The Ring programming language version 1.8 book - Part 71 of 202

1. Ring Documentation, Release 1.8
60.29 Other Widgets Events
Each Qt signal can be used in RingQt, just add Set before the signal name and add event after the signal name to get
the method that can be used to determine the event code.
For example the QProgressBar class contains a signal named valueChanged() To use it just use the function setVal-
ueChangedEvent()
Example:
Load "guilib.ring"
New qApp {
win1 = new qMainWindow() {
setwindowtitle("QProgressBar valueChanged Event")
progress1 = new qprogressbar(win1) {
setGeometry(100,100,350,30)
setvalue(10)
setvaluechangedevent("pChange()")
}
new qpushbutton(win1) {
setGeometry(10,10,100,30)
settext("increase")
setclickevent("pIncrease()")
}
showMaximized()
}
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2. Ring Documentation, Release 1.8
exec()
}
func pIncrease
progress1 { setvalue(value()+1) }
func pchange
win1.setwindowtitle("value : " + progress1.value() )
The application during the runtime
Another example for the stateChanged event of the QCheckBox class
Load "guilib.ring"
New qApp {
win1 = new qMainWindow() {
setwindowtitle("QCheckBox")
new qcheckbox(win1) {
setGeometry(100,100,100,30)
settext("New Customer!")
setstatechangedevent("pchange()")
}
showMaximized()
}
exec()
}
Func pChange
new qMessageBox(Win1) {
setWindowTitle("Checkbox")
settext("State Changed!")
show()
}
The application during the runtime
60.29. Other Widgets Events 672

3. Ring Documentation, Release 1.8
60.30 Using the QTimer Class
In this example we will learn about using the QTimer class
Load "guilib.ring"
new qApp {
win1 = new qwidget() {
setgeometry(100,100,200,70)
setwindowtitle("Timer")
label1 = new qlabel(win1) {
setgeometry(10,10,200,30)
settext(thetime())
}
new qtimer(win1) {
setinterval(1000)
settimeoutevent("pTime()")
start()
}
show()
}
exec()
}
func ptime
label1.settext(thetime())
Func thetime
return "Time : " + Time()
The application during the runtime
60.30. Using the QTimer Class 673

4. Ring Documentation, Release 1.8
60.31 Using QProgressBar and Timer
In this example we will learn about using the “animated” QProgressBar class and Timer
###------------------------------------
### ProgressBar and Timer Example
Load "guilib.ring"
new qApp
{
win1 = new qwidget()
{
setgeometry(100,100,400,100)
setwindowtitle("Timer and ProgressBar")
LabelMan = new qlabel(win1)
{
setgeometry(10,10,200,30)
settext(theTime()) ### ==>> func
}
TimerMan = new qtimer(win1)
{
setinterval(1000)
settimeoutevent("pTime()") ### ==>> func
start()
}
BarMan = new qprogressbar(win1)
{
setGeometry(100,50,300,10) ### Position X y, Length, Thickness
setvalue(0) ### Percent filled
}
show()
}
exec()
}
func pTime
LabelMan.settext(theTime()) ### ==>> func
Increment = 10
if BarMan.value() >= 100 ### ProgressBar start over.
BarMan.setvalue(0)
ok
BarMan{ setvalue(value() + Increment) }
60.31. Using QProgressBar and Timer 674

5. Ring Documentation, Release 1.8
Func theTime
return "Time : " + Time()
60.32 Display Scaled Image using QLabel
In this example we will learn about displaying and scaling an image so that it looks “animated” using the QLabel
widget
Load "guilib.ring"
#----------------------------------------------------
# REQUIRES: image = "C:RINGbinstock.jpg"
# imageStock: start dimensions for growing image
imageW = 200 ; imageH = 200 ; GrowBy = 4
###----------------------------------------------------
### Window and Box Size dimensions
WinWidth = 1280 ; WinHeight = 960
BoxWidth = WinWidth -80 ; BoxHeight = WinHeight -80
###----------------------------------------------------
New qapp {
win1 = new qwidget() {
setgeometry(50,50, WinWidth,WinHeight)
setwindowtitle("Animated Image - Display Image Scaled and Resized")
imageStock = new qlabel(win1) {
image = new qpixmap("C:RINGbinstock.jpg")
AspectRatio = image.width() / image.height()
imageW = 200
imageH = imageH / AspectRatio
### Size-H, Size-V, Aspect, Transform
setpixmap(image.scaled(imageW , imageH ,0,0))
PosLeft = (BoxWidth - imageW ) / 2
PosTop = (BoxHeight - imageH ) / 2
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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)
60.33 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()
}
60.33. Using the QFileDialog Class 676

7. Ring Documentation, Release 1.8
exec()
}
Func pOpen
new qfiledialog(win1) {
cName = getopenfilename(win1,"open file","c:","source files(*.ring)")
win1.setwindowtitle(cName)
}
The application during the runtime
60.34 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()
}
60.34. Drawing using QPainter 677

8. Ring Documentation, Release 1.8
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
60.34. Drawing using QPainter 678

9. Ring Documentation, Release 1.8
60.35 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()
60.35. Printing using QPrinter 679

10. Ring Documentation, Release 1.8
}
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")
60.36 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()
}
60.36. Creating More than one Window 680