I have created one table by using QTableview and QAbstractTableModel . i have added some vertical header by using QHeaderView . In one of the header cell i want to use delegate ..
I am using the delegate but it does not have any impact ..
Is anywhere i am doing wrong ?
Had this issue myself. The answer from the Qt documentation is simple and annoying:
Note: Each header renders the data for each section itself, and does
not rely on a delegate. As a result, calling a header's
setItemDelegate() function will have no effect.
In other words you cannot use delegates with QHeaderView.
For the record, if you want to style a QHeaderView section, you'll have to do it either via the header data model (changing Qt::FontRole, etc.) or derive your own QHeaderView (don't forget to pass it to your table with "setVerticalHeader()") and overwrite the its paintSection()-function.
i.e.:
void YourCustomHeaderView::paintSection(QPainter* in_p_painter, const QRect& in_rect, int in_section) const
{
if (nullptr == in_p_painter)
return;
// Paint default sections
in_p_painter->save();
QHeaderView::paintSection(in_p_painter, in_rect, in_section);
in_p_painter->restore();
// Paint your custom section content OVER a specific, finished
// default section (identified by index in this case)
if (m_your_custom_section_index == in_section)
{
QPen pen = in_p_painter->pen();
pen.setWidthF(5.5);
pen.setColor(QColor(m_separator_color));
in_p_painter->setPen(pen);
in_p_painter->drawLine(in_rect.right(), in_rect.top(), in_rect.right(), in_rect.bottom());
}
}
This simplified example could of course easily be done via a stylesheet instead, but you could theoretically draw whatever you like using this method.
Related
This question already has answers here:
QLabel does not display in QWidget
(2 answers)
Closed 1 year ago.
I am working with a tableView and trying to implement some size styling.
The code:
// Setup table header items
Views::TeamTableHeaderView *header = new Views::TeamTableHeaderView(Qt::Horizontal);
ui->tableView->setHorizontalHeader(header);
ui->tableView->horizontalHeader()->setSectionResizeMode(QHeaderView::ResizeToContents);
ui->tableView->horizontalHeader()->setStretchLastSection(true);
ui->tableView->horizontalHeader()->setDefaultAlignment(Qt::AlignCenter | (Qt::Alignment)Qt::TextWordWrap);
for(auto& tableModel : entitlementLicenseModelMap)
{
tableModel->setHorizontalHeaderLabels({"PRODUCT", "TOTAL SEATS", "VALID UNTIL"});
}
This does not display any header on the table at all. When the call to setHorizontalHeader(header) is removed, the header displays fine. However, the header is too thin to render the text without cutting it off, hence I require a custom header (TeamTableHeaderView) to implement the sizeHint() to make it taller.
I have tried moving the setting of the header labels before and after, but the issue is that the header is just mot displaying at all, not even with the default "1" "2" "3" labels.
Some information:
This code executes after all of the data has been (successfully) populated in the tableModel.
The tableView is a bog standard QTableView
The TeamTableHeaderView is a custom type inherited from QHeaderView which only implements sizeHint(). Currently it just returns QHeaderView::sizeHint(). There is nothing special about this class yet.
The entitlementLicenseModelMap is a bit strange, but irrelevent to this question I believe. That whole for loop you can treat as just setting a table model. That table model is a QStandardItemModel.
Earlier in the code, a custom delegate is set to the model. However this delegate is not yet implemented. It is only set in order to later do some painting stuff. It inherits from QStyledItemDelegate, and only implements the paint function, which currently only saves the painter, calls QStyledItemDelegate::paint(...) and then restores the painter. I don't believe this delegate is relevant, but happy to be corrected.
To anyone else encountering this you just need to manually call:
header->setVisible(true)
Why this is the case when the header is normally visible by default when not otherwise specified.
In Qt you can define the tab order by using the Qt Designer or by using C++. The relationships between widgets are set relatively to each other, so there is no index or such thing. What I want right now is to "break" the circular chain of widgets so that I get a beginning and an end of the chain.
A circular tab order would be:
A - B
| |
D - C
I want (note missing link between A and D):
A - B
|
D - C
which is more like a line instead of a circle:
A - B - C - D
So the user "stops" at one end and has to go back using the other direction.
Update: I have another idea now. What if i reimplement:
bool QWidget::focusNextPrevChild(bool next)
According to the documentation one can use this to implement custom focus behavior.
In my dynamic scenario where buttons in the GUI are adjusted at run-time I will have to overload the function and set, for example, an internal flag allowFocusNext and allowFocusPrev which then ignores the focus request if necessary. I will report back here, when I have tried it. Meanwhile any comments are welcome!? :-)
I found a solution, but it is a bit hacky. The QWidget::setTabOrder will not allow to chain a widget with itself, so this approach won't help (even if you are using focus proxies)
However, you can define a "Focus Forwarder":
class FocusForwarder : public QWidget
{
public:
explicit FocusForwarder(QWidget *proxy) :
QWidget((QWidget *) proxy->parent()),
m_proxy(proxy)
{
setFocusPolicy(Qt::TabFocus);
}
protected:
void focusInEvent(QFocusEvent *) {
m_proxy->setFocus();
}
private:
QWidget *m_proxy;
};
And add them at the beginning and end of you chain:
FocusForwarder *w1 = new FocusForwarder(ui->bA);
FocusForwarder *w2 = new FocusForwarder(ui->bD);
QWidget::setTabOrder(w1, ui->bA);
QWidget::setTabOrder(ui->bA, ui->bB);
QWidget::setTabOrder(ui->bB, ui->bC);
QWidget::setTabOrder(ui->bC, ui->bD);
QWidget::setTabOrder(ui->bD, w2);
Details
For setTabOrder to work, the widgets must be in the same window. To ensure this, the Forwarder is placed in the proxy's parent (in the initializer list).
For this mechanism, the focus direction (Tab or Shit+Tab) does not matter. As soon as a FocusFowarder receives the focus, it will "forward" it to its proxy.
The direction is handled by Qt internally. You just add "sentinels" around your chain.
Use in QtDesigner
When you want to use it in QtDesigner, you'd create a Widget and promote it to the forwarder. As you cannot set the proxy directly, you could add a dynamic property for the proxy's name, like this:
class FocusForwarderDesigner : public QWidget
{
Q_OBJECT
Q_PROPERTY(QString proxyName READ proxyName WRITE setProxyName)
public:
QString proxyName() {
return (m_proxy) ? m_proxy->objectName() : QString::null;
}
void setProxyName(QString name) {
m_proxy = parent()->findChild<QWidget *>(name);
}
explicit FocusForwarderDesigner(QWidget *parent = NULL) :
QWidget(parent) {}
protected:
void focusInEvent(QFocusEvent *) {
if (m_proxy) m_proxy->setFocus();
}
private:
QWidget *m_proxy;
}
In the designer, you would add a string-property with name proxyName and set it to the proxy's name. Don't forget to set the focus policy to Tab Focus in designer.
After some additional thoughts I post an answer to my own question because it is a working solution but it is not ideal. Therefore, I'm still searching for a better one! As a note, my application mainly relies on mouse wheel interactions for changing the focus of widgets.
In my question I mentioned that overriding:
bool focusNextPrevChild(bool next)
could lead to a working system. The "receiving" widget would simply ignore the focus by returning "true" if it is marked as "last item" or "first item" and the "next" parameter would lead to a circular behavior. Although this works for the tab and space+tab key combinations, there are cases where focusNextPrevChild is not called explicitly. In my case it is not called for focus changes related to mouse wheel events.
What I do instead is overriding:
void wheelEvent(QWheelEvent* event)
This gives me direct control over all the focus events related to the mouse wheel. My overridden function looks like this:
void SelectionIconButton::wheelEvent(QWheelEvent* event)
{
bool next = event->delta() > 0;
if (m_IsLastInFocusChain && next) {
event->accept();
return;
}
if (m_IsFirstInFocusChain && !next) {
event->accept();
return;
}
QPushButton::wheelEvent(event);
}
So this system's requirements are:
Each widget has to somehow implement two bools and handle their
state.
Each of those widgets has to be configured either at startup
or in dynamic screens during appliation use
Listening only to
wheelEvent does not allow me to handle tab key and space+tab key
combinations
You see that this solution works but it involves some effort to apply it to a large application. I was thinking about a more general solution. Maybe a global list that is updated when a screen is changing. This global list would then somehow decide if a focus change is allowed or not. Unfortunately, this again is problematic with mouse wheel events because some widgets are "active" and the wheel event does not even want to change focus but alter the value in an input field, for example, instead.
Edit:
I might have to add that the default implementation of QWidget::wheelEvent() and QPushButton::wheelEvent() and many more Qt-Widgets just ignore the event by setting event->ignore().
In my application all those ignored events are caught at a high level widget which then interprets the QWheelEvent and uses its delta to call focusPreNextChild() the right amount of time.
This questions to me reeks of maybe a lack of understanding of C++, as the possibilities I've considered for my problem all seem to make no sense on why this could be occuring. Feedback appreciated.
I'm using the form designer to create a form class with a table in it. I'm trying to replace the table with another table generated in a helper class. I'm only doing this so I can (hopefully) maintain the nice grid layout I've designed, and through pointer manipulation, get the replacement I desire. Here's some code snippets from the table form constructor and relevant calls :
//tableData is defined in the header file as a QTableWidget*
tableData = this->findChild<QTableWidget *>("tableData");
....
setup();
void setup(){
tableData = Utilities::createTable(this->file, tableDelim);
//createTable returns QTableWidget*
... other assignments, and label text updates, which seem to all work
}
My understanding is that tableData is a pointer, and if printed, will give the address of the QTableWidget from the layout. So then if I create a QTableWidget* and then assign tableData to that, tableData should now point to the new widget. Instead, I see only a blank screen.
I tried checking what the tableData pointer is before I assign it to the new QTableWidget*, and after. The second pointer shown is what is generated by createTable() :
QTableWidget(0x101272d40, name = "tableData") QTableWidget(0x10127b3b0, name = "test_sample2.nuc.stats")
QTableWidget(0x10127b3b0, name = "test_sample2.nuc.stats") QTableWidget(0x10127b3b0, name = "test_sample2.nuc.stats")
It seems the pointer is being reassigned, but the table drawn isn't the right one.
What gives?
My understanding is that you want to design the table layout in designer but fill in the data from an external source.
I would suggest, to just use the QTableWidget that is created in setupUi() and modify Utilities::createTable() such that it becomes Utilities::populateTable(QTableWidget & table, <all the other parameters you need>). (Or use QTableWidget * if you prefer - however I like putting the non-zero assertion responsibility on the caller...)
Apart from that, I agree with Sebastian Lange.
You are right with your assumption. You do set a variable to be a pointer to a object and next you set the variable to be a pointer to another object. You never change any objects, just your variable which is not used to display anything.
You would need to do something like:
//tableData is defined in the header file as a QTableWidget*
tableData = this->findChild<QTableWidget *>("tableData");
parentLayout = tableData->parent()->layout(); //Get the parent widget to add another table.
parentLayout->removeWidget(tableData);
delete tableData;
parentLayout->addWidget(createTable());
You need to use pTheContainerOfTheOriginalTableWidget->addWidget(tableData); See here: http://qt-project.org/forums/viewthread/16547
Be sure you remove the original tableWidget so you don't have two (I assume you don't want two).
If I understand you correctly we have such situation.
call of setupUi (which generated by qt tootls),
there there is something like this(pseudo code):
oldTablePtr = new QTableWidget(parent);
someLayout->addWidget(oldTablePtr);
So parent and layout hold value of oldTablePtr.
And if you set variable oldTablePtr nothing changed.
parent send QPaintEvent to oldTablePtr.
So you need call delete oldTablePtr, that remove this widget from list of childs of parent, and move newTablePtr to the same layout.
There's no need to replace it in code, you can do it in Qt Designer. Just place QTableWidget on form, then rightclick it and choose Promote widget in menu, then you will need just enter your classname.
Currently I don't have Qt Designer near me, so edits will be appreciated.
I'd like a graphical container that I can add and remove my custom widgets to where I can set a sort function that is automatically applied when these operations take place.
Is there a suitable object in Dojo already that I've missed? Or maybe I'm not thinking about the problem correctly?
If not, are there any examples etc. of a minimal working custom container widget out there?
Dont think there is really - how would a standard component's sort functionality know, with which parameters it should weight the order, when containers can contain any widget type?
Using a layout widget extension would be your best option imho. They each have a function to add children, following this prototype:
addChild(/*Object*/ dijit, /*Integer?*/ insertIndex)
The dijit.layout.StackContainer is a good starting point, it inherits from dijit._Container (and dijit.layout._LayoutWidget). So you choose when to call the extension functionality of your override.
dojo.declare("my.Container", [dijit._Container], {
getSortOrder : function(newDijit) {
var newIndex = -1; ??
// something to work with
var currentChildren = this.getChildren();
var currentDescendants = this.getDescendants();
return newIndex;
},
addChild: function(dijit, index) {
// figure out index
arguments[1] = this.getSortOrder(dijit);
this.inherited(arguments);
}
});
But be aware, that layoutwidgets has more to it then choosing order, also positioning like with bordercontainer's region parameter.
Use SitePen's dgrid, then define a List widget with a column of type Editor. Send your custom widget to the Editor's parameter. dgrid's List widget should be able to sort as if it were a grid based on your data, and the Editor column should be able to display anything you want as part of a List's item's content.
If you need anything I'll be around. Luck,
I found this question: How to change the background color for a QTreeView Header (aka QHeaderView)?
I want to be able to set the color for each header section. So the question seen above seems to be my solution!
The solution says "the easiest way to do that is probably to derive a new model from QAbstractItemModel or another model class and reimplement the headerData()". I went and looked at the Qt source tree for QTableWidget, QTableModel, QTableWidgetItem... these classes are supposedly "default models" so I thought they would be a good example and then I would go implement my own QAbstractTableModel.
The 3 files I saw are a whopping 3300 lines of code. That is definitely NOT "the easiest way" IMO!!!
I would like the functionality of QTableWidget but then I want to add the following ability:
horizontalHeader.setSectionColor(index,color)
verticalHeader.setSectionColor(index,color)
Do I really need to inherit/implement QAbstractTableModel if all I want is to change the color of a section header?
Update:
I am not using my own custom view and model classes. I am using the convenience class QTableWidget right now (it is called a convenience class b/c it implements the view and model). The function headerData() is part of the model. The model class, QTableModel, is not accessible via Qt lib/headers so I can't inherit from it.
Update:
I tried creating a new item with background brush QBrush(QColor(Qt::red)) and then setting the table's header with the new item (using QTableWidget::setHorizontalHeaderItem(int column, QTableWidgetItem *item). I also tried inheriting QTableWidgetItem and overriding the virtual data() method with:
QVariant HeaderItem::data(int role) const
{
if(role==Qt::BackgroundRole) {
return QVariant(QBrush(QColor(Qt::red)));
} else if(role==Qt::ForegroundRole) {
return QVariant(QBrush(QColor(Qt::green)));
} else {
return QTableWidgetItem::data(role);
}
}
I can change the header sections foreground. But when I try to change the header's background brush... nothing happens... it's like the QTableWidgetItem's background brush that I set for the header section is ignored.
Instead of creating model with custom headerData() from scratch create subclass of QTableWidgetItem with desired implementation of QTableWidgetItem::data() and use the instances of this class for QTableWidget::setHorizontalHeaderItem.