Question

I’m trying to make a movable window without actually creating any widgets (except a QWebView) and I’m wondering if is possible to emit QMouseEvent from JavaScript (inside QWebView) and catch the signal with C++?

I’m already aware how to call C++ methods from JS (and vice-versa) as described here but I’m asking if I’ll be able to generate/emit an event containing a QMouseEvent (that’s really important because of the current global position of the cursor).

Answer 1

It wasn’t that hard after all.

First of all, I exposed my window to the JavaScript engine:

this->webView()->page()->mainFrame()->addToJavaScriptWindowObject("CHtml5ApplicationViewer", this);

Then I created a simple div inside my HTML code and attached this code to handle the mouse onClick, onMove and onDrag events.

document.getElementById("bar").onmousedown = function(e){

    CHtml5ApplicationViewer.fakeMousePressEvent(e.pageX, e.pageY);
    e.preventDefault();

    document.onmousemove = function(e){
        CHtml5ApplicationViewer.fakeMouseMoveEvent(e.screenX, e.screenY);
        e.preventDefault();
    }

    this.onmouseup = function(){
        document.onmousemove = null;
    }

    document.getElementById("bar").ondragstart = function() { return false; }
}

Finally, I added two functions in my C++ code that will handle the calls from my JavaScript code:

void CHtml5ApplicationViewer::fakeMousePressEvent(int fromBorderX, int fromBorderY){
    fromBorderPosition = QPoint(fromBorderX, fromBorderY);
}

void CHtml5ApplicationViewer::fakeMouseMoveEvent(int dragX, int dragY){
    move(QPoint(dragX, dragY) - fromBorderPosition);
}

Also, make sure that you make those functions callable from JS!

public:
    Q_INVOKABLE void fakeMousePressEvent(int fromBorderX, int fromBorderY);
    Q_INVOKABLE void fakeMouseMoveEvent(int dragX, int dragY);