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This example lets the user rotate, shear and scale text and graphics arbitrarily.
Implementation:
/****************************************************************************
** $Id: qt/xform.cpp 3.2.0b2 edited May 13 09:08 $
**
** Copyright (C) 1992-2000 Trolltech AS. All rights reserved.
**
** This file is part of an example program for Qt. This example
** program may be used, distributed and modified without limitation.
**
*****************************************************************************/
#include <qapplication.h>
#include <qdialog.h>
#include <qlabel.h>
#include <qlineedit.h>
#include <qpushbutton.h>
#include <qcheckbox.h>
#include <qradiobutton.h>
#include <qbuttongroup.h>
#include <qlcdnumber.h>
#include <qslider.h>
#include <qmenubar.h>
#include <qfontdialog.h>
#include <qlayout.h>
#include <qvbox.h>
#include <qwidgetstack.h>
#include <qpainter.h>
#include <qpixmap.h>
#include <qpicture.h>
#include <stdlib.h>
class ModeNames {
public:
enum Mode { Text, Image, Picture };
};
class XFormControl : public QVBox, public ModeNames
{
Q_OBJECT
public:
XFormControl( const QFont &initialFont, QWidget *parent=0, const char *name=0 );
~XFormControl() {}
QWMatrix matrix();
signals:
void newMatrix( QWMatrix );
void newText( const QString& );
void newFont( const QFont & );
void newMode( int );
private slots:
void newMtx();
void newTxt(const QString&);
void selectFont();
void fontSelected( const QFont & );
void changeMode(int);
void timerEvent(QTimerEvent*);
private:
Mode mode;
QSlider *rotS; // Rotation angle scroll bar
QSlider *shearS; // Shear value scroll bar
QSlider *magS; // Magnification value scroll bar
QLCDNumber *rotLCD; // Rotation angle LCD display
QLCDNumber *shearLCD; // Shear value LCD display
QLCDNumber *magLCD; // Magnification value LCD display
QCheckBox *mirror; // Checkbox for mirror image on/of
QWidgetStack* optionals;
QLineEdit *textEd; // Inp[ut field for xForm text
QPushButton *fpb; // Select font push button
QRadioButton *rb_txt; // Radio button for text
QRadioButton *rb_img; // Radio button for image
QRadioButton *rb_pic; // Radio button for picture
QFont currentFont;
};
/*
ShowXForm displays a text or a pixmap (QPixmap) using a coordinate
transformation matrix (QWMatrix)
*/
class ShowXForm : public QWidget, public ModeNames
{
Q_OBJECT
public:
ShowXForm( const QFont &f, QWidget *parent=0, const char *name=0 );
~ShowXForm() {}
void showIt(); // (Re)displays text or pixmap
Mode mode() const { return m; }
public slots:
void setText( const QString& );
void setMatrix( QWMatrix );
void setFont( const QFont &f );
void setPixmap( QPixmap );
void setPicture( const QPicture& );
void setMode( int );
private:
QSizePolicy sizePolicy() const;
QSize sizeHint() const;
void paintEvent( QPaintEvent * );
void resizeEvent( QResizeEvent * );
QWMatrix mtx; // coordinate transform matrix
QString text; // text to be displayed
QPixmap pix; // pixmap to be displayed
QPicture picture; // text to be displayed
QRect eraseRect; // covers last displayed text/pixmap
Mode m;
};
XFormControl::XFormControl( const QFont &initialFont,
QWidget *parent, const char *name )
: QVBox( parent, name )
{
setSpacing(6);
setMargin(6);
currentFont = initialFont;
mode = Image;
rotLCD = new QLCDNumber( 4, this, "rotateLCD" );
rotS = new QSlider( QSlider::Horizontal, this,
"rotateSlider" );
shearLCD = new QLCDNumber( 5,this, "shearLCD" );
shearS = new QSlider( QSlider::Horizontal, this,
"shearSlider" );
mirror = new QCheckBox( this, "mirrorCheckBox" );
rb_txt = new QRadioButton( this, "text" );
rb_img = new QRadioButton( this, "image" );
rb_pic = new QRadioButton( this, "picture" );
optionals = new QWidgetStack(this);
QVBox* optionals_text = new QVBox(optionals);
optionals_text->setSpacing(6);
QVBox* optionals_other = new QVBox(optionals);
optionals_other->setSpacing(6);
optionals->addWidget(optionals_text,0);
optionals->addWidget(optionals_other,1);
fpb = new QPushButton( optionals_text, "text" );
textEd = new QLineEdit( optionals_text, "text" );
textEd->setFocus();
rotLCD->display( " 0'" );
rotS->setRange( -180, 180 );
rotS->setValue( 0 );
connect( rotS, SIGNAL(valueChanged(int)), SLOT(newMtx()) );
shearLCD->display( "0.00" );
shearS->setRange( -25, 25 );
shearS->setValue( 0 );
connect( shearS, SIGNAL(valueChanged(int)), SLOT(newMtx()) );
mirror->setText( tr("Mirror") );
connect( mirror, SIGNAL(clicked()), SLOT(newMtx()) );
QButtonGroup *bg = new QButtonGroup(this);
bg->hide();
bg->insert(rb_txt,0);
bg->insert(rb_img,1);
bg->insert(rb_pic,2);
rb_txt->setText( tr("Text") );
rb_img->setText( tr("Image") );
rb_img->setChecked(TRUE);
rb_pic->setText( tr("Picture") );
connect( bg, SIGNAL(clicked(int)), SLOT(changeMode(int)) );
fpb->setText( tr("Select font...") );
connect( fpb, SIGNAL(clicked()), SLOT(selectFont()) );
textEd->setText( "Troll" );
connect( textEd, SIGNAL(textChanged(const QString&)),
SLOT(newTxt(const QString&)) );
magLCD = new QLCDNumber( 4,optionals_other, "magLCD" );
magLCD->display( "100" );
magS = new QSlider( QSlider::Horizontal, optionals_other,
"magnifySlider" );
magS->setRange( 0, 800 );
connect( magS, SIGNAL(valueChanged(int)), SLOT(newMtx()) );
magS->setValue( 0 );
connect( magS, SIGNAL(valueChanged(int)), magLCD, SLOT(display(int)));
optionals_text->adjustSize();
optionals_other->adjustSize();
changeMode(Image);
startTimer(20); // start an initial animation
}
void XFormControl::timerEvent(QTimerEvent*)
{
int v = magS->value();
v = (v+2)+v/10;
if ( v >= 200 ) {
v = 200;
killTimers();
}
magS->setValue(v);
}
/*
Called whenever the user has changed one of the matrix parameters
(i.e. rotate, shear or magnification)
*/
void XFormControl::newMtx()
{
emit newMatrix( matrix() );
}
void XFormControl::newTxt(const QString& s)
{
emit newText(s);
changeMode(Text);
}
/*
Calculates the matrix appropriate for the current controls,
and updates the displays.
*/
QWMatrix XFormControl::matrix()
{
QWMatrix m;
if (mode != Text) {
double magVal = 1.0*magS->value()/100;
m.scale( magVal, magVal );
}
double shearVal = 1.0*shearS->value()/25;
m.shear( shearVal, shearVal );
m.rotate( rotS->value() );
if ( mirror->isChecked() ) {
m.scale( 1, -1 );
m.rotate( 180 );
}
QString tmp;
tmp.sprintf( "%1.2f", shearVal );
if ( shearVal >= 0 )
tmp.insert( 0, " " );
shearLCD->display( tmp );
int rot = rotS->value();
if ( rot < 0 )
rot = rot + 360;
tmp.sprintf( "%3i'", rot );
rotLCD->display( tmp );
return m;
}
void XFormControl::selectFont()
{
bool ok;
QFont f = QFontDialog::getFont( &ok, currentFont );
if ( ok ) {
currentFont = f;
fontSelected( f );
}
}
void XFormControl::fontSelected( const QFont &font )
{
emit newFont( font );
changeMode(Text);
}
/*
Sets the mode - Text, Image, or Picture.
*/
void XFormControl::changeMode(int m)
{
mode = (Mode)m;
emit newMode( m );
newMtx();
if ( mode == Text ) {
optionals->raiseWidget(0);
rb_txt->setChecked(TRUE);
} else {
optionals->raiseWidget(1);
if ( mode == Image )
rb_img->setChecked(TRUE);
else
rb_pic->setChecked(TRUE);
}
qApp->flushX();
}
ShowXForm::ShowXForm( const QFont &initialFont,
QWidget *parent, const char *name )
: QWidget( parent, name, WResizeNoErase )
{
setFont( initialFont );
setBackgroundColor( white );
m = Text;
eraseRect = QRect( 0, 0, 0, 0 );
}
QSizePolicy ShowXForm::sizePolicy() const
{
return QSizePolicy( QSizePolicy::Expanding, QSizePolicy::Expanding );
}
QSize ShowXForm::sizeHint() const
{
return QSize(400,400);
}
void ShowXForm::paintEvent( QPaintEvent * )
{
showIt();
}
void ShowXForm::resizeEvent( QResizeEvent * )
{
eraseRect = QRect( width()/2, height()/2, 0, 0 );
repaint(rect());
}
void ShowXForm::setText( const QString& s )
{
text = s;
showIt();
}
void ShowXForm::setMatrix( QWMatrix w )
{
mtx = w;
showIt();
}
void ShowXForm::setFont( const QFont &f )
{
m = Text;
QWidget::setFont( f );
}
void ShowXForm::setPixmap( QPixmap pm )
{
pix = pm;
m = Image;
showIt();
}
void ShowXForm::setPicture( const QPicture& p )
{
picture = p;
m = Picture;
showIt();
}
void ShowXForm::setMode( int mode )
{
m = (Mode)mode;
}
void ShowXForm::showIt()
{
QPainter p;
QRect r; // rectangle covering new text/pixmap in virtual coordinates
QWMatrix um; // copy user specified transform
int textYPos = 0; // distance from boundingRect y pos to baseline
int textXPos = 0; // distance from boundingRect x pos to text start
QRect br;
QFontMetrics fm( fontMetrics() ); // get widget font metrics
switch ( mode() ) {
case Text:
br = fm.boundingRect( text ); // rectangle covering text
r = br;
textYPos = -r.y();
textXPos = -r.x();
br.moveTopLeft( QPoint( -br.width()/2, -br.height()/2 ) );
break;
case Image:
r = pix.rect();
break;
case Picture:
// ### need QPicture::boundingRect()
r = QRect(0,0,1000,1000);
break;
}
r.moveTopLeft( QPoint(-r.width()/2, -r.height()/2) );
// compute union of new and old rect
// the resulting rectangle will cover what is already displayed
// and have room for the new text/pixmap
eraseRect = eraseRect.unite( mtx.map(r) );
eraseRect.moveBy( -1, -1 ); // add border for matrix round off
eraseRect.setSize( QSize( eraseRect.width() + 2,eraseRect.height() + 2 ) );
int pw = QMIN(eraseRect.width(),width());
int ph = QMIN(eraseRect.height(),height());
QPixmap pm( pw, ph ); // off-screen drawing pixmap
pm.fill( backgroundColor() );
p.begin( &pm );
um.translate( pw/2, ph/2 ); // 0,0 is center
um = mtx * um;
p.setWorldMatrix( um );
switch ( mode() ) {
case Text:
p.setFont( font() ); // use widget font
p.drawText( r.left() + textXPos, r.top() + textYPos, text );
#if 0
p.setPen( red );
p.drawRect( br );
#endif
break;
case Image:
p.drawPixmap( -pix.width()/2, -pix.height()/2, pix );
//QPixmap rotated = pix.xForm(mtx);
//bitBlt( &pm, pm.width()/2 - rotated.width()/2,
//pm.height()/2 - rotated.height()/2, &rotated );
break;
case Picture:
// ### need QPicture::boundingRect()
p.scale(0.25,0.25);
p.translate(-230,-180);
p.drawPicture( picture );
}
p.end();
int xpos = width()/2 - pw/2;
int ypos = height()/2 - ph/2;
bitBlt( this, xpos, ypos, // copy pixmap to widget
&pm, 0, 0, -1, -1 );
eraseRect = mtx.map( r );
}
/*
Grand unifying widget, putting ShowXForm and XFormControl
together.
*/
class XFormCenter : public QHBox, public ModeNames
{
Q_OBJECT
public:
XFormCenter( QWidget *parent=0, const char *name=0 );
public slots:
void setFont( const QFont &f ) { sx->setFont( f ); }
void newMode( int );
private:
ShowXForm *sx;
XFormControl *xc;
};
void XFormCenter::newMode( int m )
{
static bool first_i = TRUE;
static bool first_p = TRUE;
if ( sx->mode() == m )
return;
if ( m == Image && first_i ) {
first_i = FALSE;
QPixmap pm;
if ( pm.load( "image.any" ) )
sx->setPixmap( pm );
return;
}
if ( m == Picture && first_p ) {
first_p = FALSE;
QPicture p;
if (p.load( "picture.any" ))
sx->setPicture( p );
return;
}
sx->setMode(m);
}
XFormCenter::XFormCenter( QWidget *parent, const char *name )
: QHBox( parent, name )
{
QFont f( "Charter", 36, QFont::Bold );
xc = new XFormControl( f, this );
sx = new ShowXForm( f, this );
setStretchFactor(sx,1);
xc->setFrameStyle( QFrame::Panel | QFrame::Raised );
xc->setLineWidth( 2 );
connect( xc, SIGNAL(newText(const QString&)), sx,
SLOT(setText(const QString&)) );
connect( xc, SIGNAL(newMatrix(QWMatrix)),
sx, SLOT(setMatrix(QWMatrix)) );
connect( xc, SIGNAL(newFont(const QFont&)), sx,
SLOT(setFont(const QFont&)) );
connect( xc, SIGNAL(newMode(int)), SLOT(newMode(int)) );
sx->setText( "Troll" );
newMode( Image );
sx->setMatrix(xc->matrix());
}
int main( int argc, char **argv )
{
QApplication a( argc, argv );
XFormCenter *xfc = new XFormCenter;
a.setMainWidget( xfc );
xfc->setCaption("Qt Example - XForm");
xfc->show();
return a.exec();
}
#include "xform.moc" // include metadata generated by the moc
See also Examples.
| Copyright © 2003 Trolltech | Trademarks | Qt version 3.2.0b2
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