Accessing generated pixmaps in html / Custom tooltips

**Pieter from Belgium** · 31st July 2009, 10:31

Hi,

In a tooltip, I would like to include an image that is to be generated at runtime. I would do this by using html for the tooltip text.

However, how can I refer to this generated pixmap in this html?
I don't like writing this image to disk.

Can I register an in memory image as a resource?

Is there a way to have custom widgets as tooltips? Of course I could try to simulate the tooltip behavior, but it would be nice to have all look and feel aspects of tooltips, yet to make full customization of its contents possible.

Thanks,
Pieter

**yogeshgokul** · 31st July 2009, 10:37

You can use

Qt Code:

Switch view

QToolTip::setPalette

QToolTip::setPalette

To copy to clipboard, switch view to plain text mode

**nish** · 31st July 2009, 10:40

take a look at the tooltip of libqxt ..www.libqxt.org/
doc.libqxt.org/0.5.0/classQxtToolTip.html

**yogeshgokul** · 31st July 2009, 10:46

Originally Posted by Pieter from Belgium

In a tooltip, I would like to include an image that is to be generated at runtime. I would do this by using html for the tooltip text.

Go ahead and give it a try.

However, how can I refer to this generated pixmap in this html?
I don't like writing this image to disk.

I dont think so, that you can use an "image in memory" in html tags. You have to write it on disk, or use "setPalette".

Can I register an in memory image as a resource?

Try this EXMAPLE

**nish** · 31st July 2009, 10:47

abe quote to theek se kar liya kar..

**yogeshgokul** · 31st July 2009, 10:49

Originally Posted by MrDeath

abe quote to theek se kar liya kar..

bhawnao ko samjho,

**aamer4yu** · 31st July 2009, 11:22

Is there a way to have custom widgets as tooltips? Of course I could try to simulate the tooltip behavior, but it would be nice to have all look and feel aspects of tooltips, yet to make full customization of its contents possible.

Yes, there is a way.

Override the tooltip event(QEvent::ToolTip) on your main window or application.. and show your custom widget as tooltip.
You can also use a filter to catch the toopltip event . In such case you wont need to change existing code

**wagmare** · 31st July 2009, 11:56

or u can show ur tool tip at particular instance as

Qt Code:

Switch view

QPoint value (x , y );
QString test = "String";
QToolTip::setPalette(color);
QToolTip::setFont(serifFont);
QToolTip::showText(value2, test);

QPoint value (x , y );
QString test = "String";
QToolTip::setPalette(color);
QToolTip::setFont(serifFont);
QToolTip::showText(value2, test);

To copy to clipboard, switch view to plain text mode

and can hide it using
QToolTip::hideText();

**nish** · 31st July 2009, 13:05

Originally Posted by wagmare

or u can show ur tool tip at particular instance as

Qt Code:

Switch view

QPoint value (x , y );
QString test = "String";
QToolTip::setPalette(color);
QToolTip::setFont(serifFont);
QToolTip::showText(value2, test);

QPoint value (x , y );
QString test = "String";
QToolTip::setPalette(color);
QToolTip::setFont(serifFont);
QToolTip::showText(value2, test);

To copy to clipboard, switch view to plain text mode

and can hide it using
QToolTip::hideText();

he do not want this. thats simple tooltip..

**numbat** · 1st August 2009, 15:24

You can do this by subclassing QAbstractFileEngine. A bare-bones implementation (though probably enough) follows:

Header:

Qt Code:

Switch view

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QtGui/QMainWindow>
#include <QAbstractFileEngineHandler>
#include <QAbstractFileEngine>
#include <QDateTime>
#include <QByteArray>
#include <QtAlgorithms>
 
class MainWindow : public QMainWindow
{
    Q_OBJECT
 
public:
    MainWindow(QWidget *parent = 0);
    ~MainWindow();
};
 
class NumbatEngineHandler : public QAbstractFileEngineHandler
{
public:
    QAbstractFileEngine *create(const QString &fileName) const;
};
 
class NumbatEngine : public QAbstractFileEngine
{
public:
    NumbatEngine(const QString& fileName);
    bool caseSensitive () const { return false; }
    bool close ()  { return true; }
    QStringList entryList ( QDir::Filters filters, const QStringList & filterNames ) const { return QStringList(); }
    FileFlags fileFlags ( FileFlags type = FileInfoAll ) const
    { return QAbstractFileEngine::ReadOtherPerm | QAbstractFileEngine::ExeOtherPerm | QAbstractFileEngine::FileType | QAbstractFileEngine::WriteOtherPerm; }
    QString fileName ( FileName file = DefaultName ) const { return m_fileName; }
    QDateTime fileTime ( FileTime time ) const { return QDateTime(); }
    bool mkdir ( const QString & dirName, bool createParentDirectories ) const { return false; }
    QString owner ( FileOwner owner ) const { return QString(); }
    uint ownerId ( FileOwner owner ) const {  return -2; }
    bool remove () { return false; }
    bool rename ( const QString & newName ) { return false; }
    bool rmdir ( const QString & dirName, bool recurseParentDirectories ) const { return false; }
    void setFileName ( const QString & file ) { m_fileName = file; }
    bool setPermissions ( uint perms ) { return false; }
    bool setSize ( qint64 size ) { m_bytes->resize(size); return true; }
    qint64 size () const { return m_bytes->size(); }
    bool seek ( qint64 offset ) { m_filePos = offset; return true; }
    bool open ( QIODevice::OpenMode mode ) { return true; }
    bool isRelativePath () const { return false; }
    qint64 write ( const char * data, qint64 len );
    qint64 read ( char * data, qint64 maxlen );
 
private:
    QByteArray* m_bytes;
    QString m_fileName;
    qint64 m_filePos;
};
 
 
#endif // MAINWINDOW_H

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QtGui/QMainWindow>
#include <QAbstractFileEngineHandler>
#include <QAbstractFileEngine>
#include <QDateTime>
#include <QByteArray>
#include <QtAlgorithms>

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = 0);
    ~MainWindow();
};

class NumbatEngineHandler : public QAbstractFileEngineHandler
{
public:
    QAbstractFileEngine *create(const QString &fileName) const;
};

class NumbatEngine : public QAbstractFileEngine
{
public:
    NumbatEngine(const QString& fileName);
    bool caseSensitive () const { return false; }
    bool close ()  { return true; }
    QStringList entryList ( QDir::Filters filters, const QStringList & filterNames ) const { return QStringList(); }
    FileFlags fileFlags ( FileFlags type = FileInfoAll ) const
    { return QAbstractFileEngine::ReadOtherPerm | QAbstractFileEngine::ExeOtherPerm | QAbstractFileEngine::FileType | QAbstractFileEngine::WriteOtherPerm; }
    QString fileName ( FileName file = DefaultName ) const { return m_fileName; }
    QDateTime fileTime ( FileTime time ) const { return QDateTime(); }
    bool mkdir ( const QString & dirName, bool createParentDirectories ) const { return false; }
    QString owner ( FileOwner owner ) const { return QString(); }
    uint ownerId ( FileOwner owner ) const {  return -2; }
    bool remove () { return false; }
    bool rename ( const QString & newName ) { return false; }
    bool rmdir ( const QString & dirName, bool recurseParentDirectories ) const { return false; }
    void setFileName ( const QString & file ) { m_fileName = file; }
    bool setPermissions ( uint perms ) { return false; }
    bool setSize ( qint64 size ) { m_bytes->resize(size); return true; }
    qint64 size () const { return m_bytes->size(); }
    bool seek ( qint64 offset ) { m_filePos = offset; return true; }
    bool open ( QIODevice::OpenMode mode ) { return true; }
    bool isRelativePath () const { return false; }
    qint64 write ( const char * data, qint64 len );
    qint64 read ( char * data, qint64 maxlen );

private:
    QByteArray* m_bytes;
    QString m_fileName;
    qint64 m_filePos;
};


#endif // MAINWINDOW_H

To copy to clipboard, switch view to plain text mode

CPP File:

Qt Code:

Switch view

#include "mainwindow.h"
#include <QMap>
#include <QPixmap>
#include <QLabel>
#include <QApplication>
 
QAbstractFileEngine * NumbatEngineHandler::create(const QString &fileName) const
{
    // We handle all files which start with ???
    if (fileName.toLower().startsWith("???"))
           return new NumbatEngine(fileName);
    else
        return 0;
}
 
 
NumbatEngine::NumbatEngine(const QString& fileName)
            : QAbstractFileEngine(), m_fileName(fileName), m_filePos(0)
 
{
    static QMap<QString, QByteArray*> map;
 
    if (map.contains(m_fileName))
    {
        m_bytes = map.value(m_fileName);
    }
    else
    {
        m_bytes = new QByteArray;
        map[m_fileName] = m_bytes;
    }
}
 
qint64 NumbatEngine::write ( const char * data, qint64 len )
{
    if (m_filePos + len > m_bytes->size()) m_bytes->resize(m_filePos + len);
 
    qCopy(data, data + len, m_bytes->data() + m_filePos);
 
    m_filePos += len;
 
    return len;
}
 
qint64 NumbatEngine::read ( char * data, qint64 maxlen )
{
    qint64 readBytes;
 
    if (m_filePos + maxlen > m_bytes->size())
        readBytes = m_bytes->size() - m_filePos;
    else
        readBytes = maxlen;
 
    qCopy(m_bytes->constData() + m_filePos,
          m_bytes->constData() + m_filePos + readBytes, data);
 
    m_filePos += readBytes;
 
    return readBytes;
}
 
 
 
/* Demonstration. */
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    QPixmap pix("img.png");
    pix.save("???Hello.png");
 
 
    QLabel * lbl = new QLabel;
    lbl->setText("<b> this is a test</b><img src=\"???Hello.png\" />");
 
    setCentralWidget(lbl);
}
 
 
MainWindow::~MainWindow()
{
}
 
 int main(int argc, char **argv)
 {
     QApplication app(argc, argv);
 
     NumbatEngineHandler engine;
 
     MainWindow window;
     window.show();
 
     return app.exec();
 }

#include "mainwindow.h"
#include <QMap>
#include <QPixmap>
#include <QLabel>
#include <QApplication>

QAbstractFileEngine * NumbatEngineHandler::create(const QString &fileName) const
{
    // We handle all files which start with ???
    if (fileName.toLower().startsWith("???"))
           return new NumbatEngine(fileName);
    else
        return 0;
}


NumbatEngine::NumbatEngine(const QString& fileName)
            : QAbstractFileEngine(), m_fileName(fileName), m_filePos(0)

{
    static QMap<QString, QByteArray*> map;

    if (map.contains(m_fileName))
    {
        m_bytes = map.value(m_fileName);
    }
    else
    {
        m_bytes = new QByteArray;
        map[m_fileName] = m_bytes;
    }
}

qint64 NumbatEngine::write ( const char * data, qint64 len )
{
    if (m_filePos + len > m_bytes->size()) m_bytes->resize(m_filePos + len);

    qCopy(data, data + len, m_bytes->data() + m_filePos);

    m_filePos += len;

    return len;
}

qint64 NumbatEngine::read ( char * data, qint64 maxlen )
{
    qint64 readBytes;

    if (m_filePos + maxlen > m_bytes->size())
        readBytes = m_bytes->size() - m_filePos;
    else
        readBytes = maxlen;

    qCopy(m_bytes->constData() + m_filePos,
          m_bytes->constData() + m_filePos + readBytes, data);

    m_filePos += readBytes;

    return readBytes;
}



/* Demonstration. */
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    QPixmap pix("img.png");
    pix.save("???Hello.png");


    QLabel * lbl = new QLabel;
    lbl->setText("<b> this is a test</b><img src=\"???Hello.png\" />");

    setCentralWidget(lbl);
}


MainWindow::~MainWindow()
{
}

 int main(int argc, char **argv)
 {
     QApplication app(argc, argv);

     NumbatEngineHandler engine;

     MainWindow window;
     window.show();

     return app.exec();
 }

To copy to clipboard, switch view to plain text mode