code "or enums• )&ere Q;N3= is used

• Fegistering an enumeration t$e maes t&e enumeratornames a#ailable "or use in calls to Q+b4ect::setPro$ert@B%

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/o) do I do I a$$lications )it& it-

• ou can do )it& a designer lie in Qt !reator

• +r lie real N;FD=, b &and%• ea&, 4ust idding%%%

• T&e Qt !reator is mostl in t&e )a o" ou )ant to do

ant&ing more com$licated%• Its also "airl cumbersome to add our o)n

com$onents to t&e designers com$onent librar%

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/o) do I do I a$$lications )it& it-

• T&eres @at t&e momentB t)o )as o" doing I%• Qidget based a$$roac&

• ou do in&erit Qts com$onents and add "unctionalit• In&erit 4ust Qidget

• Im$lement Qidget::$aint;#ent@QPaint;#entUB• do custom $ainting )it& QPainter

•

&tt$:66doc%trolltec&%com65$ainter%&tml• se Qts stle s&eets to stle t&e )idgets

• &tt$:66doc%trolltec&%com6stles&eet%&tml

• ra$&ics Lie) "rame)or• Totall custom dra)ing%• !an use Qidgets in ra$&ics Lie) t&roug& $ro(s%• &tt$:66doc%trolltec&%com6gra$&ics#ie)%&tml

• Qt Quic• !ustom I

• Declarati#e descri$tion o" t&e I )it& ;cma=cri$t

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/o) do I do /ello orld-

include 0QtGui/QApplication#

include 0QtGui/QLabel#

int 1ain(int argc, char **argv)

2

QApplication a(argc, argv);

/** 3reate %Label to stac4* so we don5t have to delete it. */

QLabel label(67ello orld86);

/** 9how it8 */

label.show();

/** :ic4 off the event loo. */ return a.e

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/o) do I do /ello orld-

• A bit more com$licated /ello orld )it&Q3ainindo), QGrame, QLMo(

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/o) do I do e#ents-

• =ending e#ents$ bool %3orelication!!sendvent(%bect*

receiver, %vent* event)

• Fecei#ing e#ents•

se t&e s$ecialiOed e#ent &andlers• $aint;#ent• resiOe;#ent

• etcV

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/o) do I do signals and slots-

• Ill s&o) t&e e(am$le code%%%

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/o) do I do com$onents-

• T&e basic idea is to &a#e #er atomic use cases%

• Tr to ee$ t&e de$endencies as lo) as $ossible%

• se signals and slots "or communication%

• Tr to use basic t$es as $arameters "or t&e signals

and slots

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• A sim$le com$onent )it&out gra$&ical inter"ace%• Q!ounter : $ublic Q+b4ect

• $ublic• int #alue@B

• $ublic slots• increment@B• increment@int amountB• decrement@B• setLalue@int ne)LalueB

• signals• #alue!&anged@int ne)LalueB• #alue!&anged@const Q=tringC #alueB• #alue!&angedDelta@int deltaB

• $ri#ate• int m#alue

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7 © 2010 Digia Plc

/o) do I do com$onents

• e )ra$ t&at Q!ounter to a gra$&ical re$resentation• Qra$&ical!ounter : $ublic Q

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•

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• T&en )e need a reset button%• Gor t&at )e'll create a iterator )&ic& iterates o#er

Qra$&ical!ounters%

• T&e iterator )ill send a re"erence to a "oundQra$&ical!ounter e#er time it "inds one%

• e'll use t&e Q+b4ects ob4ect tree "eature to im$lement t&is"eature

• Q+b4ects are usuall created b assigning a $arent%

• T&at created ob4ect )ill be t&e c&ild o" t&e $arent ob4ect

• T&e tree can be easil iterated%

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• Vreset button continues:• e'll )ire 4ust an ordinar QPus&Mutton to a slot )&ic&

)ill gi#e t&e Q!ounterIterator a starting $oint "oriteration

• e'll )ire t&e "ound signal to one o" t&e slots )&ic& )ill

reset t&e counter%

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1 © 2010 Digia Plc

Qt Quic

• &tt$:66doc%5t%noia%com65t5uic%&tml

• Qt ser Inter"ace !onstruction Kit

• Girst bundle release o" Qt Quic on .%?

• Tec&nolog to build intuiti#e modern8looing "luid user inter"aces

•

Qt Quic is conce$t o" • Tools:

• Qt!reator

• Q3< Designer

• Q3

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2 © 2010 Digia Plc

Q3<

• =cri$t language

• ses a#a=cri$t as glue code "or controlling t&e be&a#iour o"t&e user inter"ace

• Declarati#e )a to de"ine I be&a#iour

• !ontains set o" #er basic user inter"ace controls called as Q3<elements "or e(am$le

• &tt$:66doc%5t%noia%com65declarati#eelements%&tml

• Fectangle

• Te(t

• Image

• Glicable• ;lements &a#e $ro$erties )&ic& can &a#e bindings to ot&er

$ro$erties

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* © 2010 Digia Plc

Q3<

• !om$lete a$$lications can be made )it& Q3< 9 a#a=cri$t ande(ecuted b Q3

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. © 2010 Digia Plc

Qt Quic lins

• Qt .%? and Qt !reator• &tt$:665t%noia%com6do)nloads6

• Qt Quic documentation• &tt$:66doc%5t%noia%com65t5uic%&tml

• Qt Quic Plaground• &tt$s:66$ro4ects%"orum%noia%com65t5uic$laground

• Qt Mubble

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T&an ou

tarmo%aidantaustaWdigia%com
mailto:[email protected]:[email protected]

Qt Basics GKO 2010

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