I have tried to use QQuickWidget as background of my application.
I created 2 classes: KViewer (load QML file) and GUI (main GUI of application)
GUI.cpp
GUI::GUI(QWidget *parent)
: QWidget(parent)
{
setFixedSize(500, 500);
QHBoxLayout* layout = new QHBoxLayout(this);
KViewer* viewer = new KViewer(this);
viewer->resize(size());
QLabel* label = new QLabel("TEXT HERE");
label->setFixedSize(400, 400);
label->setAlignment(Qt::AlignCenter);
label->setStyleSheet("QLabel {"
"background-color: yellow;"
"border-radius: 6px;"
"}");
layout->addWidget(label);
}
and KViewer.cpp
QHBoxLayout* layout = new QHBoxLayout(this);
layout->setSpacing(0);
layout->setMargin(0);
QQuickWidget* mQQuickWidget = new QQuickWidget;
mQQuickWidget->setResizeMode(QQuickWidget::SizeRootObjectToView);
mQQuickWidget->setSource(QUrl("qrc:/qml/main.qml"));
layout->addWidget(mQQuickWidget);
what I received
Label corner with border-radius problem
There's something wrong at corner of my label. Why black color here? Please help me solve this problem. Is there any other ways to use QML object as background of Qt application?
I have already test some demo before, you maybe need to use Absolute positioning to layout your widgets in gui.cpp．
Related
I just begin to work on making a layout with Grid. I tried to make it using the HBoxlayout and VBoxlayout. But How to set the position of the layout. I searched out and I found the setAlignment option but it isn't working on it.
So how to do its postioning of layouts like the image?
this is the layout I want to make
check this out
#include "mainscreen.h"
#include "ui_mainscreen.h"
#include<QLayout>
#include<QPushButton>
MainScreen::MainScreen(QWidget *parent) :
QWidget(parent),
ui(new Ui::MainScreen)
{
ui->setupUi(this);
QGridLayout *layout=new QGridLayout;
QHBoxLayout *hlayout=new QHBoxLayout;
QPushButton *x=new QPushButton;
hlayout->setAlignment(Qt::AlignTop);
hlayout->addWidget(x);
layout->addChildLayout(hlayout);
this->setLayout(layout);
this->show();
}
MainScreen::~MainScreen()
{
delete ui;
}
You can find good information about Layout in this Tutorial from Qt: http://doc.qt.io/qt-5/qtwidgets-layouts-basiclayouts-example.html
Two things that are important for your Layout:
You need to nest several layout. Themain layout will be a VBoxlayout that contains the top and bottom Widget and one HBoxLayout in the middle. The HBoxLayout contain the other two widgets.
Two get different size for the two middle widgtes you need to give either a Stretch factor to the Layout or define sizes for the widgets.
You may consider doing the following
QHBoxLayout *TopLayout = new QHBoxLayout;
QHBoxLayout *BottomLayout = new QHBoxLayout;
QHBoxLayout *MiddleLayout = new QHBoxLayout;
QVBoxLayout *mainLayout = new QVBoxLayout;
QPushButton *topBtn = new QPushButton;
QPushButton *bottomBtn = new QPushButton;
QPushButton *LeftMiddleBtn = new QPushButton;
QPushButton *RightMiddleBtn = new QPushButton;
TopLayout->addWidget(topBtn);
BottomLayout->addWidget(bottomBtn);
// order matters here (i.e. the first addWidget will be placed in the left)
MiddleLayout->addWidget(LeftMiddleBtn);
MiddleLayout->addWidget(RightMiddleBtn);
// order matters here
mainLayout->addLayout(TopLayout);
mainLayout->addLayout(MiddleLayout);
mainLayout->addLayout(BottomLayout);
setLayout(mainLayout);
More convenient and right approach is to use Qt Designer or Qt Creator for this matter.
QMainWindow is a spatial case. It already has a layout set and it is impossible to change layout in widget! Reason is that QMainWindow has lots of other functionalities like menu, docking, status bar.
So how to make it work?
You have to set central widget:
MainScreen::MainScreen(QWidget *parent) :
QWidget(parent),
ui(new Ui::MainScreen)
{
ui->setupUi(this);
auto widget = new QWidget();
setCentalWidget(widget);
auto vLayout = new QVBoxLayout(widget);
// add your stuff here
// some example for testing:
vLayout->addWidget(new QButton("Test button"));
vLayout->addWidget(new QLabel("Nice label"));
vLayout->addWidget(new QTextEdit);
}
Also you are doing something wrong since this line ui->setupUi(this); indicates that you are using Qt Designer (design ui by mouse) and this means that layout should not be setup directly by code!
I create interface dynamically when Application is run.
1) I have QTabWidget with 4 predefined tabs. But i must show only 1 or 2 tabs, in case of user shoice. On StackOverflow i learned, that i must keep all tabs in collection to add and destroit it.
I have QHash: twInputMethodsTabs = new QHash< int, QPair<QWidget*, QString> >();
First argument = index; Second = Tab Widget; Third = Tab Widget Caption Text;
2) I fill the collection like this:
for(int i = 0; i < ui->twInputMethods->children().length(); i++)
{
twInputMethodsTabs->insert(i, QPair<QWidget*, QString>(ui->twInputMethods->widget(i), ui->twInputMethods->tabText(i)));
}
3) I add new widget in the tab like this:
twInputMethodsTabs->value(1).first->layout()->addWidget(cmbbCommands);
4) How can i add new layout to this widget? I want to do like this:
QHBoxLayout *hblParams =new QHBoxLayout();
twInputMethodsTabs->value(1).first->layout()->addLayout(hblParams);
But it does not work, because layout() returns QLayout which havent addLayout() function. How i can do this?
Or how can i should change architecture of code to do this?
In this following code you get a widget (.first) and then select that widget's layout ->layout() and then add a Widget to that layout ->addWidget().
twInputMethodsTabs->value(1).first->layout()->addWidget(cmbbCommands);
In the following code you get a widget (.first) and then select that widget's layout ->layout() and try to set the layout on the layout.
twInputMethodsTabs->value(1).first->layout()->addLayout(hblParams);
Replacing the QLayout
To set the layout on the parent widget, you need to drop the ->layout():
twInputMethodsTabs->value(1).first->addLayout(hblParams);
Note that since you are now adding an empty layout to the widget, any widgets current in the previous layout will be lost, so you may need to re-add the widgets to the layout.
Adding new QLayout inside existing QLayout
If you want to add a layout into the existing layout, you cannot do this directly. QLayout can only accept QWidget via .addWidget(). However, you can apply a layout to an empty QWidget() and then add that to the layout. For example:
QWidget *w = new QWidget();
w.addLayout(hblParams);
twInputMethodsTabs->value(1).first->layout()->addWidget(w);
An alternative is to set the layout on the QWidget to a layout that does support .addLayout() such as QHBoxLayout or QVBoxLayout. For example:
QVBoxLayout *l = new QVBoxLayout();
cmbbCommands.setLayout(l); // Now has a layout that supports .addLayout
twInputMethodsTabs->value(1).first->layout()->addWidget(cmbbCommands);
Now the following should work because ->layout() returns a QVBoxLayout:
QHBoxLayout *hblParams =new QHBoxLayout();
twInputMethodsTabs->value(1).first->layout()->addLayout(hblParams);
I Hope, I get what you want to do:
twInputMethodsTabs->value(1).first->layout()->addWidget(cmbbCommands);
QHBoxLayout *hblParams =new QHBoxLayout();
QWidget *w = new QWidget(twInputMethodsTabs->value(1).first);
twInputMethodsTabs->value(1).first->layout()->addWidget(w);
w->addLayout(hblParams);
I just wrote the code here, so it is untested. However it should give you an idea what I tried to explain in my comment.
Cutted from "working" application:
WidgetA::WidgetA(QWidget *parent) : QWidget(parent)
{
QVBoxLayout *pLayout = new QVBoxLayout();
buildWidget(pLayout);
this->setLayout(pLayout);
}
void WidgetA::buildWidget(QVBoxLayout *layout){
for(int i=0; i<4; ++i){
this->buildSegments(layout);
}
}
void WidgetA::buildSegments(QVBoxLayout *layout){
QHBoxLayout *pHbl = new QHBoxLayout();
QLabel *pSegmentSize = new QLabel(this);
pSegmentSize->setText(tr("Segment Size(1,N)"));
QSpinBox *pSegments = new QSpinBox(this);
pHbl->addWidget(pSegmentSize);
pHbl->addWidget(pSegments);
layout->addItem(pHbl);
}
Read this one: Widgets Tutorial - Nested Layouts
I'm using QT 5.4.2 and trying to create a small panel at the bottom
of a subclassed QTreeWidget.
Here is the code:
void HmiScenarioAutoscriptPanel::searchEmitter() {
QWidget *child = new QWidget(ui->emitterTreeWidget);
//QMainWindow* child = new QMainWindow;
QLabel *labelSearch = new QLabel("Search");
QLineEdit *lineSearch = new QLineEdit();
lineSearch->setFixedSize(100, 20);
QHBoxLayout* layout = new QHBoxLayout(ui->emitterTreeWidget);
layout->setAlignment(Qt::AlignBottom);
layout->addWidget(child);
layout->addWidget(labelSearch);
layout->addWidget(lineSearch);
}
The label and search field correctly appear at the bottom of the tree,
however the fields overlap with the tree nodes (see image below).
Any idea why this behavior?
Ciao
Alf
enter image description here
It is not recommended to set layout on the tree widget. It is like other controls like a button, label etc..
I see that you are using designer. Add a blank widget (searchWidget) under the tree widget and then
void HmiScenarioAutoscriptPanel::searchEmitter() {
QWidget *child = new QWidget(ui->searchWidget);
//QMainWindow* child = new QMainWindow;
QLabel *labelSearch = new QLabel("Search", searchWidget);
QLineEdit *lineSearch = new QLineEdit(searchWidget);
lineSearch->setFixedSize(100, 20);
QHBoxLayout* layout = new QHBoxLayout(ui->searchWidget);
layout->setAlignment(Qt::AlignBottom);
layout->addWidget(child);
layout->addWidget(labelSearch);
layout->addWidget(lineSearch);
}
Just out of curiosity, why don't you add these using the designer as well?
Hi I am using QLabel to show an image in QtForm.
My code goes like this
QVBoxLayout *layout = new QVBoxLayout;
QHBoxLayout *hLayout = new QHBoxLayout;
layout->setMargin(5);
QLabel *imageLabel = new QLabel;
QPixmap pixmap("/images/test.jpg");
imageLabel->setPixmap(pixmap);
imageLabel->setMask(pixmap.mask());
imageLabel->setMinimumSize(160, 160);
imageLabel->resize(500, 320);
layout->addWidget(imageLabel,0,Qt::AlignTop | Qt::AlignCenter);
hLayout->addItem(layout);
widget->setLayout(hLayout);
scrollArea->setWidget(widget);
setCentralWidget(scrollArea);
but the image is displaying at the left corner can any one suggest me to bring the image to centre to the form
I got solution,
QPixmap pixmap("images/test.png");
imageLabel->setPixmap(pixmap);
imageLabel->setMinimumSize(160, 160);
imageLabel->resize(500, 320);
imageLabel->setAlignment(Qt::AlignCenter);
scrollArea->setWidget(widget);
setCentralWidget(imageLabel);
Change the alignment of your QLabel's content:
imageLabel->setAlignment(Qt::AlignCenter);
If the setAlignment function didn't work alone, then use it with setSizePolicy.
imageLabel->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);
imageLabel->setAlignment(Qt::AlignCenter);
I'm a Qt newbie. I want to display 2 images side-by-side using Qt. Using Qt's Image Viewer Example, I want to add another scrollable image display, such that both images are displayed side-by-side.
The example code has this snippet for the ctor:
ImageViewer::ImageViewer()
{
imageLabel = new QLabel;
imageLabel->setBackgroundRole(QPalette::Base);
imageLabel->setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored);
imageLabel->setScaledContents(true);
scrollArea = new QScrollArea;
scrollArea->setBackgroundRole(QPalette::Dark);
scrollArea->setWidget(imageLabel);
setCentralWidget(scrollArea);
...
If I understand it correctly, I want to get imageLabel to be only half width of the screen while another QLabel is displayed on the other half.
How can I do this?
Thanks.
If I understand correctly, this here should suffice:
// Left image
imageLabelLeft = new QLabel;
imageLabelLeft->setBackgroundRole(QPalette::Base);
imageLabelLeft->setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored);
imageLabelLeft->setScaledContents(true);
scrollAreaLeft = new QScrollArea;
scrollAreaLeft->setBackgroundRole(QPalette::Dark);
scrollAreaLeft->setWidget(imageLabelLeft);
// Right image
imageLabelRight = new QLabel;
imageLabelRight->setBackgroundRole(QPalette::Base);
imageLabelRight->setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored);
imageLabelRight->setScaledContents(true);
scrollAreaRight = new QScrollArea;
scrollAreaRight->setBackgroundRole(QPalette::Dark);
scrollAreaRight->setWidget(imageLabelRight);
// Do the layout
QWidget *centralWidget = new QWidget;
QHBoxLayout *layout = new QHBoxLayout(centralWidget);
layout->addWidget(scrollAreaLeft);
layout->addWidget(scrollAreaRight);
setCentralWidget(centralWidget);