1 /* |
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2 * Copyright (c) 2007 Nokia Corporation and/or its subsidiary(-ies). |
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3 * All rights reserved. |
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4 * This component and the accompanying materials are made available |
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5 * under the terms of "Eclipse Public License v1.0" |
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6 * which accompanies this distribution, and is available |
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7 * at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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8 * |
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9 * Initial Contributors: |
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10 * Nokia Corporation - initial contribution. |
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11 * |
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12 * Contributors: |
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13 * |
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14 * Description: Device state watcher class. |
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15 * |
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16 */ |
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17 |
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18 |
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19 #ifndef USBDEVICESTATEWATCHER_H |
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20 #define USBDEVICESTATEWATCHER_H |
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21 |
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22 // INCLUDE FILES |
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23 #include <e32base.h> |
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24 #include <usbman.h> |
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25 |
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26 /** |
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27 * A callback interface for informing about device state changes |
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28 */ |
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29 class MUSBDeviceStateObserver |
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30 { |
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31 public: |
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32 |
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33 /** |
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34 * Informs the observer that USB device state has changed. |
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35 * @param aPreviousState previous device state. |
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36 * @param aCurrentState current device state. |
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37 */ |
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38 virtual void DeviceStateChanged(TUsbDeviceState aPreviousState, |
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39 TUsbDeviceState aCurrentState) = 0; |
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40 }; |
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41 |
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42 // CLASS DECLARATION |
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43 |
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44 /** |
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45 * Class that listens for USB device state changes and notifies |
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46 * the observer. |
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47 */ |
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48 class CUSBDeviceStateWatcher : public CActive |
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49 { |
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50 public: // Constructors and destructor |
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51 |
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52 /** |
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53 * Two-phased constructor. Uses existing usb manager session. |
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54 * Note that it's not possible (and usually not necessary) to attach |
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55 * more than one USBDeviceStateWatcher to the same session. |
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56 * |
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57 * @param aObserver Reference to device state observer. |
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58 * @param aUsbMan Existing usb manager session. |
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59 * @return Pointer to created object. |
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60 */ |
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61 static CUSBDeviceStateWatcher* NewL(MUSBDeviceStateObserver& aObserver, |
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62 RUsb& aUsbMan); |
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63 |
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64 /** |
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65 * Two-phased constructor. Creates its own usb manager session. |
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66 * |
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67 * @param aObserver Reference to device state observer. |
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68 * @return Pointer to created object. |
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69 */ |
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70 static CUSBDeviceStateWatcher* NewL(MUSBDeviceStateObserver& aObserver); |
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71 |
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72 /** |
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73 * Destructor. |
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74 */ |
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75 virtual ~CUSBDeviceStateWatcher(); |
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76 |
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77 public: // from base class CActive |
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78 |
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79 /** |
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80 * From CActive. |
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81 * This method is called when device state has changed. |
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82 */ |
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83 void RunL(); |
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84 |
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85 /** |
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86 * From CActive. |
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87 * In this implementation this method should never be called. |
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88 * |
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89 * @param aError the leave code |
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90 * @return KErrNone |
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91 */ |
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92 TInt RunError(TInt aError); |
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93 |
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94 /** |
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95 * From CActive |
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96 * If there is outstanding request pending when Cancel() is called then |
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97 * this method must cancel request. |
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98 */ |
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99 void DoCancel(); |
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100 |
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101 private: |
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102 |
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103 /** |
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104 * Private constructor. |
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105 * |
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106 * @param aObserver Reference to MUSBDeviceStateObserver. |
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107 */ |
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108 CUSBDeviceStateWatcher(MUSBDeviceStateObserver& aObserver); |
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109 |
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110 /** |
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111 * 2nd phase constructor. |
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112 * Creates its own usb manager session. |
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113 */ |
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114 void ConstructL(); |
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115 |
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116 /** |
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117 * 2nd phase constructor. |
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118 * Uses existing usb manager session. |
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119 * |
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120 * @param aUsbMan Existing usb manager session. |
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121 */ |
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122 void ConstructL(RUsb& aUsbMan); |
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123 |
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124 /** |
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125 * Code shared by all ConstructL methods. |
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126 */ |
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127 void CommonConstructL(); |
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128 |
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129 // Disable default C++ behavior that makes no sense |
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130 // for this implementation. |
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131 CUSBDeviceStateWatcher(); |
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132 CUSBDeviceStateWatcher(const CUSBDeviceStateWatcher&); |
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133 CUSBDeviceStateWatcher& operator=(const CUSBDeviceStateWatcher&); |
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134 |
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135 private: // Data |
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136 |
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137 /** |
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138 * Handle to Usb Manager |
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139 */ |
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140 RUsb iUsbMan; |
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141 |
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142 /** |
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143 * Current device state |
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144 */ |
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145 TUsbDeviceState iCurrentState; |
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146 |
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147 /** |
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148 * Last known device state |
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149 */ |
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150 TUsbDeviceState iPreviousState; |
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151 |
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152 /** |
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153 * Refernce to the observer |
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154 */ |
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155 MUSBDeviceStateObserver& iObserver; |
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156 }; |
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157 |
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158 #endif // USBDEVICESTATEWATCHER_H |
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