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QWT example debug for Zoomer functionality

  • I wish to implement the Zoomer functionality in my application so I decided to debug the qwt examples to see how it is actually implemented in qwt. However after setting up the breakpoints , my debug execution does not stop at the breakpoint and I am not being able to understand why. Can someone please help me with this? The example that I am going through is the spectrogram example which has the zoomer functionality in it. I have set the breakpoint in 'plot.cpp' just before the zoomer object is getting created, but the code does not stop there so that I can step into it and actually check out what us happening.Please help.


  • Are you building in DEBUG (vs RELEASE) mode? If not, breakpoints will not work.

  • Will I be able to set breakpoints in the release mode as well, if yes could you please tell me where can I check to see the mode in which I am building, I am using QtCreator and as far as i know I am building in debug_and_release mode

  • I was suggesting that you SHOULD build in debug mode. I have had trouble with the "dual" mode (called DebWithRelInfo in CMake) - breakpoints don't always work as expected. I don't frequently use QtCreator , and I just tried it and was confused because even after I changed to 'debug' the breakpoints were not hit "and I got this "this is not a debug build" message box. I had to do "clean all" and then "build all" before it worked correctly. (I set it to 'debug' by click the 'Projects' button in the sidebar -> then under "build steps" I click "details" and next to "qmake build configuration" set the combobox to 'debug')

  • It is already set to debug, I am stuck bigtime :(

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