SelectionPlacementInterface Class Reference

A selection region placement interface. More...

#include <selectionPlacementInterface.h>

Inheritance diagram for SelectionPlacementInterface:

Collaboration diagram for SelectionPlacementInterface:

Signals
void	placementChanged (QRect)

Public Member Functions
	SelectionPlacementInterface (QString imageFilename, QWidget *parent=0, const char *name=0)
	Creates layout.
	~SelectionPlacementInterface ()
	Deletes objects.
QRect	getSelectedRegion ()
	Returns the selected region in image space.
void	setSelectedRegion (QRect selection)
	Set the select region using image space coordinates.
virtual QSize	sizeHint () const
virtual QSize	minimumSizeHint () const

Protected Member Functions
void	paintEvent (QPaintEvent *e)
void	mousePressEvent (QMouseEvent *e)
void	mouseReleaseEvent (QMouseEvent *)
void	mouseMoveEvent (QMouseEvent *e)

Private Member Functions
QRect	imageToDisplay (QRect r)
	convert rectangle from image coordinates to display coordinates
bool	overRegion (QPoint p)
	util function used to determine if mouse is over selected region
void	recenterSelection (QPoint mousePosition)
	util function used to center selection about mouse location

Private Attributes
QImage	scaledImage
	Scaled image used for display purposes.
QImage	unselectedScaledImage
	Unselected scaled image (desaturated version of scaled image)
QSize	origImageSize
	original image dimensions
QRect	selection
	selection
bool	currentlyDragging
	dragging the mouse only moves the selection if the mouse button is pressed first over the selected region
bool	currentMouseShapeIsDrag
	current mouse shape.

Detailed Description

A selection region placement interface.

Definition at line 29 of file selectionPlacementInterface.h.

Constructor & Destructor Documentation

SelectionPlacementInterface()

SelectionPlacementInterface::SelectionPlacementInterface	(	QString	imageFilename,
		QWidget *	parent = 0,
		const char *	name = 0 )

Creates layout.

Definition at line 29 of file selectionPlacementInterface.cpp.

                                                        : QWidget (parent, name )
{                  
  //store original image dimensions
  getImageSize( imageFilename, origImageSize );
  
  //construct scaled image
  scaleImage( imageFilename, scaledImage, 200, 200 );
  
  //construct an unselected scaled image
  unselectedScaledImage = scaledImage.copy();  
  int x, y;
  QRgb* rgb;
  uchar* scanLine;
  for( y=0; y<unselectedScaledImage.height(); y++)
  {   
    //iterate over each selected pixel in scanline
    scanLine = unselectedScaledImage.scanLine(y);
    for( x=0; x<unselectedScaledImage.width(); x++)
    {
      //compress dynamic range to 25% of original
      rgb = ((QRgb*)scanLine+x);
      
      double r = ((double)qRed(*rgb)   )/255.0;
      double g = ((double)qGreen(*rgb) )/255.0;
      double b = ((double)qBlue(*rgb)  )/255.0;
      
      //convert to hsv
      double h,s,v;
      RGBtoHSV(r,g,b,&h,&s,&v);
      
      //scale and clamp v
      v*=0.25;
      
      //convert adjusted color back to rgb colorspace and clamp
      HSVtoRGB( &r,&g,&b, h,s,v);         
      int rp = (int) MIN( MAX((r*255), 0), 255 );
      int gp = (int) MIN( MAX((g*255), 0), 255 );
      int bp = (int) MIN( MAX((b*255), 0), 255 );
      
      //set adjusted color value
      *rgb = qRgb(rp,gp,bp);          
    }
  }  
  
  //watch mouse movements in order to drag selection
  //watch mouse movements in order to move split point between adjusted and original image
  setMouseTracking(true);
  
  //by default no in dragging mode
  currentlyDragging = false;
  currentMouseShapeIsDrag = false;
  
  //accept focus when clicked on
  setFocusPolicy( Qt::ClickFocus );
 
  //init selection area
  selection.setTopLeft( QPoint( -1, -1 ) );
  selection.setBottomRight( QPoint( -1, -1 ) );
}

References b, currentlyDragging, currentMouseShapeIsDrag, getImageSize(), HSVtoRGB(), MAX, MIN, origImageSize, RGBtoHSV(), scaledImage, scaleImage(), selection, and unselectedScaledImage.

~SelectionPlacementInterface()

SelectionPlacementInterface::~SelectionPlacementInterface

(

)

Deletes objects.

Definition at line 91 of file selectionPlacementInterface.cpp.

{ }

Member Function Documentation

getSelectedRegion()

QRect SelectionPlacementInterface::getSelectedRegion

(

)

Returns the selected region in image space.

Definition at line 288 of file selectionPlacementInterface.cpp.

{
  return selection;
}

References selection.

imageToDisplay()

QRect SelectionPlacementInterface::imageToDisplay ( QRect r )

private

convert rectangle from image coordinates to display coordinates

Definition at line 264 of file selectionPlacementInterface.cpp.

{
  //set top left
  QRect res;
  res.setTopLeft(QPoint( (int) (0.5+ (1.0*scaledImage.width()*r.left()) / origImageSize.width()),
                         (int) (0.5+ (1.0*scaledImage.height()*r.top()) / origImageSize.height()) ));                 
 
  //set width/height
  res.setWidth( (scaledImage.width() *r.width()) / origImageSize.width() );
  res.setHeight( (scaledImage.height() *r.height()) / origImageSize.height() );
  
  //if against the right hand size make sure scaled display coordiantes are also
  //against edge. rounding prevents this from occuring and is noticeable since selection
  //rectangle appears to never be at every edge.
  if( r.right() == origImageSize.width() - 1)
  { res.moveBy( (scaledImage.width()-1) - res.right(), 0 ); }
 
  if( r.bottom() == origImageSize.height() - 1)
  { res.moveBy( 0, (scaledImage.height()-1) - res.bottom() ); }
  
  //return new rect
  return res; 
}

References origImageSize, and scaledImage.

Referenced by overRegion(), and paintEvent().

minimumSizeHint()

QSize SelectionPlacementInterface::minimumSizeHint ( ) const

virtual

Definition at line 165 of file selectionPlacementInterface.cpp.

{ return scaledImage.size(); }

References scaledImage.

Referenced by sizeHint().

mouseMoveEvent()

void SelectionPlacementInterface::mouseMoveEvent ( QMouseEvent * e )

protected

Definition at line 237 of file selectionPlacementInterface.cpp.

{
  //if not dragging update mosue cursor
  if(!currentlyDragging)
  { 
    if( !overRegion(e->pos() ) && currentMouseShapeIsDrag )
    { 
      currentMouseShapeIsDrag = false;
      setCursor( Qt::ArrowCursor ); 
    }
    else if( overRegion(e->pos() ) && !currentMouseShapeIsDrag )
    { 
      currentMouseShapeIsDrag = true;
      setCursor( getCursor(MOVE_SELECTION_CURSOR) );
 
    }
  }
  //move selection
  else { recenterSelection(e->pos()); }
}

References currentlyDragging, currentMouseShapeIsDrag, getCursor(), MOVE_SELECTION_CURSOR, overRegion(), and recenterSelection().

mousePressEvent()

void SelectionPlacementInterface::mousePressEvent ( QMouseEvent * e )

protected

Definition at line 223 of file selectionPlacementInterface.cpp.

{ 
  //if mouse press is not over the region then center viewed area over mouse press
  if( !currentMouseShapeIsDrag )
  { 
    recenterSelection(e->pos()); 
    currentMouseShapeIsDrag = true;
    setCursor( getCursor(MOVE_SELECTION_CURSOR) );
  }
 
  //enter dragging mode
  currentlyDragging = true; 
}

References currentlyDragging, currentMouseShapeIsDrag, getCursor(), MOVE_SELECTION_CURSOR, and recenterSelection().

mouseReleaseEvent()

void SelectionPlacementInterface::mouseReleaseEvent ( QMouseEvent * )

protected

Definition at line 258 of file selectionPlacementInterface.cpp.

{
  //disable dragging
  currentlyDragging = false;
}

References currentlyDragging.

overRegion()

bool SelectionPlacementInterface::overRegion ( QPoint p )

private

util function used to determine if mouse is over selected region

Definition at line 168 of file selectionPlacementInterface.cpp.

{
  if( selection.width()  == 0 || selection.height() == 0 )
  { return false; }
  
  QRect displayRect = imageToDisplay( selection );
 
  //if the entire image is visible then no rectangle can be dragged so just
  //return false so a drag cursor never becomes visible since it might
  //confuse the user into thinking s/he could actually drag it
  if( displayRect.width() == scaledImage.width() &&
      displayRect.height() == scaledImage.height() )
    return false;
 
  //determine if mouse cursor is over region
  int xOffset = (width()  - scaledImage.width() ) / 2;
  int yOffset = (height() - scaledImage.height()) / 2;
 
  return ( p.x() >= xOffset + displayRect.left()  &&
           p.x() <= xOffset + displayRect.right() &&
           p.y() >= yOffset + displayRect.top()   &&
           p.y() <= yOffset + displayRect.bottom() );
}

References height, imageToDisplay(), scaledImage, selection, and width.

Referenced by mouseMoveEvent().

paintEvent()

void SelectionPlacementInterface::paintEvent ( QPaintEvent * e )

protected

Definition at line 93 of file selectionPlacementInterface.cpp.

{ 
  //if no scaled image just return
  if(scaledImage.isNull()) { return; }
  
  //create buffer to draw in
  QPixmap buffer( size() );
  
  //create a painter pointing to the buffer
  QPainter bufferPainter( &buffer );
  
  //turn off clipping to make painting operations faster
  bufferPainter.setClipping(false);
 
  //initialize buffer with background brush
  bufferPainter.fillRect( buffer.rect(), backgroundBrush() );
 
  int xOffset = (width() - scaledImage.width()) / 2;
  int yOffset = (height() - scaledImage.height()) / 2;
 
  //selection not set yet, simply paint the scaled image normally
  if(selection.width() == 0 || selection.height() == 0 )
  {
    bufferPainter.drawImage( QPoint(xOffset, yOffset), scaledImage );
  }
  //selection present...
  else
  {
    //first paint using unselected coloring
    bufferPainter.drawImage( QPoint(xOffset, yOffset), unselectedScaledImage );
    
    //convert selection coordinates to display space
    QRect displayRect = imageToDisplay( selection );
    QPoint topLeft = displayRect.topLeft() + QPoint( xOffset, yOffset );
    QPoint bottomRight = displayRect.bottomRight() + QPoint( xOffset, yOffset );
    
    //now paint selected region in color
    bufferPainter.drawImage( topLeft.x(), topLeft.y(),
                             scaledImage,
                             displayRect.left(), displayRect.top(),
                             displayRect.width(), displayRect.height() );                                   
    
 
    //paint thin line around selected region to help it stand out even more
    if( selection.width() < origImageSize.width() ||
        selection.height() < origImageSize.height() )
    {
      QPen pen;
      pen.setColor( Qt::gray );
      pen.setStyle( Qt::SolidLine );
      pen.setWidth( 2 );
      bufferPainter.setPen( pen);
    
      QRect selctRect( topLeft, bottomRight );
      bufferPainter.drawRect(selctRect);       
    }
  }
  
  //end painter  
  bufferPainter.end();
  
  //blit buffer to screen
  bitBlt( this,
          e->rect().x(), e->rect().y(),
          &buffer, 
          e->rect().x(), e->rect().y(),
          e->rect().width(), e->rect().height() );
}

References bottomRight, buffer, height, imageToDisplay(), origImageSize, scaledImage, selection, topLeft, unselectedScaledImage, and width.

placementChanged

void SelectionPlacementInterface::placementChanged ( QRect )

signal

Referenced by recenterSelection().

recenterSelection()

void SelectionPlacementInterface::recenterSelection ( QPoint mousePosition )

private

util function used to center selection about mouse location

Definition at line 192 of file selectionPlacementInterface.cpp.

{
  //compute new viewing center
  QPoint center = QPoint( ((origImageSize.width()-1) * mousePosition.x()) / (width()-1),
                          ((origImageSize.height()-1) * mousePosition.y()) / (height()-1) );
  //move selection
  int sW = selection.width();
  int sH = selection.height();
  selection.setLeft( center.x() - sW/2 );
  selection.setTop( center.y() - sH/2 );
  selection.setRight( selection.left() + sW -1 );
  selection.setBottom( selection.top() + sH -1 );
  
  //ensure selection window never goes out of bounds
  if(selection.left() < 0 )
    selection.moveBy( -selection.left(), 0 );
  
  if(selection.right() > origImageSize.width() - 1 )
    selection.moveBy( (origImageSize.width() - 1) - selection.right(), 0 );
  
  if(selection.top() < 0 )
    selection.moveBy( 0, -selection.top() );
  
  if(selection.bottom() > origImageSize.height() - 1 )
    selection.moveBy( 0, (origImageSize.height() - 1) - selection.bottom() );
  
  //repaint and emit placement changed signal
  repaint(false); 
  emit placementChanged( selection );
}

References height, origImageSize, placementChanged(), selection, and width.

Referenced by mouseMoveEvent(), and mousePressEvent().

setSelectedRegion()

void SelectionPlacementInterface::setSelectedRegion

(

QRect

selection

)

Set the select region using image space coordinates.

Definition at line 293 of file selectionPlacementInterface.cpp.

{
  this->selection = selection;
  repaint(false); 
}

References selection.

Referenced by GrainEditor::previewResized().

sizeHint()

QSize SelectionPlacementInterface::sizeHint ( ) const

virtual

Definition at line 162 of file selectionPlacementInterface.cpp.

{ return minimumSizeHint(); }

References minimumSizeHint().

Member Data Documentation

currentlyDragging

bool SelectionPlacementInterface::currentlyDragging

private

dragging the mouse only moves the selection if the mouse button is pressed first over the selected region

Definition at line 81 of file selectionPlacementInterface.h.

Referenced by mouseMoveEvent(), mousePressEvent(), mouseReleaseEvent(), and SelectionPlacementInterface().

currentMouseShapeIsDrag

bool SelectionPlacementInterface::currentMouseShapeIsDrag

private

current mouse shape.

by caching this value we avoid resetting the mouse cursor every time it moves etc.

Definition at line 85 of file selectionPlacementInterface.h.

Referenced by mouseMoveEvent(), mousePressEvent(), and SelectionPlacementInterface().

origImageSize

QSize SelectionPlacementInterface::origImageSize

private

original image dimensions

Definition at line 74 of file selectionPlacementInterface.h.

Referenced by imageToDisplay(), paintEvent(), recenterSelection(), and SelectionPlacementInterface().

scaledImage

QImage SelectionPlacementInterface::scaledImage

private

Scaled image used for display purposes.

Definition at line 68 of file selectionPlacementInterface.h.

Referenced by imageToDisplay(), minimumSizeHint(), overRegion(), paintEvent(), and SelectionPlacementInterface().

selection

QRect SelectionPlacementInterface::selection

private

selection

Definition at line 77 of file selectionPlacementInterface.h.

Referenced by getSelectedRegion(), overRegion(), paintEvent(), recenterSelection(), SelectionPlacementInterface(), and setSelectedRegion().

unselectedScaledImage

QImage SelectionPlacementInterface::unselectedScaledImage

private

Unselected scaled image (desaturated version of scaled image)

Definition at line 71 of file selectionPlacementInterface.h.

Referenced by paintEvent(), and SelectionPlacementInterface().

---

The documentation for this class was generated from the following files:

• selectionPlacementInterface.h
• selectionPlacementInterface.cpp