TGTextEdit disable/change return key

ROOT
1

Hi rooters,
I’m writing a GUI and I have a TGTextEntry where I can write the cut to apply and
I have a line like this to connect the return key to a function

fEntryCutExpression->Connect("ReturnPressed()","TPulseViewer",this,"ApplyCut()");

Sometimes I need to write very long string and the TGTextEntry is not always very useful.
I thought to use a TGTextEdit instead, but in the TGTextEdit environment
I cannot write a code line like the one above, because the return key is equal to a break line.

So that’s my question: is it possible to change the return key command from break line to a something like the ReturnPressed() of TGTextEntry Class?

Cheers,
Stefano

2

You can try to connect to the ProcessedEvent(Event_t *event) signal of your TGTextEdit widget (or its container) and properly handle the return key event into the slot

3

Hi,
you mean something similar to what is shown here?

How to detect mouse roll over or hover for TGPictureButton

I tried something similar changing the kEnterNotify with a kGKeyPress but then I don’t know how to detect the return key and use it then. Any suggestions?

Stefano

4

Yes, for example… (you can also use a class method)

You could try something like this:

   if (event->fType == kGKeyPress) {
      UInt_t keysym;
      char input[10];
      gVirtualX->LookupString(event, input, sizeof(input), keysym);
      if ((EKeySym)keysym == kKey_Enter) {
         // Your code goes here ...
      }
   }
5

Sorry for the late answer.
I tried the solution you proposed but doesn’t seem to work :confused:
I also tried to put a cout after the LookupString but nothing happens.

Cheers
Stefano

6 
   fTextEdit->GetCanvas()->Connect("ProcessedEvent(Event_t*)", ...);
7

And here is a simple working example:

#include "TGFrame.h"
#include "TGButton.h"
#include "TGTextEdit.h"
#include "Riostream.h"
#include "KeySymbols.h"

const char *eventNames[] = {
   "KeyPress", "KeyRelease", "ButtonPress", "ButtonRelease",
   "MotionNotify", "EnterNotify", "LeaveNotify", "FocusIn",
   "FocusOut", "Expose", "ConfigureNotify", "MapNotify",
   "UnmapNotify", "DestroyNotify", "ClientMessage", "SelectionClear",
   "SelectionRequest", "SelectionNotify", "ColormapNotify",
   "DoubleClick", "OtherEvent"
};

class MyMainFrame : public TGMainFrame
{
private:
   TGTextButton *fButton;
   TGTextEdit   *fTextEdit;

public:
   MyMainFrame(const TGWindow *p, UInt_t w, UInt_t h);
   virtual ~MyMainFrame() {}
   void EventSlot(Event_t *event);

   ClassDef(MyMainFrame, 0)
};

void PrintMessage(Event_t *event)
{
   // Slot function connected to the ProcessedEvent signal.
   UInt_t keysym;
   char str[2];
   if (event->fType == kGKeyPress) {
      gVirtualX->LookupString(event, str, sizeof(str), keysym);
      std::cout << "PrintMessage() : event = " << eventNames[event->fType];
      std::cout << "; key (ASCII) value = " << (int)str[0] << std::endl;
   }
}

//______________________________________________________________________________
MyMainFrame::MyMainFrame(const TGWindow *p, UInt_t w, UInt_t h) : TGMainFrame(p, w, h)
{
   // Default constructor.
   fButton = new TGTextButton(this, "Exit Application", "gApplication->Terminate()");
   AddFrame(fButton, new TGLayoutHints(kLHintsExpandX | kLHintsCenterY, 20, 20, 20, 20));
   fTextEdit = new TGTextEdit(this, 150, 50);
   AddFrame(fTextEdit, new TGLayoutHints(kLHintsExpandX | kLHintsCenterY, 20, 20, 20, 20));
   // connect the ProcessedEvent signal to a class method
   fTextEdit->GetCanvas()->Connect("ProcessedEvent(Event_t*)", "MyMainFrame", this, "EventSlot(Event_t*)");
   // connect the ProcessedEvent signal to a free function
   fTextEdit->GetCanvas()->Connect("ProcessedEvent(Event_t*)", 0, 0, "PrintMessage(Event_t*)");
   MapSubwindows();
   Layout();
   MapWindow();
   Resize(150,100);
}

//______________________________________________________________________________
void MyMainFrame::EventSlot(Event_t *event)
{
   // Slot method connected to the ProcessedEvent signal.
   UInt_t keysym;
   char str[2];
   if (event->fType == kGKeyPress) {
      gVirtualX->LookupString(event, str, sizeof(str), keysym);
      std::cout << "MyMainFrame::EventSlot() : event = " << eventNames[event->fType];
      std::cout << "; key (ASCII) value = " << (int)str[0] << std::endl;
   }
}

void testgui3()
{
   new MyMainFrame(gClient->GetRoot(), 200, 100);
}
1 Like
8

Thanks a lot it work perfectly.

Cheers
Stefano

1 Like
9

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