1 /* |
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2 * Copyright (c) 2004 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: Image Transforms subsystem. |
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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 |
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20 |
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21 |
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22 #ifndef CVTIMAGESCALER_H |
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23 #define CVTIMAGESCALER_H |
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24 |
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25 // INCLUDE FILES |
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26 |
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27 #include <e32base.h> |
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28 |
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29 // FORWARD DECLARATIONS |
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30 |
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31 class CVtImageScalerImpl; |
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32 class CVtImage; |
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33 class CFbsBitmap; |
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34 |
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35 // CLASS DECLARATIONS |
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36 |
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37 /** |
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38 * Image scaler observer interface. |
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39 * |
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40 * @lib videosource.lib |
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41 */ |
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42 class MVtImageScalerObserver |
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43 { |
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44 public: |
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45 /** |
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46 * Callback method that is called by CVtImageScaler when scaling has |
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47 * finished. |
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48 * @param "aError" KErrNone if the scaling was done successfully, one |
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49 * of the system wide error codes otherwise. |
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50 * @return Pointer to newly created instance. |
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51 */ |
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52 virtual void ScalingFinished( TInt aError ) = 0; |
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53 }; |
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54 |
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55 /** |
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56 * Image scaler. |
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57 * |
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58 * @lib videosource.lib |
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59 */ |
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60 class CVtImageScaler : public CActive |
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61 { |
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62 public: |
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63 |
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64 /** |
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65 * An enumeration within the CVtImageScaler namespace. |
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66 * It provides a set of panic codes that may happen during |
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67 * scaling process. |
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68 */ |
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69 enum TPanics |
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70 { |
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71 /** |
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72 * RotateL() is called while previous rotation process |
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73 * has not yet been finished. |
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74 */ |
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75 EBusy = 1 |
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76 }; |
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77 |
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78 /** |
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79 * An enumeration within the CVtImageScaler namespace. |
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80 * It provides a set of supported scaling quality settings. |
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81 */ |
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82 enum TQuality |
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83 { |
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84 /** |
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85 * Nearest neigbour algorithm. Fast but poor image quality |
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86 * when scale factor exceeds 2x. |
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87 */ |
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88 ENearest, |
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89 |
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90 /** |
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91 * Weighted average algorithm. Slower than Nearest Neighbour |
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92 * but also better image quality when scaling at factor 2x or |
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93 * higher. |
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94 */ |
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95 EWeightedAverage, |
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96 |
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97 /** |
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98 * Bilinear scaling algorithm. Slower than Weighted Average |
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99 * but also better image quality. |
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100 */ |
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101 EBilinear |
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102 }; |
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103 |
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104 public: |
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105 |
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106 /** |
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107 * Creates new instance of CVtImageScaler. |
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108 * @param "aObserver" Reference to instance observer. |
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109 * @param "aQuality" Scaling quality. If this is omitted, then default |
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110 * value of EWeightedAverage is used. |
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111 * @param "aPriority" Active object priority. |
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112 * @exception In error situation leaves with one of the system wide |
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113 * error codes. |
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114 * @return Pointer to newly created instance. |
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115 */ |
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116 IMPORT_C static CVtImageScaler* NewL( |
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117 MVtImageScalerObserver& aObserver, |
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118 TQuality aQuality = EWeightedAverage, |
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119 TPriority aPriority = EPriorityStandard ); |
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120 |
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121 /** |
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122 * C++ destructor. |
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123 */ |
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124 IMPORT_C ~CVtImageScaler(); |
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125 |
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126 /** |
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127 * Sets scaling quality. |
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128 * @param "aQuality" Scaling quality. |
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129 * @exception In error situation leaves with one of the system wide |
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130 * error codes. |
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131 */ |
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132 IMPORT_C void SetQualityL( TQuality aQuality ); |
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133 |
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134 /** |
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135 * Scales image to new size. |
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136 * @param "aSource" Source image that will be scaled. |
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137 * @param "aTarget" Target image that will hold the scaled image. New |
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138 * image's dimensions |
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139 * will be taken from the size of target image. |
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140 * @exception In error situation leaves with one of the system wide |
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141 * error codes. |
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142 */ |
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143 IMPORT_C void ScaleL( const CVtImage& aSource, CVtImage& aTarget ); |
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144 |
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145 /** |
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146 * Scales image to new size. Possible error during initialization is |
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147 * returned via MVtImageScalerObserver. |
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148 * @param "aSource" Source image that will be scaled. |
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149 * @param "aTarget" Target image that will hold the scaled image. New |
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150 * image's dimensions will be taken from the size of target image. |
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151 */ |
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152 IMPORT_C void Scale( const CVtImage& aSource, CVtImage& aTarget ); |
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153 |
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154 /** |
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155 * Scales image to new size. This scale method is synchronous and |
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156 * aTarget will contain scaled image of aSource on return. This method |
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157 * may leave if aSource and/or aTarget are not suitable for scaling. |
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158 * MVtImageScalerObserver::ScalingFinished is not called when this |
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159 * method is used. |
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160 * @param "aSource" Source image that will be scaled. |
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161 * @param "aTarget" Target image that will hold the scaled image. New |
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162 * image's dimensions will be taken from the size of target image. |
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163 */ |
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164 IMPORT_C void ScaleNowL( const CVtImage& aSource, CVtImage& aTarget ); |
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165 |
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166 private: // internal |
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167 |
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168 /** |
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169 * C++ default constructor. |
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170 */ |
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171 CVtImageScaler(); |
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172 |
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173 /** |
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174 * C++ constructor. |
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175 * @param "aObserver" Reference to observer. |
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176 * @param "aPriority" Active object priority. |
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177 * @exception In error situation leaves with one of the system wide |
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178 * error codes. |
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179 */ |
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180 CVtImageScaler( MVtImageScalerObserver& aObserver, TPriority aPriority ); |
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181 |
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182 /** |
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183 * Second phase constructor. |
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184 * @param "aQuality" Quality of the scaling. |
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185 * @exception In error situation leaves with one of the system wide |
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186 * error codes. |
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187 */ |
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188 void ConstructL( TQuality aQuality ); |
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189 |
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190 /** |
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191 * Sets iStatus to KRequestPending and calls CActive::SetActive(). |
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192 */ |
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193 void Activate(); |
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194 |
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195 /** |
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196 * Signals this instance AO with given error code. |
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197 * @param "aError" Signalling error code. |
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198 */ |
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199 void Signal( TInt aError ); |
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200 |
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201 private: // from CActive |
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202 |
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203 /** |
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204 * This is defined in CActive. Check CActive for description. |
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205 */ |
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206 void RunL(); |
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207 |
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208 /** |
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209 * This is defined in CActive. Check CActive for description. |
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210 */ |
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211 void DoCancel(); |
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212 |
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213 /** |
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214 * Scale method called by the CAsyncCallBack. |
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215 */ |
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216 static TInt StaticScale( TAny* aPtr ); |
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217 |
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218 /** |
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219 * Scale method called by the StaticScale. |
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220 */ |
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221 void DoScale(); |
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222 |
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223 private: |
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224 |
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225 // Scaling observer |
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226 MVtImageScalerObserver& iObserver; |
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227 |
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228 // Active quality implementation |
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229 CVtImageScalerImpl* iScalerImpl; // owned |
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230 |
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231 // Bitmap that will be used for locking global bitmap heap |
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232 CFbsBitmap* iHeapLock; // owned |
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233 |
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234 // Asynccallback instance |
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235 CAsyncCallBack* iAsyncCallBack; // owned |
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236 |
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237 // This is set to ETrue in DoCancel() method, and when CAsyncCallBack |
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238 // gets executed, iCancelled is checked whether scaling should be done |
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239 // or not. |
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240 TBool iCancelled; |
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241 }; |
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242 |
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243 #endif // CVTIMAGESCALER_H |
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244 |
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245 // End of File |
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246 |
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247 |
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