What event do I need to write in my wxWidgets program so that I can track mouse dragging.
I mean hold down the left mouse button and track the movement while it is pressed.
Perhaps surprisingly, this is not such a simple task. You may look at the implementation of wxMouseEventsManager to see an example of working code doing it, but the main point is that you need to capture the mouse on button press, in order to follow its movement even if it exits the window, and then you need to also react to wxEVT_MOUSE_CAPTURE_LOST events to know when the capture is forcibly broken.
Bind(wxEVT_MOTION, [&](wxMouseEvent& event) {
if (event.Dragging()) {
if (event.LeftIsDown()) {
// code
}
}
});
Related
I am trying to catch the mouse motion when I hold the mouse middle button. The goal is to implement a rotation feature in an stl viewer.
I found the event mask BUTTON2_MOTION_MASK. But I have a hard time figuring out which signal catches it.
Here's the two line I use to create and hook the event. These two line are inside a GtkApplicationWindow Constructor.
glWidget.add_events(Gdk::BUTTON2_MOTION_MASK);
glWidget.signal_motion_notify_event().connect(sigc::mem_fun(*this,&mainWindow::rotate));
Here's the function I am trying to connect.
bool mainWindow::rotate(GdkEventMotion* motion_event)
{
cout<<"test"<<endl;
}
Am I using the correct method? The code does not react when I hold the middle mouse button and move mouse.
I managed to get glArea widget to react to scrolling this way.
glWidget.add_events(Gdk::SMOOTH_SCROLL_MASK);
glWidget.signal_scroll_event().connect(sigc::mem_fun(*this,&mainWindow::zoom));
the function I connected:
bool mainWindow::zoom(GdkEventScroll *eventScroll)
{
cout<<"test"<<endl;
return true;
}
I figured it out. You need to both add the Gdk::Button1_MOTION_MASK and the Gdk::BUTTON_PRESS_MASK.
glWidget.add_events(Gdk::Button1_MOTION_MASK | Gdk::BUTTON_PRESS_MASK);
This will catch the signal when the left mouse button is clicked and positioned on the widget.
BUTTON2_MOTION_MASK will require that 2 button are pressed. For some reason, it's only the left mouse button(I want the middle button).
I'm new in working with SDL and now I've faced a problem.
Well, I'm about to make a program like Paint.
In order to do that I need a command for mouse that when I'm holding the left button and moving the mouse, a line would be drawing in where the mouse is going.
I have found an event for it, SDL_MouseButtonDown. but it only works for one second like I only click on the screen for one time!
I will appreciate any comments!
The event fires when the button goes down. It doesn't repeatedly fire for as long as the button is down, and this wouldn't be of much use to you anyway.
Write your code so that you set some variable when the button goes down, and unset it when SDL_MouseButtonUp is invoked. Whenever the mouse moves, and your variable is set, draw more of the line.
I have a strange issue that I have been unable to determine the cause. Basically, I created a 2D view with pan and zoom functionality and a scene with items that can moved with grid snapping. To move an item in the scene I extended Scene::mousePressEvent to get a pointer to the item and Scene::mouseMoveEvent to keep the item tracked on the cursor. To drop the item, I used Scene::mousePressEvent again. To pan, I extended View::mousePressEvent, View::mouseReleaseEvent, and View::mouseMoveEvent and to zoom I extended View::wheelEvent.
Now for the symptoms:
I start the application with an item in the Scene. If I click and hold, then move the mouse, the item moves as intended. As soon as I release the mouse button, the item stops moving. I can click to drop and the item is placed according to the drop code in Scene::mousePressEvent. Try again and still the item only moves when the mouse button is pressed.
Then comes the strange part: If I use the mouse wheel to zoom the View, everything performs as expected after that event. The mouse is clicked to select an item, it moves as I move the mouse and drops when I click again.
So the obvious solution:
wheelEvent(new QWheelEvent(QPointF(0,0),0,Qt::NoButton,Qt::NoModifier));
called at the creation of the View and everything works fine. It calls the extended View::wheelEvent with no change to the view and before the scene is even created, but afterwards the programs behaves as expected.
So I'm here to see if any of the excellent Qt experts out there can explain this strange behavior. Any comments or direction are appreciated.
In case it helps, here is the View::wheelEvent override code. tform is a QTransform with which I maintain zoom. Also, I've tried with and without the call to the base method but there is no change in behavior.
void SchematicView::wheelEvent(QWheelEvent* event)
{
// Scale the view / do the zoom
double scaleFactor = 1.1;
if(event->delta() > 0 && tform.m11() < max_zoom) {
tform.scale(scaleFactor,scaleFactor);
} else if (event->delta() < 0 && tform.m11() > min_zoom){
tform.scale(1.0/scaleFactor,1.0/scaleFactor);
}
setTransformationAnchor(QGraphicsView::AnchorUnderMouse);
setTransform(tform);
QGraphicsView::wheelEvent(event);
}
Without a SSCCE to look at and test with, it's hard to say for sure, but what you're describing sounds a lot like your mouseMoveEvent() callback is only getting called when the mouse button is being held down during the move. That, in turn, sounds a lot like the expected behavior for mouseMoveEvent(), as documented in QWidget::mouseMoveEvent():
If mouse tracking is switched off, mouse move events only occur if a
mouse button is pressed while the mouse is being moved. If mouse
tracking is switched on, mouse move events occur even if no mouse
button is pressed.
If that is indeed the problem, then a call to setMouseTracking(true) may get you the behavior you are looking for.
On a broader level, note that there are easier ways of obtaining the behavior you are trying to implement -- for example, to allow the user to drag and drop items in a QGraphicsScene, all you really have to do is call setFlags(QGraphicsItem::ItemIsMovable) on any QGraphicsItems that you want the user to be able to drag around. No hand-coding of event handlers is necessary unless you are trying to obtain some non-standard behaviors.
I am working on a c++ CLI application and am having some difficulty with events. I am wondering if I can get events to fire while the mouse button is clicked. For example, I am wanting to check whether or not the mouse has moved to the next square over only if they have the mouse clicked in. Meaning if they click on square 1 they should be able to hold that click and move the square 2 and my program recognize this.
I have run a number of different events on the mouse, including the "Click" event, but the neither the hover, mouse enter, or mouse down event get triggered while the button is pressed. The "MouseClick" event, which does the same. I tried using just the mouseDown event, but this does not let another mouseDown event, mouse enter, or hover event fire.
Short of checking mouse position I do not know what I can do. I would like to not have to do mouse position checking.
If anyone has any ideas, they would be greatly appreciated.
Clearly you'll want to pay attention to the MouseMove event so you can see the mouse moving into another square. Roughly:
void panel1_MouseMove(Object^ sender, MouseEventArgs^ e) {
if ((e->Button & System::Windows::Forms::MouseButtons::Left) ==
System::Windows::Forms::MouseButtons::Left) {
int square = MapPosToSquare(e->Location);
if (square != currentSquare) {
currentSquare = square;
OnSquareClicked(currentSquare);
}
}
}
If these "squares" are actually controls then you have a different problem. You have to set the control's Capture property to false in the MouseDown event handler so it doesn't capture the mouse.
I'm making my first game in Irrlicht (C++), an RTS with mouse control
and when you select a tile (by clicking on it) it lights up and some gui button appear on the screen (not in a gui window mind you, I like it this way):
http://i1139.photobucket.com/albums/n549/Adam_Halley-Prinable/Untitled2.png
However, since i switched to mouse control, the buttons wont register my mouse clicks. The click goes straight through the button and selects the tile behind instead:
http://i1139.photobucket.com/albums/n549/Adam_Halley-Prinable/Untitled3.png
Is there a way I can say "Buttons get top priority for clicks"?
I'm using MyEventReceiver, which i've messed around with to accept mouse clicks and that.
Thanks a bunch :D
If anyone else has the same problem, ill tell you how I solved it :)
Go through the MyEventReceiver.h and get rid of all the "return true;"'s in the mouse section.
Don't ask me why, but it works, and appears to have no side effects. Make sure you leave the "return false;" at the end of the section there.
Your event receiver fires before the GUI gets access to the event, if you want to pass it to the GUI then you can do this by manually posting it to the GUIEnvironment in your event receiver.
if (guienv->postEventFromUser(event))
return true; // abort because the gui wanted it
// .. pick nodes
// possibly post event to scene manager
return true; // remember to return true so gui/smgr don't get the event again