Merge lp://qastaging/~ubuntu-calculator-dev/ubuntu-calculator-app/ubuntu-calculator-app-remember-last-formula into lp://qastaging/ubuntu-calculator-app

PASSED: Continuous integration, rev:247
https://core-apps-jenkins.ubuntu.com/job/calculator-app-ci/35/
Executed test runs:
    None: https://core-apps-jenkins.ubuntu.com/job/generic-update-mp/200/console

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Hi Bartosz,
thanks for working on this.

Unfortunately, I don't think this is the right way to fix the problem: Qt.labs.settings writes on a file the setting, so you add a very big overhead: every time user presses a button there is an I/O operation, that is very expensive.

IMO the right direction to fix this bug is saving the actual formula only when app is closed (using Component.onDestruction) and when it losts focus (creating a bind on Qt.application.state[0]).

Let me know what you think.

[0]: http://doc.qt.io/qt-5/qml-qtqml-qt.html#application-prop

From user point of view it will be great to save progress every change.

I will check the impact on performance and give you performance comparison.

I checked that and saving is very fast, so from user perspective there is more benefits of savings formula every change (due to out of memory, which happens when you will open too many tabs in webbrowser).

Could you please double check that issue with profiler?

I checked that and saving is very fast, so from user perspective there is more benefits of savings formula every change (due to out of memory, which happens when you will open too many tabs in webbrowser).

Could you please double check that issue with profiler?