This document provides examples of using various Qt GUI classes in Ring programming language. It shows how to: 1. Load the GUI library, create windows and widgets, and handle events like button clicks. 2. Use timer to grow an image over time and scale it to fit inside a window. 3. Open files using QFileDialog and get the selected filename. 4. Draw shapes on a widget using QPainter. 5. Print to PDF using QPrinter. 6. Create multiple windows and switch between them. Play sound files using QMediaPlayer. 7. Get and set colors using QColorDialog. Display numbers using qLCDNumber. Animate a movable label.

1. Ring Documentation, Release 1.5.4
setGeometry(PosLeft,PosTop,imageW,imageH)
}
TimerMan = new qtimer(win1) {
setinterval(100) ### interval 100 millisecs.
settimeoutevent("pTime()") ### ==>> func
start()
}
show()
}
exec()
}
###------------------------------------------------------
### Fuction TimerMan: calling interval 100 milliseconds
func pTime
### Stop Timer when image is size of Window area
if imageW > BoxWidth
TimerMan.stop()
imageStock.clear() ### Will clear the image
ok
### Grow image
imageW += GrowBy
imageH = imageW / AspectRatio
### Scaled Image: Size-H, Size-V, Aspect, Transform
imageStock.setpixmap(image.scaled(imageW , imageH ,0,0))
### Center the image
PosLeft = (WinWidth - imageW ) / 2
PosTop = (WinHeight - imageH ) / 2
imageStock.setGeometry(PosLeft,PosTop,imageW,imageH)
56.33 Using the QFileDialog Class
Example
Load "guilib.ring"
New qapp {
win1 = new qwidget() {
setwindowtitle("open file")
setgeometry(100,100,400,400)
new qpushbutton(win1) {
setgeometry(10,10,200,30)
settext("open file")
setclickevent("pOpen()")
}
show()
}
56.33. Using the QFileDialog Class 615

2. Ring Documentation, Release 1.5.4
exec()
}
Func pOpen
new qfiledialog(win1) {
cName = getopenfilename(win1,"open file","c:","source files(*.ring)")
win1.setwindowtitle(cName)
}
The application during the runtime
56.34 Drawing using QPainter
In this example we will learn about drawing using the QPainter class
Load "guilib.ring"
New qapp {
win1 = new qwidget() {
setwindowtitle("Drawing using QPainter")
setgeometry(100,100,500,500)
label1 = new qlabel(win1) {
setgeometry(10,10,400,400)
settext("")
}
new qpushbutton(win1) {
setgeometry(200,400,100,30)
settext("draw")
setclickevent("draw()")
}
show()
}
56.34. Drawing using QPainter 616

3. Ring Documentation, Release 1.5.4
exec()
}
Func draw
p1 = new qpicture()
color = new qcolor() {
setrgb(0,0,255,255)
}
pen = new qpen() {
setcolor(color)
setwidth(10)
}
new qpainter() {
begin(p1)
setpen(pen)
drawline(500,150,950,450)
drawline(950,550,500,150)
endpaint()
}
label1 { setpicture(p1) show() }
The application during the runtime
56.34. Drawing using QPainter 617

4. Ring Documentation, Release 1.5.4
56.35 Printing using QPrinter
In this example we will learn how to print to PDF file using QPrinter
Load "guilib.ring"
new qApp {
win1 = new qwidget() {
setwindowtitle("Printer")
setgeometry(100,100,500,500)
myweb = new qwebview(win1) {
setgeometry(100,100,1000,500)
loadpage(new qurl("http://google.com"))
}
new qpushbutton(win1) {
setGeometry(20,20,100,30)
settext("Print")
setclickevent("print()")
}
showmaximized()
56.35. Printing using QPrinter 618

5. Ring Documentation, Release 1.5.4
}
exec()
}
func print
printer1 = new qPrinter(0) {
setoutputformat(1) # 1 = pdf
setoutputfilename("test.pdf")
painter = new qpainter() {
begin(printer1)
myfont = new qfont("Times",50,-1,0)
setfont(myfont)
drawtext(100,100,"test")
printer1.newpage()
drawtext(100,100,"test2")
endpaint()
}
}
printer1 = new qPrinter(0) {
setoutputformat(1)
setoutputfilename("test2.pdf")
myweb.print(printer1)
myweb.show()
}
system ("test.pdf")
system ("test2.pdf")
56.36 Creating More than one Window
The next example demonstrates how to create more than one window
Load "guilib.ring"
app1 = new qapp {
win1 = new qwidget() {
setwindowtitle("First")
setgeometry(100,100,500,500)
new qpushbutton(win1) {
setgeometry(100,100,100,30)
settext("close")
setclickevent("app1.quit()")
}
new qpushbutton(win1) {
setgeometry(250,100,100,30)
settext("Second")
setclickevent("second()")
}
showmaximized()
}
exec()
}
56.36. Creating More than one Window 619

6. Ring Documentation, Release 1.5.4
func second
win2 = new qwidget() {
setwindowtitle("Second")
setgeometry(100,100,500,500)
setwindowflags(Qt_dialog)
show()
}
The application during the runtime
56.37 Playing Sound
Example:
Load "guilib.ring"
new qapp {
win1 = new qwidget() {
setwindowtitle("play sound!") show()
}
new qmediaplayer() {
setmedia(new qurl("footstep.wav"))
setvolume(50) play()
}
exec()
}
56.38 Using the QColorDialog Class
Example:
56.37. Playing Sound 620

7. Ring Documentation, Release 1.5.4
Load "guilib.ring"
oApp = new myapp { start() }
Class MyApp
oColor win1
Func start
myapp = new qapp
win1 = new qMainWindow() {
setwindowtitle("Color Dialog")
setgeometry(100,100,400,400)
}
new qpushbutton(win1) {
setgeometry(10,10,100,30)
settext("Get Color")
setclickevent("oApp.pColor()")
}
win1.show()
myapp.exec()
Func pColor
myobj = new qcolordialog()
aColor = myobj.GetColor()
r=acolor[1] g=acolor[2] b=acolor[3]
win1.setstylesheet("background-color: rgb("+r+", " + g+ "," + b + ")")
The application during the runtime
56.38. Using the QColorDialog Class 621

8. Ring Documentation, Release 1.5.4
56.39 Using qLCDNumber Class
In this example we will learn about using the qLCDNumber class
Load "guilib.ring"
New qApp
{
win1 = new qWidget()
{
setwindowtitle("LCD Number")
setgeometry(100,100,250,120)
new qLCDNumber(win1)
{
setgeometry(10,10,100,40)
display(100)
}
new qLCDNumber(win1)
{
setgeometry(10,60,100,40)
display(80)
}
show()
}
exec()
}
The application during the runtime
56.40 Movable Label Example
Load "guilib.ring"
new qApp {
win1 = new qWidget()
{
56.39. Using qLCDNumber Class 622

9. Ring Documentation, Release 1.5.4
label1 = new qLabel(win1)
{
setText("Welcome")
setgeometry(10,10,200,50)
setstylesheet("color: purple ; font-size: 30pt;")
}
new qTimer(win1)
{
setInterVal(10)
setTimeOutEvent("pMove()")
start()
}
setWindowTitle("Movable Label")
setgeometry(100,100,600,80)
setStyleSheet("background-color: white;")
show()
}
exec()
}
Func pMove
label1
{
move(x()+1,y())
if x() > 600
move(10,y())
ok
}
The application during the runtime
56.41 QMessagebox Example
In this section we will learn how to check the output of the Message box
Load "guilib.ring"
new qApp {
win1 = new qWidget()
{
label1 = new qpushbutton(win1)
{
setText("Test")
setgeometry(10,10,200,50)
56.41. QMessagebox Example 623

10. Ring Documentation, Release 1.5.4
setstylesheet("color: purple ; font-size: 30pt;")
setclickevent("pWork()")
}
setWindowTitle("Messagebox")
setgeometry(100,100,600,80)
setStyleSheet("background-color: white;")
show()
}
exec()
}
func pWork
new qmessagebox(win1)
{
setwindowtitle("messagebox title")
settext("messagebox text")
setInformativeText("Do you want to save your changes?")
setstandardbuttons(QMessageBox_Yes | QMessageBox_No | QMessageBox_Close)
result = exec()
win1 {
if result = QMessageBox_Yes
setwindowtitle("Yes")
but result = QMessageBox_No
setwindowtitle("No")
but result = QMessageBox_Close
setwindowtitle("Close")
ok
}
}
The application during the runtime
56.42 Using QInputDialog Class
In the next example we will learn about using the QInputDialog class
56.42. Using QInputDialog Class 624