`v2win/v2net` - `WantContinuousButtonPressed` does not repeat.

[tig]

To Reproduce
Steps to reproduce the behavior:

1. Go to 'Buttons' Scenario
2. Press and hold on the 'Repeat (press-and-hold):' button.

Expected behavior

Actual Behavior

[tznind]

Hmn, if there are no mouse events being raised by I/O layer then counter shouldn't go up surely.

[BDisp]

They must be generated when ButtonPressed is true until a ButtonRelease is performed to be used on views that has WantContinuousButtonPressed enabled. So a new timer must be created for that behavior.

[tznind]

I think this should be handled in view not mouse/events layer.

If the mouse is not moving then there should be no mouse events being raised by driver layer.

If a View wants to run a timer that starts on mouse down and stops on mouse release then it should do it itself.

If it's a super common requirement then it should be in view base class.

[tznind]

Here is a POC of how I think this kind of thing should work. I've used subclass for simplicity but we could put into base class View if we want.

Advantages:

• View is in control of how often the 'tick' happens
• Makes use of existing Application level subsystem (GrabMouse) instead of inventing new one
• Doesn't introduce a driver level reliance on TimedEvents subsystem
• Works with all drivers implicitly because it is view level functionality

class MouseDownView : View
{
    private bool down = false;

    public MouseDownView ()
    {
        Text = "0";
    }

    /// <inheritdoc />
    protected override bool OnMouseEvent (MouseEventArgs mouseEvent)
    {
        if (mouseEvent.IsPressed)
        {
            if (!down)
            {
                down = true;
                Application.GrabMouse (this);

                // Give first tick
                TickWhileMouseIsHeldDown ();

                // Then periodic ticks
                Application.AddTimeout (TimeSpan.FromMilliseconds (500), TickWhileMouseIsHeldDown);
            }
        }
        else
        {
            Application.UngrabMouse ();
            down = false;
        }

        return base.OnMouseEvent (mouseEvent);
    }

    private bool TickWhileMouseIsHeldDown ()
    {
        if (down)
        {
            Text = (int.Parse (Text) + 1).ToString ();
            SetNeedsDraw ();
        }
        return down;
    }
}

private static int Main (string [] args)
{

    Application.Init (null,"v2win");
    var w = new Window ();

    var v = new MouseDownView ()
    {
        CanFocus = true,
        Width = 5,
        Height = 1,
        X = 2,
        Y = 2,
    };
    w.Add (v);
    Application.Run (w);

    return 0;
}

[BDisp]

I agree with this approach in the View base class which will raise the same event after elapsed time. Maybe starting with low speed and increasing the speed with steps which can be configurable by the sub-class. The sub-class will process the desired behavior, in the case of numeric button up/down will count, in the case of scroll bar will scroll up/down/left/right, etc...

[tznind]

@BDisp want me to replace WantContinuousButtonPressed with this above approach?

Want to make sure you have not started to work on it before I begin in case to prevent duplicating effort.

[BDisp]

Please, yes I want. I didn't started anything. Fell free to do towards this @tznind. Thanks.