Mercurial > projects > dynamin
annotate dynamin/core/event.d @ 7:1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
and clean up code a little.
| author | Jordan Miner <jminer7@gmail.com> |
|---|---|
| date | Wed, 15 Jul 2009 13:59:16 -0500 |
| parents | aa4efef0f0b1 |
| children | ccc108b25a0a |
| rev | line source |
|---|---|
| 0 | 1 // Written in the D programming language |
| 2 // www.digitalmars.com/d/ | |
| 3 | |
| 4 /* | |
| 5 * The contents of this file are subject to the Mozilla Public License Version | |
| 6 * 1.1 (the "License"); you may not use this file except in compliance with | |
| 7 * the License. You may obtain a copy of the License at | |
| 8 * http://www.mozilla.org/MPL/ | |
| 9 * | |
| 10 * Software distributed under the License is distributed on an "AS IS" basis, | |
| 11 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License | |
| 12 * for the specific language governing rights and limitations under the | |
| 13 * License. | |
| 14 * | |
| 15 * The Original Code is the Dynamin library. | |
| 16 * | |
| 17 * The Initial Developer of the Original Code is Jordan Miner. | |
| 18 * Portions created by the Initial Developer are Copyright (C) 2006-2009 | |
| 19 * the Initial Developer. All Rights Reserved. | |
| 20 * | |
| 21 * Contributor(s): | |
| 22 * Jordan Miner <jminer7@gmail.com> | |
| 23 * | |
| 24 */ | |
| 25 | |
| 26 module dynamin.core.event; | |
| 27 | |
| 28 import tango.io.Stdout; | |
| 29 import dynamin.core.global; | |
| 30 import tango.core.Exception; | |
|
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1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
|
31 public import tango.core.Traits; |
| 0 | 32 |
| 33 /** | |
| 34 * A class used to notify handlers of an event. It is similar to .NET's events. | |
| 35 * Here is an example of its usage: | |
| 36 * ----- | |
| 37 * class Control { | |
| 38 * public { | |
| 39 * Event!(PaintingEventArgs) painting; | |
| 40 * protected void whenPainting(PaintingEventArgs e) { | |
| 41 * /+ painting code goes here +/ | |
| 42 * } | |
| 43 * this() { | |
| 44 * painting = new Event!(PaintingEventArgs)(&whenPainting); | |
| 45 * } | |
| 46 * } | |
| 47 * } | |
| 48 * ----- | |
| 49 * Then to add a handler to it: | |
| 50 * ----- | |
| 51 * Control control = new Control(); | |
| 52 * control.painting += (PaintingEventArgs e) { | |
| 53 * /+ painting code goes here +/ | |
| 54 * }; | |
| 55 * ----- | |
| 56 * And fire it in the Control like this: | |
| 57 * ----- | |
| 58 * painting(new PaintingEventArgs()); | |
| 59 * ----- | |
| 60 * Not as easy to use as I would like, but still much better than Java's | |
| 61 * event handling. | |
| 62 * When the event is fired, all the handlers are called first, followed | |
| 63 * by the delegate passed into the constructor. | |
| 64 */ | |
| 65 class Event(ArgsT = EventArgs) { | |
| 66 protected: | |
| 67 /// void delegate(ArgsT e) | |
| 68 public alias void delegate(ArgsT e) EventHandler; | |
| 69 /// void delegate(ArgsT e) | |
| 70 public alias void delegate(ArgsT e) EventDispatcher; | |
| 71 | |
| 72 EventHandler[] handlers; | |
| 73 EventHandler mainHandler; | |
| 74 EventDispatcher dispatcher; | |
| 75 public: | |
| 76 | |
| 77 /** | |
| 78 * Creates an event object. mainHandler is called after all | |
| 79 * the other handlers. | |
| 80 */ | |
| 81 this(EventHandler mainHandler) { | |
| 82 this.mainHandler = mainHandler; | |
| 83 dispatcher = &defaultDispatch; | |
| 84 } | |
| 85 /** | |
| 86 * Creates an event object. mainHandler is called after all | |
| 87 * the other handlers. | |
| 88 */ | |
| 89 this(EventHandler mainHandler, EventDispatcher dispatcher) { | |
| 90 this.mainHandler = mainHandler; | |
| 91 if(!dispatcher.funcptr) throw new Exception("dispatcher cannot be null"); | |
| 92 this.dispatcher = dispatcher; | |
| 93 } | |
| 94 /** | |
| 95 * Calls all the handlers added to this event, passing e to them. | |
| 96 */ | |
| 97 void opCall(ArgsT e) { | |
| 98 if(e is null) | |
| 99 Stdout("Warning: EventArgs null").newline; | |
| 100 dispatcher(e); | |
| 101 } | |
| 102 /** | |
| 103 * Adds handler to this event. handler will be called when the event is fired. | |
| 104 */ | |
| 105 void opAddAssign(EventHandler handler) { | |
| 106 if(!handler.funcptr) | |
| 107 throw new IllegalArgumentException("handler is null"); | |
| 108 handlers.length = handlers.length + 1; | |
| 109 handlers[length-1] = handler; | |
| 110 // TODO: use a list? | |
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7
1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
|
111 //handlers.add(handler); |
| 0 | 112 } |
| 113 /// ditto | |
| 114 void opAddAssign(void delegate() handler) { | |
| 115 struct Foo { | |
| 116 void delegate() handler; | |
| 117 void wrapper(ArgsT e) { handler(); } | |
| 118 } | |
| 119 Foo* f = new Foo; | |
| 120 f.handler = handler; | |
| 121 this += &f.wrapper; | |
| 122 // I really wish D could do this: | |
| 123 //this += (ArgsT e) { handler(); }; | |
| 124 } | |
| 125 /// TODO: implement this method | |
| 126 void opSubAssign(EventHandler handler) { | |
| 127 throw new Exception("Removing handlers not yet implemented"); | |
| 128 } | |
| 129 /** | |
| 130 * Calls the handlers (not including the main handler) added to this event. | |
| 131 * Only use this method from a method that does custom dispatching. | |
| 132 */ | |
| 133 void callHandlers(ArgsT e) { | |
| 134 foreach(handler; handlers) | |
| 135 handler(e); | |
| 136 } | |
| 137 /** | |
| 138 * Calls the main handler unless the StopEventArgs.stopped has been | |
| 139 * set to true. | |
| 140 * Only use this method from a method that does custom dispatching. | |
| 141 */ | |
| 142 void callMainHandler(ArgsT e) { | |
| 143 auto stopEventArgs = cast(StopEventArgs)e; | |
| 144 // if e is an instance of StopEventArgs, then check if it is canceled | |
| 145 if(stopEventArgs is null || !stopEventArgs.stopped) | |
| 146 mainHandler(e); | |
| 147 } | |
| 148 /** | |
| 149 * | |
| 150 */ | |
| 151 void defaultDispatch(ArgsT e) { | |
| 152 callHandlers(e); | |
| 153 callMainHandler(e); | |
| 154 } | |
| 155 } | |
| 156 | |
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1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
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157 // usage: mixin Event!(whenMoved) moved; |
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1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
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diff
changeset
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158 // mixin Event!(whenMoved, dispatchMoved) moved; |
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1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
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159 template Event2(alias mainHandler, alias dispatcher) { |
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1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
|
160 private: |
| 0 | 161 alias ParameterTupleOf!(mainHandler)[0] ArgsType; |
| 162 /// void delegate(ArgsType e) | |
| 163 public alias void delegate(ArgsType e) Handler; | |
| 164 /// void delegate(ArgsType e) | |
| 165 public alias void delegate(ArgsType e) Dispatcher; | |
| 166 | |
| 167 // TODO: use a list-like struct? | |
| 168 Handler[] handlers; | |
| 169 public: | |
| 170 | |
| 171 /** | |
| 172 * Calls all the handlers added to this event, passing e to them. | |
| 173 */ | |
| 174 void opCall(ArgsType e) { | |
| 175 if(e is null) | |
| 176 Stdout("Warning: EventArgs null").newline; | |
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1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
|
177 dispatcher(e); |
| 0 | 178 } |
| 179 /** | |
| 180 * Adds the specified handler to this event. The handler will be called | |
| 181 * when the event is fired. | |
| 182 */ | |
| 183 void opAddAssign(Handler handler) { | |
| 184 if(!handler.funcptr) throw new Exception("handler cannot be null"); | |
| 185 handlers.length = handlers.length + 1; | |
| 186 handlers[length-1] = handler; | |
| 187 // TODO: use a list? | |
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7
1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
|
188 //handlers.add(handler); |
| 0 | 189 } |
| 190 /// ditto | |
| 191 void opAddAssign(void delegate() handler) { | |
| 192 struct Foo { | |
| 193 void delegate() handler; | |
| 194 void wrapper(ArgsType e) { handler(); } | |
| 195 } | |
| 196 Foo* f = new Foo; | |
| 197 f.handler = handler; | |
| 198 this += &f.wrapper; | |
| 199 // I really wish D could do this: | |
| 200 //this += (ArgsType e) { handler(); }; | |
| 201 } | |
| 202 /// TODO: implement this method | |
| 203 void opSubAssign(Handler handler) { | |
| 204 throw new Exception("removing handlers not yet implemented"); | |
| 205 } | |
| 206 /** | |
| 207 * Calls the handlers (not including the main handler) added to this event. | |
| 208 * Only use this method from a method that does custom dispatching. | |
| 209 */ | |
| 210 void callHandlers(ArgsType e) { | |
| 211 foreach(handler; handlers) | |
| 212 handler(e); | |
| 213 } | |
| 214 /** | |
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7
1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
|
215 * Calls the main handler unless the StopEventArgs.stopped has been |
| 0 | 216 * set to true. |
| 217 * Only use this method from a method that does custom dispatching. | |
| 218 */ | |
| 219 void callMainHandler(ArgsType e) { | |
| 220 auto stopEventArgs = cast(StopEventArgs)e; | |
| 221 // if e is an instance of StopEventArgs, then check if it is stopped | |
| 222 if(stopEventArgs is null || !stopEventArgs.stopped) | |
| 223 mainHandler(e); | |
| 224 } | |
| 225 } | |
| 226 | |
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7
1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
|
227 template Event2(alias mainHandler) { |
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1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
|
228 alias ParameterTupleOf!(mainHandler)[0] ArgsType; |
|
1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
|
229 void defaultDispatch(ArgsType e) { |
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1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
|
230 callHandlers(e); |
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1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
|
231 callMainHandler(e); |
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1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
|
232 } |
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1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
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233 mixin Event2!(mainHandler, defaultDispatch); |
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1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
|
234 } |
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1311fae1ca9b
Change template mixin (still unused) to take a dispatcher
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
|
235 |
| 0 | 236 /// The base class for passing arguments to event handlers. |
| 237 // TODO: shorter name? | |
| 238 class EventArgs { | |
| 239 } | |
| 240 class StopEventArgs : EventArgs { | |
| 241 /** | |
| 242 * If Stopped is set to true, then the Control will not respond to | |
| 243 * the event. Like if a key is typed while a text box is focused, | |
| 244 * but a handler sets Stopped to true, the text box will not | |
| 245 * respond to the key. | |
| 246 */ | |
| 247 bool stopped = false; | |
| 248 } |