Creating diagonal table headers

Hi--

I'm trying to create diagonal table headers. So far, it's kind of working, but I'm running into what might be deep problems. My goal is to create a table that looks like this:

Attachment 9541

So far, I have subclassed the header and added a custom delegate, getting me here:

Attachment 9540

The diagonal and text elements are in the right spot, but they're being drawn on top of by other paint commands or are being stopped by the widgets boundaries.

Questions:
1) How can I expand the header boundaries so that my diagonal lines don't get truncated?
2) How can I draw the diagonal lines on top of the table, instead of having them be draw on top of?


diagonal_table.cpp

Code:

---

#include "diagonal_table.h"
#include <qnamespace.h>
 
 #include <Qt>
 
DiagonalTable::DiagonalTable(QWidget *parent) : QTableView(parent)
{
    DiagonalHeaderView *horizontalDiagonalHeader = new DiagonalHeaderView(Qt::Horizontal, this);
    DiagonalHeaderView *verticalDiagonalHeader = new DiagonalHeaderView(Qt::Vertical, this);
    setHorizontalHeader(horizontalDiagonalHeader);
    setVerticalHeader(verticalDiagonalHeader);
 
    setItemDelegate(new MyDelegate(this));
    setShowGrid(false);
 
}
 
DiagonalHeaderView::DiagonalHeaderView(Qt::Orientation orientation, QWidget *parent) : QHeaderView(orientation, parent)
{
 
}
 
void DiagonalHeaderView::paintSection(QPainter *painter, const QRect &rect, int logicalIndex) const
{
    if (!rect.isValid())
        return;
 
    QStyleOptionHeader opt;
    initStyleOption(&opt);
 
    opt.text = model()->headerData(logicalIndex, orientation(), Qt::DisplayRole).toString();
 
 
    // the section position
    int visual = visualIndex(logicalIndex);
    Q_ASSERT(visual != -1);
    if (count() == 1)
        opt.position = QStyleOptionHeader::OnlyOneSection;
    else if (visual == 0)
        opt.position = QStyleOptionHeader::Beginning;
    else if (visual == count() - 1)
        opt.position = QStyleOptionHeader::End;
    else
        opt.position = QStyleOptionHeader::Middle;
    opt.orientation = orientation();
 
    // Get rotation, and wrap to (-180, 180]
    double rotation = model()->headerData(logicalIndex, orientation(), DiagonalTable::RotationRole).toFloat();
    while (rotation > 180)
        rotation -=360;
    while (rotation <= -180)
        rotation +=360;
 
    int separatorLength;
    int sumLinePositionX;
    int sumLinePositionY;
    int textOffsetX;
    int textOffsetY;
    int textWidth = opt.fontMetrics.width(opt.text);
    int textHeight = opt.fontMetrics.height();
 
    switch (orientation()) {
    case Qt::Horizontal:
    {
        // Cast parent so that we can use its methods
        DiagonalTable * diagonalTable = dynamic_cast<DiagonalTable *>(this->parent());
        if (diagonalTable == NULL)
            Q_ASSERT(0);
 
        // Calculate the rectangle for the box in which we will draw
        int firstRow = model()->headerData(logicalIndex, orientation(),DiagonalTable::RowRole).toInt();
 
        sumLinePositionX  = rect.bottomLeft().x();
        sumLinePositionY = rect.bottomLeft().y();
 
        for (int i=0; i<firstRow; i++) {
            int rowHeight = diagonalTable->rowHeight(i+1);
            sumLinePositionY += rowHeight;
        }
 
        textOffsetX = rect.width()/2 + textHeight/2;
        textOffsetY = 0;
 
    }
        break;
    case Qt::Vertical:
    {
        if (rotation == 0) {
            style()->drawControl(QStyle::CE_Header, &opt, painter, this);
        } else {
            // Cast parent so that we can use its methods
            DiagonalTable * diagonalTable = dynamic_cast<DiagonalTable *>(this->parent());
            if (diagonalTable == NULL)
                Q_ASSERT(0);
 
            // Calculate the rectangle for the box in which we will draw
            int firstColumn = model()->headerData(logicalIndex, orientation(), DiagonalTable::ColumnRole).toInt();
 
            sumLinePositionX  = rect.bottomRight().x();
            sumLinePositionY = rect.bottomRight().y();
 
            for (int i=0; i<firstColumn; i++) {
                int columnWidth = diagonalTable->columnWidth(i+1);
                sumLinePositionX += columnWidth;
            }
 
            textOffsetX = 0;
            textOffsetY = -rect.height()/2 + textHeight/2;
        }
    }
        break;
    }
 
    // Paint the diagonal line
    // Adjust for rotation
    if (rotation > -90 && rotation < 90)
        separatorLength = 30;
    else
        separatorLength = 90;
    painter->setRenderHint(QPainter::Antialiasing);
    painter->translate(sumLinePositionX, sumLinePositionY);
    painter->rotate(rotation);
    painter->drawLine(0, 0, separatorLength, 0);
 
    // Paint text
    painter->resetTransform();
    // Adjust for rotation
    if (rotation > -90 && rotation < 90) {
        painter->translate(sumLinePositionX + textOffsetX, sumLinePositionY + textOffsetY);
        painter->rotate(rotation);
        painter->translate(2, 0); // Shift text up (along new axis)
    } else {
        painter->translate(sumLinePositionX + textOffsetX, sumLinePositionY + textOffsetY);
        painter->rotate(rotation + 180); // Always draw text from left to right
        painter->translate(-textWidth - 2, 0); // Back text up (along new axis)
    }
    painter->setFont(font()); // This font should be system dependent. Not sure how to get this.
    painter->drawText(0, 0, opt.text);
 
}
 
 
void MyDelegate::paint( QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index ) const
{
    int row = index.row();
    int col = index.column();
 
    int firstRow = index.model()->headerData(col, Qt::Horizontal,DiagonalTable::RowRole).toInt();
    if (row < firstRow) {
    } else {
        QPen pen;
        int shift = 18; // This makes no sense yet, but for whatever reason the colors are shifted when drawn in the table
        pen.setColor(QColor(143+shift, 142+shift, 147+shift));
        pen.setWidth(1);
        painter->setPen( pen );
 
        painter->drawRect( option.rect.x()-1,  option.rect.y()-1,  option.rect.width(), option.rect.height() );
        QItemDelegate::paint( painter, option, index );
    }
 
}

---

diagonal_table.h

Code:

---

#ifndef DIAGONALTABLE_H
#define DIAGONALTABLE_H
#include <QWidget>
#include <QHeaderView>
#include <QItemDelegate>
#include <QPainter>
#include <QTableView>
 
class DiagonalTable : public QTableView
{
    Q_OBJECT
 
public:
    enum {RotationRole = Qt::UserRole + 0,
         RowRole = Qt::UserRole + 1,
         ColumnRole = Qt::UserRole + 2};
 
public:
    explicit DiagonalTable(QWidget *parent = 0);
    ~DiagonalTable();
 
};
 
 
class MyDelegate : public QItemDelegate {
  public:
    MyDelegate( QObject *parent ) : QItemDelegate( parent ) { }
    void paint( QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index ) const;
};
 
class DiagonalHeaderView : public QHeaderView
{
    Q_OBJECT
 
public:
    DiagonalHeaderView(Qt::Orientation orientation, QWidget *parent = 0);
     ~DiagonalHeaderView();
    void paintSection(QPainter *painter, const QRect &rect, int logicalIndex) const;
 
};
 
#endif // DIAGONALTABLE_H

---

mainwindow.cpp

Code:

---

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "diagonal_table.h"
#include <QStandardItemModel>
 
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
 
 
    QStandardItemModel *sim = new QStandardItemModel(0,0,ui->tableView);
    ui->tableView->setModel(sim);
 
    QStringList horizontalHeaderLabels;
    horizontalHeaderLabels << "Output channel" << "Channel type" << "Live view" << "Curve 1"  << "Curve 2" << "Roll" << "Pitch" << "Yaw";
    sim->setHorizontalHeaderLabels(horizontalHeaderLabels);
 
    // Set horizontal header rotation
    sim->setHeaderData(0, Qt::Horizontal, -150, DiagonalTable::RotationRole);
    sim->setHeaderData(1, Qt::Horizontal, -150, DiagonalTable::RotationRole);
    sim->setHeaderData(2, Qt::Horizontal, -150, DiagonalTable::RotationRole);
    sim->setHeaderData(3, Qt::Horizontal, -45, DiagonalTable::RotationRole);
    sim->setHeaderData(4, Qt::Horizontal, -45, DiagonalTable::RotationRole);
    sim->setHeaderData(5, Qt::Horizontal, -45, DiagonalTable::RotationRole);
    sim->setHeaderData(6, Qt::Horizontal, -45, DiagonalTable::RotationRole);
    sim->setHeaderData(7, Qt::Horizontal, -45, DiagonalTable::RotationRole);
 
    // Set row for horizontal header. All cella above this point will be empty
    sim->setHeaderData(0, Qt::Horizontal, 1, DiagonalTable::RowRole);
    sim->setHeaderData(1, Qt::Horizontal, 1, DiagonalTable::RowRole);
    sim->setHeaderData(2, Qt::Horizontal, 1, DiagonalTable::RowRole);
 
    QStringList verticalHeaderLabels;
    verticalHeaderLabels << "Live view" << "Channel 1" << "Channel 2" << "Channel 3"
                             << "Channel 4" << "Channel 5" << "Channel 6";
    sim->setVerticalHeaderLabels(verticalHeaderLabels);
 
    // Set vertical header rotation
    sim->setHeaderData(0, Qt::Vertical, -150, DiagonalTable::RotationRole);
 
    // Set column for vertical header. All cells to the left of this point will be empty
    sim->setHeaderData(0, Qt::Vertical, 3, DiagonalTable::ColumnRole);
 
    for (int j=0; j < sim->rowCount(); j++) {
        for (int i=0; i < sim->columnCount(); i++) {
            int firstRow = sim->headerData(i, Qt::Horizontal,DiagonalTable::RowRole).toInt();
            if (j < firstRow)
                continue;
 
            sim->setItem(j,i,new QStandardItem("-1.00"));
        }
    }
 
    ui->tableView->resizeColumnsToContents();
}
 
MainWindow::~MainWindow()
{
    delete ui;
}

---

See the below link which creates hierarchical headers, might be helpful to you.

http://qt-apps.org/content/show.php/...content=103154