Planet maemo

Henri Bergius

Atreus: Building a custom ergonomic keyboard

2017-04-20 00:00 UTC  by  Henri Bergius
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As mentioned in my Working on Android post, I’ve been using a mechanical keyboard for a couple of years now. Now that I work on Flowhub from home, it was a good time to re-evaluate the whole work setup. As far as regular keyboards go, the MiniLa was nice, but I wanted something more compact and ergonomic.

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Philip Van Hoof

Asynchronous undoable and redoable APIs

2017-04-13 21:32 UTC  by  Philip Van Hoof
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Combining QFuture with QUndoCommand made a lot of sense for us. The undo and the redo methods of the QUndoCommand can also be asynchronous, of course. We wanted to use QFuture without involving threads, because our asynchronosity is done through a process and IPC, and not a thread. It’s the design mistake of QtConcurrent‘s run method, in my opinion. That meant using QFutureInterface instead (which is undocumented, but luckily public – so it’ll remain with us until at least Qt’s 6.y.z releases).

So how do we make a QUndoCommand that has a undo, and that has a redo method that returns a asynchronous QFuture<ResultType>?

We just did that, today. I’m very satisfied with the resulting API and design. It might have helped if QUndoStack would be a QUndoStack<T> and QUndoCommand would have been a QUndoCommand<T> with undo and redo’s return type being T. Just an idea for the Qt 6.y.z developers.

Categories: condescending
Alberto Mardegan

Looking for new adventures

2017-04-10 19:07 UTC  by  Alberto Mardegan
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Yes, I'm looking for a job. :-)

These six years I've spent at Canonical have literally been flying. I enjoyed my work from the very first day, when I was assigned to the Unity 2D team, developing a lightweight desktop environment for Ubuntu, though I stayed in that team just for a few weeks. The next task, which I've been carrying on till today, has been implementing the Online Accounts feature in Ubuntu; this project has been especially dear to me, given that I got to reuse and improve much of the work we developed for the Nokia N9 phone. Seeing it being adopted also by Sailfish OS and KDE has been a major satisfaction, and a proof that we were on the right track. And indeed, porting the UI to Qt/QML for running in Unity 8, plus extending and simplifying the APIs and helping with the development of client applications has been a fantastic ride.
In the times where calm was reigning in the project, I reached out to other teams and offered help, mainly for improving the geolocation service and the webapps project.

Unfortunately, with the decision to terminate the development of Unity8 and to set aside the convergence goals, all of the above is no longer relevant for Canonical's future and I, along many other developers, have left the company.

So, here's my CV.

Given that reading is boring, here's a few pictures (and even a video!) of programs I've done, not as part of my daily work but in my spare time; though, to be honest, I do enjoy middleware and logic development (and even kernel, though I got little chances to work on that so far) more than UI development:
Imaginario on the Ubuntu phone Imaginario for your desktop (under development)
Mappero Geotagger If you wish to see my code, please have a look at my gitlab, github and launchpad accounts.


Categories: english
Philip Van Hoof

Among the problems we’ll face is that we want asynchronous APIs that are undoable and that we want to switch to read only, undoable editing, non-undoable editing and that QML doesn’t really work well with QFuture. At least not yet. We want an interface that is easy to talk with from QML. Yet we want to switch between complicated behaviors.

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Categories: condescending
Philip Van Hoof

Perfection

2017-03-23 00:17 UTC  by  Philip Van Hoof
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Perfection has been reached not when there is nothing left to add, but when there is nothing left to take away.

Categories: Art culture
Enrique Ocaña González

A lot of good things have happened to the Media Source Extensions support since my last post, almost a year ago.

The most important piece of news is that the code upstreaming has kept going forward at a slow, but steady pace. The amount of code Igalia had to port was pretty big. Calvaris (my favourite reviewer) and I considered that the regular review tools in WebKit bugzilla were not going to be enough for a good exhaustive review. Instead, we did a pre-review in GitHub using a pull request on my own repository. It was an interesting experience, because the change set was so large that it had to be (artificially) divided in smaller commits just to avoid reaching GitHub diff display limits.

394 GitHub comments later, the patches were mature enough to be submitted to bugzilla as child bugs of Bug 157314 – [GStreamer][MSE] Complete backend rework. After some comments more in bugzilla, they were finally committed during Web Engines Hackfest 2016:

Some unforeseen regressions in the layout tests appeared, but after a couple of commits more, all the mediasource WebKit tests were passing. There are also some other tests imported from W3C, but I kept them still skipped because webm support was needed for many of them. I’ll focus again on that set of tests at its due time.

Igalia is proud of having brought the MSE support up to date to WebKitGTK+. Eventually, this will improve the browser video experience for a lot of users using Epiphany and other web browsers based on that library. Here’s how it enables the usage of YouTube TV at 1080p@30fps on desktop Linux:

Our future roadmap includes bugfixing and webm/vp9+opus support. This support is important for users from countries enforcing patents on H.264. The current implementation can’t be included in distros such as Fedora for that reason.

As mentioned before, part of this upstreaming work happened during Web Engines Hackfest 2016. I’d like to thank our sponsors for having made this hackfest possible, as well as Metrological for giving upstreaming the importance it deserves.

Thank you for reading.

 

Categories: Hacking (english)
Philip Van Hoof

Duck typing

2017-03-17 10:34 UTC  by  Philip Van Hoof
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Imagine you have a duck. Imagine you have a wall. Now imagine you throw the duck with a lot of force against a wall. Duck typing means that the duck hitting the wall quacks like a duck would.

ps. Replace wall with API and duck with ugly stupid script written by an idiot. You can leave quacks.

Categories: condescending
madman2k

Migrating from owncloud 9.1 to nextcloud 11

2017-02-10 23:33 UTC  by  madman2k
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First one should ask though: why? My main motivation was that many of the apps I use were easily available in the nextcloud store, while with owncloud I had to manually pull them from github.
Additionally some of the app authors migrated to nextcloud and did not provide further updates for owncloud.

Another reason is this:

the graphs above show the number of commits for owncloud and nextcloud. Owncloud has taken a very noticeable hit here after the fork – even though they deny it.

From the user perspective the lack of contribution is visible for instance in the admin interface where with nextcloud you get a nice log browser and system stats while with owncloud you do not. Furthermore the nextcloud android app handles Auto-Upload much better and generally seems more polished – I think one can expect nextcloud to advance faster in general.

Migrating

For migrating you can follow the excellent instructions of Jos Poortvliet.

In my case owncloud 9.1 was installed on Ubuntu in /var/www/owncloud and I put nextcloud 11 to /var/www/nextcloud. Then the following steps had to be applied:

  1. put owncloud in maintenance mode
    sudo -u www-data php occ maintenance:mode --on
  2. copy over the config.php
    cp /var/www/owncloud/config/config.php /var/www/nextcloud/config/
  3. adapt the path in config.php
    # from 
    'path' => '/var/www/owncloud/apps',
    # to
    'path' => '/var/www/nextcloud/apps',
  4. adapt the path in crontab
    sudo crontab -u www-data -e
  5. adapt the paths in the apache config
  6. run the upgrade script which takes care of the actual migration. Then disable the maintanance mode.
    sudo -u www-data php occ upgrade
    sudo -u www-data php occ maintenance:mode --off

and thats it.

Categories: News
Henri Bergius

Working on an Android tablet, 2017 edition

2017-02-10 00:00 UTC  by  Henri Bergius
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Back in 2013 I was working exclusively on an Android tablet. Then with the NoFlo Kickstarter I needed a device with a desktop browser. What followed were brief periods working on a Chromebook, on a 12” MacBook, and even an iPad Pro.

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Philip Van Hoof

MyPlugin/MyPlugin.cpp:

#include <ViewModels/MyListClass.h>
#include <ViewModels/DisplayViewModel.h>

qmlRegisterUncreatableType<MyListClass>( a_uri, 1, 0, "MyListClass",
         "Use access via DisplayViewModel instead");
qmlRegisterType<DisplayViewModel>( a_uri, 1, 0, "DisplayViewModel");

Utils/MyQMLListUtils.h

#define MY_DECLARE_QML_LIST(type, name, owner, prop) \
QQmlListProperty<type> name(){ \
   return QQmlListProperty<type>( \
               this, 0,&owner::count ## type ## For ## name ## List, \
               &owner::at ## type ## For ## name ## List); \
} \
static int count ## type ## For ## name ## List(QQmlListProperty<type>*property){ \
   owner *m = qobject_cast<owner *>(property->object); \
   return m->prop.size(); \
} \
static type *at ## type ## For ## name ## List( \
        QQmlListProperty<type>*property, int index){ \
   owner *m = qobject_cast<owner *>(property->object); \
   return m->prop[index]; \
}

ViewModels/DisplayViewModel.h

#ifndef DISPLAYVIEWMODEL_H
#define DISPLAYVIEWMODEL_H

#include <QObject>
#include <QtQml>
#include <ViewModels/MyListClass.h>
#include <Utils/MyQMLListUtils.h>

class DisplayViewModel : public QObject
{
    Q_OBJECT

    Q_PROPERTY(constQString title READ title WRITE setTitle NOTIFY titleChanged )
    Q_PROPERTY(constQList<MyListClass*> objects READ objects
                                          NOTIFY objectsChanged ) 
    Q_PROPERTY( QQmlListProperty<MyListClass> objectList READ objectList
                                              NOTIFY objectsChanged )
public:
    explicit DisplayViewModel( QObject *a_parent = nullptr );
    explicit DisplayViewModel( const QString &a_title,
                               QList<MyListClass*> a_objects,
                               QObject *a_parent = nullptr );
    const QString title()
        { return m_title; }
    void setTitle( const QString &a_title ); 
    const QList<MyListClass*> objects ()
        { return m_objects; } 
    Q_INVOKABLE void appendObject( MyListClass *a_object);
    Q_INVOKABLE void deleteObject( MyListClass *a_object);
    Q_INVOKABLE void reset( );

protected:
    MY_DECLARE_QML_LIST(MyListClass, objectList, DisplayViewModel, m_objects)

signals:
    void titleChanged();
    void objectsChanged();

private:
    QString m_title;
    QList<MyListObject*> m_objects;
};

#endif// DISPLAYVIEWMODEL_H

DisplayViewModel.cpp

#include "DisplayViewModel.h"

DisplayViewModel::DisplayViewModel( const QString &a_title,
                                    QList<MyListClass*> a_objects,
                                    QObject *a_parent )
    : QObject ( a_parent )
    , m_title ( a_title )
    , m_objects ( a_objects )
{
    foreach (MyListClass* mobject, m_objects) {
        mobject->setParent (this);
    }
}

void DisplayViewModel::setTitle (const QString &a_title )
{
    if ( m_title != a_title ) {
        m_title = a_title;
        emit titleChanged();
    }
}

void DisplayViewModel::reset( )
{
    foreach ( MyListClass *mobject, m_objects ) {
        mobject->deleteLater();
    }
    m_objects.clear();
    emit objectsChanged();
}

void DisplayViewModel::appendObject( MyListClass *a_object )
{
    a_object->setParent( this );
    m_objects.append( a_object );
    emit objectsChanged();
}

void DisplayViewModel::deleteObject( MyListClass *a_object )
{
    if (m_objects.contains( a_object )) {
        m_objects.removeOne( a_object );
        a_object->deleteLater();
        emit objectsChanged();
    }
}

Tester.cpp

#include <ViewModels/DisplayViewModel.h>
#include <ViewModels/MyListClass.h>

QList<MyListClass*> objectList;
for( int i = 0; i < 100 ; ++i ) {
    objectList.append ( new MyListClass (i) );
}
DisplayViewModel *viewModel = new DisplayViewModel (objectList);
viewModel->appendObject ( new MyListClass (101) );

Display.qml

import QtQuick 2.5
import MyPlugin 1.0

Repeater { 
    property DisplayViewModel viewModel: DisplayViewModel { } 
    model: viewModel.objectList
    delegate: Item {
        property MyListClass object: modelData
        Text {
            text: object.property
        }
    }
}
Categories: controversial
Alberto Garcia

QEMU and the qcow2 metadata checks

2017-02-08 08:52 UTC  by  Alberto Garcia
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When choosing a disk image format for your virtual machine one of the factors to take into considerations is its I/O performance. In this post I’ll talk a bit about the internals of qcow2 and about one of the aspects that can affect its performance under QEMU: its consistency checks.

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Categories: Debian
Henri Bergius

Process API for NoFlo components

2017-01-05 00:00 UTC  by  Henri Bergius
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It has been a while that I’ve written about flow-based programming — but now that I’m putting most of my time to Flowhub things are moving really quickly.

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