Hi Fons, If I execute the macro { // create pad if (!Pad()) { if (!gROOT->GetMakeDefCanvas()) return; (gROOT->GetMakeDefCanvas())(); } Pad()->Clear(); // creat view TView *view = Pad()->GetView(); if (!view) { view = new TView(1); view->SetRange(-100, -100, -100, 100, 100, 100); } } I get: root [0] .x PadTest.C Error: illegal pointer to class object Pad() 0x0 218 FILE:/afs/cern.ch/user/r/rutger/mycmt/ot/RootTest/v5/macros/PadTest.C LINE:7 *** Interpreter error recovered *** I also noticed tab-completions doesn't work for Pad() ... Rutger On Mon, 28 Feb 2000, Fons Rademakers wrote: > Hi Rutger, > > in the current version gPad is actually a function with the name Pad(). > So you can use if (Pad())... However, due to possible name clashes with > other global functions from other libraries we've changed Pad() to R__Pad() > in the coming release. So, use Pad() now and change to R__Pad() when you > get the next release. > > Cheers, Fons. > > > Rutger van der Eijk wrote: > > > > Hi, > > > > When is gPad known in an interactive ROOT session? I know gPad became a > > macro to improve thread support. However if I just start interactive ROOT, > > gPad is not know until I draw some object. This is inconvenient because I, > > e.g. want to check if a canvas is already present. > > > > i.e. the macro > > > > // create pad > > if (!gPad) { > > if (!gROOT->GetMakeDefCanvas()) return; > > (gROOT->GetMakeDefCanvas())(); > > } > > gPad->Clear(); > > > > crashes with: > > > > Error: No symbol gPad in current scope FILE:/tmp/29646eaa_cint LINE:1 > > > > I probably missed a roottalk or release note about this (because more ppl > > should have this), or am doing something stupid. Can anybody point me out > > to the documentation? (Version 2.23/12 1 February 2000) > > > > cheers, > > > > Rutger > > -- > Org: CERN, European Laboratory for Particle Physics. > Mail: 1211 Geneve 23, Switzerland > E-Mail: Fons.Rademakers@cern.ch Phone: +41 22 7679248 > WWW: http://root.cern.ch/~rdm/ Fax: +41 22 7677910 >
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