mac 2,9 "Cannot nest wxDCs on the same window"
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From: Riccardo Cohen on 1 Oct 2007 12:48 Hi I have a program that works on wxmac2,7 , but with 2,9 it displays the following assertion : "Cannot nest wxDCs on the same window" this happens when I do wxClientDC *dc=new wxClientDC(diag); dc->DrawRectangle(rec); delete(dc); inside a timer_wake event. I do not understand exactly what it means. Is there something changed from 2,7 to 2,9 on dc creation ? Thanks for any info. -- Tr�s cordialement, Riccardo Cohen ------------------------------------------- Articque http://www.articque.com 149 av G�n�ral de Gaulle 37230 Fondettes - France tel : 02-47-49-90-49 fax : 02-47-49-91-49 --------------------------------------------------------------------- To unsubscribe, e-mail: wx-users-unsubscribe(a)lists.wxwidgets.org For additional commands, e-mail: wx-users-help(a)lists.wxwidgets.org
From: Robin Dunn on 1 Oct 2007 12:55 Riccardo Cohen wrote: > Hi > I have a program that works on wxmac2,7 , but with 2,9 it displays the > following assertion : "Cannot nest wxDCs on the same window" > > this happens when I do > > wxClientDC *dc=new wxClientDC(diag); > dc->DrawRectangle(rec); > delete(dc); > > inside a timer_wake event. > I do not understand exactly what it means. You can not have more than one wxDC active at the same time for the same window. Somewhere you have another DC already using diag when the code above is called. > Is there something changed > from 2,7 to 2,9 on dc creation ? wxMac is now using the CoreGraphics APIs which have a few more restrictions than what was being used before. -- Robin Dunn Software Craftsman http://wxPython.org Java give you jitters? Relax with wxPython! --------------------------------------------------------------------- To unsubscribe, e-mail: wx-users-unsubscribe(a)lists.wxwidgets.org For additional commands, e-mail: wx-users-help(a)lists.wxwidgets.org
From: Stefan Csomor on 2 Oct 2007 00:52 Hi > On Mon, 01 Oct 2007 09:55:15 -0700 Robin Dunn <robin(a)alldunn.com> wrote: > > RD> Riccardo Cohen wrote: > RD> > Hi > RD> > I have a program that works on wxmac2,7 , but with 2,9 it displays the > RD> > following assertion : "Cannot nest wxDCs on the same window" > RD> > > RD> > this happens when I do > RD> > > RD> > wxClientDC *dc=new wxClientDC(diag); > RD> > dc->DrawRectangle(rec); > RD> > delete(dc); > RD> > > RD> > inside a timer_wake event. > RD> > I do not understand exactly what it means. > RD> > RD> You can not have more than one wxDC active at the same time for the same > RD> window. Somewhere you have another DC already using diag when the code > RD> above is called. > > This seems like a rather bad restriction. I wonder if we couldn't make > all wxClientDC instances on the same window use the same underlying > CGContext somehow. It could still result in problems with changing DC > attributes but if we restored them carefully, it would allow something > (common) like this: > I've tried this in earlier times, but I was not successful when another context for another wxWindow on the same toplevel window that was currently drawing was requested, but since now all code is Quartz only, I could try again. Neverthelesss I really think that every drawing has to be moved to a OnPaint event, and the only reason to use a dc outside is for measuring purposes, which already can be done. It is the way the new drawing systems perform optimally, intermittent drawing leads to synchronization bottlenecks. Best, Stefan --------------------------------------------------------------------- To unsubscribe, e-mail: wx-users-unsubscribe(a)lists.wxwidgets.org For additional commands, e-mail: wx-users-help(a)lists.wxwidgets.org
From: Riccardo Cohen on 2 Oct 2007 06:09 I agree and admit that it is the safiest way, but it is often easyer to do a "draw now" under certain user action, rather than "change data" then "refresh"... For instance when a user select a zone, I have a mouse motion event, and I want to draw a rectangle that follows the mouse to show the zone, I can resize a rectangle object and then refresh, but it is easyer to call drawrectangle() immediatly. The same for timer event : for blinking objects I simpy change the color at each timer event and draw a little point with this color. My present problem is that I used this method quite often. Buf if quartz does not allow it, I'll change my code. By the way you spoke about measuring, it happens that in the destructor of one of my windows, I have call some cleaning code that create a DC to measure text size. This lead to an exception while in the window destructor. Maybe you've got an idea for that point also. Thanks for your great work anyway. Stefan Csomor wrote: > Hi >> On Mon, 01 Oct 2007 09:55:15 -0700 Robin Dunn <robin(a)alldunn.com> wrote: >> >> RD> Riccardo Cohen wrote: >> RD> > Hi >> RD> > I have a program that works on wxmac2,7 , but with 2,9 it >> displays the RD> > following assertion : "Cannot nest wxDCs on the >> same window" >> RD> > RD> > this happens when I do >> RD> > RD> > wxClientDC *dc=new wxClientDC(diag); >> RD> > dc->DrawRectangle(rec); >> RD> > delete(dc); >> RD> > RD> > inside a timer_wake event. >> RD> > I do not understand exactly what it means. >> RD> RD> You can not have more than one wxDC active at the same time >> for the same RD> window. Somewhere you have another DC already using >> diag when the code RD> above is called. >> >> This seems like a rather bad restriction. I wonder if we couldn't make >> all wxClientDC instances on the same window use the same underlying >> CGContext somehow. It could still result in problems with changing DC >> attributes but if we restored them carefully, it would allow something >> (common) like this: >> > I've tried this in earlier times, but I was not successful when another > context for another wxWindow on the same toplevel window that was > currently drawing was requested, but since now all code is Quartz only, > I could try again. > > Neverthelesss I really think that every drawing has to be moved to a > OnPaint event, and the only reason to use a dc outside is for measuring > purposes, which already can be done. It is the way the new drawing > systems perform optimally, intermittent drawing leads to synchronization > bottlenecks. > > Best, > > Stefan > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: wx-users-unsubscribe(a)lists.wxwidgets.org > For additional commands, e-mail: wx-users-help(a)lists.wxwidgets.org > > -- Tr�s cordialement, Riccardo Cohen ------------------------------------------- Articque http://www.articque.com 149 av G�n�ral de Gaulle 37230 Fondettes - France tel : 02-47-49-90-49 fax : 02-47-49-91-49 --------------------------------------------------------------------- To unsubscribe, e-mail: wx-users-unsubscribe(a)lists.wxwidgets.org For additional commands, e-mail: wx-users-help(a)lists.wxwidgets.org
From: Riccardo Cohen on 2 Oct 2007 08:19 Actually I found an unnecessary wxClientDC creation, I removed it and all went all right. I changed my code to call some RefreshRect() instead of drawing directly... thanks Riccardo Cohen wrote: > I agree and admit that it is the safiest way, but it is often easyer to > do a "draw now" under certain user action, rather than "change data" > then "refresh"... > > For instance when a user select a zone, I have a mouse motion event, and > I want to draw a rectangle that follows the mouse to show the zone, I > can resize a rectangle object and then refresh, but it is easyer to call > drawrectangle() immediatly. The same for timer event : for blinking > objects I simpy change the color at each timer event and draw a little > point with this color. > > My present problem is that I used this method quite often. Buf if quartz > does not allow it, I'll change my code. > > By the way you spoke about measuring, it happens that in the destructor > of one of my windows, I have call some cleaning code that create a DC to > measure text size. This lead to an exception while in the window > destructor. Maybe you've got an idea for that point also. > > > Thanks for your great work anyway. > > Stefan Csomor wrote: >> Hi >>> On Mon, 01 Oct 2007 09:55:15 -0700 Robin Dunn <robin(a)alldunn.com> wrote: >>> >>> RD> Riccardo Cohen wrote: >>> RD> > Hi >>> RD> > I have a program that works on wxmac2,7 , but with 2,9 it >>> displays the RD> > following assertion : "Cannot nest wxDCs on the >>> same window" >>> RD> > RD> > this happens when I do >>> RD> > RD> > wxClientDC *dc=new wxClientDC(diag); >>> RD> > dc->DrawRectangle(rec); >>> RD> > delete(dc); >>> RD> > RD> > inside a timer_wake event. >>> RD> > I do not understand exactly what it means. >>> RD> RD> You can not have more than one wxDC active at the same time >>> for the same RD> window. Somewhere you have another DC already using >>> diag when the code RD> above is called. >>> >>> This seems like a rather bad restriction. I wonder if we couldn't make >>> all wxClientDC instances on the same window use the same underlying >>> CGContext somehow. It could still result in problems with changing DC >>> attributes but if we restored them carefully, it would allow something >>> (common) like this: >>> >> I've tried this in earlier times, but I was not successful when >> another context for another wxWindow on the same toplevel window that >> was currently drawing was requested, but since now all code is Quartz >> only, I could try again. >> >> Neverthelesss I really think that every drawing has to be moved to a >> OnPaint event, and the only reason to use a dc outside is for >> measuring purposes, which already can be done. It is the way the new >> drawing systems perform optimally, intermittent drawing leads to >> synchronization bottlenecks. >> >> Best, >> >> Stefan >> >> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: wx-users-unsubscribe(a)lists.wxwidgets.org >> For additional commands, e-mail: wx-users-help(a)lists.wxwidgets.org >> >> > -- Tr�s cordialement, Riccardo Cohen ------------------------------------------- Articque http://www.articque.com 149 av G�n�ral de Gaulle 37230 Fondettes - France tel : 02-47-49-90-49 fax : 02-47-49-91-49 --------------------------------------------------------------------- To unsubscribe, e-mail: wx-users-unsubscribe(a)lists.wxwidgets.org For additional commands, e-mail: wx-users-help(a)lists.wxwidgets.org
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