/* This file is part of the KDE project Copyright (C) 2001-2002 Matthias Kretz 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 QColor; class QSize; class QImage; class QRect; class QPoint; class QWidget; #include #include #include namespace KImageViewer { /** * An image canvas widget * * @author Matthias Kretz * * 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: * * 
   QWidget * widget = KParts::ComponentFactory::createInstanceFromQuery( "KImageViewer/Canvas", QString::null, this );
   m_canvas = static_cast( widget->qt_cast( "KImageViewer::Canvas" ) );
   if( ! ( widget && m_canvas ) )
   {
     KMessageBox::error( this, "Could not find the Canvas!" );
     kapp->quit();
   }
   setCentralWidget( widget );
   connect( widget, SIGNAL( contextPress( const QPoint & ) ), SLOT( mySlot( const QPoint & ) ) );
   connect( m_canvas->widget(), SIGNAL( contextPress( const QPoint & ) ), SLOT( mySlot( const QPoint & ) ) );
* * You can't connect signals or slots using KImageViewer::Canvas, because this interface * doesn't inherit from QObject. But you can cast to QWidget and use that instead (or just * keep the original pointer to QWidget 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 QColor & ) = 0; /** * returns the current background color */ virtual const QColor & bgColor() const = 0; /** * the depth of the contained image */ virtual int imageDepth() const = 0; /** * the size of the unzoomed image */ virtual QSize imageSize() const = 0; /** * the size of the zoomed (current) image */ virtual QSize 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 QImage * 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 QRect 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 QString blendEffectDescription( unsigned int ) const { return QString::null; } /** * 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 QSize & maximumImageSize() const = 0; /** * @return the current minimum image size */ virtual const QSize & minimumImageSize() const = 0; /** * @return a pointer to the QWidget interface of this object */ virtual QWidget * widget() = 0; signals: /** * a mouse button was pressed and a context menu should be openend */ virtual void contextPress( const QPoint & ) = 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 QSize & ) = 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 QRect & ) = 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 QPoint & ) = 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 QImage & ) = 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 QImage &, const QSize & ) = 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 QSize & 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 QSize & ) = 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 QSize & ) = 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 QSize & ) = 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