I am using QT to create a chat messenger client. To display the list of online users, I'm using a QListWidget, as created like this:
listWidget = new QListWidget(horizontalLayoutWidget);
listWidget->setObjectName("userList");
QSizePolicy sizePolicy1(QSizePolicy::Preferred, QSizePolicy::Expanding);
sizePolicy1.setHorizontalStretch(0);
sizePolicy1.setVerticalStretch(0);
sizePolicy1.setHeightForWidth(listWidget->sizePolicy().hasHeightForWidth());
listWidget->setSizePolicy(sizePolicy1);
listWidget->setMinimumSize(QSize(30, 0));
listWidget->setMaximumSize(QSize(150, 16777215));
listWidget->setBaseSize(QSize(100, 0));
listWidget->setContextMenuPolicy(Qt::CustomContextMenu);
Users are shown by constantly refreshing the list, like this: (Note: There are different channels, with different userlists, so refreshing it is the most efficient thing to do, as far as I know.)
void FMessenger::refreshUserlist()
{
if (currentPanel == 0)
return;
listWidget = this->findChild<QListWidget *>(QString("userList"));
listWidget->clear();
QList<FCharacter*> charList = currentPanel->charList();
QListWidgetItem* charitem = 0;
FCharacter* character;
foreach(character, charList)
{
charitem = new QListWidgetItem(character->name());
// charitem->setIcon(QIcon(":/Images/status.png"));
listWidget->addItem(charitem);
}
}
This has always worked perfectly. The line that I commented out is the one I have problems with: my current goal is to be able to display a user's online status with an image, which represents whether they are busy, away, available, etc. Using setIcon() does absolutely nothing though, apparently; the items still show up as they used to, without icons.
I'm aware that this is probably not the way this function needs to be used, but I have found little documentation about it online, and absolutely no useful examples of implementations. My question is, can anybody help me with fixing this problem?
This is how you may conduct your debugging:
Try the constructor that has both icon and text as arguments.
Try to use that icon in another context to ensure it is displayable (construct a QIcon with same argument and use it elsewhere, e.g. QLabel!).
Use icon() from the QListWidgetItem to receive back the icon and then look at that QIcon.
Create a new QListWidget, change nothing, and ordinarily add some stock items in your MainWidget's constructor. See if the icons show up there.
Related
One of my dialog window's title is shortened (like "My Dialogt..."). If the dialog was slightly wider, the whole title would be completely displayed, which would look nicer.
It seems as if there is no setting in Qt to do that. I have found a hack for a QMessageBox here: Can QMessageBox::about adjust size to title length?, but it is not general. For example it would have to take also the sizes of the icons to the left and to the right of the window title into account to compute a really good minimal size where still the title is completely shown.
Is there a general way to accomplish that? Is there also a simple way to do that? Or is this overengineering?
Not only this goal is questionable (see vahanco comment) but it is hard to achieve, because the window title bar is not Qt territory at all: apart from being able to set its text and manage to show or hide close/min/max button using window flags, there is little else in control, there.
By the way, a very raw way to set a dialog minimum width which could (could) make room to the whole text is the following:
const QString text = "Very very very very very very very very very very very very very long window title";
setWindowTitle(text);
QFontMetrics metrics(font(), this);
setMinimumWidth( metrics.horizontalAdvance(text));
This won't work out of the box, and it's very likely that the text stay cut, because the font used is supposed to be the same used in the title bar (which usually isn't) and we're not taking into account the frame width, the icon width, the title bar buttons width, and everything else which is owned by the window manager and is totally unknown to Qt.
So, you can figure out how much extra space is needed by all these stuff, and adjust the width with a totally arbitrary extra padding like
setMinimumWidth( metrics.horizontalAdvance(text) + 256);
and maybe get what you wanted in the first place (if you still really want it).
The accepted answer did not work for me.
The below code works in QT 5.15. According to the documentation after you call setMinumumWidth() you must call updateGeometry() update geometry docs. Setting minimumWidth should update the sizeHint. That was not happening for me. Also QFontMetrics::horizontalAdvance was not returning the width of the text. I had to use QFontMetrics::boundingRect({title_string}).width().
Calling resize on the dialog is what finally got it working for me. If the accepted answer doesn't work for you give this a try.
QString message = "Message for the user";
QInputDialog dialog = QInputDialog(this);
dialog.setLabelText(message);
QString longTitle = QString("Super long test title for making sure the widget will show all of the stupid long title.");
dialog.setWindowTitle(longTitle);
dialog.setInputMode(QInputDialog::TextInput);
auto fontMetrics = dialog.fontMetrics();
auto width = fontMetrics.boundingRect(longTitle).width();
dialog.resize(width + 200, dialog.rect().height());
const int ret = dialog.exec();
I have been working for a little while now on creating a QT custom designer widget for GUI menus. The idea being that you simply drag it into the designer, select the number of frames you'd like, how many buttons per frame, etc. and it generates and sizes everything for you.
The way the widget is structured there are properties to configure each button for the frame you are in. For example, you would use the button0Text field to enter text under Button0 while editing in frame 0, then use it again to edit Button0 which is in frame 1. Both buttons would retain the individual changes for each frame.
The Problem
Normally when I switch frames all of my properties are updated to reflect the status of the frame. The exception being QIcon. The correct icon is retained in the actual graphical representation and builds correctly, however the file path in the property list is always of the last edited for that property. I think this will be extremely confusing to an end user and I have found no way to fix it. So for example, if I set text and icons in frame 0 then switch to frame 1 the text in the property list will update to reflect the state of frame 1 but the icon path names will still show my last edit in frame 0 and not the actual icon in frame 1.
I have tried things as simple as:
setProperty("button0Icon", getButton0Icon());
That code works on properties like text, but not for the icon. I try executing it immediately after changing frames.
I have also tried:
#ifndef Q_WS_QWS
QDesignerFormWindowInterface *form = QDesignerFormWindowInterface::findFormWindow(this);
if(form){
QDesignerFormEditorInterface *editor = form->core();
QExtensionManager *manager = editor->extensionManager();
QDesignerPropertySheetExtension *sheet;
sheet = qt_extension<QDesignerPropertySheetExtension*>(manager, this);
int propertyIndex = sheet->indexOf("button0Icon");
sheet->setChanged(propertyIndex, true);
sheet->setProperty(propertyIndex, getButton0Icon());
}
#endif
And:
int propertyIndex = this->metaObject()->indexOfProperty("button0Icon");
QMetaProperty property = this->metaObject()->property(propertyIndex);
property.write(this, QIcon());
Nothing seems to update the property list in the designer.
I have all properties, including all QIcon properties properly declared in the header file with Q_PROPERTY and assigned getter and setter functions.
To be clear, the icon values are indeed retained through each frame when compiled. So it is functioning, just unclear for most users.
If anyone has any experience with this or any ideas please let me know. Thanks.
I have discovered that QIcon does not store file names/paths. The file names are only used for the creation of the QIcon. I think this is most likely the reason I do not get any feedback in the Property Browser for my QIcon properties.
Instead I have chosen to hide this property in the designer and add three new ones. Three QUrl properties, each of which is used to supply an image file. I use three because I want to construct a QIcon that contains Modes/States for normal, disabled, and pressed operations.
I take each of these QUrls and save them in QStringLists behind the scenes so their values are stored. I then construct my QIcon using the file names provided from the QUrls.
I would much prefer to be using the native QIcon in the designer for this, any thoughts or feedback are appreciated.
I've run into a bit of an issue related to a whitelist Web Browser my company has been developing / maintaining for one of our product lines. The browser runs on top of Qt 4.8.6, using qtwebkit (Migration to 5.X would be ideal, but the embedded Linux OS we're using is too old to support the newer versions based on our testing, and upgrading to a newer OS is too costly to us / our customers). The primary interface to the browser is a 6x8 touchscreen, mounted inside an aircraft cockpit.
For sites that have things like scrollable/embedded maps (ex. Google Maps), the users of the browser want the ability to drag the entire page when they are selecting something outside of the map, and drag just the map (without the entire page scrolling) when the map is selected (Ala most of the popular mobile browsers).
Thus far, I am able to do one or the other, but not both:
When I hook mouse handlers into a QWebView or QGraphicsWebView, I can turn the cursor into a hand and very easily support dragging of the entire web page. However, that inhibits the page's ability to handle the mouse events for when a user is pulling over a map (i.e. When a user drags over a map, it drags the entire page without moving the map).
When I don't add in the hooks to handle mouse events, things like maps are scrollable by grapping/dragging them, but of course the user loses the ability to drag the entire page.
Right now, the browser uses the later, with scroll bars disabled and a directional-arrow overlay to allow the user to scroll the entire page (as the display size is limited, and scrollbars take up too much space when they are sized large enough for the user to interact with them)...but this is not ideal.
My Question: Is there any easy way to make it so that the page, and elements in a page, can be scrolled seamlessly?
Thanks!
Rob
Seems to me like you need to check if you are over such a map and ignore(pass along) the event in that case. I think you should be able to do something like this:
bool GraphicsWebView::isOverMap(QPoint pos) {
QWebPage* webPage = this->page();
if (webPage) {
QWebFrame* webFrame = webPage->frameAt(pos);
if (webFrame) {
QString selectorQuery = "#map-canvas"; // Based on https://developers.google.com/maps/tutorials/fundamentals/adding-a-google-map
QList<QWebElement> list = webFrame->findAllElements(selectorQuery).toList(); // Find all the maps!
foreach(QWebElement element, list) {
if (element.geometry().contains(pos)) {
return true; // Cursor is over a map
}
}
}
}
return false; // No match
}
Obviously this is a pretty specific function but there is probably a way to come up with a better selector query that will apply to all those kinds of QWebElement.
Assuming you hook mouse events by subclassing QGraphicsWebView and reimplementing void mouseMoveEvent(QGraphicsSceneMouseEvent * event), I suggest you do something like:
void GraphicsWebView::mouseMoveEvent(QGraphicsSceneMouseEvent* event) {
if (isOverMap(mapFromScene(event->scenePos()).toPoint())) { // We got a map!
event.ignore(); // Clear the accept flag
return; // Return, we're done here
}
handleMoveView(); // Not over any maps, let's scroll the page
}
This part of the doc explains how events are handled with regard to the topmost item. I especially recommend you read the third paragraph.
Hope that helps!
EDIT: Did a bit more research and it looks like something like that could be more generic:
graphicsView.focusItem()->flags().testFlag(QGraphicsItem::ItemIsMovable);
It's at the very least worth investigating as a replacement to isOverMap()
EDIT: Gotcha, here is something you can try then.
Start by subclassing QGraphicsSceneMouseEvent and add a signal called void destroyedWithoutAccept() that's emitted in the destructor if the event has not been accepted.
Then modify mouseMoveEvent to look like this:
void GraphicsWebView::mouseMoveEvent(QGraphicsSceneMouseEvent* event) {
MyEvent myEvent = new MyEvent(event); // Copy event
event.accept(); // accept original event
connect(myEvent, SIGNAL(destroyedWithoutAccept),
this, SLOT(handleMoveView)); // Callback if unused
QGraphicsWebView::mouseMoveEvent(myEvent); // Pass it to Base class
}
If that works, it might introduce a bit of delay if deleteLater is used to destroy it. But in that case reimplement it as well.
i do have two Labels in my applications. They are both in each tab. Now i want to witch between those labels by using an pointer that switchs between those labels when tab was changed.
my ui_mainwindow.h defines:
ProLabel *imageLabel;
ProLabel *imageLabel_1;
ProLabel *imageLabel_2;
but only imageLabel_1 and imageLabel_2 are shown in the GUI. I added a third Label (imageLabel) to use it as a variable to switch between the Labels (1/2). So I wrote follwing code in a slot which proves tab changed. So if tab is changed, the other imageLabel_1/2 (pointer) should be used in the hole code, when it says: imageLabel.
my slot when tab changed:
if(tab == 0)
{
this->ui->imageLabel = this->ui->imageLabel_1;
}
else{
this->ui->imageLabel = this->ui->imageLabel_2;
}
I also set the imageLabel_1 whe MainWindow is created. The Window disapear like normal. But if I try to load an image (than it should display the image in the imageLabel) it crashes.
Don't know if it was understandable. Does anybody has an idea if i can handle the pointers like that.. or how to do it different?
Thank you!
Two simpler ways: 1) Change the label contents, either the image or the text it contains, or 2) set the label to hidden with ui->label2->isVisible(false).
So I'm making a text editor using Qt and right now I have a button that opens a dialog called "Format text". I want it to work kind of like the dialog in notepad called "font" where you select a few text attributes from some drop down lists and it shows you what your text will look like. Right now I have it working where you can select the font style, font color, and font size and hit preview and it shows you in a box in the dialog what your text will look like. However, I have a button called "okay" which is supposed to change the highlighted text or the text you are about to type, but I can't figure out how to display those changes on the main window. The .ui files are private and a lot of the already made functions and pointers are the same in every ui file so if I change the ui file to pubic I have to change a whole bunch of things. Can anyway give me a simple answer? I'm trying to do this with as little confusion as possible. More coding and less confusion is better than less coding and more confusion for someone of my skill level. Sorry that this is all one giant paragraph and that I didn't provide any code, but I didn't think the code was necessary, however if you do need some of the code i'd be happy to share it.
Thank you for your help and your time. I hope you all have a nice evening.
QDialog have a signal called finished(), you can connect this signal with your slot. To accomplish your work, pass a QSettings or for simplicity QStringList to dialog settings (responsible for changing font, color ...), the QStringList will save user defined settings, after closing the dialog, iterate through QStringList member to alert Main window.
A pseudo code will look like this
Class Editor:
Editor::Editor()
{
TextSettings textSettings;
textSettings.setSettings(settings); // settings is a member
connect(textSettings, &finished(int)), this, SLOT(alertEditor(int)))
}
Editor::alertEditor(int s)
{
if(s == 0)
{
for (int i = 0; i < settings.size(); ++i)
settings.at(i).toLocal8Bit().constData(); // extract various user settings
}
}
Class TextSettings:
TextSettings::TextSettings(QStringList settings)
{
settings << ui->combobox->currentItem(); // font name as example
}