I have been working on writing Qt Linux application on my Chromebook and deploying it on a ubuntu machine. By far all qt widget works fine except one: Qt Data Visualization.
I can compile the example code with the correct setting of Qt5_DIR. However, when I run the app, the image part is just a black screen. Nevertheless, if I just copy-paste it to a ubuntu machine, it displays properly.
I have installed opencv on my chromebook and wrote some demo programs. I wonder is it just chromebook's problem? Or I am missing something.
The code I ran was the example code from Qt
main.cpp
/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the Qt Data Visualization module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:GPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 or (at your option) any later version
** approved by the KDE Free Qt Foundation. The licenses are as published by
** the Free Software Foundation and appearing in the file LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "scatterdatamodifier.h"
#include <QtWidgets/QApplication>
#include <QtWidgets/QWidget>
#include <QtWidgets/QHBoxLayout>
#include <QtWidgets/QVBoxLayout>
#include <QtWidgets/QPushButton>
#include <QtWidgets/QCheckBox>
#include <QtWidgets/QComboBox>
#include <QtWidgets/QFontComboBox>
#include <QtWidgets/QLabel>
#include <QtWidgets/QMessageBox>
#include <QtGui/QScreen>
#include <QtGui/QFontDatabase>
int main(int argc, char **argv)
{
//! [0]
QApplication app(argc, argv);
Q3DScatter *graph = new Q3DScatter();
QWidget *container = QWidget::createWindowContainer(graph);
//! [0]
if (!graph->hasContext()) {
QMessageBox msgBox;
msgBox.setText("Couldn't initialize the OpenGL context.");
msgBox.exec();
return -1;
}
QSize screenSize = graph->screen()->size();
container->setMinimumSize(QSize(screenSize.width() / 2, screenSize.height() / 1.5));
container->setMaximumSize(screenSize);
container->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
container->setFocusPolicy(Qt::StrongFocus);
//! [2]
QWidget *widget = new QWidget;
QHBoxLayout *hLayout = new QHBoxLayout(widget);
QVBoxLayout *vLayout = new QVBoxLayout();
hLayout->addWidget(container, 1);
hLayout->addLayout(vLayout);
//! [2]
widget->setWindowTitle(QStringLiteral("A Cosine Wave"));
//! [4]
QComboBox *themeList = new QComboBox(widget);
themeList->addItem(QStringLiteral("Qt"));
themeList->addItem(QStringLiteral("Primary Colors"));
themeList->addItem(QStringLiteral("Digia"));
themeList->addItem(QStringLiteral("Stone Moss"));
themeList->addItem(QStringLiteral("Army Blue"));
themeList->addItem(QStringLiteral("Retro"));
themeList->addItem(QStringLiteral("Ebony"));
themeList->addItem(QStringLiteral("Isabelle"));
themeList->setCurrentIndex(6);
QPushButton *labelButton = new QPushButton(widget);
labelButton->setText(QStringLiteral("Change label style"));
QCheckBox *smoothCheckBox = new QCheckBox(widget);
smoothCheckBox->setText(QStringLiteral("Smooth dots"));
smoothCheckBox->setChecked(true);
QComboBox *itemStyleList = new QComboBox(widget);
itemStyleList->addItem(QStringLiteral("Sphere"), int(QAbstract3DSeries::MeshSphere));
itemStyleList->addItem(QStringLiteral("Cube"), int(QAbstract3DSeries::MeshCube));
itemStyleList->addItem(QStringLiteral("Minimal"), int(QAbstract3DSeries::MeshMinimal));
itemStyleList->addItem(QStringLiteral("Point"), int(QAbstract3DSeries::MeshPoint));
itemStyleList->setCurrentIndex(0);
QPushButton *cameraButton = new QPushButton(widget);
cameraButton->setText(QStringLiteral("Change camera preset"));
QPushButton *itemCountButton = new QPushButton(widget);
itemCountButton->setText(QStringLiteral("Toggle item count"));
QCheckBox *backgroundCheckBox = new QCheckBox(widget);
backgroundCheckBox->setText(QStringLiteral("Show background"));
backgroundCheckBox->setChecked(true);
QCheckBox *gridCheckBox = new QCheckBox(widget);
gridCheckBox->setText(QStringLiteral("Show grid"));
gridCheckBox->setChecked(true);
QComboBox *shadowQuality = new QComboBox(widget);
shadowQuality->addItem(QStringLiteral("None"));
shadowQuality->addItem(QStringLiteral("Low"));
shadowQuality->addItem(QStringLiteral("Medium"));
shadowQuality->addItem(QStringLiteral("High"));
shadowQuality->addItem(QStringLiteral("Low Soft"));
shadowQuality->addItem(QStringLiteral("Medium Soft"));
shadowQuality->addItem(QStringLiteral("High Soft"));
shadowQuality->setCurrentIndex(4);
QFontComboBox *fontList = new QFontComboBox(widget);
fontList->setCurrentFont(QFont("Arial"));
//! [4]
//! [5]
vLayout->addWidget(labelButton, 0, Qt::AlignTop);
vLayout->addWidget(cameraButton, 0, Qt::AlignTop);
vLayout->addWidget(itemCountButton, 0, Qt::AlignTop);
vLayout->addWidget(backgroundCheckBox);
vLayout->addWidget(gridCheckBox);
vLayout->addWidget(smoothCheckBox, 0, Qt::AlignTop);
vLayout->addWidget(new QLabel(QStringLiteral("Change dot style")));
vLayout->addWidget(itemStyleList);
vLayout->addWidget(new QLabel(QStringLiteral("Change theme")));
vLayout->addWidget(themeList);
vLayout->addWidget(new QLabel(QStringLiteral("Adjust shadow quality")));
vLayout->addWidget(shadowQuality);
vLayout->addWidget(new QLabel(QStringLiteral("Change font")));
vLayout->addWidget(fontList, 1, Qt::AlignTop);
//! [5]
//! [2]
ScatterDataModifier *modifier = new ScatterDataModifier(graph);
//! [2]
//! [6]
QObject::connect(cameraButton, &QPushButton::clicked, modifier,
&ScatterDataModifier::changePresetCamera);
QObject::connect(labelButton, &QPushButton::clicked, modifier,
&ScatterDataModifier::changeLabelStyle);
QObject::connect(itemCountButton, &QPushButton::clicked, modifier,
&ScatterDataModifier::toggleItemCount);
QObject::connect(backgroundCheckBox, &QCheckBox::stateChanged, modifier,
&ScatterDataModifier::setBackgroundEnabled);
QObject::connect(gridCheckBox, &QCheckBox::stateChanged, modifier,
&ScatterDataModifier::setGridEnabled);
QObject::connect(smoothCheckBox, &QCheckBox::stateChanged, modifier,
&ScatterDataModifier::setSmoothDots);
QObject::connect(modifier, &ScatterDataModifier::backgroundEnabledChanged,
backgroundCheckBox, &QCheckBox::setChecked);
QObject::connect(modifier, &ScatterDataModifier::gridEnabledChanged,
gridCheckBox, &QCheckBox::setChecked);
QObject::connect(itemStyleList, SIGNAL(currentIndexChanged(int)), modifier,
SLOT(changeStyle(int)));
QObject::connect(themeList, SIGNAL(currentIndexChanged(int)), modifier,
SLOT(changeTheme(int)));
QObject::connect(shadowQuality, SIGNAL(currentIndexChanged(int)), modifier,
SLOT(changeShadowQuality(int)));
QObject::connect(modifier, &ScatterDataModifier::shadowQualityChanged, shadowQuality,
&QComboBox::setCurrentIndex);
QObject::connect(graph, &Q3DScatter::shadowQualityChanged, modifier,
&ScatterDataModifier::shadowQualityUpdatedByVisual);
QObject::connect(fontList, &QFontComboBox::currentFontChanged, modifier,
&ScatterDataModifier::changeFont);
QObject::connect(modifier, &ScatterDataModifier::fontChanged, fontList,
&QFontComboBox::setCurrentFont);
//! [6]
//! [3]
widget->show();
return app.exec();
//! [3]
}
scatterdatamodifier.h
/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the Qt Data Visualization module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:GPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 or (at your option) any later version
** approved by the KDE Free Qt Foundation. The licenses are as published by
** the Free Software Foundation and appearing in the file LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef SCATTERDATAMODIFIER_H
#define SCATTERDATAMODIFIER_H
#include <QtDataVisualization/q3dscatter.h>
#include <QtDataVisualization/qabstract3dseries.h>
#include <QtGui/QFont>
using namespace QtDataVisualization;
class ScatterDataModifier : public QObject
{
Q_OBJECT
public:
explicit ScatterDataModifier(Q3DScatter *scatter);
~ScatterDataModifier();
void addData();
void changeStyle();
void changePresetCamera();
void changeLabelStyle();
void changeFont(const QFont &font);
void changeFontSize(int fontsize);
void setBackgroundEnabled(int enabled);
void setGridEnabled(int enabled);
void setSmoothDots(int smooth);
void toggleItemCount();
void start();
public Q_SLOTS:
void changeStyle(int style);
void changeTheme(int theme);
void changeShadowQuality(int quality);
void shadowQualityUpdatedByVisual(QAbstract3DGraph::ShadowQuality shadowQuality);
Q_SIGNALS:
void backgroundEnabledChanged(bool enabled);
void gridEnabledChanged(bool enabled);
void shadowQualityChanged(int quality);
void fontChanged(QFont font);
private:
QVector3D randVector();
Q3DScatter *m_graph;
int m_fontSize;
QAbstract3DSeries::Mesh m_style;
bool m_smooth;
int m_itemCount;
float m_curveDivider;
};
#endif
/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the Qt Data Visualization module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:GPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 or (at your option) any later version
** approved by the KDE Free Qt Foundation. The licenses are as published by
** the Free Software Foundation and appearing in the file LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "scatterdatamodifier.h"
#include <QtDataVisualization/qscatterdataproxy.h>
#include <QtDataVisualization/qvalue3daxis.h>
#include <QtDataVisualization/q3dscene.h>
#include <QtDataVisualization/q3dcamera.h>
#include <QtDataVisualization/qscatter3dseries.h>
#include <QtDataVisualization/q3dtheme.h>
#include <QtCore/qmath.h>
#include <QtCore/qrandom.h>
#include <QtWidgets/QComboBox>
using namespace QtDataVisualization;
//#define RANDOM_SCATTER // Uncomment this to switch to random scatter
const int numberOfItems = 3600;
const float curveDivider = 3.0f;
const int lowerNumberOfItems = 900;
const float lowerCurveDivider = 0.75f;
ScatterDataModifier::ScatterDataModifier(Q3DScatter *scatter)
: m_graph(scatter),
m_fontSize(40.0f),
m_style(QAbstract3DSeries::MeshSphere),
m_smooth(true),
m_itemCount(lowerNumberOfItems),
m_curveDivider(lowerCurveDivider)
{
//! [0]
m_graph->activeTheme()->setType(Q3DTheme::ThemeEbony);
QFont font = m_graph->activeTheme()->font();
font.setPointSize(m_fontSize);
m_graph->activeTheme()->setFont(font);
m_graph->setShadowQuality(QAbstract3DGraph::ShadowQualitySoftLow);
m_graph->scene()->activeCamera()->setCameraPreset(Q3DCamera::CameraPresetFront);
//! [0]
//! [2]
QScatterDataProxy *proxy = new QScatterDataProxy;
QScatter3DSeries *series = new QScatter3DSeries(proxy);
series->setItemLabelFormat(QStringLiteral("@xTitle: @xLabel @yTitle: @yLabel @zTitle: @zLabel"));
series->setMeshSmooth(m_smooth);
m_graph->addSeries(series);
//! [2]
//! [3]
addData();
//! [3]
}
ScatterDataModifier::~ScatterDataModifier()
{
delete m_graph;
}
void ScatterDataModifier::addData()
{
// Configure the axes according to the data
//! [4]
m_graph->axisX()->setTitle("X");
m_graph->axisY()->setTitle("Y");
m_graph->axisZ()->setTitle("Z");
//! [4]
//! [5]
QScatterDataArray *dataArray = new QScatterDataArray;
dataArray->resize(m_itemCount);
QScatterDataItem *ptrToDataArray = &dataArray->first();
//! [5]
#ifdef RANDOM_SCATTER
for (int i = 0; i < m_itemCount; i++) {
ptrToDataArray->setPosition(randVector());
ptrToDataArray++;
}
#else
//! [6]
float limit = qSqrt(m_itemCount) / 2.0f;
for (float i = -limit; i < limit; i++) {
for (float j = -limit; j < limit; j++) {
ptrToDataArray->setPosition(QVector3D(i + 0.5f,
qCos(qDegreesToRadians((i * j) / m_curveDivider)),
j + 0.5f));
ptrToDataArray++;
}
}
//! [6]
#endif
//! [7]
m_graph->seriesList().at(0)->dataProxy()->resetArray(dataArray);
//! [7]
}
//! [8]
void ScatterDataModifier::changeStyle(int style)
{
QComboBox *comboBox = qobject_cast<QComboBox *>(sender());
if (comboBox) {
m_style = QAbstract3DSeries::Mesh(comboBox->itemData(style).toInt());
if (m_graph->seriesList().size())
m_graph->seriesList().at(0)->setMesh(m_style);
}
}
void ScatterDataModifier::setSmoothDots(int smooth)
{
m_smooth = bool(smooth);
QScatter3DSeries *series = m_graph->seriesList().at(0);
series->setMeshSmooth(m_smooth);
}
void ScatterDataModifier::changeTheme(int theme)
{
Q3DTheme *currentTheme = m_graph->activeTheme();
currentTheme->setType(Q3DTheme::Theme(theme));
emit backgroundEnabledChanged(currentTheme->isBackgroundEnabled());
emit gridEnabledChanged(currentTheme->isGridEnabled());
emit fontChanged(currentTheme->font());
}
void ScatterDataModifier::changePresetCamera()
{
static int preset = Q3DCamera::CameraPresetFrontLow;
m_graph->scene()->activeCamera()->setCameraPreset((Q3DCamera::CameraPreset)preset);
if (++preset > Q3DCamera::CameraPresetDirectlyBelow)
preset = Q3DCamera::CameraPresetFrontLow;
}
void ScatterDataModifier::changeLabelStyle()
{
m_graph->activeTheme()->setLabelBackgroundEnabled(!m_graph->activeTheme()->isLabelBackgroundEnabled());
}
void ScatterDataModifier::changeFont(const QFont &font)
{
QFont newFont = font;
newFont.setPointSizeF(m_fontSize);
m_graph->activeTheme()->setFont(newFont);
}
void ScatterDataModifier::shadowQualityUpdatedByVisual(QAbstract3DGraph::ShadowQuality sq)
{
int quality = int(sq);
emit shadowQualityChanged(quality); // connected to a checkbox in main.cpp
}
void ScatterDataModifier::changeShadowQuality(int quality)
{
QAbstract3DGraph::ShadowQuality sq = QAbstract3DGraph::ShadowQuality(quality);
m_graph->setShadowQuality(sq);
}
void ScatterDataModifier::setBackgroundEnabled(int enabled)
{
m_graph->activeTheme()->setBackgroundEnabled((bool)enabled);
}
void ScatterDataModifier::setGridEnabled(int enabled)
{
m_graph->activeTheme()->setGridEnabled((bool)enabled);
}
//! [8]
void ScatterDataModifier::toggleItemCount()
{
if (m_itemCount == numberOfItems) {
m_itemCount = lowerNumberOfItems;
m_curveDivider = lowerCurveDivider;
} else {
m_itemCount = numberOfItems;
m_curveDivider = curveDivider;
}
m_graph->seriesList().at(0)->dataProxy()->resetArray(0);
addData();
}
QVector3D ScatterDataModifier::randVector()
{
return QVector3D(
(float)(QRandomGenerator::global()->bounded(100)) / 2.0f -
(float)(QRandomGenerator::global()->bounded(100)) / 2.0f,
(float)(QRandomGenerator::global()->bounded(100)) / 100.0f -
(float)(QRandomGenerator::global()->bounded(100)) / 100.0f,
(float)(QRandomGenerator::global()->bounded(100)) / 2.0f -
(float)(QRandomGenerator::global()->bounded(100)) / 2.0f);
}
In the end, the CMakeLists.txt
cmake_minimum_required(VERSION 3.16)
project(scatter LANGUAGES CXX)
# set(CMAKE_INCLUDE_CURRENT_DIR ON)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)
set(CMAKE_AUTOUIC ON)
# set(CMAKE_FIND_DEBUG_MODE 1)
if(NOT DEFINED INSTALL_EXAMPLESDIR)
set(INSTALL_EXAMPLESDIR "examples")
endif()
message(STATUS ${CMAKE_MODULE_PATH})
set (Qt5_FOUND false)
find_package(Qt5 COMPONENTS Core Widgets Gui DataVisualization REQUIRED)
if(Qt5_FOUND)
message("QT5 Found")
else(Qt5_FOUND)
message("FATAL Qt5 Not Found")
endif(Qt5_FOUND)
add_executable(scatter
main.cpp
scatterdatamodifier.cpp scatterdatamodifier.h
)
# set_target_properties(scatter PROPERTIES
# WIN32_EXECUTABLE TRUE
# MACOSX_BUNDLE TRUE
# )
target_link_libraries(scatter Qt5::Core Qt5::Gui Qt5::Widgets Qt5::DataVisualization)
# install(TARGETS scatter
# RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
# BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
# LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
# )
[1]: https://i.sstatic.net/1oueS.png
[2]: https://i.sstatic.net/TdUkh.png
According to https://doc.qt.io/qt-6/qtdatavisualization-known-issues.html
Some platforms like Android and WinRT cannot handle multiple native windows properly, so only the Qt Quick 2 graphs are available in practice for those platforms.
It is probably the case.
p.s. adding qputenv("QSG_RHI_BACKEND", "opengl"); did not improve the condition in this case.