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Qt 5.2 Alpha Gets Love From Bluetooth, NFC, QML

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  • Qt 5.2 Alpha Gets Love From Bluetooth, NFC, QML

    Phoronix: Qt 5.2 Alpha Gets Love From Bluetooth, NFC, QML

    As was expected to happen, Qt 5.2 Alpha 1 is now available for downloading. Qt 5.2 is set to introduce several new default modules, tidies up the Android and iOS support, has a new JavaScript engine for Qt QML, and there's a whole host of other changes for this leading open-source tool-kit...

    http://www.phoronix.com/vr.php?view=MTQ3MzI

  • #2
    Originally posted by phoronix View Post
    Phoronix: Qt 5.2 Alpha Gets Love From Bluetooth, NFC, QML

    As was expected to happen, Qt 5.2 Alpha 1 is now available for downloading. Qt 5.2 is set to introduce several new default modules, tidies up the Android and iOS support, ...

    http://www.phoronix.com/vr.php?view=MTQ3MzI
    Does it compile to native code for android ? It would be good for better performance of the qt apps in comparison of other apps.

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    • #3
      Originally posted by doom_Oo7 View Post
      Does it compile to native code for android ? It would be good for better performance of the qt apps in comparison of other apps.
      If by "native code" you mean non-Java code, then yes. It uses the NDK and JNI to mix the native Qt C++ code with the Java interface of Android. However, using "native code" usually doesn't result in much of a speed gain (if any). Anecdotally, I haven't noticed any kind of a difference in speed between Java-only and Qt apps of a similar nature (of course, they were simple test cases that I made, nothing overly complex).

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      • #4
        Originally posted by Etzos View Post
        If by "native code" you mean non-Java code, then yes. It uses the NDK and JNI to mix the native Qt C++ code with the Java interface of Android. However, using "native code" usually doesn't result in much of a speed gain (if any). Anecdotally, I haven't noticed any kind of a difference in speed between Java-only and Qt apps of a similar nature (of course, they were simple test cases that I made, nothing overly complex).
        On which phone ? With my nexus S, Jelly bean 4.2.2 and mostly every apps are quite laggy even with no apps running...

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        • #5
          Originally posted by doom_Oo7 View Post
          On which phone ? With my nexus S, Jelly bean 4.2.2 and mostly every apps are quite laggy even with no apps running...
          I tested on an old Droid X2 and on a Samsung Galaxy S4.

          Just because it's "native code" doesn't mean that it can do anything much faster. It still has to go through Dalvik and interfacing from C/C++ to Java has its own overhead. The only gains you would really see are when doing things only in C/C++ (i.e. collection manipulation). Qt, by nature, has to interface with the Android SDK/NDK because it's a GUI library, so it hits the Dalvik bottleneck just the same as plain old Java.

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          • #6
            Originally posted by Etzos View Post
            If by "native code" you mean non-Java code, then yes. It uses the NDK and JNI to mix the native Qt C++ code with the Java interface of Android. However, using "native code" usually doesn't result in much of a speed gain (if any). Anecdotally, I haven't noticed any kind of a difference in speed between Java-only and Qt apps of a similar nature (of course, they were simple test cases that I made, nothing overly complex).

            C/C++ tends to be better at consistent performance and memory management (which can result in much better multitasking performance), but the average performance is not that different between Java or C++.

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            • #7
              Completely on another topic, I find it interesting that they went with bluez4 given that its discontinued and bluez5 is an incompatible API break.

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              • #8
                Originally posted by Ericg View Post
                Completely on another topic, I find it interesting that they went with bluez4 given that its discontinued and bluez5 is an incompatible API break.
                I believe there is an abstraction layer called Solid to deal with API breakage in platform libraries, so it should be possible to switch to bluez5 with just another plugin, don't know for sure though.

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