I have a child class of QGraphicsItem with Selectable and Movable flags. When I select many items and moving them, all recieves itemChange event. Is there any way to detect in itemChanged that mouse's button is still pressed?
Please refer to the QApplication::mouseButtons() function that will return the current state of the mouse buttons Qt::MouseButtons.
Qt::MouseButtons btns = QApplication::mouseButtons();
if (btns & Qt::LeftButton) {
// The left button is pressed.
[..]
}
Related
I want hide a QWidget when mouse clicks out of that widget just like it have a popup flag:
auto widget = new QWidget(this);
widget->setWindowFlag(Qt::Popup); // this widget will hide, when mouse click out of that widget.
For some reason, I can't set these flags and must implement some thing myself which behaves like this.
Or can I get a mouse event out of that widget?
Solution:
As I said, I can't use Qt flags and have to implement the similar behavior myself.My solution is installEventFilter to QApplication, in the override method eventFilter,I filter the QMouseEvent and send a signal.
Yes, you can get a mouse event out of the widget.
Make a custom widget and reimplement mousePressEvent, which will catch the last click (the ouside-the-widget click that hides the "popup"). But be careful to add the call to QWidget::mousePressEvent(event) in the end, otherwise the last click will be lost and your widget will remain onscreen.
CustomWidget::CutomWidget(QWidget *parent) : QWidget(parent)
{
setWindowFlags(Qt::Popup);
}
void CustomWidget::mousePressEvent(QMouseEvent *event)
{
if (!this->underMouse()) {
//if the click is not on the widget, i.e. if it's the click that hides it,
// you caught it, do what you want to do here.
}
QWidget::mousePressEvent(event);
}
Hope it helps.
I am wondering how i can distinguish wheel click event from mouse press event. Because i want to do different handling for these two events in pyside. Currently, every time I click the wheel button, the event is catched by mousepressevent. Can anyone explain ?
Edit: I want to implement this in a subclass of
qglwidget class
From its name, the mousePressEvent is responsible for mouse clicks while the wheelEvent is for scrolling solely. The wheelEvent will not catch the wheel button click. It is how the Qt's API is designed when it comes to mouse events processing.
In order to separate which mouse button is pressed (right, wheel or left), use button property of QMouseEvent.
This is how the code would look like using C++ (I imagine it is easy to translate it to pyside)
void GLWidget::mousePressEvent(QMouseEvent *event) // redefine the mouse event
{
switch( event->button() ) {
case Qt::LeftButton:
// do stuff for left button pressed
break;
case Qt::MiddleButton:
// do stuff for wheel button pressed
break;
// ...
}
}
So, for pyside, you only need to compare the button property of event in mousePressEvent and see whether it is Qt.LeftButton , Qt.RightButton or Qt.MidButton. Hope that helps.
I have a scene object derived from QGraphicsScene and custom item on it, derived from QGraphicsItem.
I want this item be "transparent" for mouse events so clicking on the item area will call
QGraphicsScene::mousePressEvent();
From the documentation:
"...To disable mouse events for an item (i.e., make it transparent for
mouse events), call setAcceptedMouseButtons(0)."
But still the scene does not receive mouce events if I click on the item area.
MyItem::MyItem(QGraphicsItem * parent) :
QGraphicsItem(parent)
{
setAcceptedMouseButtons(Qt::NoButton);
}
QRectF MyItem::boundingRect() const
{
return QRectF(0,0,100,100);
}
void MyItem::paint(QPainter * painter, const QStyleOptionGraphicsItem * option, QWidget * widget)
{
painter->fillRect(boundingRect(),QColor(0,0,160,10));
}
So how can I ignore mouse events for the item?
It is possible then in the future I will need to process mouse events with the item so may be right decision is to implement QGraphicsItem::mousePressEvent() and just to pass somehow the event to the scene.
You messed up evrything.
QGraphicsScene always process ALL mouse events! It is responsible for passing those events to its children (QGraphicsItems in scene). So scene receives mouse events then event is passed to respective item in scene.
So if item doesn't accept mouse event this doesn't mean the scene will process mouse event again.
It looks like that you messed up something when you did subclass a scene.
Bottom line your question is wrong.
When I select several QGraphicsItem (with Ctrl key) I can move them together, but the mouseMoveEvent is triggered only for the item that actually receives the event. Is there a way to make every selected items receive the event ? I can't find it in Qt's doc.
Could I group selected items together and handle it within QGraphicsView's mouseMoveEvent ?
Thanks a lot for any help :)
No there is no default way to do what you want as far as I know. Something you could do is the following:
Subclass QGraphicsScene and implement the mouseMoveEvent
In the mouse move event check if there is an item at the event position using the itemAt function
If there is an item and it is selected (isSelected), get all selected items of the scene.
For all selected items call the same function you would call.
Sample code follows:
void mouseMoveEvent(QGraphicsSceneMouseEvent * mouseEvent)
{
QPointF mousePosition = mouseEvent->scenePos();
QGraphicsItem* pItem = itemAt(mousePosition.x(), mousePosition.y());
if (pItem == NULL)
{
QGraphicsScene::mouseMoveEvent(mouseEvent);
return;
}
if (pItem->isSelected() == false)
{
QGraphicsScene::mouseMoveEvent(mouseEvent);
return;
}
// Get all selected items
QList<QGraphicsItem *> items = selectedItems();
for (unsinged i=0; i<items.count(); i++)
// Do what you want to do when a mouse move over a selected item.
items[i]->doSomething();
QGraphicsScene::mouseMoveEvent(mouseEvent);
}
I'm reading between the lines of your question a little, but it sounds like you might be better served by implementing QGraphicsItem::itemChange on your QGraphicsItem class(es). This will get called whenever the position changes--whether by mouse, keyboard, programmatic, etc. You can even cancel the change if you want to.
http://doc.qt.io/qt-5/qgraphicsitem.html#itemChange
I have a datagrid that I want the user to sort the rows on. To make it obvious that it's sortable I am implementing some custom cursors. But I'm having a problem when I actually drag an item.
here's a pseudo demonstration of the problem
Application = normal cursor // fine
Rollover datagrid = open hand cursor // good so far
mousedown on datagrid = closed hand cursor // good
dragging item around = closed hand cursor // switches back to normal cursor (if I move it around real fast I can see my custom curser for an instant)
mouse up on datadrid = open hand cursor // not sure, after I drop it goes back to open hand but if I mouse down, dont move and mouse up I have a closed hand
rollout of datagrid = normal cursor //good
datagrid code:
<mx:DataGrid id="sectQuestionsDG" x="10" y="204" width="558" height="277" headerHeight="0" selectable="{editMode}"
dragMoveEnabled="{editMode}" dragEnabled="{editMode}" dropEnabled="{editMode}"
dragDrop="sectQuestReOrder(event);" rollOver="over();" mouseDown="down();" mouseUp="up();" rollOut="out();"/>
functions:
public function over():void{
CursorManager.setCursor(grabCursor,CursorManagerPriority.LOW,0,0);
}
public function down():void{
CursorManager.setCursor(grabbingCursor,CursorManagerPriority.HIGH,0,0);
}
public function up():void{
CursorManager.setCursor(grabCursor,CursorManagerPriority.LOW,0,0);
}
public function out():void{
CursorManager.removeAllCursors();
}
Edit 12/17/09:
I've made a little bit of progress, I'm now doing this on rollOver
var styleSheet:CSSStyleDeclaration = StyleManager.getStyleDeclaration("DragManager");
styleSheet.setStyle("moveCursor", grabbingCursor);
CursorManager.setCursor(grabCursor,CursorManagerPriority.LOW);
This is giving me the correct rollover and correct drag, but if I try to add any
function to rollOut it screws up again, so now I'm stuck with the grabCursor. It
seems like when I set a rollOut on the dataGrid it's firing for each row, same
with mouseOut, is there any way to avoid that?
Edit 12/21/09:
It is a confirmed thing that roll/mouse out/over fire for every item in the datagrid. The solution I need is how to prevent that and only fire it when the user mouses out of the datagrid as a whole. I need flex to see the forest, not the trees.
PS. the rollout only fires on every item when I am dragging. mouseout fires on every item regardless
EDIT 12/21/09, End of the day:
I have managed to answer my own question so my bounty rep is lost to me :-( Anyway since my answer solves my problem I will award the bounty to anyone that can answer this. My solution uses AS to remove the the rollOut/rollOver while a user is dragging. In a dataGrid. How can you get the same result without removing the rollOut/rollOver (so that rollOut is not firing for each item as you drag another item over it)?
Why not use the property isDragging of DragManager if you are doig a drag you dont need to change the cursor. And dont forget to check for the dragExit event in case you drop outside the datagrid.
N.B
sometimes the cursor keep with the dragging shape after the drop so you can in your sectQuestReOrder remove the cursor and set it back to over state.
sample:
public function over(evt:Event):void{ //on mouse over, added with AS
if (DragManager.isDragging) // you are dragging so no cursor changed
return;
CursorManager.removeAllCursors();
CursorManager.setCursor(grabCursor,CursorManagerPriority.LOW,-7,-7);
var styleSheet:CSSStyleDeclaration = StyleManager.getStyleDeclaration("DragManager");
styleSheet.setStyle("moveCursor",grabbingCursor); //style set for the drag cursor
}
public function down(evt:Event):void{ // on mouse down
CursorManager.removeAllCursors();
CursorManager.setCursor(grabbingCursor,CursorManagerPriority.LOW,-7,-7);
}
public function up(evt:Event):void{
CursorManager.removeAllCursors();
CursorManager.setCursor(grabCursor,CursorManagerPriority.LOW,-7,-7);
}
public function out(evt:Event):void{
if (DragManager.isDragging) // you are dragging so no cursor changed
return;
CursorManager.removeAllCursors();
}
public function sectQuestReOrder(e:Event):void{
// sometime you will be stuck with the moving cursor
// so after the drop done reset cursor to what you want
CursorManager.removeAllCursors();
CursorManager.setCursor(grabCursor,CursorManagerPriority.LOW,-7,-7);
...
}
public function onDragExit(e:Event):void {
// in case you go out of the datagrid reset the cursor
// so when you do a drop outside you ll not get one of your dragging cursor
CursorManager.removeAllCursors();
}
And in your grid add dragExit
<mx:DataGrid
id="sectQuestionsDG"
x="10" y="204" width="558" height="277" headerHeight="0"
selectable="{editMode}"
dragExit="onDragExit(event)"
dragMoveEnabled="{editMode}"
dragEnabled="{editMode}"
dropEnabled="{editMode}"
dragDrop="sectQuestReOrder(event);"
rollOver="over(event);"
mouseDown="down(event);"
mouseUp="up(event);"
rollOut="out(event);"/>
I would look at the mouseOut event and determine if its firing when you're moving the mouse during a drag. I have seen cases where the dragged object doesn't move exactly with the mouse, and for a short while, the mouse is actually hovering over another object (causing the mouseOut event to fire, thus changing the cursor).
OK some props to Gabriel there for getting my mind out of a rut and back into this problem in full mode. I had to go through a few steps to get to my answer
1)remove the listeners for rollOver, rollOut, and mouseUp from the mxml and add rollOver and rollOut through the addEventListener method in AS
2) add the listener dragComplete to the mxml and assign the function previously assigned to mouseUP to it
3) change the main function to this:
public function over(evt:Event):void{ //on mouse over, added with AS
CursorManager.removeAllCursors();
CursorManager.setCursor(grabCursor,CursorManagerPriority.LOW,-7,-7);
var styleSheet:CSSStyleDeclaration = StyleManager.getStyleDeclaration("DragManager");
styleSheet.setStyle("moveCursor",grabbingCursor); //style set for the drag cursor
}
public function down(evt:Event):void{ // on mouse down
CursorManager.removeAllCursors();
CursorManager.setCursor(grabbingCursor,CursorManagerPriority.LOW,-7,-7);
sectQuestionsDG.removeEventListener(MouseEvent.ROLL_OVER,over);
sectQuestionsDG.removeEventListener(MouseEvent.ROLL_OUT,out);
//this is why I had to take it off the mxml, can only remove listeners
//added with the addEventListener, I don't remember where I read that.
}
public function up(evt:Event):void{
CursorManager.removeAllCursors();
CursorManager.setCursor(grabCursor,CursorManagerPriority.LOW,-7,-7);
sectQuestionsDG.addEventListener(MouseEvent.ROLL_OVER,over);
sectQuestionsDG.addEventListener(MouseEvent.ROLL_OUT,out);
}
public function out(evt:Event):void{
CursorManager.removeAllCursors();
}