Auto-scrolling QTextBrowser

[MTK358]

It it possible to make a subclass of QTextBrowser that automatically scrolls to the bottom whenever it was scrolled to the bottom when text was added?

Also, is it possible to make it stay scrolled to the same place in the text when resized?

[Spitfire]

1 - This QTextBrowser does it by default when text is appended. When text is inserted it doesn't but it requires very little work:

MyBrowser::MyBrowser( QWidget* parent ) :
    QTextBrowser( parent ),
    atBottom( false )
{
    connect( this, SIGNAL( textChanged() ), this, SLOT( scrollToBottom() ) );
    connect( this->verticalScrollBar(), SIGNAL( valueChanged( int ) ), this, SLOT( scrolledTo( int ) ) );
}
 
void    MyBrowser::scrollToBottom( void )
{
    if( this->atBottom )
    {
        this->verticalScrollBar()->setValue( this->verticalScrollBar()->maximum() );
    }
}
 
void    MyBrowser::scrolledTo( int val )
{
    this->atBottom = val == this->verticalScrollBar()->maximum();
}

MyBrowser::MyBrowser( QWidget* parent ) :
    QTextBrowser( parent ),
    atBottom( false )
{
    connect( this, SIGNAL( textChanged() ), this, SLOT( scrollToBottom() ) );
    connect( this->verticalScrollBar(), SIGNAL( valueChanged( int ) ), this, SLOT( scrolledTo( int ) ) );
}

void    MyBrowser::scrollToBottom( void )
{
    if( this->atBottom )
    {
        this->verticalScrollBar()->setValue( this->verticalScrollBar()->maximum() );
    }
}

void    MyBrowser::scrolledTo( int val )
{
    this->atBottom = val == this->verticalScrollBar()->maximum();
}

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2 - I don't quite get your question. The browser doesn't scroll anywhere when you resize it, just show more/less text.

[MTK358]

1 - This QTextBrowser does it by default when text is appended. When text is inserted it doesn't but it requires very little work:

MyBrowser::MyBrowser( QWidget* parent ) :
    QTextBrowser( parent ),
    atBottom( false )
{
    connect( this, SIGNAL( textChanged() ), this, SLOT( scrollToBottom() ) );
    connect( this->verticalScrollBar(), SIGNAL( valueChanged( int ) ), this, SLOT( scrolledTo( int ) ) );
}
 
void    MyBrowser::scrollToBottom( void )
{
    if( this->atBottom )
    {
        this->verticalScrollBar()->setValue( this->verticalScrollBar()->maximum() );
    }
}
 
void    MyBrowser::scrolledTo( int val )
{
    this->atBottom = val == this->verticalScrollBar()->maximum();
}

MyBrowser::MyBrowser( QWidget* parent ) :
    QTextBrowser( parent ),
    atBottom( false )
{
    connect( this, SIGNAL( textChanged() ), this, SLOT( scrollToBottom() ) );
    connect( this->verticalScrollBar(), SIGNAL( valueChanged( int ) ), this, SLOT( scrolledTo( int ) ) );
}

void    MyBrowser::scrollToBottom( void )
{
    if( this->atBottom )
    {
        this->verticalScrollBar()->setValue( this->verticalScrollBar()->maximum() );
    }
}

void    MyBrowser::scrolledTo( int val )
{
    this->atBottom = val == this->verticalScrollBar()->maximum();
}

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First of all, I'm inserting text using a QTextCursor, not the QTextBrowser's append method. Second, it should only auto-scroll if it was already at the bottom before text was inserted.

2 - I don't quite get your question. The browser doesn't scroll anywhere when you resize it, just show more/less text.

When I make it smaller horizontally, it scrolls up, and when I make it bigger horizontally, it scrolls down.

[MTK358]

I misread your code, it actually does only autoscroll when at the bottom.

[Spitfire]

I understand that first of your problems is now solved.

As to the second one.
The browsers scrolls up/down when you resize it horizontally because of text wrapping feature.
I think that unless you turn it off you won't be able to keep the text in place and turning it off doesn't make much sense.