path: root/qtjava/javalib/examples/showimg/ImageViewer.java

/***************************************************************************
* $Id$
**
* 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.
**
****************************************************************************/

import org.kde.qt.*;
import java.util.*;

class ImageViewer  extends QWidget
{
private int		conversion_flags;
private int		alloc_context;
private String filename;
private QImage	image = new QImage();			// the loaded image
private QPixmap	pm = new QPixmap();			// the converted pixmap
private QPixmap	pmScaled;		// the scaled pixmap

private QMenuBar   menubar;
private QPopupMenu  file;
private QPopupMenu   saveimage;
private QPopupMenu   savepixmap;
private QPopupMenu  edit;
private QPopupMenu  options;

private QWidget    helpmsg;
private QLabel     status;
private int         si, sp, ac, co, mo, fd, bd, // Menu item ids
		td, ta, ba, fa, au, ad, dd,
		ss, cc, t1, t8, t32;
private int[]		pickx = { 0 };
private int[]		picky = { 0 };
private int[]		clickx = { 0 };
private int[]		clicky = { 0 };
private boolean	may_be_other;
private static ImageViewer other = null;




/*
  In the constructor, we just pass the standard parameters on to
  QWidget.

  The menu uses a single slot to simplify the process of adding
  more items to the options menu.
*/
ImageViewer( QWidget parent, String name, int wFlags )
{
    super( parent, name, wFlags );
    conversion_flags = PreferDither;
	filename = "";
    helpmsg = null;
    pickx[0] = -1;
    picky[0] = -1;
    clickx[0] = -1;
    clicky[0] = -1;
    alloc_context = 0;

    menubar = new QMenuBar(this);
    menubar.setSeparator( QMenuBar.InWindowsStyle );

    ArrayList fmt = QImage.outputFormats();
    saveimage = new QPopupMenu( menubar );
    savepixmap = new QPopupMenu( menubar );
	Iterator it = fmt.iterator();
	while (it.hasNext()) {
	String f = (String) it.next();
	saveimage.insertItem( f );
	savepixmap.insertItem( f );
    }
    connect( saveimage, SIGNAL("activated(int)"), this, SLOT("saveImage(int)") );
    connect( savepixmap, SIGNAL("activated(int)"), this, SLOT("savePixmap(int)") );

    file = new QPopupMenu( menubar );
    menubar.insertItem( "&File", file );
    file.insertItem( "&New window", this,  SLOT("newWindow()"), new QKeySequence(CTRL+Key_N) );
    file.insertItem( "&Open...", this,  SLOT("openFile()"), new QKeySequence(CTRL+Key_O) );
    si = file.insertItem( "Save image", saveimage );
    sp = file.insertItem( "Save pixmap", savepixmap );
    file.insertSeparator();
    file.insertItem( "E&xit", qApp(),  SLOT("quit()"), new QKeySequence(CTRL+Key_Q) );

    edit =  new QPopupMenu( menubar );
    menubar.insertItem( "&Edit", edit );
    edit.insertItem("&Copy", this, SLOT("copy()"), new QKeySequence(CTRL+Key_C));
    edit.insertItem("&Paste", this, SLOT("paste()"), new QKeySequence(CTRL+Key_V));
    edit.insertSeparator();
    edit.insertItem("&Horizontal flip", this, SLOT("hFlip()"), new QKeySequence(ALT+Key_H));
    edit.insertItem("&Vertical flip", this, SLOT("vFlip()"), new QKeySequence(ALT+Key_V));
    edit.insertItem("&Rotate 180", this, SLOT("rot180()"), new QKeySequence(ALT+Key_R));
    edit.insertSeparator();
    edit.insertItem("&Text...", this, SLOT("editText()"));
    edit.insertSeparator();
    t1 = edit.insertItem( "Convert to &1 bit", this, SLOT("to1Bit()") );
    t8 = edit.insertItem( "Convert to &8 bit", this, SLOT("to8Bit()") );
    t32 = edit.insertItem( "Convert to &32 bit", this, SLOT("to32Bit()") );

    options =  new QPopupMenu( menubar );
    menubar.insertItem( "&Options", options );
    ac = options.insertItem( "AutoColor" );
    co = options.insertItem( "ColorOnly" );
    mo = options.insertItem( "MonoOnly" );
    options.insertSeparator();
    fd = options.insertItem( "DiffuseDither" );
    bd = options.insertItem( "OrderedDither" );
    td = options.insertItem( "ThresholdDither" );
    options.insertSeparator();
    ta = options.insertItem( "ThresholdAlphaDither" );
    ba = options.insertItem( "OrderedAlphaDither" );
    fa = options.insertItem( "DiffuseAlphaDither" );
    options.insertSeparator();
    ad = options.insertItem( "PreferDither" );
    dd = options.insertItem( "AvoidDither" );
    options.insertSeparator();
    ss = options.insertItem( "Smooth scaling" );
    cc = options.insertItem( "Use color context" );
    if ( QApplication.colorSpec() == QApplication.ManyColor )
	options.setItemEnabled( cc, false );
    options.setCheckable( true );
    setMenuItemFlags();

    menubar.insertSeparator();

    QPopupMenu help = new QPopupMenu( menubar );
    menubar.insertItem( "&Help", help );
    help.insertItem( "Help!", this, SLOT("giveHelp()"), new QKeySequence(CTRL+Key_H) );

    connect( options, SIGNAL("activated(int)"), this, SLOT("doOption(int)") );

    status = new QLabel(this);
    status.setFrameStyle( QFrame.WinPanel | QFrame.Sunken );
    status.setFixedHeight( fontMetrics().height() + 4 );

    setMouseTracking( true );
}

void cleanUp()
{
    if ( alloc_context != 0 )
	QColor.destroyAllocContext( alloc_context );
    if ( other == this )
	other = null;
}

/*
  This function modifies the conversion_flags when an options menu item
  is selected, then ensures all menu items are up to date, and reconverts
  the image if possibly necessary.
*/
void doOption(int item)
{
    if ( item == ss || item == cc ) {
	// Toggle
	boolean newboolean = !options.isItemChecked(item);
	options.setItemChecked(item, newboolean);
	// And reconvert...
	reconvertImage();
	repaint(image.hasAlphaBuffer());	// show image in widget
	return;
    }

    if ( options.isItemChecked( item ) ) return; // They are all radio buttons

    int ocf = conversion_flags;

    if ( item == ac ) {
	conversion_flags = conversion_flags & ~ColorMode_Mask | AutoColor;
    } else if ( item == co ) {
	conversion_flags = conversion_flags & ~ColorMode_Mask | ColorOnly;
    } else if ( item == mo ) {
	conversion_flags = conversion_flags & ~ColorMode_Mask | MonoOnly;
    } else if ( item == fd ) {
	conversion_flags = conversion_flags & ~Dither_Mask | DiffuseDither;
    } else if ( item == bd ) {
	conversion_flags = conversion_flags & ~Dither_Mask | OrderedDither;
    } else if ( item == td ) {
	conversion_flags = conversion_flags & ~Dither_Mask | ThresholdDither;
    } else if ( item == ta ) {
	conversion_flags = conversion_flags & ~AlphaDither_Mask | ThresholdAlphaDither;
    } else if ( item == fa ) {
	conversion_flags = conversion_flags & ~AlphaDither_Mask | DiffuseAlphaDither;
    } else if ( item == ba ) {
	conversion_flags = conversion_flags & ~AlphaDither_Mask | OrderedAlphaDither;
    } else if ( item == ad ) {
	conversion_flags = conversion_flags & ~DitherMode_Mask | PreferDither;
    } else if ( item == dd ) {
	conversion_flags = conversion_flags & ~DitherMode_Mask | AvoidDither;
    }

    if ( ocf != conversion_flags ) {
	setMenuItemFlags();
	// And reconvert...
	reconvertImage();
	repaint(image.hasAlphaBuffer());	// show image in widget
    }
}

/*
  Set the options menu to reflect the conversion_flags value.
*/
void setMenuItemFlags()
{
    // File
    boolean valid_image = pm.size().width() != 0 || pm.size().height() != 0;
    file.setItemEnabled( si, valid_image );
    file.setItemEnabled( sp, valid_image );

    // Edit
    edit.setItemEnabled( t1, image.depth() != 1 );
    edit.setItemEnabled( t8, image.depth() != 8 );
    edit.setItemEnabled( t32, image.depth() != 32 );

    // Options
    boolean may_need_color_dithering =
	    !valid_image
	|| image.depth() == 32 && QPixmap.defaultDepth() < 24;
    boolean may_need_dithering = may_need_color_dithering
	 || image.depth() > 1 && options.isItemChecked(mo)
	 || image.depth() > 1 && QPixmap.defaultDepth() == 1;
    boolean has_alpha_mask = !valid_image || image.hasAlphaBuffer();

    options.setItemEnabled( fd, may_need_dithering );
    options.setItemEnabled( bd, may_need_dithering );
    options.setItemEnabled( td, may_need_dithering );

    options.setItemEnabled( ta, has_alpha_mask );
    options.setItemEnabled( fa, has_alpha_mask );
    options.setItemEnabled( ba, has_alpha_mask );

    options.setItemEnabled( ad, may_need_color_dithering );
    options.setItemEnabled( dd, may_need_color_dithering );

    options.setItemChecked( ac, (conversion_flags & ColorMode_Mask) == AutoColor );
    options.setItemChecked( co, (conversion_flags & ColorMode_Mask) == ColorOnly );
    options.setItemChecked( mo, (conversion_flags & ColorMode_Mask) == MonoOnly );
    options.setItemChecked( fd, (conversion_flags & Dither_Mask) == DiffuseDither );
    options.setItemChecked( bd, (conversion_flags & Dither_Mask) == OrderedDither );
    options.setItemChecked( td, (conversion_flags & Dither_Mask) == ThresholdDither );
    options.setItemChecked( ta, (conversion_flags & AlphaDither_Mask) == ThresholdAlphaDither );
    options.setItemChecked( fa, (conversion_flags & AlphaDither_Mask) == DiffuseAlphaDither );
    options.setItemChecked( ba, (conversion_flags & AlphaDither_Mask) == OrderedAlphaDither );
    options.setItemChecked( ad, (conversion_flags & DitherMode_Mask) == PreferDither );
    options.setItemChecked( dd, (conversion_flags & DitherMode_Mask) == AvoidDither );
}

void updateStatus()
{
    if ( pm.size().width() == 0 && pm.size().height() == 0 ) {
	if ( !filename.equals("") )
	    status.setText("Could not load image");
	else
	    status.setText("No image - select Open from File menu.");
    } else {
	String message, moremsg;
	message = "" + image.width() + "x" + image.height();
	if ( pm.size().width() != pmScaled.size().width()
	     || pm.size().height() != pmScaled.size().height() )
	{
	    moremsg = " [" + pmScaled.width() + "x" + pmScaled.height() + "]";
	    message += moremsg;
	}
	moremsg = ", " +  image.depth() + " bits ";
	message += moremsg;
	if (image.valid(pickx[0],picky[0])) {
	    moremsg = "("
			  + pickx[0] + "," + picky[0] + ")=#"
			  + Integer.toHexString(image.pixel(pickx[0],picky[0]))
			  + " ";
	    message += moremsg;
	}
	if ( image.numColors() > 0 ) {
	    if (image.valid(pickx[0],picky[0])) {
		moremsg = ", " + image.pixelIndex(pickx[0],picky[0]) + "/"
		    + image.numColors() + " colors";
	    } else {
		moremsg = ", " + image.numColors() + " colors";
	    }
	    message += moremsg;
	}
	if ( image.hasAlphaBuffer() ) {
	    if ( image.depth() == 8 ) {
		int i;
		boolean alpha[] = new boolean[256];
		int nalpha=0;

		for (i=0; i<256; i++)
		    alpha[i] = false;

		for (i=0; i<image.numColors(); i++) {
		    int alevel = image.color(i) >> 24;
			// Hack - image.color() returns a C++ unsigned int, but alevel is a signed int.
			// If the top 8 bits are 0xffffffff, alevel is -1, not 255, and needs fixing up
			if (alevel == -1) {
				alevel = 255;
			}
		    if (!alpha[alevel]) {
			alpha[alevel] = true;
			nalpha++;
		    }
		}
		moremsg = ", " + nalpha + " alpha levels";
	    } else {
		// Too many pixels to bother counting.
		moremsg = ", 8-bit alpha channel";
	    }
	    message += moremsg;
	}
	status.setText(message);
    }
}

/*
  This function saves the image.
*/
void saveImage( int item )
{
    String fmt = saveimage.text(item);
    String savefilename = QFileDialog.getSaveFileName("", "",
					this, filename);
    if ( !savefilename.equals("") )
	if ( !image.save( savefilename, fmt ) )
	    QMessageBox.warning( this, "Save failed", "Error saving file" );
}

/*
  This function saves the converted image.
*/
void savePixmap( int item )
{
    String fmt = savepixmap.text(item);
    String savefilename = QFileDialog.getSaveFileName("",
					"", this, filename);
    if ( !savefilename.equals("") )
	if ( !pmScaled.save( savefilename, fmt ) )
	    QMessageBox.warning( this, "Save failed", "Error saving file" );
}


void newWindow()
{
    ImageViewer that = new ImageViewer(null, "new window", WDestructiveClose);
    that.options.setItemChecked( that.cc, useColorContext() );
    that.show();
}

/*
  This function is the slot for processing the Open menu item.
*/
void openFile()
{
    String newfilename = QFileDialog.getOpenFileName();
    if ( !newfilename.equals("") ) {
	loadImage( newfilename ) ;
	repaint();			// show image in widget
    }
}

/*
  This function loads an image from a file and resizes the widget to
  exactly fit the image size. If the file was not found or the image
  format was unknown it will resize the widget to fit the errorText
  message (see above) displayed in the current font.

  Returns true if the image was successfully loaded.
*/

boolean loadImage( String fileName )
{
    filename = fileName;
    boolean ok = false;
    if ( ! filename.equals("") ) {
	QApplication.setOverrideCursor( waitCursor() ); // this might take time
	ok = image.load(filename, null);
	pickx[0] = -1;
	clickx[0] = -1;
	if ( ok )
	    ok = reconvertImage();
	if ( ok ) {
	    setCaption( filename );			// set window caption
	    int w = pm.width();
	    int h = pm.height();

	    int reasonable_width = 128;
	    if ( w < reasonable_width ) {
		// Integer scale up to something reasonable
		int multiply = ( reasonable_width + w - 1 ) / w;
		w *= multiply;
		h *= multiply;
	    }

	    h += menubar.heightForWidth(w) + status.height();
	    resize( w, h );				// we resize to fit image
	} else {
	    pm.resize(0,0);				// couldn't load image
	    update();
	}
	QApplication.restoreOverrideCursor();	// restore original cursor
    }
    updateStatus();
    setMenuItemFlags();
    return ok;
}

boolean reconvertImage()
{
    boolean success = false;

    if ( image.isNull() ) return false;

    if ( alloc_context != 0 ) {
	QColor.destroyAllocContext( alloc_context );
	alloc_context = 0;
    }
    if ( useColorContext() ) {
	alloc_context = QColor.enterAllocContext();
	// Clear the image to hide flickering palette
	QPainter painter = new QPainter(this);
	painter.eraseRect(0, menubar.heightForWidth( width() ), width(), height());
    }

    QApplication.setOverrideCursor( waitCursor() ); // this might take time
    if ( pm.convertFromImage(image, conversion_flags) )
    {
	pmScaled = new QPixmap();
	scale();
	resize( width(), height() );
	success = true;				// load successful
    } else {
	pm.resize(0,0);				// couldn't load image
    }
    updateStatus();
    setMenuItemFlags();
    QApplication.restoreOverrideCursor();	// restore original cursor

    if ( useColorContext() )
	QColor.leaveAllocContext();

    return success;				// true if loaded OK
}

boolean smooth()
{
    return options.isItemChecked(ss);
}

boolean useColorContext()
{
    return options.isItemChecked(cc);
}

/*
  This functions scales the pixmap in the member variable "pm" to fit the
  widget size and  puts the resulting pixmap in the member variable "pmScaled".
*/

void scale()
{
    int h = height() - menubar.heightForWidth( width() ) - status.height();

    if ( image.isNull() ) return;

    QApplication.setOverrideCursor( waitCursor() ); // this might take time
    if ( width() == pm.width() && h == pm.height() )
    {						// no need to scale if widget
	pmScaled = pm;				// size equals pixmap size
    } else {
	if (smooth()) {
	    pmScaled.convertFromImage(image.smoothScale(width(), h),
		conversion_flags);
	} else {
	    QWMatrix m = new QWMatrix();				// transformation matrix
	    m.scale(((double)width())/pm.width(),// define scale factors
		    ((double)h)/pm.height());
	    pmScaled = (QPixmap) pm.xForm( m );		// create scaled pixmap
	}
    }
    QApplication.restoreOverrideCursor();	// restore original cursor
}

/*
  The resize event handler, if a valid pixmap was loaded it will call
  scale() to fit the pixmap to the new widget size.
*/

protected void resizeEvent( QResizeEvent e )
{
    status.setGeometry(0, height() - status.height(),
			width(), status.height());

    if ( pm.size().width() == 0 && pm.size().height() == 0 )		// we couldn't load the image
	return;

    int h = height() - menubar.heightForWidth( width() ) - status.height();
    if ( width() != pmScaled.width() || h != pmScaled.height())
    {						// if new size,
	scale();				// scale pmScaled to window
	updateStatus();
    }
    if ( image.hasAlphaBuffer() )
	erase();
}

protected boolean convertEvent( QMouseEvent e, int[] x, int[] y)
{
    if ( pm.size().width() != 0 || pm.size().height() != 0 ) {
	int h = height() - menubar.heightForWidth( width() ) - status.height();
	int nx = e.x() * image.width() / width();
	int ny = (e.y()-menubar.heightForWidth( width() )) * image.height() / h;
	if (nx != x[0] || ny != y[0] ) {
	    x[0] = nx;
	    y[0] = ny;
	    updateStatus();
	    return true;
	}
    }
    return false;
}

protected void mousePressEvent( QMouseEvent e )
{
    may_be_other = convertEvent(e, clickx, clicky);
}

protected void mouseReleaseEvent( QMouseEvent e )
{
    if ( may_be_other )
	other = this;
}

/*
  Record the pixel position of interest.
*/
protected void mouseMoveEvent( QMouseEvent e )
{
    if (convertEvent(e,pickx,picky)) {
	updateStatus();
	if ((e.state()&LeftButton) != 0) {
	    may_be_other = false;
	    if ( clickx[0] >= 0 && other != null) {
		copyFrom(other);
	    }
	}
    }
}

/*
  Draws the portion of the scaled pixmap that needs to be updated or prints
  an error message if no legal pixmap has been loaded.
*/

protected void paintEvent( QPaintEvent e )
{
    if ( pm.size().width() != 0 || pm.size().height() != 0 ) {		// is an image loaded?
	QPainter painter = new QPainter(this);
	painter.setClipRect(e.rect());
	painter.drawPixmap(0, menubar.heightForWidth( width() ), pmScaled);
    }
}


/*
  Explain anything that might be confusing.
*/
void giveHelp()
{
    if (helpmsg == null) {
	String helptext =
	    "<b>Usage:</b> <tt>showimg [-m] <i>filename ...</i></tt>"
	    + "<blockquote>"
		+ "<tt>-m</tt> - use <i>ManyColor</i> color spec"
	    + "</blockquote>"
	    + "<p>Supported input formats:"
	    + "<blockquote>";
	Iterator it = QImage.inputFormatList().iterator();
	if (it.hasNext())
        helptext += (String) it.next();
	while (it.hasNext()) {
    	helptext += ", " + (String) it.next();
	}
	helptext += "</blockquote>";

	helpmsg = new QMessageBox( "Help", helptext,
	    QMessageBox.Information, QMessageBox.Ok, 0, 0, null, null, false );
    }
    helpmsg.show();
    helpmsg.raise();
}

void copyFrom(ImageViewer s)
{
    if ( clickx[0] >= 0 ) {
	int dx = clickx[0];
	int dy = clicky[0];
	int sx = s.clickx[0];
	int sy = s.clicky[0];
	int sw = Math.abs(clickx[0] - pickx[0])+1;
	int sh = Math.abs(clicky[0] - picky[0])+1;
	if ( clickx[0] > pickx[0] ) {
	    dx = pickx[0];
	    sx -= sw-1;
	}
	if ( clicky[0] > picky[0] ) {
	    dy = picky[0];
	    sy -= sh-1;
	}
	bitBlt( new QPixmap(image), dx, dy, new QPixmap(s.image), sx, sy, sw, sh );
	reconvertImage();
	repaint( image.hasAlphaBuffer() );
    }
}

void hFlip()
{
    setImage(image.mirror(true,false));
}

void vFlip()
{
    setImage(image.mirror(false,true));
}

void rot180()
{
    setImage(image.mirror(true,true));
}

void copy()
{
    QApplication.clipboard().setImage(image); // Less information loss
}

void paste()
{
    QImage p = QApplication.clipboard().image();
    if ( !p.isNull() ) {
	filename = "pasted";
	setImage(p);
    }
}

void setImage(QImage newimage)
{
    image = newimage;

    pickx[0] = -1;
    clickx[0] = -1;
    setCaption( filename );			// set window caption
    int w = image.width();
    int h = image.height();
    if ( w == 0 )
	return;

    int reasonable_width = 128;
    if ( w < reasonable_width ) {
	// Integer scale up to something reasonable
	int multiply = ( reasonable_width + w - 1 ) / w;
	w = multiply;
	h = multiply;
    }

    h += menubar.heightForWidth(w) + status.height();
    resize( w, h );				// we resize to fit image

    reconvertImage();
    repaint( image.hasAlphaBuffer() );

    updateStatus();
    setMenuItemFlags();
}

void editText()
{
    ImageTextEditor editor = new ImageTextEditor(image,this);
    editor.exec();
}

void to1Bit()
{
    toBitDepth(1);
}

void to8Bit()
{
    toBitDepth(8);
}

void to32Bit()
{
    toBitDepth(32);
}

void toBitDepth(int d)
{
    image = image.convertDepth(d);
    reconvertImage();
    repaint( image.hasAlphaBuffer() );
}
}