Re: [wxhaskell-users] From mouse position to character index (textCtrl)

[Arthur v. L. <art...@cs...>]

On 20-feb-2007, at 22:29, Mads Lindstr=F8m wrote:

> Hi All
>
> Arthur van Leeuwen wrote:
>> On 18-feb-2007, at 18:23, Mads Lindstr=F8m wrote:
>>
>>> Hi all
>>>
>>> I have created a text-control and I want to know which character the
>>> mouse is hovering over. Getting the mouse position is easy enough.
>>> However converting the mouse position to a character index (into the
>>> text-control's text) seems very difficult.
>>>
>>> Anybody knows how to go from mouse position to character index?
>>
>> First, you need to get a hold of the TextCtrl. Then on that
>> you can use textCtrlPositionToXY to get the x- and y- coordinate =20
>> of the
>> character in character increments. textCtrlPositionToXY is in WXCore.
>
> textCtrlPositionToXY get the character position. That is, in the text:
>
> ab
> c
> def
>
> a, b, c, d, e, and f will have character positions (0,0), (1,0), =20
> (0,1),
> (0,2), (1,2), and (2,2) respectively.

Yes, and it gets this from the mouse position you pass to the function.
 =46rom these coordinates you can generate the position in the string
"ab\nc\ndef", e.g.

Is this not what you want?

> When I wrote the mouse position, I was referring to the bitmap =20
> position
> on the canvas (on which the characters are drawn) - I should have =20
> been a
> bit more precise there. I get this position by capturing mouse events
> by:
>
>    set textCtrl [ on mouse :=3D ... ]

Yes. The canvas contains the textCtrl, and the textCtrl draws the =20
string.
Therefore it can perform the mapping back to character coordinate from
mouse position. =46rom that you can map back to position in string =20
yourself.

Maybe I am just completely misunderstanding what you want to do.

Doei, Arthur.

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