How to remove spacebar action from QToolButton - qt

I have a QToolBar on which there is a QToolButton. When QToolButton is pressed by mouse click then it perform some action. The same action is performed when space bar is pressed. I dont want the action to be fired on space bar press, but I want it on mouse click. How I can do this?

Subclass QToolButton using inheritance and override QWidget::keyPressEvent(). There, check if the key you get is Qt::Key_Space and if it is, return and do nothing. if it isn't pass the event to QToolButton.

Use the set focus policy with no focus, this prevents the keyboard from having focus but still allows mouse clicks.
Button->setFocusPolicy(Qt::NoFocus)

Make sure you didn't accidentally assign 'Space' as the shortcut to the action associated with the QToolButton in question (check out Qt Creater's action editor).

Related

Qt QTreeView mouse entered/left event?

There is a "entered" signal for a QTreeView Widget, which I can use to check if my mouse moves over an item.
Is there a way to implement an "left" signal?
Why:
I have a treeView with a lot of items which I also plot via QChart. I want to highlight the plot when someone mouse over the data in the treeview.
I can highlight it via the "entered" signal, but I have no idea how to change it back to the default if the mouse left/mouse is over another item...
entered is a member of QAbstractItemView. You should probably reimplement QAbstractItemView::dragLeaveEvent virtual method.
See this method documentation: http://doc.qt.io/qt-5/qabstractitemview.html#dragLeaveEvent

Let QTabWidget switch to corresponding page when mouse cursor hover on the tab

I want to show the corresponding page when mouse cursor hover on the tab of a QTabWidget.
For example, when the mouse cursor hover on tab ‘page2’ here , I hope the QTabWidget shows the corresponding page automatically instead of clicking. How to implement this feature?
You may try adding an event filter on the QTabWidget object's QTabBar in order to trap the mouse move event. In the filter handler, use QTabBar::tabAt( QPoint ) to find which tab is below the cursor. Set up a timer when the cursor first enters a given tab, reset time when cursor leaves it. When the timer fires, switch active tabs.
You may try using setTabToolTop function.
ui->tabWidgetHz->setTabToolTip(0,"tooltip for tab1.");
ui->tabWidgetHz->setTabToolTip(1,"tooltip for tab2.");
ui->tabWidgetHz->setTabToolTip(2,"tooltip for tab3");

Qt: How to click and drag in a QGraphicsView to rubber band select items that accept mouse clicks?

According to the QGraphicsView docs, dragMode's behavior "only affects mouse clicks that are not handled by any item." It then says "You can define a custom behavior by creating a subclass of QGraphicsView."
In my case I'd like clicks on an item that accepts mouse clicks to call the item's mouse clicks as normal. And I'd like clicks not on those items to start a rubber band drag (also as normal). However, I'd like to be able to ctrl-click the view, and have that start a rubber band drag selection rather than call the item's mouse event methods.
I know how to assess whether or not ctrl is associated with a mouse click event:
if (event->modifiers().testFlag(Qt::ControlModifier))
However, I don't know what to do with this condition, or where exactly to put it. Should I put it in QGraphicsItem, QGraphicsScene, or QGraphicsView? QGraphicsView seems most likely, as the docs somewhat hint.
You need to put the condition to QGraphicsItem like this:
if (event->modifiers().testFlag(Qt::ControlModifier))
{event->setAccepted(false); return;}
Now You can handle the event in Your QGraphicsView.

QSlider focus with a hotkey?

The QSlider documentation says, "A slider accepts focus on Tab and provides both a mouse wheel and a keyboard interface." Is there an easy way to assign a hotkey to it to give it focus similar to how one can assign an Alt key for QCheckboxes?
If you have an associated label, you should be able to use QLabel::setBuddy(QWidget*). Otherwise, you could override the keyPressEvent for the parent form that would have focus and then call QSlider::setFocus(Qt::FocusReason).

Setting button focus in a graphcisview

I have placed a few buttons in a Qgraphicsscene, but I don’t know how to navigate to the button from a keyboard.
How would I set the focus to a button from the keyboard?
I assume that you used QGraphicsScene::addWidget() to add the button to the scene? It gives you a proxy object back, QGraphicsProxyWidget *, which inherits QGraphicsItem::setFocus(). But remember that it needs to have set the ItemIsFocusable flag and needs to be visible and active as well.
Additionally (from the setFocus() documentation):
As a result of calling this function, this item will receive a focus in event with focusReason. If another item already has focus, that item will first receive a focus out event indicating that it has lost input focus.

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