/* This file is part of the KDE project
Copyright (C) 2001-2002 Matthias Kretz <kretz@kde.org>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License version 2 as published by the Free Software Foundation.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
// $Id$
#ifndef KIMAGEVIEWER_CANVAS_H
#define KIMAGEVIEWER_CANVAS_H
class TQColor;
class TQSize;
class TQImage;
class TQRect;
class TQPoint;
class TQWidget;
#include <tqstring.h>
#include <tqobjectdefs.h>
#include <kdemacros.h>
namespace KImageViewer
{
/**
* An image canvas widget
*
* @author Matthias Kretz <kretz@kde.org>
*
* You'll find an implementation in kdegraphics (KView). You may
* still use this interface in your program but it will only work
* if you have an implementation installed.
*
* This is what you have to do to get an image canvas embedded in
* your program:
*
* <pre>
TQWidget * widget = KParts::ComponentFactory::createInstanceFromQuery<TQWidget>( "KImageViewer/Canvas", TQString(), this );
m_canvas = static_cast<KImageViewer::Canvas *>( widget->qt_cast( "KImageViewer::Canvas" ) );
if( ! ( widget && m_canvas ) )
{
KMessageBox::error( this, "Could not find the Canvas!" );
kapp->quit();
}
setCentralWidget( widget );
connect( widget, TQT_SIGNAL( contextPress( const TQPoint & ) ), TQT_SLOT( mySlot( const TQPoint & ) ) );
connect( m_canvas->widget(), TQT_SIGNAL( contextPress( const TQPoint & ) ), TQT_SLOT( mySlot( const TQPoint & ) ) );
</pre>
*
* You can't connect signals or slots using KImageViewer::Canvas, because this interface
* doesn't inherit from TQObject. But you can cast to TQWidget and use that instead (or just
* keep the original pointer to TQWidget around, like shown in the example).
*
* This interface is not guaranteed to be kept binary or source compatible
* until it's finished. So if you're using this interface please get in contact
* with me.
*/
class KDE_EXPORT Canvas
{
public:
/**
* set the background color of the canvas
*/
virtual void setBgColor( const TQColor & ) = 0;
/**
* returns the current background color
*/
virtual const TQColor & bgColor() const = 0;
/**
* the depth of the contained image
*/
virtual int imageDepth() const = 0;
/**
* the size of the unzoomed image
*/
virtual TQSize imageSize() const = 0;
/**
* the size of the zoomed (current) image
*/
virtual TQSize currentSize() const = 0;
/**
* returns the zoom factor
*/
virtual double zoom() const = 0;
/**
* @return The current (unzoomed) image
* Take care that the canas may delete the image so you probably need to
* make a copy of the image if you want to keep it around.
*/
virtual const TQImage * image() const = 0;
/**
* Scrolls the content so that the point (x, y) is in the top-left corner.
*/
virtual void setXYOffset( int x, int y ) = 0;
/**
* Returns the leftmost visible X coordinate of the image.
*/
virtual int xOffset() const = 0;
/**
* Returns the topmost visible Y coordinate of the image.
*/
virtual int yOffset() const = 0;
/**
* Returns whether to use fast or smooth scaling
*/
virtual bool fastScale() const = 0;
/**
* Return whether the image should always be centered.
*/
virtual bool centered() const = 0;
/**
* Return the selected rectangle. If nothing is selected the rectangle is
* empty but doesn't have to be null.
*/
virtual TQRect selection() const = 0;
/**
* Returns whether the aspect ratio of the image is kept
*/
virtual bool keepAspectRatio() const = 0;
/**
* @return the number of available blend effects
*/
virtual unsigned int numOfBlendEffects() const { return 0; }
/**
* @return the description of the blend effect
*/
virtual TQString blendEffectDescription( unsigned int ) const { return TQString(); }
/**
* Sets the blending effect used to create a transition between images
*/
virtual void setBlendEffect( unsigned int idx ) { m_iBlendEffect = idx; }
/**
* @return the current blend effect index
*/
virtual unsigned int blendEffect() const { return m_iBlendEffect; }
/**
* @return the current maximum image size
*/
virtual const TQSize & maximumImageSize() const = 0;
/**
* @return the current minimum image size
*/
virtual const TQSize & minimumImageSize() const = 0;
/**
* @return a pointer to the TQWidget interface of this object
*/
virtual TQWidget * widget() = 0;
signals:
/**
* a mouse button was pressed and a context menu should be openend
*/
virtual void contextPress( const TQPoint & ) = 0;
/**
* the size of the image has changed (a new image was loaded, or the
* image was zoomed or cropped)
*
* it passes the new size of the image
*/
virtual void imageSizeChanged( const TQSize & ) = 0;
/**
* The zoom of the image has changed.
*/
virtual void zoomChanged( double zoom ) = 0;
/**
* The selection has changed. Connect to this signal if you want to
* do something with a selection of the image (e.g. crop).
*/
virtual void selectionChanged( const TQRect & ) = 0;
/**
* Emitted when an image is finished being shown. If a blend effect is being used
* the signal is emitted when the effect is finished.
*/
virtual void showingImageDone() = 0;
/**
* This signal is emitted whenever the canvas changes between image/no-image. For
* example, if someone calls @ref clear() hasImage( false ) is emitted if an image
* was shown before.
*/
virtual void hasImage( bool ) = 0;
/**
* Some methods of the canvas not only change the way the image is shown (e.g. zoom)
* but also change the image itself (e.g. rotation) - @ref image() returns something
* different. If such a change happens this signal is emitted.
* It is not emitted when a new image is set with the @ref setImage() methods.
*/
virtual void imageChanged() = 0;
/**
* The current mouse cursor position on the image.
*/
virtual void cursorPos( const TQPoint & ) = 0;
public slots:
/**
* Set if the image should always be centered if the canvas is
* bigger than the image.
*/
virtual void setCentered( bool ) = 0;
/**
* Give the canvas a new image to show. The zoom level is kept.
*/
virtual void setImage( const TQImage & ) = 0;
/**
* Give the canvas a new image to show.
*
* You have to pass the size the image should have when it appears
* on screen.
*/
virtual void setImage( const TQImage &, const TQSize & ) = 0;
/**
* Set the zoom to be used when showing the image.
*/
virtual void setZoom( double ) = 0;
/**
* Fit the image into the requested width and height.
*/
virtual void boundImageTo( const TQSize & size ) = 0;
/**
* Set the maximum size of the image. If this is set the image will
* never exceed this size.
*
* If you set this to 0x0 the image size may be as big as possible
*/
virtual void setMaximumImageSize( const TQSize & ) = 0;
/**
* Set the minimum size of the image. If this is set the image will
* never be smaller than this size.
*
* If you set this to 0x0 the image size can be as small as possible
*/
virtual void setMinimumImageSize( const TQSize & ) = 0;
/**
* Resize the image to the given size. It will keep the aspect ratio
* as long as keepAspectRatio is true (default). The image will be as
* large as possible within the given constraints.
*/
virtual void resizeImage( const TQSize & ) = 0;
/**
* Hides the scrollbars of the canvas. It's still possible to scroll
* by moving the image with the mouse.
*/
virtual void hideScrollbars( bool ) = 0;
/**
* Changes the zoom behaviour: Normally the aspect ratio of the image
* won't change, but if you want to allow it you may do.
*/
virtual void setKeepAspectRatio( bool ) = 0;
/**
* If the canvas supports different methods for scaling you may
* switch between fast and smooth scaling.
*
* It defaults to smooth scaling.
*/
virtual void setFastScale( bool ) = 0;
/**
* clears the canvas (no image loaded)
*/
virtual void clear() = 0;
/**
* flip the image horizontally
*
* @param change If set to true the internal image will be changed, else
* only the shown image changes and @ref image() still returns
* the same as before this call.
*/
virtual void flipHorizontal( bool change = false ) = 0;
/**
* flip the image vertically
*
* @param change If set to true the internal image will be changed, else
* only the shown image changes and @ref image() still returns
* the same as before this call.
*/
virtual void flipVertical( bool change = false ) = 0;
/**
* rotate the image a degrees counterclockwise
*
* @param angle The angle in degrees that the image should be rotated.
* @param change If set to true the internal image will be changed, else
* only the shown image changes and @ref image() still returns
* the same as before this call.
*/
virtual void rotate( double angle, bool change = false ) = 0;
protected:
Canvas();
virtual ~Canvas();
unsigned int m_iBlendEffect;
}; //class Canvas
} //namespace KImageViewer
// vim:sw=4:ts=4
#endif // KIMAGEVIEWER_CANVAS_H