2.5 KiB
First steps with the Final Cut widget toolkit
How to use the library
At the beginning of this introduction to the Final Cut we will start with a small example.
The following example creates an empty 30×10 character dialog.
File: dialog.cpp
#include <final/final.h>
int main (int argc, char* argv[])
{
finalcut::FApplication app(argc, argv);
finalcut::FDialog dialog(&app);
dialog.setText ("A dialog");
dialog.setGeometry (25, 5, 30, 10);
app.setMainWidget(&dialog);
dialog.show();
return app.exec();
}
(Note: Use mouse or Shift+F10 or Ctrl+^ to close the dialog)
After entering the source code in dialog.cpp you can compile the above program with gcc:
g++ -O2 -lfinal dialog.cpp -o dialog
How it works
#include <final/final.h>
All final cut programs must include the final.h header.
finalcut::FApplication app(argc, argv);
This line creates the finalcut::FApplication
object app
with
the command line arguments argc
and argv
. This object manages
the application main event loop. It receives keyboard and mouse events
and sends them to the target widgets. You must create an application
object before you can create a widgets object.
The next line
finalcut::FDialog dialog(&app);
creates the finalcut::FDialog
object dialog
with the object app
as parent object. The finalcut::FDialog
class is the base class for
creating dialog windows.
dialog.setText ("A dialog");
The title bar of the dialog box gets the text "A dialog".
dialog.setGeometry (25, 5, 30, 10);
The dialog window gets a width of 30 and a height of 10 characters. The window in the terminal is located at the positions x=25 and y=5 (note: x=1 and y=1 represents the upper left corner).
app.setMainWidget(&dialog);
The dialog
object was now selected as the main widget for the application.
When you close the main widget, the entire application quits.
dialog.show();
A window or widget is not visible directly after its creation.
Only the call of show()
makes it (and its child objects,
if available) visible.
return app.exec();
The last line calls exec()
to start the application and return
the result to the operating system. When the application starts,
it enters the main event loop. This loop doesn't end until the
window/application is closed.