C++ QScrollBar::singleStep方法代码示例

bool ChatWindow::eventFilter(QObject* watched, QEvent* e)
{
    if(e->type() == QEvent::KeyPress)
    {
        QKeyEvent* ke = static_cast<QKeyEvent*>(e);

        bool scrollMod = (Preferences::self()->useMultiRowInputBox() ? false : (ke->modifiers() == Qt::ShiftModifier));

        if(ke->key() == Qt::Key_Up && scrollMod)
        {
            if(textView)
            {
                QScrollBar* sbar = textView->verticalScrollBar();
                sbar->setValue(sbar->value() - sbar->singleStep());
            }

            return true;
        }
        else if(ke->key() == Qt::Key_Down && scrollMod)
        {
            if(textView)
            {
                QScrollBar* sbar = textView->verticalScrollBar();
                sbar->setValue(sbar->value() + sbar->singleStep());
            }

            return true;
        }
        else if(ke->modifiers() == Qt::NoModifier && ke->key() == Qt::Key_PageUp)
        {
            if(textView)
            {
                QScrollBar* sbar = textView->verticalScrollBar();
                sbar->setValue(sbar->value() - sbar->pageStep());
            }

            return true;
        }
        else if(ke->modifiers() == Qt::NoModifier && ke->key() == Qt::Key_PageDown)
        {
            if(textView)
            {
                QScrollBar* sbar = textView->verticalScrollBar();
                sbar->setValue(sbar->value() + sbar->pageStep());
            }

            return true;
        }

    }

    return QWidget::eventFilter(watched, e);
}

/*! \internal
*/
void QAbstractScrollAreaPrivate::replaceScrollBar(QScrollBar *scrollBar,
                                                  Qt::Orientation orientation)
{
    Q_Q(QAbstractScrollArea);

    QAbstractScrollAreaScrollBarContainer *container = scrollBarContainers[orientation];
    bool horizontal = (orientation == Qt::Horizontal);
    QScrollBar *oldBar = horizontal ? hbar : vbar;
    if (horizontal)
        hbar = scrollBar;
    else
        vbar = scrollBar;
    scrollBar->setParent(container);
    container->scrollBar = scrollBar;
    container->layout->removeWidget(oldBar);
    container->layout->insertWidget(0, scrollBar);
    scrollBar->setVisible(oldBar->isVisibleTo(container));
    scrollBar->setInvertedAppearance(oldBar->invertedAppearance());
    scrollBar->setInvertedControls(oldBar->invertedControls());
    scrollBar->setRange(oldBar->minimum(), oldBar->maximum());
    scrollBar->setOrientation(oldBar->orientation());
    scrollBar->setPageStep(oldBar->pageStep());
    scrollBar->setSingleStep(oldBar->singleStep());
    scrollBar->setSliderDown(oldBar->isSliderDown());
    scrollBar->setSliderPosition(oldBar->sliderPosition());
    scrollBar->setTracking(oldBar->hasTracking());
    scrollBar->setValue(oldBar->value());
    delete oldBar;

    QObject::connect(scrollBar, SIGNAL(valueChanged(int)),
                     q, horizontal ? SLOT(_q_hslide(int)) : SLOT(_q_vslide(int)));
    QObject::connect(scrollBar, SIGNAL(rangeChanged(int,int)),
                     q, SLOT(_q_showOrHideScrollBars()), Qt::QueuedConnection);
}

TabsView::TabsView( QGraphicsWidget *parent )
    : QGraphicsProxyWidget( parent )
{
    // tree view which holds the collection of fetched tabs
    m_treeView = new TabsTreeView( 0 );
    connect( m_treeView, SIGNAL( clicked( const QModelIndex & ) ),
             this, SLOT( itemClicked( const QModelIndex & ) ) );

    m_model = new QStandardItemModel();
    m_model->setColumnCount( 1 );
    m_treeView->setModel( m_model );

    m_treeProxy = new QGraphicsProxyWidget( this );
    m_treeProxy->setWidget( m_treeView );

    // the textbrowser widget to display the tabs
    m_tabTextBrowser = new Plasma::TextBrowser( );
    KTextBrowser *browserWidget = m_tabTextBrowser->nativeWidget();
    browserWidget->setFrameShape( QFrame::StyledPanel );
    browserWidget->setAttribute( Qt::WA_NoSystemBackground );
    browserWidget->setOpenExternalLinks( true );
    browserWidget->setUndoRedoEnabled( true );
    browserWidget->setAutoFillBackground( false );
    browserWidget->setWordWrapMode( QTextOption::NoWrap );
    browserWidget->viewport()->setAutoFillBackground( true );
    browserWidget->viewport()->setAttribute( Qt::WA_NoSystemBackground );
    browserWidget->setTextInteractionFlags( Qt::TextBrowserInteraction | Qt::TextSelectableByKeyboard );

    QScrollBar *treeScrollBar = m_treeView->verticalScrollBar();
    m_scrollBar = new Plasma::ScrollBar( this );
    m_scrollBar->setFocusPolicy( Qt::NoFocus );

    // synchronize scrollbars
    connect( treeScrollBar, SIGNAL( rangeChanged( int, int ) ), SLOT( slotScrollBarRangeChanged( int, int ) ) );
    connect( treeScrollBar, SIGNAL( valueChanged( int ) ), m_scrollBar, SLOT( setValue( int ) ) );
    connect( m_scrollBar, SIGNAL( valueChanged( int ) ), treeScrollBar, SLOT( setValue( int ) ) );
    m_scrollBar->setRange( treeScrollBar->minimum(), treeScrollBar->maximum() );
    m_scrollBar->setPageStep( treeScrollBar->pageStep() );
    m_scrollBar->setSingleStep( treeScrollBar->singleStep() );

    // arrange textbrowser and treeview in a horizontal layout
    QGraphicsLinearLayout *layout = new QGraphicsLinearLayout( Qt::Horizontal );
    layout->addItem( m_treeProxy );
    layout->addItem( m_scrollBar );
    layout->addItem( m_tabTextBrowser );
    layout->setSpacing( 2 );
    layout->setContentsMargins( 0, 0, 0, 0 );
    setLayout( layout );
    setSizePolicy( QSizePolicy::Expanding, QSizePolicy::Expanding );
    updateScrollBarVisibility();
}

void QConsolePrivate::updateScrollBar (void)
{
  m_scrollBar->setMinimum (0);
  if (m_bufferSize.height () > m_consoleRect.height ())
    m_scrollBar->setMaximum (m_bufferSize.height () - m_consoleRect.height ());
  else
    m_scrollBar->setMaximum (0);
  m_scrollBar->setSingleStep (1);
  m_scrollBar->setPageStep (m_consoleRect.height ());
  m_scrollBar->setValue (m_consoleRect.top ());

  log ("Scrollbar parameters updated: %d/%d/%d/%d\n",
       m_scrollBar->minimum (), m_scrollBar->maximum (),
       m_scrollBar->singleStep (), m_scrollBar->pageStep ());
}

void
chat::_cond_scroll_prepare() {
    // Chack that if the last line before new text is entered is not visible,
    // then do not do the scrolling because it means user has scrolled the
    // buffer back and wants to view older text.
    QScrollBar *vbar = verticalScrollBar();
    int maximum = vbar->maximum();
    int value = vbar->value();
    int single_step = vbar->singleStep();
    _saved_pre_insert_vertical_value = value;

    _allow_scroll = (maximum - value < single_step);

    ACE_DEBUG((LM_DEBUG, "chat::_cond_scroll_prepare: max %d, val %d, singleStep %d, allow_scroll: %d\n", maximum, value, single_step, _allow_scroll));

    // Ensure text is inserted at the end of the buffer
    QTextCursor c = this->textCursor();
    c.movePosition(QTextCursor::End);
    setTextCursor(c);
}

// Set the extent of the vertical and horizontal scrollbars and return true if
// the view needs re-drawing.
bool QsciScintillaQt::ModifyScrollBars(int nMax,int nPage)
{
    bool modified = false;
    QScrollBar *sb;

    int vNewPage = nPage;
    int vNewMax = nMax - vNewPage + 1;

    if (vMax != vNewMax || vPage != vNewPage)
    {
        vMax = vNewMax;
        vPage = vNewPage;
        modified = true;

        sb = qsb->verticalScrollBar();
        sb->setMaximum(vMax);
        sb->setPageStep(vPage);
    }

    int hNewPage = GetTextRectangle().Width();
    int hNewMax = (scrollWidth > hNewPage) ? scrollWidth - hNewPage : 0;
    int charWidth = vs.styles[STYLE_DEFAULT].aveCharWidth;

    sb = qsb->horizontalScrollBar();

    if (hMax != hNewMax || hPage != hNewPage || sb->singleStep() != charWidth)
    {
        hMax = hNewMax;
        hPage = hNewPage;
        modified = true;

        sb->setMaximum(hMax);
        sb->setPageStep(hPage);
        sb->setSingleStep(charWidth);
    }

    return modified;
}

void ClientTextEdit::scrollBarReleased() {
//    if(action == QAbstractSlider::SliderReleased) {
        QScrollBar* sb = verticalScrollBar();
        int val = sb->value()+sb->pageStep();
        int singleStep = sb->singleStep();
        qDebug() << "* singleStep is:" << singleStep;
        //int docSize = sb->maximum() - sb->minimum() + sb->pageStep();
        if(val%singleStep != 0) {
            qDebug() << "* val is:" << val;
            // here's what's left over
            int newVal = val/singleStep;
            int pixels = newVal*singleStep;
            qDebug() << "* newVal is:" << newVal;
            if(val-pixels < singleStep/2) {
                val = pixels;
            } else {
                val = pixels + singleStep;
            }
        }
        sb->setSliderPosition(val-sb->pageStep());
        qDebug() << "* set slider position to" << val;
//    }
}

void Main::moveDefinicio(QEvent *event)
{
	int type = event->type();
	int step,pagestep;

	QScrollBar *bar;
	bar=ui.definicio->verticalScrollBar();
	
	step=bar->singleStep();
	pagestep=bar->pageStep();

	if (type == QEvent::User+Auxiliar::KeyDown()) {
		bar->setSliderPosition(bar->sliderPosition()+step);
	}
	else if (type == QEvent::User+Auxiliar::KeyUp()) {
		bar->setSliderPosition(bar->sliderPosition()-step);
	}
	else if (type == QEvent::User+Auxiliar::KeyNextPage()) {
		bar->setSliderPosition(bar->sliderPosition()+pagestep);
	}
	else if (type == QEvent::User+Auxiliar::KeyPrevPage()) {
		bar->setSliderPosition(bar->sliderPosition()-pagestep);
	}
}

//.........这里部分代码省略.........
            if (!ui->debugCheckBox->isChecked()) {
                return;
            }

            // print debug messages to stderr if in release-mode but debug
            // logging is enabled in the log panel
#ifndef QT_DEBUG
            fprintf(stderr, "Debug: %s\n", text.toLocal8Bit().constData());
#endif

            // gray
            color = QColor(98, 98, 98);
            break;
        case InfoLogType:
            if (!ui->infoCheckBox->isChecked()) {
                return;
            }
            color = QColor(Qt::darkBlue);
            break;
        case WarningLogType:
            if (!ui->warningCheckBox->isChecked()) {
                return;
            }

            // this is a "fix" for crashes that occur when a network goes away
            // and this message should be printed, I haven't managed to get
            // around this crash with other methods
            if (text.contains(
                    "/org/freedesktop/NetworkManager/ActiveConnection")) {
                return;
            }

            // orange
            color = QColor(255, 128, 0);
            break;
        case CriticalLogType:
            if (!ui->criticalCheckBox->isChecked()) {
                return;
            }
            // light red
            color = QColor(192, 0, 0);
            break;
        case FatalLogType:
            if (!ui->fatalCheckBox->isChecked()) {
                return;
            }
            // lighter red
            color = QColor(210, 0, 0);
            break;
        case StatusLogType:
            if (!ui->statusCheckBox->isChecked()) {
                return;
            }
            // green
            color = QColor(0, 128, 0);
            break;
        case ScriptingLogType:
            if (!ui->scriptingCheckBox->isChecked()) {
                return;
            }
            // blue
            color = QColor(0, 102, 255);
            break;
    }

    QDateTime dateTime = QDateTime::currentDateTime();
//    text.prepend("[" + dateTime.toString("hh:mm:ss") + "] [" + type + "] ");
//    text.append("\n");

    QString html = QString("<div style=\"color: %1\">[%2] [%3] %4</div>")
            .arg(color.name(), dateTime.toString("hh:mm:ss"), type,
                 text.toHtmlEscaped());

    QScrollBar *scrollBar = ui->logTextEdit->verticalScrollBar();

    // we want to scroll down later if the scrollbar is near the bottom
    bool scrollDown = scrollBar->value() >=
            (scrollBar->maximum() - scrollBar->singleStep());

    // return if logging isn't enabled any more
    if (!qApp->property("loggingEnabled").toBool()) {
        return;
    }

    const QSignalBlocker blocker(ui->logTextEdit);
    Q_UNUSED(blocker);

    // insert the text at the end
    ui->logTextEdit->appendHtml(html.trimmed());

    if (scrollDown) {
        // move the text cursor to the end
        ui->logTextEdit->moveCursor(QTextCursor::End);
//        scrollBar->setValue(scrollBar->maximum());
    }
#else
    Q_UNUSED(logType);
    Q_UNUSED(text);
#endif
}

/**
 * Adds a log entry
 */
void LogWidget::log(LogType logType, QString text) {
#ifndef INTEGRATION_TESTS
    // return if logging wasn't enabled
    if (!qApp->property("loggingEnabled").toBool()) {
        return;
    }

    QString type = "";
    QColor color = QColor(Qt::black);

    switch (logType) {
        case DebugLogType:
            if (!ui->debugCheckBox->isChecked()) {
                return;
            }
            type = "debug";
            // gray
            color = QColor(98, 98, 98);
            break;
        case InfoLogType:
            if (!ui->infoCheckBox->isChecked()) {
                return;
            }
            type = "info";
            color = QColor(Qt::darkBlue);
            break;
        case WarningLogType:
            if (!ui->warningCheckBox->isChecked()) {
                return;
            }
            type = "warning";
            // orange
            color = QColor(255, 128, 0);
            break;
        case CriticalLogType:
            if (!ui->criticalCheckBox->isChecked()) {
                return;
            }
            type = "critical";
            // light red
            color = QColor(192, 0, 0);
            break;
        case FatalLogType:
            if (!ui->fatalCheckBox->isChecked()) {
                return;
            }
            type = "fatal";
            // lighter red
            color = QColor(210, 0, 0);
            break;
        case StatusLogType:
            if (!ui->statusCheckBox->isChecked()) {
                return;
            }
            type = "status";
            // green
            color = QColor(0, 128, 0);
            break;
        case ScriptingLogType:
            if (!ui->scriptingCheckBox->isChecked()) {
                return;
            }
            type = "scripting";
            // blue
            color = QColor(0, 102, 255);
            break;
        default:
            type = "unknown";
            break;
    }

    QDateTime dateTime = QDateTime::currentDateTime();
//    text.prepend("[" + dateTime.toString("hh:mm:ss") + "] [" + type + "] ");
//    text.append("\n");

    QString html = QString("<div style=\"color: %1\">[%2] [%3] %4</div><br />")
            .arg(color.name(), dateTime.toString("hh:mm:ss"), type,
                 text.toHtmlEscaped());

    QScrollBar *scrollBar = ui->logTextEdit->verticalScrollBar();

    // we want to scroll down later if the scrollbar is near the end bottom
    bool scrollDown = scrollBar->value() >=
            (scrollBar->maximum() - scrollBar->singleStep());

    QTextCursor c = ui->logTextEdit->textCursor();

    // insert the text at the end
    c.movePosition(QTextCursor::End);
    c.insertHtml(html);

    if (scrollDown) {
        // move the text cursor to the end
        ui->logTextEdit->moveCursor(QTextCursor::End);
    }
#else
    Q_UNUSED(logType);
//.........这里部分代码省略.........

void VMdEditor::makeBlockVisible(const QTextBlock &p_block)
{
    if (!p_block.isValid() || !p_block.isVisible()) {
        return;
    }

    QScrollBar *vbar = verticalScrollBar();
    if (!vbar || (vbar->minimum() == vbar->maximum())) {
        // No vertical scrollbar. No need to scroll.
        return;
    }

    int height = rect().height();
    QScrollBar *hbar = horizontalScrollBar();
    if (hbar && (hbar->minimum() != hbar->maximum())) {
        height -= hbar->height();
    }

    bool moved = false;

    QAbstractTextDocumentLayout *layout = document()->documentLayout();
    QRectF rect = layout->blockBoundingRect(p_block);
    int y = GETVISUALOFFSETY;
    int rectHeight = (int)rect.height();

    // Handle the case rectHeight >= height.
    if (rectHeight >= height) {
        if (y < 0) {
            // Need to scroll up.
            while (y + rectHeight < height && vbar->value() > vbar->minimum()) {
                moved = true;
                vbar->setValue(vbar->value() - vbar->singleStep());
                rect = layout->blockBoundingRect(p_block);
                rectHeight = (int)rect.height();
                y = GETVISUALOFFSETY;
            }
        } else if (y > 0) {
            // Need to scroll down.
            while (y > 0 && vbar->value() < vbar->maximum()) {
                moved = true;
                vbar->setValue(vbar->value() + vbar->singleStep());
                rect = layout->blockBoundingRect(p_block);
                rectHeight = (int)rect.height();
                y = GETVISUALOFFSETY;
            }

            if (y < 0) {
                // One step back.
                moved = true;
                vbar->setValue(vbar->value() - vbar->singleStep());
            }
        }

        if (moved) {
            qDebug() << "scroll to make huge block visible";
        }

        return;
    }

    while (y < 0 && vbar->value() > vbar->minimum()) {
        moved = true;
        vbar->setValue(vbar->value() - vbar->singleStep());
        rect = layout->blockBoundingRect(p_block);
        rectHeight = (int)rect.height();
        y = GETVISUALOFFSETY;
    }

    if (moved) {
        qDebug() << "scroll page down to make block visible";
        return;
    }

    while (y + rectHeight > height && vbar->value() < vbar->maximum()) {
        moved = true;
        vbar->setValue(vbar->value() + vbar->singleStep());
        rect = layout->blockBoundingRect(p_block);
        rectHeight = (int)rect.height();
        y = GETVISUALOFFSETY;
    }

    if (moved) {
        qDebug() << "scroll page up to make block visible";
    }
}