Re: text widget: drag and drop

Thanks Bryan.
I found that I was binding the text "tags" directly when it was far simpler
to bind the text widget with "%x %y" and then use "$text tag names @%x,%y" -
it amazes me that I never realised it could be so much simpler (and more
efficient).

I am only dragging items within the same text widget so the dragging is
working perfectly for me now.



"Bryan Oakley" <oakley@xxxxxxxxxxxxxxxxxxxx> wrote in message
news:rRQif.26316$Zv5.24510@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> Ihug wrote:
>> I am trying to get drag and drop to work.
>>
>> One thing I am trying to understand is when events get triggered - this
>> differs once the mouse button is depressed.
>>
>> When the user moves the mouse over the various tags they are highlighted
>> (as per the Motion binding below).
>> When the user presses button-1 the drag gets initiated.
>> When the user releases button-1 the drop gets initiated.
>>
>> The problem is once the button is pressed no more motion events get
>> triggered, hence nullifying the "drag" effect.
>> Can the text widget ($tw) be configured to activate motion events while
>> the buttons are pressed?
>>
>
> Short answer: no.
>
> What you do is put a <Motion> binding on the thing being clicked on. Then,
> use the winfo command to determine the window below the mouse as it is
> being dragged. Use this information to know what to highlight. If it is a
> text widget, you can get the index of the character under the pointer,
> determine any bindings on that character, and Do The Right Thing.
>
> This behavior of the widget handling the ButtonPress event also getting
> all the Motion events is documented briefly in the bind man page.
>
> A rudimentary drag and drop example can be found at this wiki page:
> http://wiki.tcl.tk/416
>
> The example doesn't explicitly address text widgets, but it shows how as
> the drag occurs, the widget that was clicked on gets the motion events and
> can highlight the item under the pointer.


.

Quantcast