Make the cursor visible in textEdit (Qt3.3.5)

Hello everybody,
I have problem regarding QtextEdit and scrollView. My target is to make the cursor in TextEdit to be visible whenever I type something in it. The horizontal scrollBars should move accordingly once the cursor in the textEdit is at the end of the visible area of the frame. For this I have defined 3 classes namely

1) class myFrame : public QFrame
A frame which has a QtextEdit in it.

2) class myScroll : public QScrollView
ScrollView for scrolling purpose, which has myFrame in it. myFrame makes use of viewport defined in this class

3) class myWidget : public QMainWindow
A mainWidow which has scrollview

When I just type in the TextEdit, I want the scrollView to move the scrolls accordingly. This basically means I want the cursor in TextEdit to be visible anyTime I type in it.

I have written sample code but is unable to find what is wrong.
//test.h

Code:

---

#include <qscrollview.h>
#include <qframe.h>
#include <qtextedit.h>
#include <qmainwindow.h>
 
class myFrame : public QFrame
{
	Q_OBJECT
public:
	myFrame ( QWidget *parent=0, const char *name="myFrame" );
	~myFrame();
	QTextEdit* getEditor()
	{
		return myEditor;
	}
public slots:
	void slotTextChanged();	
private:
	QTextEdit* myEditor;
};
 
class myScroll : public QScrollView
{
public:
	myScroll ( QWidget *parent=0, const char *name="ScrollChemCanvas" );
	~myScroll();
private:
	myFrame* f;
};
 
class myWidget : public QMainWindow
{
	public:
	myWidget ( QWidget *parent=0, const char *name="myWidget" );
	~myWidget();
private:
	 myScroll* scroll;
};

---

//test.cpp

Code:

---

#include "test.h"
 
myWidget::myWidget ( QWidget *parent, const char *name )
:QMainWindow(parent, name)
{
	scroll = new myScroll(this);
	CHECK_PTR( scroll );
	scroll->setFrameStyle( QFrame::Box  | QFrame::Raised );
	scroll->setMinimumSize( 200, 200 );
	setCentralWidget( scroll );
}
 
myWidget::~myWidget()
{
 
}
 
myScroll ::myScroll ( QWidget *parent, const char *name )
:QScrollView(parent, name)
{
	f = new myFrame(viewport());
	f->setBackgroundColor( Qt::blue );
	f->resize( parentWidget()->width(), parentWidget()->height() );
	f->getEditor()->resize( f->width(), f->getEditor()->height() );
	addChild(f);
	addChild(f->getEditor());	
	f->getEditor()->ensureCursorVisible();	
}
 
myScroll::~myScroll()
{
 
}
 
myFrame::myFrame ( QWidget *parent, const char *name )
: QFrame(parent, name)
{
	myEditor = new QTextEdit(parentWidget());		
	connect( myEditor, SIGNAL( textChanged () ), this, SLOT(slotTextChanged()));
}
 
myFrame::~myFrame()
{
 
}
 
void myFrame::slotTextChanged()
{
}

---

//main.cpp

Code:

---

#include <qapplication.h>
#include "test.h"
 
int main( int argc, char ** argv )
{
    QApplication a( argc, argv );
    myWidget w;
    w.show();
    a.connect( &a, SIGNAL( lastWindowClosed() ), &a, SLOT( quit() ) );
    return a.exec();
}

---

Help me to fix this problem.

Thanks in advance

Guys please help.....

Waiting for a reply

Hi wysota,
PLease give me some idea....

Thanks

Is the question really tough to be answered r M I not making any sense...

Please help me to solve this problem.....

It seems that you are trying to implement something that QTextEdit already does.

Quote:

---

Originally Posted by jacek

It seems that you are trying to implement something that QTextEdit already does.

---

Yes, I know QTextEdit does it. But what if I dont need QTextEdit's scrollView and want to define my own scrollView and ensure that the curosr in the textEdit is always visible.

I need this because I'm creating my own headers and footers.
I have a frame where the drawings happen. There is a header(a QFrame) with TextEdit in it, a footer(a QFrame) with textEdit in it (Both are children of drawing area)....In this case the drawing area uses scrollView's viewport to move the scrolls to and fro.....But what if I want the header's/footer's textEdit to be conntected to scrollView(defined by me). In this case it doesnot make sense using textEdit's builtin scrollView.

I have also disabled the textEdit's scrollView in my example as I dont need it.

Or Is there a better approach to achieve this.

Waiting for a reply.....

Is there anyone who can help me solve this problem?????????

I need it for my project. Please help!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Check the attachment. It's a quick & dirty solution and needs some additional work, but it should at least get you started.

Quote:

---

Originally Posted by jacek

Check the attachment. It's a quick & dirty solution and needs some additional work, but it should at least get you started.

---

Hi jacek thank you for your reply,
I went through your solution. I found it helpful.

But I have still one more problem. The solution what you have
provided is for vertical scrollBar but I need the same for horizontal one.

I have done some modification to your code but is unable to calculate the exact points( x and y coordinates)

Is there anything in QTextEdit which can give me the current QPoint
position of the cursor.

Here is the code

Code:

---

Test()
      {
		QSignalMapper *m = new QSignalMapper( this );
		for( int i = 0; i < N; ++i ) 
		{
			_t[i] = new QTextEdit( viewport() );
			_t[i]->resize( WIDTH, HEIGHT );
			_t[i]->setVScrollBarMode( QScrollView::AlwaysOff );
			_t[i]->setHScrollBarMode( QScrollView::AlwaysOff );
			_t[i]->setWrapPolicy ( QTextEdit::AtWordOrDocumentBoundary );
			addChild( _t[i] );
			m->setMapping( _t[i], i );
			connect( _t[i], SIGNAL( textChanged() ), m, SLOT( map() ) );
		}
 
		connect( m, SIGNAL( mapped(int) ), this, SLOT( resize(int) ) );
		updatePositions();
      }
 
   private slots:
      void resize( int i )
      {
		QTextEdit *t = _t[i];
		int w = t->width();
 
		QFontMetrics fm(t->QWidget::font());
		int fontWidth = fm.width(t->text());
		int contentX = QscrollView::visibleWidth();		
 
		if( fontWidth  >= contentX )
		{			
			int para = 0;
			int index = 0;
 
			t->getCursorPosition( &para, &index );
 
			QRect r( t->paragraphRect( para ) );
			int line = t->lineOfChar( para, index );
			int totLines = t->linesOfParagraph( para );			
 
//the problem is here. Here y gives me the correct value but how do I get the correct
//x value. If I have the current QPoint position of the cursor I need not calculate the 
                                          //x and y values and my work becomes easier
			int x = fontWidth;   //fontWidth return the total pixelWidth of the text in current textEdit
			int y = r.top() + ( line * r.height() ) / totLines; 
 
			QPoint pt( x, y );
			pt = t->mapToParent( pt );
			pt = viewportToContents( pt );
			QScrollView::ensureVisible( pt.x(), pt.y() );
		}
      }

---

thanks in advance

Quote:

---

Originally Posted by vermarajeev

Is there anything in QTextEdit which can give me the current QPoint position of the cursor.

---

Yes, there is, but it isn't a part of public API. QTextEdit can give you a pointer to QTextCursor and that cursor object knows its exact position.