[Qt-interest] QRect::contains is lying to me

[Scott Aron Bloom]

Look at the docs again.. For the QRect::contains( QRect, bool )
overload, it says:
bool QRect::contains ( const QRect & rectangle, bool proper = false )
const
This is an overloaded function.

Returns true if the given rectangle is inside this rectangle. otherwise
returns false. If proper is true, this function only returns true if the
rectangle is entirely inside this rectangle (not on the edge).


I read that as, if the edges are the same, it returns false, otherwise
it has to be fully contained... 

Not if the other rect is partially contained.

Scott

-----Original Message-----
From: qt-interest-bounces at trolltech.com
[mailto:qt-interest-bounces at trolltech.com] On Behalf Of Paul England
Sent: Monday, December 21, 2009 12:31 AM
Cc: qt-interest at trolltech.com
Subject: Re: [Qt-interest] QRect::contains is lying to me

Hi Scott:

>From the documentation, it returnd true when it's completely contained
if you call QRect::contains( const QRect&, bool proper = false ). 
Default is false.  Or maybe I'm reading that wrong?

Another user suggested  intersects(), and it works much better, although
not perfect.  I can sometimes drop a QTableWidget on to a subclassed
QGroupBox.  Never the other way around though.  I've not poked hard
enough to point any fingers yet, however, it's mostly working. :)

Cheers for the help
Paul

Scott Aron Bloom wrote:
> Its not lying.. its telling the truth...
>
> At least of the example you are showing...
>
> QRect::Contains( QRect) returns true if the second rectangle is 100%
> contained by the first...
>
> It looks like you want QRet::intersected
>
> Scott
>
> -----Original Message-----
> From: qt-interest-bounces at trolltech.com
> [mailto:qt-interest-bounces at trolltech.com] On Behalf Of Paul England
> Sent: Sunday, December 20, 2009 9:33 PM
> To: qt-interest at trolltech.com
> Subject: [Qt-interest] QRect::contains is lying to me
>
> Hello:
>
> This is a little irksome.  I'm basically storing geometries of
QWidgets
> in a std::map.  When a widget moves, before dropping it I make sure
it's
> not going to be on top of another QWidget.  Sounds easy enough, right?

> I'm checking to make sure the geometries of the QObjects don't collide
> with QRect::contains().  It keeps telling me they don't when they
> clearly do.  Am I missing something?  Here's the code:
>
> std::map<QWidget*, QRect> geometries;
>
> int drag_dialog::geometry_okay( QWidget* self, const QRect& rect )
const
> {
>     map<QWidget*, QRect>::const_iterator it;
>     for ( it = geometries.begin(); it != geometries.end(); it++ ) {
>
>         if ( (*it).first == self ) {
>             continue;
>         }
>
>         if ( rect.contains( (*it).second ) ) {
>             printf( "Bubuuu... no dice\n" );
>             return 0;
>         } else {
>             printf( "%d,%d -> %d,%d does not conflict with %d,%d ->
> %d,%d\n",
>             rect.topLeft().x(), rect.topLeft().y(),
> rect.bottomRight().x(), rect.bottomRight().y(),
>             (*it).second.topLeft().x(), (*it).second.topLeft().y(),
> (*it).second.bottomRight().x(), (*it).second.bottomRight().y() );
>         }
>     }
>
>     return 1;
> }
>
> Output I got when I clearly dropped one widget on another:
> 9,8 -> 109,254 does not conflict with 0,0 -> 99,245
>
> Thanks.
> _______________________________________________
> Qt-interest mailing list
> Qt-interest at trolltech.com
> http://lists.trolltech.com/mailman/listinfo/qt-interest
>
> _______________________________________________
> Qt-interest mailing list
> Qt-interest at trolltech.com
> http://lists.trolltech.com/mailman/listinfo/qt-interest
>   

_______________________________________________
Qt-interest mailing list
Qt-interest at trolltech.com
http://lists.trolltech.com/mailman/listinfo/qt-interest