qgridlayout.cpp

奇趣公司比较新的qt/emd版本

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#include "qgridlayout.h"
#include "qapplication.h"
#include "qwidget.h"
#include "qlist.h"
#include "qsizepolicy.h"
#include "qvector.h"
#include "qvarlengtharray.h"
#include "qlayoutengine_p.h"
#include "qlayout_p.h"

struct QGridLayoutSizeTriple
{
    QSize minS;
    QSize hint;
    QSize maxS;
};

/*
  Three internal classes related to QGridLayout: (1) QGridBox is a
  QLayoutItem with (row, column) information and (torow, tocolumn) information; (3) QGridLayoutData is
  the internal representation of a QGridLayout.
*/

class QGridBox
{
public:
    QGridBox(QLayoutItem *lit) { item_ = lit; }

    QGridBox(QWidget *wid) { item_ = new QWidgetItem(wid); }
    ~QGridBox() { delete item_; }

    QSize sizeHint() const { return item_->sizeHint(); }
    QSize minimumSize() const { return item_->minimumSize(); }
    QSize maximumSize() const { return item_->maximumSize(); }
    Qt::Orientations expandingDirections() const { return item_->expandingDirections(); }
    bool isEmpty() const { return item_->isEmpty(); }

    bool hasHeightForWidth() const { return item_->hasHeightForWidth(); }
    int heightForWidth(int w) const { return item_->heightForWidth(w); }

    void setAlignment(Qt::Alignment a) { item_->setAlignment(a); }
    void setGeometry(const QRect &r) { item_->setGeometry(r); }
    Qt::Alignment alignment() const { return item_->alignment(); }
    QLayoutItem *item() { return item_; }
    QLayoutItem *takeItem() { QLayoutItem *i = item_; item_ = 0; return i; }

    int hStretch() { return item_->widget() ?
                         item_->widget()->sizePolicy().horizontalStretch() : 0; }
    int vStretch() { return item_->widget() ?
                         item_->widget()->sizePolicy().verticalStretch() : 0; }

private:
    friend class QGridLayoutPrivate;

    inline int toRow(int rr) const { return torow >= 0 ? torow : rr - 1; }
    inline int toCol(int cc) const { return tocol >= 0 ? tocol : cc - 1; }

    QLayoutItem *item_;
    int row, col;
    int torow, tocol;
};

class QGridLayoutPrivate : public QLayoutPrivate
{
    Q_DECLARE_PUBLIC(QGridLayout)
public:
    QGridLayoutPrivate();

    void add(QGridBox*, int row, int col);
    void add(QGridBox*, int row1, int row2, int col1, int col2);
    QSize sizeHint(int hSpacing, int vSpacing) const;
    QSize minimumSize(int hSpacing, int vSpacing) const;
    QSize maximumSize(int hSpacing, int vSpacing) const;

    Qt::Orientations expandingDirections(int hSpacing, int vSpacing) const;

    void distribute(QRect rect, int hSpacing, int vSpacing);
    inline int numRows() const { return rr; }
    inline int numCols() const { return cc; }
    inline void expand(int rows, int cols)
        { setSize(qMax(rows, rr), qMax(cols, cc)); }
    inline void setRowStretch(int r, int s)
        { expand(r + 1, 0); rStretch[r] = s; setDirty(); }
    inline void setColStretch(int c, int s)
        { expand(0, c + 1); cStretch[c] = s; setDirty(); }
    inline int rowStretch(int r) const { return rStretch.at(r); }
    inline int colStretch(int c) const { return cStretch.at(c); }
    inline void setRowMinimumHeight(int r, int s)
        { expand(r + 1, 0); rMinHeights[r] = s; setDirty(); }
    inline void setColumnMinimumWidth(int c, int s)
        { expand(0, c + 1); cMinWidths[c] = s; setDirty(); }
    inline int rowSpacing(int r) const { return rMinHeights.at(r); }
    inline int colSpacing(int c) const { return cMinWidths.at(c); }

    inline void setReversed(bool r, bool c) { hReversed = c; vReversed = r; }
    inline bool horReversed() const { return hReversed; }
    inline bool verReversed() const { return vReversed; }
    inline void setDirty() { needRecalc = true; hfw_width = -1; }
    inline bool isDirty() const { return needRecalc; }
    bool hasHeightForWidth(int hSpacing, int vSpacing);
    int heightForWidth(int width, int hSpacing, int vSpacing);
    int minimumHeightForWidth(int width, int hSpacing, int vSpacing);

    inline void getNextPos(int &row, int &col) { row = nextR; col = nextC; }
    inline int count() const { return things.count(); }
    QRect cellRect(int row, int col) const;

    inline QLayoutItem *itemAt(int index) const {
        if (index < things.count())
            return things.at(index)->item();
        else
            return 0;
    }
    inline QLayoutItem *takeAt(int index) {
        QLayoutItem *item = 0;
        if (index < things.count()) {
            QGridBox *b = things.takeAt(index);
            if (b) {
                item = b->takeItem();
                delete b;
            }
        }
        return item;
    }

    void getItemPosition(int index, int *row, int *column, int *rowSpan, int *columnSpan) {
        if (index < things.count()) {
            QGridBox *b =  things.at(index);
            int toRow = b->toRow(rr);
            int toCol = b->toCol(cc);
            *row = b->row;
            *column = b->col;
            *rowSpan = toRow - *row + 1;
            *columnSpan = toCol - *column +1;
        }
    }
    void deleteAll();

private:
    void setNextPosAfter(int r, int c);
    void recalcHFW(int w);
    void addHfwData(QGridBox *box, int width);
    void init();
    QSize findSize(int QLayoutStruct::*, int hSpacing, int vSpacing) const;
    void addData(QGridBox *b, const QGridLayoutSizeTriple &sizes, bool r, bool c);
    void setSize(int rows, int cols);
    void setupSpacings(QVector<QLayoutStruct> &chain, QGridBox *grid[], int fixedSpacing,
                       Qt::Orientation orientation);
    void setupLayoutData(int hSpacing, int vSpacing);
    void setupHfwLayoutData();
    void effectiveMargins(int *left, int *top, int *right, int *bottom) const;

    int rr;
    int cc;
    QVector<QLayoutStruct> rowData;
    QVector<QLayoutStruct> colData;
    QVector<QLayoutStruct> *hfwData;
    QVector<int> rStretch;
    QVector<int> cStretch;
    QVector<int> rMinHeights;
    QVector<int> cMinWidths;
    QList<QGridBox *> things;

    int hfw_width;
    int hfw_height;
    int hfw_minheight;
    int nextR;
    int nextC;

    int horizontalSpacing;
    int verticalSpacing;
    int leftMargin;
    int topMargin;
    int rightMargin;
    int bottomMargin;

    uint hReversed : 1;
    uint vReversed : 1;
    uint needRecalc : 1;
    uint has_hfw : 1;
    uint addVertical : 1;
};

void QGridLayoutPrivate::effectiveMargins(int *left, int *top, int *right, int *bottom) const
{
    int l = leftMargin;
    int t = topMargin;
    int r = rightMargin;
    int b = bottomMargin;
#ifdef Q_WS_MAC
    int leftMost = INT_MAX;
    int topMost = INT_MAX;
    int rightMost = 0;
    int bottomMost = 0;

    QWidget *w = 0;
    const int n = things.count();
    for (int i = 0; i < n; ++i) {
        QGridBox *box = things.at(i);
        QLayoutItem *itm = box->item();
        w = itm->widget();
        if (w) {
            bool visualHReversed = hReversed != (w->layoutDirection() == Qt::RightToLeft);
            QRect lir = itm->geometry();
            QRect wr = w->geometry();
            if (box->col <= leftMost) {
                if (box->col < leftMost) {
                    // we found an item even closer to the margin, discard.
                    leftMost = box->col;
                    if (visualHReversed)
                        r = rightMargin;
                    else
                        l = leftMargin;
                }
                if (visualHReversed) {
                    r = qMax(r, wr.right() - lir.right());
                } else {
                    l = qMax(l, lir.left() - wr.left());
                }
            }
            if (box->row <= topMost) {
                if (box->row < topMost) {
                    // we found an item even closer to the margin, discard.
                    topMost = box->row;
                    if (vReversed)
                        b = bottomMargin;
                    else
                        t = topMargin;
                }
                if (vReversed)
                    b = qMax(b, wr.bottom() - lir.bottom());
                else
                    t = qMax(t, lir.top() - wr.top());
            }
            if (box->toCol(cc) >= rightMost) {
                if (box->toCol(cc) > rightMost) {
                    // we found an item even closer to the margin, discard.
                    rightMost = box->toCol(cc);
                    if (visualHReversed)
                        l = leftMargin;
                    else
                        r = rightMargin;
                }
                if (visualHReversed) {
                    l = qMax(l, lir.left() - wr.left());
                } else {
                    r = qMax(r, wr.right() - lir.right());
                }

            }
            if (box->toRow(rr) >= bottomMost) {
                if (box->toRow(rr) > bottomMost) {
                    // we found an item even closer to the margin, discard.
                    bottomMost = box->toRow(rr);
                    if (vReversed)
                        t = topMargin;
                    else
                        b = bottomMargin;
                }
                if (vReversed)
                    t = qMax(t, lir.top() - wr.top());
                else
                    b = qMax(b, wr.bottom() - lir.bottom());
            }
        }
    }

#endif
    if (left)
        *left = l;
    if (top)
        *top = t;
    if (right)
        *right = r;
    if (bottom)
        *bottom = b;
}

QGridLayoutPrivate::QGridLayoutPrivate()
{
    addVertical = false;
    setDirty();
    rr = cc = 0;
    nextR = nextC = 0;
    hfwData = 0;
    hReversed = false;
    vReversed = false;
    horizontalSpacing = -1;
    verticalSpacing = -1;
}

#if 0
QGridLayoutPrivate::QGridLayoutPrivate(int nRows, int nCols)
    : rowData(0), colData(0)
{
    init();
    if (nRows  < 0) {
        nRows = 1;
        addVertical = false;
    }
    if (nCols  < 0) {
        nCols = 1;
        addVertical = true;
    }
    setSize(nRows, nCols);
}
#endif

void QGridLayoutPrivate::deleteAll()
{
    while (!things.isEmpty())
        delete things.takeFirst();
    delete hfwData;
}

bool QGridLayoutPrivate::hasHeightForWidth(int hSpacing, int vSpacing)
{
    setupLayoutData(hSpacing, vSpacing);
    return has_hfw;
}

/*
  Assumes that setupLayoutData() has been called, and that
  qGeomCalc() has filled in colData with appropriate values.
*/
void QGridLayoutPrivate::recalcHFW(int w)
{
    /*
      Go through all children, using colData and heightForWidth()
      and put the results in hfwData.
    */
    if (!hfwData)
        hfwData = new QVector<QLayoutStruct>(rr);
    setupHfwLayoutData();
    QVector<QLayoutStruct> &rData = *hfwData;

    int h = 0;
    int mh = 0;
    for (int r = 0; r < rr; r++) {
        int spacing = rData.at(r).spacing;
        h += rData.at(r).sizeHint + spacing;
        mh += rData.at(r).minimumSize + spacing;
    }

    hfw_width = w;
    hfw_height = qMin(QLAYOUTSIZE_MAX, h);
    hfw_minheight = qMin(QLAYOUTSIZE_MAX, mh);
}

int QGridLayoutPrivate::heightForWidth(int w, int hSpacing, int vSpacing)
{
    setupLayoutData(hSpacing, vSpacing);
    if (!has_hfw)
        return -1;
    int left, top, right, bottom;
    effectiveMargins(&left, &top, &right, &bottom);

    int hMargins = left + right;
    if (w - hMargins != hfw_width) {
        qGeomCalc(colData, 0, cc, 0, w - hMargins);
        recalcHFW(w - hMargins);
    }
    return hfw_height + top + bottom;
}

int QGridLayoutPrivate::minimumHeightForWidth(int w, int hSpacing, int vSpacing)
{
    (void)heightForWidth(w, hSpacing, vSpacing);
    if (!has_hfw)
        return -1;
    int top, bottom;
    effectiveMargins(0, &top, 0, &bottom);
    return hfw_minheight + top + bottom;
}

QSize QGridLayoutPrivate::findSize(int QLayoutStruct::*size, int hSpacing, int vSpacing) const
{
    QGridLayoutPrivate *that = const_cast<QGridLayoutPrivate*>(this);
    that->setupLayoutData(hSpacing, vSpacing);

    int w = 0;
    int h = 0;

    for (int r = 0; r < rr; r++)
        h += rowData.at(r).*size + rowData.at(r).spacing;
    for (int c = 0; c < cc; c++)
        w += colData.at(c).*size + colData.at(c).spacing;

    w = qMin(QLAYOUTSIZE_MAX, w);
    h = qMin(QLAYOUTSIZE_MAX, h);

    return QSize(w, h);
}

Qt::Orientations QGridLayoutPrivate::expandingDirections(int hSpacing, int vSpacing) const
{
    QGridLayoutPrivate *that = const_cast<QGridLayoutPrivate*>(this);
    that->setupLayoutData(hSpacing, vSpacing);
    Qt::Orientations ret;

    for (int r = 0; r < rr; r++) {
        if (rowData.at(r).expansive) {
            ret |= Qt::Vertical;
            break;
        }
    }
    for (int c = 0; c < cc; c++) {
        if (colData.at(c).expansive) {
            ret |= Qt::Horizontal;
            break;
        }
    }
    return ret;
}

QSize QGridLayoutPrivate::sizeHint(int hSpacing, int vSpacing) const
{
    return findSize(&QLayoutStruct::sizeHint, hSpacing, vSpacing);
}

QSize QGridLayoutPrivate::maximumSize(int hSpacing, int vSpacing) const
{
    return findSize(&QLayoutStruct::maximumSize, hSpacing, vSpacing);
}

QSize QGridLayoutPrivate::minimumSize(int hSpacing, int vSpacing) const
{
    return findSize(&QLayoutStruct::minimumSize, hSpacing, vSpacing);
}