C++ QScrollBar::setEnabled方法代码示例

void ThumbnailStrip::refreshLayout()
{
  QRect avail = geometry();
  avail.adjust(6, 6, -6, -6);

  int numActive = 0;
  for(ResourcePreview *c : m_Thumbnails)
    if(c->isActive())
      numActive++;

  // depending on overall aspect ratio, we either lay out the strip horizontally or
  // vertically. This tries to account for whether the strip is docked along one side
  // or another of the texture viewer
  if(avail.width() > avail.height())
  {
    avail.setWidth(avail.width() + 6);    // controls implicitly have a 6 margin on the right

    int aspectWidth = (int)((float)avail.height() * 1.3f);

    ui->scrollArea->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

    delete layout;
    layout = new QHBoxLayout(ui->scrollAreaWidgetContents);
    for(ResourcePreview *w : m_Thumbnails)
      layout->addWidget(w);
    layout->setSpacing(6);
    layout->setContentsMargins(6, 6, 6, 6);
    layout->setAlignment(Qt::AlignTop);

    int noscrollWidth = numActive * (aspectWidth + 20);

    if(noscrollWidth <= avail.width())
    {
      ui->scrollArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

      for(ResourcePreview *c : m_Thumbnails)
        c->setSize(QSize(aspectWidth, avail.height()));
    }
    else
    {
      ui->scrollArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOn);

      QScrollBar *hs = ui->scrollArea->horizontalScrollBar();

      avail.setHeight(avail.height() - hs->geometry().height());

      aspectWidth = (int)((float)avail.height() * 1.3f);

      int totalWidth = numActive * (aspectWidth + 20);
      hs->setEnabled(totalWidth > avail.width());

      for(ResourcePreview *c : m_Thumbnails)
        c->setSize(QSize(aspectWidth, avail.height()));
    }
  }
  else
  {
    avail.setHeight(avail.height() + 6);    // controls implicitly have a 6 margin on the bottom

    int aspectHeight = (int)((float)avail.width() / 1.3f);

    ui->scrollArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

    delete layout;
    layout = new QVBoxLayout(ui->scrollAreaWidgetContents);
    for(ResourcePreview *w : m_Thumbnails)
      layout->addWidget(w);
    layout->setSpacing(6);
    layout->setContentsMargins(6, 6, 6, 6);
    layout->setAlignment(Qt::AlignTop);

    int noscrollHeight = numActive * (aspectHeight + 6);

    if(noscrollHeight <= avail.height())
    {
      ui->scrollArea->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

      for(ResourcePreview *c : m_Thumbnails)
        c->setSize(QSize(avail.width(), aspectHeight));
    }
    else
    {
      ui->scrollArea->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);

      QScrollBar *vs = ui->scrollArea->verticalScrollBar();

      avail.setWidth(avail.width() - vs->geometry().width());

      aspectHeight = (int)((float)avail.width() / 1.3f);

      int totalHeight = numActive * (aspectHeight + 6);
      vs->setEnabled(totalHeight > avail.height());

      for(ResourcePreview *c : m_Thumbnails)
        c->setSize(QSize(avail.width(), aspectHeight));
    }
  }
}

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent), ui(new Ui::MainWindow),
    logNewMessages(0), logHasErrors(false), showNewLogNumber(true)
{
    ui->setupUi(this);

    setWindowIcon(QIcon(c_icon_app));
    setWindowTitle(c_qtau_name);
    setAcceptDrops(true);
    setContextMenuPolicy(Qt::NoContextMenu);

    //-----------------------------------------

    QLabel *meterLabel = new QLabel(QString("%1/%2") .arg(ns.notesInBar).arg(ns.noteLength), this);
    QLabel *tempoLabel = new QLabel(QString("%1 %2").arg(ns.tempo).arg(tr("bpm")),           this);

    QHBoxLayout *bpmHBL = new QHBoxLayout();
    bpmHBL->setContentsMargins(0,0,0,0);
    bpmHBL->addSpacing(5);
    bpmHBL->addWidget(meterLabel);
    bpmHBL->addWidget(tempoLabel);
    bpmHBL->addSpacing(5);

    QFrame *tempoPanel = new QFrame(this);
    tempoPanel->setMinimumSize(c_piano_min_width, c_meter_min_height);
    tempoPanel->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Minimum);
    tempoPanel->setContentsMargins(1,0,1,1);
    tempoPanel->setFrameStyle(QFrame::Panel | QFrame::Raised);

    tempoPanel->setLayout(bpmHBL);

    meter = new qtauMeterBar(this);
    meter->setMinimumHeight(c_meter_min_height);
    meter->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Minimum);
    meter->setContentsMargins(0,0,0,0);

    piano = new qtauPiano(ui->centralWidget);
    piano->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Expanding);
    piano->setMinimumSize(c_piano_min_width, c_piano_min_height);
    piano->setContentsMargins(0,0,0,0);

    zoom = new QSlider(Qt::Horizontal, ui->centralWidget);
    zoom->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Preferred);
    zoom->setRange(0, c_zoom_num - 1);
    zoom->setSingleStep(1);
    zoom->setPageStep(1);
    zoom->setValue(cdef_zoom_index);
    zoom->setMinimumWidth(c_piano_min_width);
    zoom->setGeometry(0,0,c_piano_min_width,10);
    zoom->setContentsMargins(0,0,0,0);

    noteEditor = new qtauNoteEditor(ui->centralWidget);
    noteEditor->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
    noteEditor->setContentsMargins(0,0,0,0);

    hscr = new QScrollBar(Qt::Horizontal, ui->centralWidget);
    vscr = new QScrollBar(Qt::Vertical,   ui->centralWidget);

    hscr->setContentsMargins(0,0,0,0);
    vscr->setContentsMargins(0,0,0,0);
    hscr->setRange(0, ns.note.width() * ns.notesInBar * cdef_bars);
    vscr->setRange(0, ns.note.height() * 12 * ns.numOctaves);
    hscr->setSingleStep(ns.note.width());
    vscr->setSingleStep(ns.note.height());
    hscr->setContextMenuPolicy(Qt::NoContextMenu);
    vscr->setContextMenuPolicy(Qt::NoContextMenu);

    //---- vocal and music waveform panels, hidden until synthesized (vocal wave) and/or loaded (music wave)

    QScrollBar *dummySB = new QScrollBar(this);
    dummySB->setOrientation(Qt::Vertical);
    dummySB->setRange(0,0);
    dummySB->setEnabled(false);

    QFrame *vocalControls = new QFrame(this);
    vocalControls->setContentsMargins(0,0,0,0);
    vocalControls->setMinimumSize(c_piano_min_width, c_waveform_min_height);
    vocalControls->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Expanding);
    vocalControls->setFrameStyle(QFrame::Panel | QFrame::Raised);

    vocalWave = new qtauWaveform(this);
    vocalWave->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Minimum);
    vocalWave->setMinimumHeight(c_waveform_min_height);
    vocalWave->setContentsMargins(0,0,0,0);

    QHBoxLayout *vocalWaveL = new QHBoxLayout();
    vocalWaveL->setContentsMargins(0,0,0,0);
    vocalWaveL->setSpacing(0);
    vocalWaveL->addWidget(vocalControls);
    vocalWaveL->addWidget(vocalWave);
    vocalWaveL->addWidget(dummySB);

    vocalWavePanel = new QWidget(this);
    vocalWavePanel->setContentsMargins(0,0,0,0);
    vocalWavePanel->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Minimum);

    vocalWavePanel->setLayout(vocalWaveL);
    vocalWavePanel->setVisible(false);

    //---------
//.........这里部分代码省略.........