A one-click event is trigger by double click event, which cause the program work not as expected.

[vuthede]

1> When I double-click at a bounding box, then is_bbox_selected is set to True
2> Right after that, a one-click event is trigger automatically, and is_bbox_selected is set to False
I found 2 solutions for that:
First: Using timer as mentioned on this https://stackoverflow.com/questions/21373110/how-to-distinguish-between-click-and-double-click-in-opencv
Second: I changed the code a bit in the event listener:

  elif event == cv2.EVENT_LBUTTONDOWN:
    if not prev_was_double_click:
        print('Normal left click')
        if point_1[0] is -1:
            if is_bbox_selected:
                if is_mouse_inside_delete_button():
                    edit_bbox('delete')
                is_bbox_selected = False

            else:
                # first click (start drawing a bounding box or delete an item)
                point_1 = (x, y)
        else:
            # minimal size for bounding box to avoid errors
            threshold = 20
            if abs(x - point_1[0]) > threshold or abs(y - point_1[1]) > threshold:
                # second click
                point_2 = (x, y)

    if prev_was_double_click:
        #print('Finish double click')
        prev_was_double_click = False

[Cartucho]

Hello, thanks for your feedback.
Why do you say that it causes the program to work not as expected? In terms of usability, what were you expecting?

[vuthede]

Yeah, I have tried to select a bbox, and then change the class of this bbox. But the class of bbox never change.
I think it is because :when I double-click to select a bbox, the parameter is_bbox_selected is turn into True and immediately is turned into False because a one-click event is triggered also.
The class of bbox is able to be changed only if is_bbox_selected is True, which never happen.
Btw, I use opencv 3.4

[Cartucho]

That's weird... On my computer:

1. I double click and bounding box gets selected (it should show the x button)
   

2. I press w or s the class changes
   

In your computer step 1 is not working, right? When you select a bbox it automatically de-selects itself and you don't even see the red x button?

[vuthede]

Sorry for late reply.
yeah, in my computer, the bbox automatically de-selects itself and don't even see the red x button.
I have tried to uninstall my opencv 3.4.3 and quick install the 3.2.0 instead, then the problem is resolved.

[Cartucho]

Does the problem remain with 3.2.0? I would actually recommend going to the newest version the 4.0.0.21

[vuthede]

It is so weird now,
If using 3.2.0 this problem is resolved
If using 4.0.0.21, the problem is raising a gain.

[Cartucho]

Gosh, I will try with other OpenCV versions (in 3.3.1 it works).
It may be the case that it is an OpenCV bug.

[vuthede]

yeah i think so!