Begin Drag on more then 2 pixels

GoXam
1

Hi there,
I want my Node to Drag only if they are 5 Pixels away from their original position, cause some users unlink them when double clicking cause of shaky hands.

Searching the forum leads my to override IsBeyondDragSize, but if I do so and try to drag the pan mouse cursor is showing up and no drag is happening.

Where is the mistake?

2

Did you override DraggingTool.IsBeyondDragSize?

3

Yes, and I removed the / 2 to achieve a greater distance.

    protected override bool IsBeyondDragSize()
    {
        Diagram diagram = this.Diagram;
        if (diagram == null) return false;
        DiagramPanel panel = diagram.Panel;
        if (panel == null) return false;
        // Get all of the points in screen/view coordinates
        Point first = panel.TransformModelToView(diagram.FirstMousePointInModel);
        Point last = panel.TransformModelToView(diagram.LastMousePointInModel);
        return (Math.Abs(last.X - first.X) > SystemParameters.MinimumHorizontalDragDistance ||
                Math.Abs(last.Y - first.Y) > SystemParameters.MinimumVerticalDragDistance);
    }

But instead of dragging the Panning-Cursor was shown.

4

I assume that is because the PanningTool is actually running? That’s odd, though, because that can only happen if the mouse-down is not over a Node or a Link (unless you customized that).

You could try overriding PanningTool.IsBeyondDragSize in the same manner. FYI, the DragSelectingTool is another tool whose CanStart method depends on IsBeyondDragSize.

5

You can reproduce this, if you modify your FlowGrammer-Demo CustomDraggingTool.
Override CanStart and IsBeyondDragSize and you see the same Effekt.

6

You don’t need to reproduce it.
I created a PanningTool and override the IsBeyondDragSize the same way as in the DraggingTool and now it is working.

Thank you.