Qteveloper

Build your first 'Qt for MCUs' application

2020-07-17T14:01:00.001-07:00

Qt for MCUs is a complete graphics framework and toolkit with everything you need to design, develop, and deploy GUIs on MCUs. Run your application on bare metal or a real-time operating system.

Join this tutorial to learn how to build your first MCU application.

More info: https://www.qt.io/product/develop-software-microcontrollers-mcu

Hello World Qt, hand made from Empty qmake Project

2015-10-30T10:17:00.004-07:00

This video show how to create Empty qmake Project in Qt Creator, create .cpp and edit .pro to make a Hello World application.

main.cpp


#include <QApplication>
#include <QPushButton>

int main(int argc, char *argv[]){
    QApplication app(argc, argv);
    QPushButton qPushButton("Hello Qt");
    qPushButton.show();
    return app.exec();
}

You will be reported with error of:
QApplication: No such file or directory
QPushButton: No such file or directory

To fix it: Edit HelloQt.pro to add the code QT+=widgets.

QT+=widgets
SOURCES += \
    main.cpp

libGL error: core dri or dri2 extension not found and failed to load driver: vboxvideo

2015-10-30T03:49:00.001-07:00

In case you install QtCreator on Ubuntu under VirtualBox, and QtCreator cannot run caused by:

libGL error: core dri or dri2 extension not found
libGL error: failed to load driver: vboxvideo

Try to close Ubuntu, disable 3D Acceleration of Setting > Display in VirtualBox, and restart Ubuntu again.

Chage Qt5 Example of Calendar to set today

2015-10-28T13:49:00.004-07:00

The Qt Creator Examples: Qt5 Calendar preset date to 2014 January 1. By default, the date of Calendar is today.

To change the data of Qt Calendar Example, edit qml/main.qml, simple comment the code selectedDate: new Date(2014, 0, 1)

Qt Creator Examples - Qt Quick Controls Gallery

2015-10-26T16:53:00.000-07:00

This example project demonstrates the various UI components provided by Qt Quick Controls.

error: qtquickcontrolsapplication.h: No such file or directory

2015-10-26T16:42:00.002-07:00

If you try to build Qt Creator Examples and reported error of qtquickcontrolsapplication.h: No such file or directory.

Most probably you install Qt with sudo, the default install location is /opt, a user un-writable location. When you build Qt Creator Examples, you have to copy the project to another user writable location, it break the links and lost the shared directory.

May be you have to un-install Qt. Re-install to another user writable location, or re-install WITHOUT sudo (the default location is your HOME). Such that you need not copy the project when create examples.

How to uninstall Qt

2015-10-26T16:01:00.003-07:00

To unstall Qt:

open terminal, go to the installed directory, run MaintenanceTools:

$ ./MaintenanceTool

Qt Creator Examples: Qt5 Calendar

2015-10-26T10:30:00.001-07:00

The Calendar example displays a Calendar control and an events list for the selected date. It uses a C++ class to fetch the event details from an SQLite database. The example app uses a custom CalendarStyle to highlight the selected date and mark the dates that have events.

To set date to today: Chage Qt5 Example of Calendar to set today

Qt Contributors' Summit 2014 opening and state of the project

2014-06-13T11:54:00.001-07:00

Internet of Things and Qt

2014-05-20T22:03:00.001-07:00

Qt 5.3 available now

2014-05-20T21:58:00.002-07:00

Qt 5.3 is the latest version of Qt, the leading cross-platform application and UI software development framework. With Qt you can take your application natively to all major desktop, embedded or mobile platforms or create highly powerful modern embedded devices with alternative screens or remote controllers running on desktop or mobile platforms--Implement Internet-of-Things or Bring-Your-Own-Device with the same, one technology: Qt.

Know more: http://qt-project.org/qt5/qt53

Introducing Qt 5.3

Qt WebEngine with new features on multiple platforms

2014-05-13T02:54:00.001-07:00

The video is presented by the Digia,Qt WebEngine team. The following video shows Qt WebEngine in action on multiple platforms. Some very exciting features shown in the video include WebRTC being used for video conferencing and WebGL and CSS animations running on embedded linux. Further it also shows HTML5 Video running on an off-the-shelf embedded device.

Qt WebEngine on Multiple Devices

Qt in Embedded World 2014

2014-03-14T17:28:00.002-07:00

Qt Snapshots from Embedded World 2014 (Nuremberg, Germany), the largest embedded systems show in Europe.

Further information about the showcases presented in the video can be found from: http://qt.digia.com/Embedded-World/

Qt 5.2.1 and Qt Creator 3.0.1 Released

2014-02-05T09:10:00.002-08:00

Know more:

Qt 5.2 and Qt Creator 3.0 Released

2013-12-12T10:32:00.004-08:00

Read Qt Blog:

A Book about Qt5

2013-12-12T09:11:00.002-08:00

The entire collection of chapters covering Qt5 programming, written by Juergen Bocklage-Ryannel and Johan Thelin, is available here.

Qt 5.2 and Qt Creator 3.0 Release Candidate 1 Available

2013-11-29T09:41:00.002-08:00

Example of QtQuick.Controls SpinBox

2013-11-18T01:52:00.000-08:00

Example to implement QtQuick.Controls SpinBox with qml.

example of QtQuick.Controls SpinBox

import QtQuick 2.1
import QtQuick.Controls 1.0
import QtQuick.Window 2.0

ApplicationWindow {
    title: qsTr("qteveloper.blogspot.com")
    width: 400
    height: 350

    menuBar: MenuBar {
        Menu {
            title: qsTr("File")
            MenuItem {
                text: qsTr("Exit")
                onTriggered: Qt.quit();
            }
        }
    }

    Column{
        Label {
            id: label
        }

        SpinBox{
            id: spinbox1
            width: 100
            maximumValue: 100
            minimumValue: 0
            value: 50
            onValueChanged: label.text = "spinbox1: " + value
        }
        SpinBox{
            id: spinbox2
            width: 100
            maximumValue: 100
            minimumValue: 0
            value: 50
            stepSize: 5
            prefix: "prefix: "
            onValueChanged: label.text = "spinbox2: " + value
        }
        SpinBox{
            id: spinbox3
            width: 100
            maximumValue: 100
            minimumValue: 0
            value: 50
            stepSize: 10
            suffix: "-suffix"
            onValueChanged: label.text = "spinbox3: " + value
        }

    }
}

QtQuick.Controls example, Slider.

2013-11-17T08:15:00.000-08:00

qml example to implement QtQuick.Controls Slider.

QtQuick.Controls Slider

import QtQuick 2.1
import QtQuick.Controls 1.0
import QtQuick.Window 2.0

ApplicationWindow {
    title: qsTr("qteveloper.blogspot.com")
    width: 400
    height: 350

    menuBar: MenuBar {
        Menu {
            title: qsTr("File")
            MenuItem {
                text: qsTr("Exit")
                onTriggered: Qt.quit();
            }
        }
    }

    Column{

        Label {
            id: label
        }

        Slider{
            id: slider1
            maximumValue: 100
            minimumValue: 0
            value: 50
            onValueChanged: label.text = "slider1: " + value
        }
        Slider{
            id: slider2
            maximumValue: 100
            minimumValue: 0
            value: 50
            stepSize: 10
            onValueChanged: label.text = "slider2: " + value
        }
        Slider{
            id: slider3
            maximumValue: 100
            minimumValue: 0
            value: 50
            stepSize: 25
            orientation: Qt.Vertical
            onValueChanged: label.text = "slider3: " + value
        }
    }
}

Qt 5 on Windows ANGLE and OpenGL

2013-11-15T21:13:00.002-08:00

Qt 5 on Windows can be configured to use either OpenGL drivers, or DirectX drivers through the ANGLE library. What you want depends on your use case. The Qt project offers binary installers for both variants.

Read more: http://qt-project.org/wiki/Qt-5-on-Windows-ANGLE-and-OpenGL

QtQuick.Controls example, ProgressBar.

2013-11-11T04:57:00.001-08:00

qml example to implement QtQuick.Controls ProgressBar.

QtQuick.Controls ProgressBar

import QtQuick 2.1
import QtQuick.Controls 1.0
import QtQuick.Window 2.0

ApplicationWindow {
    title: qsTr("qteveloper.blogspot.com")
    width: 400
    height: 350

    menuBar: MenuBar {
        Menu {
            title: qsTr("File")
            MenuItem {
                text: qsTr("Exit")
                onTriggered: Qt.quit();
            }
        }
    }

    Column{

        ProgressBar{
            id: progressBar1
            maximumValue: 100
            minimumValue: 0
            value: 50
        }
        ProgressBar{
            id: progressBar2
            maximumValue: 100
            minimumValue: 0
            value: 50
            indeterminate: true
        }
        ProgressBar{
            id: progressBar3
            maximumValue: 100
            minimumValue: 0
            value: 50
            orientation: Qt.Vertical
        }

        Button {
            id: buttonInc
            text: "+10"
            onClicked: {
                progressBar1.value += 10
                progressBar2.value += 10
                progressBar3.value += 10
            }
        }
        Button {
            id: buttonDec
            text: "-10"
            onClicked: {
                progressBar1.value -= 10
                progressBar2.value -= 10
                progressBar3.value -= 10
            }
        }

    }
}

QtQuick.Controls example, RadioButton and GroupBox

2013-11-06T09:19:00.001-08:00

qml example to implement QtQuick.Controls RadioButton and GroupBox.

qml example of QtQuick.Controls RadioButton and GroupBox

import QtQuick 2.1
import QtQuick.Controls 1.0
import QtQuick.Window 2.0

ApplicationWindow {
    title: qsTr("qteveloper.blogspot.com")
    width: 400
    height: 350

    menuBar: MenuBar {
        Menu {
            title: qsTr("File")
            MenuItem {
                text: qsTr("Exit")
                onTriggered: Qt.quit();
            }
        }
    }

    ExclusiveGroup {
        id: exclusiveGroup1
    }

    ExclusiveGroup {
        id: exclusiveGroup2
    }

    Column{
        GroupBox {
            title: "GroupBox 1 (exclusive)"
            Column {
                RadioButton {
                    id: radioButton1a
                    text: "RadioButton 1a"
                    exclusiveGroup: exclusiveGroup1
                    checked: true
                }
                RadioButton {
                    id: radioButton1b
                    text: "RadioButton 1b"
                    exclusiveGroup: exclusiveGroup1
                }
                RadioButton {
                    id: radioButton1c
                    text: "RadioButton 1c"
                    exclusiveGroup: exclusiveGroup1
                }
            }
        }

        GroupBox {
            title: "GroupBox 2"
            Row {
                RadioButton {
                    id: radioButton2a
                    text: "2a"
                    checked: true
                }
                RadioButton {
                    id: radioButton2b
                    text: "2b"
                }
                RadioButton {
                    id: radioButton2c
                    text: "2c"
                }
            }
        }
    }
}

QtQuick.Controls examples - single selectable CheckBox in ExclusiveGroup

2013-11-04T13:45:00.001-08:00

To make a group of CheckBox to be single selectable, we can apply the CheckBoxes to ExclusiveGroup.

Only one CheckBox can be checked in a ExclusiveGroup

Example:

import QtQuick 2.1
import QtQuick.Controls 1.0
import QtQuick.Window 2.0

ApplicationWindow {
    title: qsTr("qteveloper.blogspot.com")
    width: 400
    height: 350

    menuBar: MenuBar {
        Menu {
            title: qsTr("File")
            MenuItem {
                text: qsTr("Exit")
                onTriggered: Qt.quit();
            }
        }
    }

    ExclusiveGroup {
        id: exclusiveGroup1
    }

    ExclusiveGroup {
        id: exclusiveGroup2
    }

    Column{
        Column {
            CheckBox {
                text: "option 1"
                exclusiveGroup: exclusiveGroup1
            }
            CheckBox {
                text: "option 2"
                exclusiveGroup: exclusiveGroup1
            }
            CheckBox {
                text: "option 3"
                exclusiveGroup: exclusiveGroup1
            }
        }
        Row {
            CheckBox {
                text: "option A"
                checked: true
                exclusiveGroup: exclusiveGroup2
            }
            CheckBox {
                text: "option B"
                exclusiveGroup:
                    exclusiveGroup2
            }
            CheckBox {
                text: "option C"
                exclusiveGroup: exclusiveGroup2
            }
        }
    }
}

QtQuick.Controls examples - CheckBox

2013-11-03T12:56:00.001-08:00

A CheckBox of QtQuick.Controls is an option button that can be toggled on (checked) or off (unchecked).

QtQuick.Controls examples - CheckBox

Example code:

import QtQuick 2.1
import QtQuick.Controls 1.0
import QtQuick.Window 2.0

ApplicationWindow {
    title: qsTr("qteveloper.blogspot.com")
    width: 400
    height: 350

    menuBar: MenuBar {
        Menu {
            title: qsTr("File")
            MenuItem {
                text: qsTr("Exit")
                onTriggered: Qt.quit();
            }
        }
    }

    Column{
        Column {
            CheckBox { text: "option 1" }
            CheckBox { text: "option 2" }
            CheckBox { text: "option 3" }
        }
        Row {
            CheckBox { text: "option A" }
            CheckBox { text: "option B" }
            CheckBox { text: "option C" }
        }
    }
}

Getting Started with Qt Enterprise Embedded

2013-10-26T22:58:00.000-07:00

Getting Started with Qt Enterprise Embedded

A demonstration of how easy it is to get started developing for embedded hardware with Qt Enterprise Embedded. The video shows basic usage and features of Qt Enterprise Embedded like creating a project, deploying to a device and on-device-debugging.

To learn more about Qt Enterprise Embedded, visit http://qt.digia.com/QtEnterpriseEmbedded