/* * Copyright (c) 1999-2000, Eric Moon. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions, and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions, and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ // DiagramItem.h (Cortex/DiagramView) // // * PURPOSE // Provides a base class for all items that can be handled // by the DiagramView implementation. A basic interface with // some common implementation is defined, with methods related // to drawing, mouse handling, selecting, dragging, comparison // for sorting, and access to the drawing context which is the // DiagramView instance. // // * HISTORY // c.lenz 25sep99 Begun // #ifndef __DiagramItem_H__ #define __DiagramItem_H__ #include <OS.h> #include <InterfaceDefs.h> #include <Region.h> class BMessage; class BView; #include "cortex_defs.h" __BEGIN_CORTEX_NAMESPACE class DiagramItemGroup; class DiagramView; class DiagramBox; int compareSelectionTime(const void *lValue, const void *rValue); class DiagramItem { friend class DiagramItemGroup; friend class DiagramView; friend class DiagramBox; public: // *** types enum diagram_item_t { M_BOX = 0x1, M_WIRE = 0x2, M_ENDPOINT = 0x4, M_ANY = 0x7 }; public: // *** ctor/dtor DiagramItem( uint32 itemType); virtual ~DiagramItem(); public: // *** accessors // returns the item type assigned in the ctor uint32 type() const { return m_type; } // returns pointer to the drawing context of the DiagramView // object DiagramView *view() const { return m_view; } // returns pointer to the DiagramItemGroup the item belongs to DiagramItemGroup *group() const { return m_group; } // returns true if the item is currently selected bool isSelected() const { return m_selected; } public: // *** operations // changes the selection state of the item, and updates the // m_selectionTime member in the process to ensure proper // sorting; calls the selected() hook if the state has // actually changed void select(); // sets the item to selected without changing m_selectionTime // to the time of selection but prior to the last "replacing" // selection (i.e. thru select()) use this method for additive // selecting; still calls the selected() hook void selectAdding(); // deselects the item; calls the deselected() hook if the // state has actually changed void deselect(); // moves the items frame to a given point by calling MoveBy with the // absolute coords translated into relative shift amount void moveTo( BPoint point, BRegion *updateRegion = 0) { MoveBy(point.x - Frame().left, point.y - Frame().top, updateRegion); } // resizes the items frame to given dimensions; simply calls the ResizeBy // implementation void resizeTo( float width, float height) { ResizeBy(width - Frame().Width(), height - Frame().Height()); } public: // *** hook functions // is called when the item has been attached to the DiagramView // and the view() pointer is valid virtual void attachedToDiagram() { /* does nothing */ } // is called just before the item is being detached from the // the DiagramView virtual void detachedFromDiagram() { /* does nothing */ } // is called from the DiagramViews MouseDown() function after // finding out the mouse buttons and clicks quantity. virtual void MouseDown( BPoint point, uint32 buttons, uint32 clicks) {/* does nothing */} // is called from the DiagramViews MouseMoved() when *no* message is being // dragged, i.e. the mouse is simply floating above the item virtual void MouseOver( BPoint point, uint32 transit) {/* does nothing */} // is called from the DiagramViews MouseMoved() when a message is being // dragged; always call the base class version when overriding! virtual void MessageDragged( BPoint point, uint32 transit, const BMessage *message) {/* does nothing */} // is called from the DiagramViews MessageReceived() function when an // message has been received through Drag&Drop; always call the base // class version when overriding! virtual void MessageDropped( BPoint point, BMessage *message) {/* does nothing */} // is called when the item has been selected or deselected in some way virtual void selected() { /* does nothing */ } virtual void deselected() { /* does nothing */ } public: // *** interface definition // this function must be implemented by derived classes to return the // items frame rectangle in the DiagramViews coordinates virtual BRect Frame() const = 0; // this function should be implemented for non-rectangular subclasses // (like wires) to estimate how close a given point is to the object; // the default implementation returns 1.0 when the point lies within // the Frame() rect and 0.0 if not virtual float howCloseTo( BPoint point) const; // this is the hook function called by DiagramView when it's time to // Draw the object virtual void Draw( BRect updateRect) = 0; // should move the items frame by the specified amount and do the // necessary drawing instructions to update the display; if the // caller supplied a BRegion pointer in updateRegion, this method // should add other areas affected by the move to it (e.g. wire // frames) virtual void MoveBy( float x, float y, BRegion *updateRegion = 0) { /* does nothing */ } // should resize the items frame by the specified amount virtual void ResizeBy( float horizontal, float vertical) { /* does nothing */ } protected: // *** selecting/dragging // turn on/off the built-in selection handling void makeSelectable( bool selectable) { m_selectable = selectable; } bool isSelectable() const { return m_selectable; } // turn on/off the built-in drag & drop handling void makeDraggable( bool draggable) { m_draggable = draggable; } bool isDraggable() const { return m_draggable; } protected: // *** compare functions // compares the time when each item was last selected and // returns -1 for the most recent. friend int compareSelectionTime( const void *lValue, const void *rValue); protected: // *** internal methods // called only by DiagramItemGroup objects in the method // addItem() virtual void _SetOwner( DiagramView *owner) { m_view = owner; } private: // *** data members // the items type (M_BOX, M_WIRE or M_ENDPOINT) uint32 m_type; // a pointer to the drawing context (the DiagramView instance) DiagramView *m_view; // a pointer to the DiagramItemGroup the item belongs to DiagramItemGroup *m_group; // can the object be dragged bool m_draggable; // can the object be selected bool m_selectable; // is the object currently selected bool m_selected; // when was the object selected the last time or added (used // for drawing order) bigtime_t m_selectionTime; // stores the most recent time a item was selected thru // the select() method static bigtime_t m_lastSelectionTime; // counts the number of selections thru selectAdding() // since the last call to select() static int32 m_countSelected; }; __END_CORTEX_NAMESPACE #endif /* __DiagramItem_H__ */
