1/* 2 * Copyright (c) 1999-2000, Eric Moon. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions, and the following disclaimer. 11 * 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions, and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * 3. The name of the author may not be used to endorse or promote products 17 * derived from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 23 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 24 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 25 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 26 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR 27 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 32// DiagramItem.h (Cortex/DiagramView) 33// 34// * PURPOSE 35// Provides a base class for all items that can be handled 36// by the DiagramView implementation. A basic interface with 37// some common implementation is defined, with methods related 38// to drawing, mouse handling, selecting, dragging, comparison 39// for sorting, and access to the drawing context which is the 40// DiagramView instance. 41// 42// * HISTORY 43// c.lenz 25sep99 Begun 44// 45 46#ifndef __DiagramItem_H__ 47#define __DiagramItem_H__ 48 49#include <OS.h> 50#include <InterfaceDefs.h> 51#include <Region.h> 52 53class BMessage; 54class BView; 55 56#include "cortex_defs.h" 57__BEGIN_CORTEX_NAMESPACE 58 59class DiagramItemGroup; 60class DiagramView; 61class DiagramBox; 62 63int compareSelectionTime(const void *lValue, const void *rValue); 64 65class DiagramItem 66{ 67 friend class DiagramItemGroup; 68 friend class DiagramView; 69 friend class DiagramBox; 70 71public: // *** types 72 73 enum diagram_item_t { 74 M_BOX = 0x1, 75 M_WIRE = 0x2, 76 M_ENDPOINT = 0x4, 77 M_ANY = 0x7 78 }; 79 80public: // *** ctor/dtor 81 82 DiagramItem( 83 uint32 itemType); 84 85 virtual ~DiagramItem(); 86 87public: // *** accessors 88 89 // returns the item type assigned in the ctor 90 uint32 type() const 91 { return m_type; } 92 93 // returns pointer to the drawing context of the DiagramView 94 // object 95 DiagramView *view() const 96 { return m_view; } 97 98 // returns pointer to the DiagramItemGroup the item belongs to 99 DiagramItemGroup *group() const 100 { return m_group; } 101 102 // returns true if the item is currently selected 103 bool isSelected() const 104 { return m_selected; } 105 106public: // *** operations 107 108 // changes the selection state of the item, and updates the 109 // m_selectionTime member in the process to ensure proper 110 // sorting; calls the selected() hook if the state has 111 // actually changed 112 void select(); 113 114 // sets the item to selected without changing m_selectionTime 115 // to the time of selection but prior to the last "replacing" 116 // selection (i.e. thru select()) use this method for additive 117 // selecting; still calls the selected() hook 118 void selectAdding(); 119 120 // deselects the item; calls the deselected() hook if the 121 // state has actually changed 122 void deselect(); 123 124 // moves the items frame to a given point by calling MoveBy with the 125 // absolute coords translated into relative shift amount 126 void moveTo( 127 BPoint point, 128 BRegion *updateRegion = 0) 129 { MoveBy(point.x - Frame().left, point.y - Frame().top, updateRegion); } 130 131 // resizes the items frame to given dimensions; simply calls the ResizeBy 132 // implementation 133 void resizeTo( 134 float width, 135 float height) 136 { ResizeBy(width - Frame().Width(), height - Frame().Height()); } 137 138public: // *** hook functions 139 140 // is called when the item has been attached to the DiagramView 141 // and the view() pointer is valid 142 virtual void attachedToDiagram() 143 { /* does nothing */ } 144 145 // is called just before the item is being detached from the 146 // the DiagramView 147 virtual void detachedFromDiagram() 148 { /* does nothing */ } 149 150 // is called from the DiagramViews MouseDown() function after 151 // finding out the mouse buttons and clicks quantity. 152 virtual void MouseDown( 153 BPoint point, 154 uint32 buttons, 155 uint32 clicks) 156 {/* does nothing */} 157 158 // is called from the DiagramViews MouseMoved() when *no* message is being 159 // dragged, i.e. the mouse is simply floating above the item 160 virtual void MouseOver( 161 BPoint point, 162 uint32 transit) 163 {/* does nothing */} 164 165 // is called from the DiagramViews MouseMoved() when a message is being 166 // dragged; always call the base class version when overriding! 167 virtual void MessageDragged( 168 BPoint point, 169 uint32 transit, 170 const BMessage *message) 171 {/* does nothing */} 172 173 // is called from the DiagramViews MessageReceived() function when an 174 // message has been received through Drag&Drop; always call the base 175 // class version when overriding! 176 virtual void MessageDropped( 177 BPoint point, 178 BMessage *message) 179 {/* does nothing */} 180 181 // is called when the item has been selected or deselected in some way 182 virtual void selected() 183 { /* does nothing */ } 184 virtual void deselected() 185 { /* does nothing */ } 186 187public: // *** interface definition 188 189 // this function must be implemented by derived classes to return the 190 // items frame rectangle in the DiagramViews coordinates 191 virtual BRect Frame() const = 0; 192 193 // this function should be implemented for non-rectangular subclasses 194 // (like wires) to estimate how close a given point is to the object; 195 // the default implementation returns 1.0 when the point lies within 196 // the Frame() rect and 0.0 if not 197 virtual float howCloseTo( 198 BPoint point) const; 199 200 // this is the hook function called by DiagramView when it's time to 201 // Draw the object 202 virtual void Draw( 203 BRect updateRect) = 0; 204 205 // should move the items frame by the specified amount and do the 206 // necessary drawing instructions to update the display; if the 207 // caller supplied a BRegion pointer in updateRegion, this method 208 // should add other areas affected by the move to it (e.g. wire 209 // frames) 210 virtual void MoveBy( 211 float x, 212 float y, 213 BRegion *updateRegion = 0) 214 { /* does nothing */ } 215 216 // should resize the items frame by the specified amount 217 virtual void ResizeBy( 218 float horizontal, 219 float vertical) 220 { /* does nothing */ } 221 222protected: // *** selecting/dragging 223 224 // turn on/off the built-in selection handling 225 void makeSelectable( 226 bool selectable) 227 { m_selectable = selectable; } 228 bool isSelectable() const 229 { return m_selectable; } 230 231 // turn on/off the built-in drag & drop handling 232 void makeDraggable( 233 bool draggable) 234 { m_draggable = draggable; } 235 bool isDraggable() const 236 { return m_draggable; } 237 238protected: // *** compare functions 239 240 // compares the time when each item was last selected and 241 // returns -1 for the most recent. 242 friend int compareSelectionTime( 243 const void *lValue, 244 const void *rValue); 245 246protected: // *** internal methods 247 248 // called only by DiagramItemGroup objects in the method 249 // addItem() 250 virtual void _SetOwner( 251 DiagramView *owner) 252 { m_view = owner; } 253 254private: // *** data members 255 256 // the items type (M_BOX, M_WIRE or M_ENDPOINT) 257 uint32 m_type; 258 259 // a pointer to the drawing context (the DiagramView instance) 260 DiagramView *m_view; 261 262 // a pointer to the DiagramItemGroup the item belongs to 263 DiagramItemGroup *m_group; 264 265 // can the object be dragged 266 bool m_draggable; 267 268 // can the object be selected 269 bool m_selectable; 270 271 // is the object currently selected 272 bool m_selected; 273 274 // when was the object selected the last time or added (used 275 // for drawing order) 276 bigtime_t m_selectionTime; 277 278 // stores the most recent time a item was selected thru 279 // the select() method 280 static bigtime_t m_lastSelectionTime; 281 282 // counts the number of selections thru selectAdding() 283 // since the last call to select() 284 static int32 m_countSelected; 285}; 286 287__END_CORTEX_NAMESPACE 288#endif /* __DiagramItem_H__ */ 289