How to make perform many functions in mousepressevent - c++

Question

I want to make some functions on a dicom serie (with qt and vtk) , and I want to make some connections between the qt window and the mouse.
This is my primary design:
For example, if I click on zoombutton, then I click on my image with the left button of the mouse, I want that the image will be zoomed,
I know that we must use the function mousePressEvent but I have seen that we must use this name for any connection with the mouse, or I want to do 4 or 5 functions like this one, each one for one pushbutton.
How can I do this ?

Answer 1

As you suggested correctly, you should use mousePressEvent to capture a mouse press action. To perform the correct action on a mouse press (zoom, pan, ...), you should remember the last pressed button and call the appropriate method accordingly. This can be implemented as follows:
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow ()
{
connect(ui->panButton, &QPushButton::clicked, this, &MainWindow::onPan)
connect(ui->zoomButton, &QPushButton::clicked, this, &MainWindow::onZoom)
...
}
protected slots:
enum Action {None, Pan, Zoom, ...};
void onPan () {currentAction = Pan;}
void onZoom () {currentAction = Zoom;}
protected:
void mousePressEvent(QMouseEvent *event)
{
switch(currentAction)
{
case Pan:
// perform Pan operation
break;
case Zoom:
// perform Zoom operation
break;
}
}
protected:
Action currentAction;
};