Posts Tagged ‘QtQuick2.0’

Update: How to create Qt5 QMLExtensionPlugin

Thursday, August 30th, 2012

Some time ago I wrote a post how to port QtQuick1.X extensions to Qt5. In that post, I wrote how I created a VideoWidget QMLExtensionPlugin on Qt 4.7 and then what it takes to make it run on Qt5 too. Well, things has changed a bit since that post an I thought that I should share what it takes now to make it work again.

Step 1: You can remove deprecated macro Q_EXPORT_PLUGIN2() from your plugin code

Step 2: Add a new macro  Q_PLUGIN_METADATA(IID “module.uri” FILE “yourfile.json”) after Q_OBJECT macro in your extension plugin class.

   #ifndef VIDEOWIDGET_QML_PLUGIN_PLUGIN_H
   #define VIDEOWIDGET_QML_PLUGIN_PLUGIN_H

   #include <QtQml/QQmlExtensionPlugin>

   class VideoWidget_QML_PluginPlugin : public QQmlExtensionPlugin
   {
       Q_OBJECT
       Q_PLUGIN_METADATA(IID "com.dpointer.media" FILE "videowidget.json")
    public:
       void registerTypes(const char *uri);
   };

   #endif // VIDEOWIDGET_QML_PLUGIN_PLUGIN_H

 

Step 3: Add JSON file to your project e.g. using OTHER_FILES = videowidget.json

{
        "Keys": [ "VideoWidget" ]
}

 

If I remembered everything, that’s all folks. You may also want to checkout the instructions from http://qt-project.org/wiki/Transition_from_Qt_4.x_to_Qt5

This post was a short and fast, but I hope it will help other devs who are using a bleeding edge Qt5 too. And if you have followed the news, Qt5 Beta is out!

 

Thanks for reading my blog!

Tags: , , , ,
Posted in Programming, Qt | No Comments »

Porting QtQuick1.X extensions to Qt5

Wednesday, March 7th, 2012

A friend of mine (@jan_ekholm/twitter and chakie/@freenode) developed a cool C++ VideoWidget using Qt a some time ago. The idea of making this kind of own custom widget, was that Qt’s multimedia isn’t the best multimedia kit on earth. The problem is that it’s not really a cross platform because it depends on underlying platform multimedia kit. For example on linux it may depend on streamer or phonon backend, on Windows it depends on DirectShow and on Mac on QuickTime. This also means that something that works on one platform, may not work on another platform.

One weird thing about Qt’s multimedia is that QML bindings are provided only by Qt Mobility’s multimedia module. Then again Phonon isn’t very efficient and it doesn’t have QML bindings. If using VLC with Qt, it’s almost impossible to make overlays (text) visible on a video. So Chakie made a solution, which doesn’t depend any of these, is a cross platform (Windows, Mac, Linux) and works quite nicely.

I thought that it would be great to port that QWidget/C++ based solution to QML. Actually, it was quite straight forward to do that, thanks to Chakie’s original solution, it took only a few hours to get the first version to work. Of course, fine tuning takes time, but it didn’t really take more than two hours to make the QML extension to show a video.

(more…)

Tags: , , , , ,
Posted in Programming, Qt | No Comments »