Mouse Input - Click, & Drag & Drop on the same item?

Extended
1

My InputHandler works well. There are 4 methods:

    public bool LeftButtonPressed()
    {
        if (mouseState.LeftButton == ButtonState.Pressed
            && prevMouseState.LeftButton == ButtonState.Released)
            return true;
        else return false;
    }

    public bool LeftButtonReleased()
    {
        if (mouseState.LeftButton == ButtonState.Released
            && prevMouseState.LeftButton == ButtonState.Pressed)
            return true;
        else return false;
    }

    public bool LeftButtonDrag()
    {
        if ((mouseState.LeftButton == ButtonState.Pressed)
            && (prevMouseState.LeftButton == ButtonState.Pressed))
            return true;
        else return false;
    }

    public bool LeftButtonDrop()
    {
        if ((mouseState.LeftButton == ButtonState.Released)
            && (prevMouseState.LeftButton == ButtonState.Pressed))
            return true;
        else return false;
    }

However, If I use LeftButtonPressed when the user clicks on the item, It does the same thing as LeftButtonDrag.
If I use LeftButtonReleased when the user clicks on the item, It does the same thing as LeftButtonDrop.

How do I resolve this conflict so that I can determine whether the user is clicking or dragging an item?

Thanks in advance!!

2

I made this years and years ago i haven’t altered it much in all that time.

What you’re missing is the notion of when a thing happens or a sequence of actions and what has just been done prior to that. In order to determine the difference between things like a Click Held or a Drag.

You have a item you press and hold the mouse left down this may or may not be a item grab? So you move your mouse you release the left button if the position is a valid drop location and the source was a valid grab its a drop.
This is down move up as a sequence of events the position of down determines if a item grab is occuring the movement of the mouse and its current position when released determines if a drop is valid.
if it is not then no drop occurs. That depends on item rectangles.

3

Thank you so much for your reply.

I think I understood the sequence of the actions but what I realized was that the state of the mouse does not uniquely determine the user actions. As you pointed out the Drag is determined by mouse position and the Drop is determined by a previous held.

I had put a delay timer in to determine the Drag and it worked except the left button pressed had to be held until the delay for the drag to start. Then I put a test to see if the mouse had moved to determine the Drag.

Thanks again.

4

you’d normally determine a dragstart, when the mouse button is down (on a dragable object) and the mouse was moved for a minimum of a threshold.

You may check it with (mostly) every browser, when you press&hold over an image nothing happens - when you move the mouse (not 1 px but 3 px or whatever) it goes into drag mode. But a timer-based approach may be more easy to implement in a game :slight_smile:

5

Thanks.

I’ve implemented a rectangle

Rectangle rect = new Rectangle((int)(prevPosition.X - 2f), (int)(prevPosition.Y - 2f), 4, 4);

When the current mouse position is not within the rectangle then it starts drag mode. Also set a state variable “isHeld”. When left button released “isHeld” is checked to see if this is a drop else it is a click.
Everything works as it should.
Thanks.