Re: How to make a gui

Hi Roger,

 From the included code it seems that fMainV is not a data member of your class MyMainFrame, i.e. not known symbol in the method MyMainFrame::DoComboSelect.

Next, I see that you have assigned the same widgets ID to any pair of slider and text entry. This is wrong, because the widget's id are used for event processing and they should be unique. So, you could apply a simple formula using 'i' to generate them.

In addition, be careful when re-using the same layout hints (fLslider) for several widgets in AddFrame method. I hope you will delete fLslider in the destructor, as well as all created GUI elements in your application, i.e. you will use the Cleanup() method for container frames.

Cheers, Ilka

Roger Mason wrote:

>Hello Rene,
>
>Rene Brun <Rene.Brun_at_cern.ch> writes:
>
>
>
>>see tutorial Slider3Demo.C (introduced a few weeks ago in CVS)
>>
>>Rene Brun
>>
>>
>
>Thanks for your reply. I had a look through that tutorial and I think
>I understand much of its workings.
>
>perhaps I should be more specific about the problem I'm having.
>I have the following code fragment in a class MyMainFrame:
>
> // Vertical frame
> fMainV = new TGVerticalFrame(fMainH,w/3,h);
> fMainH->AddFrame(fMainV, new TGLayoutHints(kLHintsExpandY | kLHintsExpandX,10,10,10,1));
> fComboFuncNames = new TGComboBox(fMainV,100);
> for (Int_t i = 0; i < 4; i++) {
> fComboFuncNames->AddEntry(funcnames[i], i+1);
> }
> fComboFuncNames->Resize(w/10,h/20);
> fComboFuncNames->Select(1);
> fComboFuncNames->Connect("Selected(Int_t)","MyMainFrame",this,"DoComboSelect(Int_t)");
> fLcombo = new TGLayoutHints(kLHintsTop | kLHintsLeft,5,5,5,5);
> fMainV->AddFrame(fComboFuncNames,fLcombo);
> // Sliders should be added here but defer until the selection is made in
> // fComboFuncNames so we know how many to create.
>
>When an item is selected in fComboFuncNames the following function is
>called. It is intended that this function should create a number of
>sliders, the number created being dependent on the selected function.
>
>void MyMainFrame::DoComboSelect(Int_t sel) {
> // Update the sliders depending on which function gets selected in
> // the function selection combo.
>
> Int_t nparm;
> switch (sel) {
> case 1 : nparm = 3; // Gaussian
> break;
> case 2 : nparm = 3; // Lorentzian
> break;
> case 3 : nparm = 5; // Voigtian
> break;
> case 4 : nparm = 10; // Background (max order)
> break;
> default: nparm = 9;
> }
> // cout << "nparm = " << nparm << endl;
>
> for (Int_t i = 0; i < nparm; i++ ) {
> VSid[i] = i;
> TEid[i] = i;
> fVSparms[i] = new TGVSlider(fMainV, 100, kSlider2, VSid[i]);
> fTEparms[i] = new TGTextEntry(fMainV, fTBparms[i] = new TGTextBuffer(10), TEid[i]);
> fTBparms[i]->AddText(0, "0");
> }
>
> //--- layout for sliders
> fLslider = new TGLayoutHints(kLHintsTop | kLHintsLeft, 0, 0, 3, 0);
>
> for (Int_t i = 0; i < nparm; i++ ) {
> fMainV->AddFrame(fVSparms[i], fLslider);
> fMainV->AddFrame(fTEparms[i], fLslider);
> fTEparms[i]->Connect("TextChanged(char*)", "MyMainFrame", this, "DoText(char*)");
> }
>
>}
>
>The combo box is drawn correctly but when I make a selection the
>following error is returned:
>
>root [0] .x MyExample.C
>.x MyExample.C
>root [1] Error: Can't call TGVerticalFrame::AddFrame(fVSparms[i],fLslider) in current scopePossible candidates are...
>filename line:size busy function type and name (in TGVerticalFrame)
>filename line:size busy function type and name (in TGCompositeFrame)
>/usr/local/lib/root/libGui.so -1:-1 0 public: virtual void AddFrame(TGFrame* f,TGLayoutHints* l=0);
>filename line:size busy function type and name (in TGFrame)
>filename line:size busy function type and name (in TGWindow)
>filename line:size busy function type and name (in TGObject)
>filename line:size busy function type and name (in TObject)
>filename line:size busy function type and name (in TQObject)
>Error: Can't call TGVerticalFrame::AddFrame(fVSparms[i],fLslider) in current scope /home/rmason/Programming/rootmac/MyExample.C:265:
>Possible candidates are...
>filename line:size busy function type and name (in TGVerticalFrame)
>filename line:size busy function type and name (in TGCompositeFrame)
>/usr/local/lib/root/libGui.so -1:-1 0 public: virtual void AddFrame(TGFrame* f,TGLayoutHints* l=0);
>filename line:size busy function type and name (in TGFrame)
>filename line:size busy function type and name (in TGWindow)
>filename line:size busy function type and name (in TGObject)
>filename line:size busy function type and name (in TObject)
>filename line:size busy function type and name (in TQObject)
>Error: Symbol fMainV is not defined in current scope /home/rmason/Programming/rootmac/MyExample.C:265:
>Error: Failed to evaluate fMainV->AddFrame(fVSparms[i],fLslider)Possible candidates are...
>filename line:size busy function type and name
>
>I'm sure my poor understanding of C++ is responsible for the problem.
>Any help you can offer will be most appreciated.
>
>Thanks,
>
>Roger
>
>
>
Received on Wed Feb 22 2006 - 15:37:57 MET