62.QT-QScroller实现home界面滑动效果

QScrollerProperties::MousePressEventDelay
//设置鼠标按下的延迟时间,比如设置按下多少ms后开始真正触发滑动器.

QScrollerProperties::DragStartDistance
//设置移动阀值(按下后需要移动最少多少距离后,触发滑动),用来避免误操作.

QScrollerProperties::DragVelocitySmoothingFactor
//平滑滑动速度，当滑动后手离开屏幕后,进行平滑滑动的速度,此值应介于0和1之间。值越小，速度越慢。

QScrollerProperties::DecelerationFactor
//减速速度因子,减速到0速度所需的时间。对于大多数类型，该值应在0.1到2.0的范围内
QScrollerProperties::MinimumVelocity
//平滑滑动的最小速度
QScrollerProperties::MaximumVelocity
//平滑滑动的最大速度
QScrollerProperties::SnapTime
//滚动曲线的时间因子。设置滚动的时长,值越小，滚动时间越长.
QScrollerProperties::FrameRate
//设置平滑滑动的刷新频率,可以设置的值有如下几种:
//QScrollerProperties::Fps60 
//QScrollerProperties::Fps30
//QScrollerProperties::Fps20

QScrollerProperties::VerticalOvershootPolicy
//垂直越区策略

table = new QTableWidget(this);
table->setVerticalScrollMode(QAbstractItemView::ScrollPerPixel);
QScroller* scroller = QScroller::scroller(table->viewport()); //也可以填入直接填入table,只是点击滑动条时会无反应.
scroller->grabGesture(table->viewport(),QScroller::LeftMouseButtonGesture);
QScrollerProperties properties = scroller->scrollerProperties();
properties.setScrollMetric(QScrollerProperties::DragVelocitySmoothingFactor,0.3);
properties.setScrollMetric(QScrollerProperties::FrameRate,QScrollerProperties::Fps60);
scroller->setScrollerProperties(properties);

class ScrollHome : public QTableWidget
{
Q_OBJECT

int iconSize; 
QSize itemSize; 
int iconSpacing; 
int iconColumn; 
QMargins margins; 

QFont font;
QPalette palette;
QWidget *parent;

QPushButton* newAppButton(QWidget* app,AppRes& appRes);

QWidget* newAppIcon(AppRes& appRes);

public:
explicit ScrollHome(QWidget *parent );

void InitHome(int iconColumn, int iconSpacing, int widgetWidth, int widgetHeight );

int GetIconSize();

signals:
void appClicked(AppRes* app);

protected slots:
void onIcon();

};

QWidget* ScrollHome::newAppIcon(AppRes& appRes)
{
QWidget *app = new QWidget(this);

app->setFixedSize(itemSize);

QPushButton *btn = newAppButton(app,appRes);
btn->move(iconSpacing/2,iconSpacing/2);

QLabel *label = new QLabel(appRes.appName,app);
label->setFont(font);
label->setAlignment(Qt::AlignTop | Qt::AlignHCenter);
label->setGeometry(0,iconSize + btn->y()+4,itemSize.width(),itemSize.height()-iconSize - btn->y());
label->setPalette(palette);

return app;
}

void ScrollHome::InitHome(int iconColumn, int iconSpacing, int widgetWidth, int widgetHeight)
{
this->iconColumn = iconColumn;
this->iconSpacing = iconSpacing;
this->setFixedSize(widgetWidth, widgetHeight);
this->viewport()->setFixedWidth(widgetWidth);


iconSize = (widgetWidth - iconSpacing * iconColumn)/iconColumn;
font.setPixelSize(iconSize/5.2);
itemSize = QSize(iconSize + iconSpacing,iconSize+iconSpacing + font.pixelSize() +10);

this->setColumnCount(iconColumn);
for(int i = 0; i < iconColumn; ++i)
{
this->setColumnWidth(i,itemSize.width());
}

this->clearContents();
int rowCount = g_appResSize/iconColumn +(g_appResSize%iconColumn==0 ? 0 : 1);
this->setRowCount(rowCount);

for(int i = 0; i < rowCount; ++i) {
for(int j = 0; j < iconColumn; ++j) {

int crtIndex = i * iconColumn + j;

if(crtIndex >= g_appResSize)
break;

g_appRes[crtIndex].resIndex = crtIndex;

this->setCellWidget(i, j, newAppIcon(g_appRes[crtIndex]));

this->setRowHeight(i,itemSize.height());
}
}
}