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1 // Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies). |
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2 // All rights reserved. |
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3 // This component and the accompanying materials are made available |
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4 // under the terms of "Eclipse Public License v1.0" |
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5 // which accompanies this distribution, and is available |
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6 // at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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7 // |
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8 // Initial Contributors: |
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9 // Nokia Corporation - initial contribution. |
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10 // |
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11 // Contributors: |
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12 // |
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13 // Description: |
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14 // |
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15 |
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16 #ifndef __CALLBACK_H__ |
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17 #define __CALLBACK_H__ |
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18 |
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19 /** |
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20 @file |
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21 @internalTechnology |
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22 */ |
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23 |
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24 #include <e32cmn.h> |
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25 |
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26 /** enum to identify why callback is invoked. */ |
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27 enum TCallBackId |
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28 { |
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29 ECallBackId_None = 0, |
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30 ECallBackId_ImplUpgrade, |
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31 ECallBackId_SwiEvent, |
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32 ECallBackId_BurEvent |
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33 }; |
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34 |
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35 /** enum to generalize start and end of SWI or BUR */ |
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36 enum TCallBackState |
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37 { |
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38 ECallBackState_EventEnd, |
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39 ECallBackState_EventStart |
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40 }; |
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41 |
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42 /** |
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43 This description is cloned from TCallBack in e32std.h. The only difference |
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44 between TCallBack and TCallBackWithArg is that the callback of the |
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45 latter takes 3 arguments. |
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46 TCallBackWithArg encapsulates a general call-back function. |
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47 The class encapsulates: |
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48 1. a pointer to a function which takes 3 arguments, TAny*, TInt, and TAny* |
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49 and returns a TInt. |
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50 2. a pointer which is passed to the function every time it is called. |
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51 The pointer can point to any object. This pointer is required in the constructor |
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52 but can be NULL if not used. |
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53 3. The TInt and the other TAny* arguments are passed in when invoking the callback |
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54 function. |
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55 Do not let the names of the 3 callback arguments dictate their uses. Feel free |
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56 to store anything you want or ignore anyone that is not needed. |
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57 |
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58 The callback function can be a static function of a class, |
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59 e.g. static TInt X::Foo(TAny*, TInt, TAny*) or |
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60 it can be a function which is not a member of any class, e.g. |
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61 TInt Foo(TAny *, TInt, TAny*). |
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62 */ |
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63 class TCallBackWithArg |
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64 { |
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65 public: |
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66 // default constructor |
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67 inline TCallBackWithArg(); |
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68 |
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69 // Real constructor requires the callback function and a pointer. |
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70 inline TCallBackWithArg(TInt (*aFunction)(TAny* aObj, TInt aEvent, TAny* aData), TAny* aObj); |
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71 |
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72 inline TInt CallBack(TInt aEvent = ECallBackId_None, |
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73 TAny* aData = NULL) const; |
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74 public: |
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75 /** A pointer to the callback function. */ |
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76 TInt (*iFunction)(TAny* aObj, TInt aEvent, TAny* aData); |
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77 |
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78 /** the first argument in the callback function. */ |
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79 TAny* iObj; |
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80 }; |
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81 |
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82 // |
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83 // Implementation of TCallBackWithArg |
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84 // |
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85 |
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86 /** Default contructor sets the callback function |
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87 to NULL. This way a not yet initialized callback object will just |
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88 do nothing. */ |
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89 inline TCallBackWithArg::TCallBackWithArg() |
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90 : iFunction(NULL), iObj(NULL) |
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91 { } |
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92 |
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93 inline TCallBackWithArg::TCallBackWithArg(TInt (*aFunction)(TAny*, TInt, TAny*), TAny* aObj) |
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94 : iFunction(aFunction), iObj(aObj) |
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95 { } |
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96 |
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97 inline TInt TCallBackWithArg::CallBack(TInt aEvent, TAny* aData) const |
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98 { |
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99 return (iFunction ? (*iFunction)(iObj, aEvent, aData) : 0); |
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100 } |
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101 |
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102 #endif |