I'am implementing a simple program with QT5.5 which contains a HTML window (QWebview) like the following screenshot:
HTML window on the right side
Now I want the program also installed for iOS e.g. for iPad. I found that the QWebview class isn't available for mobile system, so I had to change my HTML window to QQuickView with QML files (or is there a better way?). I found the following code online:
QQuickView *view = new QQuickView();
QWidget *container = QWidget::createWindowContainer(view, this);
container->setMinimumSize(200,400);
container->setMaximumSize(200,400);
container->setFocusPolicy(Qt::TabFocus);
view->setSource(QUrl("qrc:///webview.qml"));
layout->addWidget(container);
Then i added the container to the mainWindow.
The webview.qml:
import QtQuick 2.5
import QtWebView 1.0
Rectangle {
id: rectangle
width: 200
height: 400
WebView {
id: webview
url: "file:///test.html"
anchors.fill: parent
width: 200
height: 400
}
}
But somehow I can't get the layout right.
HTML window on iOS
There is a blank/white rectangle behind the container, and the container is also not in the HTML window on the right side where it should be. When I change the width and the height of the rectangle in the qml file, it only changes the size of the webview, not the white background.
Can anyone tell me, how can I get this right? I have also used container->setParent() but the view is always on the left.
The visibility of the author's code is maybe not enough but overall it is easier to set the widget in layout with certain alignment. This way you command the widget to be on certain side and make the placement not to depend on coordinates / host widget size etc. The layout variable is assumed to be horizontal box layout or QHBoxLayout.
// make sure that QHBoxLayout* layout = new QHBoxLayout(this);
// or set the horizontal layout somehow else
QQuickView *view = new QQuickView();
QWidget *container = QWidget::createWindowContainer(view, this);
container->serFixedWidth(200); // the layout is horizontal
// and we *may* want to fix the width
container->setFocusPolicy(Qt::TabFocus);
view->setSource(QUrl("qrc:///webview.qml"));
layout->addWidget(container, Qt::AlignRight); // align to the right
Mind that the rest of horizontal layout should be filled like that with respecting relative positions in it.
Related
I am trying a play a video(640 * 360) through rtsp in QGraphicsView. But the issue is that it is not fitting completely within the view and scroll bar is appearing, which should not happen. And moreover, I am able to get the same peace of code working properly in Linux environment but I am getting the issue in windows.
Please find the code snippet below, If anyone can point out the error I am making will be helpful.
scene = new QGraphicsScene(this);
view= new graphicsView();
view->setScene(scene);
videoItem = new QGraphicsVideoItem;
player= new QMediaPlayer;
player->setVideoOutput(videoItem);
view->scene()->addItem(videoItem);
controlLayout = new QHBoxLayout;
controlLayout->setMargin(0);
controlLayout->addWidget(view);
view->setSceneRect(scene->sceneRect());
view->scale(1.97,1.97);
ui.m_pframePlay->setLayout(controlLayout);
ui.m_pframePlay->show();
player->setMedia(QUrl("rtsp:..."));
player->play();
The documentation for QGraphicsView sais about setSceneRect
The scene rectangle defines the extent of the scene, and in the view's case, this means the area of the scene that you can navigate using the scroll bars.
This means, setSceneRect does not resize the visible area of the view but only which area of the scene is visible in the view. So I guess you simply have to resize your view, e.g.
view->resize(scene->width()*1.97, scene->height()*1.97)
(I scaled width/height with 1.97 because you scale your view using factor 1.97 for some reason).
So in my UI designer I have a ScrollArea Widget, I then in my MainWindow.cpp, I create a QGraphicScene and a QGraphics View. I create a new widget and give that widget a QVBoxLayout so that it will auto-size(which is correct to my understanding).
I then use ui->scrollArea->setWidget(widget); to make this new widget the child of my scrollView.
All of this seems correct because I have scroll bars that I can navigate my scene with. However; using the line ui->scrollArea->horizontalScrollBar()->setValue(0); still has no effect on the scroll bar values.
scene = new QGraphicsScene();
scene->setSceneRect(0,0,2500,2500);
view = new QGraphicsView(scene);
QWidget *widget = new QWidget;
view->setBackgroundBrush(Qt::white);
QVBoxLayout* bLayout = new QVBoxLayout(widget);
ui->scrollArea->setWidget(widget);
bLayout->addWidget(view);
widget->show();
ui->scrollArea->horizontalScrollBar()->setValue(0);
ui->scrollArea->verticalScrollBar()->setValue(0);
I just had the this problem. Then, after debugging with ui->scrollArea->verticalScrollBar()->value() I realized that the scrolling area has no size before the component is show on the screen, i.e., it does not change the scrolling because it is not visible yet.
This is a sample Python code, but the is the same for C++, except the Language Syntax.
from PyQt5.QtWidgets import QDialog
...
dialog = QDialog()
...
verticalScrollBar = dialog.QPlainTextEdit.verticalScrollBar()
horizontalScrollBar = dialog.QPlainTextEdit.horizontalScrollBar()
# Has no effect, if you print the values, you will see always 0
verticalScrollBar.setValue( horizontalScrollBar.maximum() )
horizontalScrollBar.setValue( horizontalScrollBar.minimum() )
dialog.show()
# Now it has effect
verticalScrollBar.setValue( horizontalScrollBar.maximum() )
horizontalScrollBar.setValue( horizontalScrollBar.minimum() )
Autoscroll PyQT QTextWidget
If you are sure to address the correct scrollbar (as pointed in the comments by thuga), maybe check if your scroll area is modified after that init. I mean I'm not sure of the bahaviour, but if you modified some text in your widget for example, I think the scrollbar will be impacted.
You may need to catch some of your widget's event to reapply those:
ui->scrollArea->horizontalScrollBar()->setValue(0);
ui->scrollArea->verticalScrollBar()->setValue(0);
If it doesn't help, you should try to debug by tracking scrollbar value with
ui->scrollArea->verticalScrollBar()->value()
and see if your set is well applied, and maybe when it is overriden
Just in case, you may also try some of the methods indicated here, but it's probably not relevant to your issue: setValue of ScrollBar Don't work at first time
QtCreator's designer allows you to edit user interface graphically. I was just trying to make some sense of it - what I wanted was a header text centered in the middle and some widget under it, like this:
But my results look like this, when using vertical layout:
I placed QLabel on top and QOpenGLWidget on bottom - I only used QOpenGlWidget because it has black background on screenshot. What I really plan on doing is using another QWidget. I used vertical layout then. So how do I get the result on the first image, using QLabel and QWidget?
Qt's use of XML is not a replacement for HTML.
HTML is designed for marking up web pages. Qt's widgets are not web pages!
It appears that you're looking at the box with the text 'content' and thinking of a generic widget. I see that and see a QLabel, which is derived from QWidget after all.
It's probably easier to explain in code how I would go about this, which you can then translate to doing the same in Qt Creator.
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
// Create a root widget (this could also be a QMainWindow, or any other widget)
QWidget* pWidget = new QWidget;
// Layout to arrange the widgets vertically
QVBoxLayout* pBoxLayout = new QVBoxLayout;
pWidget->setLayout(pBoxLayout);
// The header widget
QLabel* pHeader = new QLabel("Header");
pHeader->setAlignment(Qt::AlignCenter);
pHeader->setMinimumSize(200, 20);
pHeader->setMaximumSize(200, 20);
QFont font = pHeader->font();
font.setBold(true);
font.setPixelSize(16);
pHeader->setFont(font);
// the content widget
QLabel* plabel = new QLabel("content");
plabel->setMinimumSize(200, 200);
plabel->setMaximumSize(200, 200);
plabel->setStyleSheet("background-color: rgb(182, 182, 182); border: 5px solid black;");
plabel->setAlignment(Qt::AlignCenter);
pBoxLayout->addWidget(pHeader);
pBoxLayout->addWidget(plabel);
pWidget->show();
return a.exec();
}
As you can see here, I've styled the content widget with the use of a Style Sheet. This is really the easiest method, after a bit of practice with them.
The resulting code produces a widget which looks like this: -
You can play with dimensions and fonts to match your original image exactly.
I am new QT and trying to develop the desktop application.
Currently I am facing a issue of alignment. I am using QTCreator 3.1.2 based on qt 5.3.1
I have 3 buttons placed in the windows as
After running application, If I resize the windows then buttons didn't stay in the center. like image 1 and if size is less then it is like image 2
I have tried using the hbox, but it didn't solve the problem and also scroll bar is also not visible in the window.
Would you please tell me how can I make these buttons to stay in the center only?
Thanks a lot
You can create QHBoxLayout passing this as its parent, which will set that layout as the layout of that widget, then add QPushButtons to that layout:
Widget::Widget(QWidget *parent) : QWidget(parent) {
// Prepare the horizonal layout, adding buttons
horizontalLayout = new QHBoxLayout(this);
pushButton = new QPushButton(this);
horizontalLayout->addWidget(pushButton);
pushButton_2 = new QPushButton(this);
horizontalLayout->addWidget(pushButton_2);
pushButton_3 = new QPushButton(this);
horizontalLayout->addWidget(pushButton_3);
// Set the layout of the central widget
setLayout(horizontalLayout);
}
I have a QMainWindow whose central widget has been set to a QGraphicsView viewing a black scene (for test purposes). Note that in the code below, I use my class derived from QGraphicsView, called CQtGlView, which reimplements only the resizeEvent function.
Regardless of whether I add the view directly,
CQtMainWindow::CQtMainWindow() {
m_glView = new CQtGlView();
setCentralWidget(m_glView);
}
or stick it in a layout with margins of 0 in a dummy widget,
CQtMainWindow::CQtMainWindow() {
m_glView = new CQtGlView();
QWidget* dummy = new QWidget();
QHBoxLayout* l = new QHBoxLayout();
l->setContentsMargins(0,0,0,0);
l->addWidget(m_glView);
dummy->setLayout(l);
setCentralWidget(dummy);
}
I get an unwanted grey border around the widget.
The screenshot below illustrates the problem, visible between my scene and the windows aero border.
This would not be a problem if my application did not allow switching to full screen. The border is very obvious once the rest of the screen is black.
It's possible this area represents the DockWidgetAreas around the outside of the central widget.
Is there anything I can do to solve this other than not use QMainWindow? (Undesirable due to my use of menuBar, tool bars, and statusBar.)
It turns out that QGraphicsView derives from QFrame, where I assumed it was only a QWidget.
The solution to this problem was to call setFrameStyle(QFrame::NoFrame); in the constructor of my QGraphicsView subclass. Or if it was not a subclass,
m_glView->setFrameStyle(QFrame::NoFrame);
Have you tried setFrameShape(QFrame::NoFrame) on the QGraphicsView?