Qt3 to Qt4 porting approach
The large-scale application usually consists of many libraries and some executable modules.
To reduce time-to-market the following approach looks attractive:
- Port the application using Q3Support module. Get it up and running
- In the continues way remove Q3Support classes, replace them with Qt4 equivalents and get benefits from all Qt4 improvements
- Check library dependencies and order them for “one-pass” build. Probably, it is already done in your Qt3 build environment
- Start from the library that does not depend on any other, and follow in the build order
- Compile the library using Qt3
- Create the test application that uses main classes from the library (just display widgets and fill them with data) for Qt3
- Port library to Qt4
- Port test application to Qt4
- Test that the ported application works in the same way as Qt3-based version.
- After processing of all libraries start to port and debug the main application.