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1 /**************************************************************************** |
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2 ** |
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3 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). |
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38 ** $QT_END_LICENSE$ |
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39 ** |
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40 ****************************************************************************/ |
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41 |
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42 /*! |
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43 \example tools/treemodelcompleter |
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44 \title Tree Model Completer Example |
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45 |
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46 The Tree Model Completer example shows how to provide completion |
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47 facilities for a hierarchical model, using a period as the separator |
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48 to access Child, GrandChild and GrandGrandChild level objects. |
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49 |
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50 \image treemodelcompleter-example.png |
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51 |
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52 Similar to the \l{Completer Example}, we provide QComboBox objects to |
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53 enable selection for completion mode and case sensitivity, as well as |
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54 a QCheckBox for wrap completions. |
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55 |
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56 \section1 The Resource File |
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57 |
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58 The contents of the TreeModelCompleter is read from \e treemodel.txt. |
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59 This file is embedded within the \e treemodelcompleter.qrc resource file, |
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60 which contains the following: |
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61 |
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62 \quotefile examples/tools/treemodelcompleter/treemodelcompleter.qrc |
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63 |
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64 \section1 TreeModelCompleter Class Definition |
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65 |
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66 The \c TreeModelCompleter is a subclass of QCompleter with two |
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67 constructors - one with \a parent as an argument and another with |
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68 \a parent and \a model as arguments. |
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69 |
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70 \snippet examples/tools/treemodelcompleter/treemodelcompleter.h 0 |
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71 |
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72 The class reimplements the protected functions |
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73 \l{QCompleter::splitPath()}{splitPath()} and |
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74 \l{QCompleter::pathFromIndex()}{pathFromIndex()} to suit a tree model. |
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75 For more information on customizing QCompleter to suit tree models, refer |
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76 to \l{QCompleter#Handling Tree Models}{Handling Tree Models}. |
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77 |
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78 \c TreeModelCompleter also has a separator property which is declared |
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79 using the Q_PROPERTY() macro. The separator has READ and WRITE attributes |
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80 and the corresponding functions \c separator() and \c setSeparator(). For |
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81 more information on Q_PROPERTY(), refer to \l{Qt's Property System}. |
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82 |
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83 \section1 TreeModelCompleter Class Implementation |
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84 |
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85 The first constructor constructs a \c TreeModelCompleter object with a |
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86 parent while the second constructor constructs an object with a parent |
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87 and a QAbstractItemModel, \a model. |
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88 |
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89 \snippet examples/tools/treemodelcompleter/treemodelcompleter.cpp 0 |
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90 \codeline |
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91 \snippet examples/tools/treemodelcompleter/treemodelcompleter.cpp 1 |
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92 |
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93 The \c separator() function is a getter function that returns the |
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94 separator string. |
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95 |
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96 \snippet examples/tools/treemodelcompleter/treemodelcompleter.cpp 2 |
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97 |
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98 As mentioned earlier, the \c splitPath() function is reimplemented because |
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99 the default implementation is more suited to QDirModel or list models. In |
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100 order for QCompleter to split the path into a list of strings that are |
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101 matched at each level, we split it using QString::split() with \c sep as its |
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102 separator. |
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103 |
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104 \snippet examples/tools/treemodelcompleter/treemodelcompleter.cpp 3 |
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105 |
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106 The \c pathFromIndex() function returns data for the completionRole() for a |
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107 tree model. This function is reimplemented as its default implementation is |
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108 more suitable for list models. If there is no separator, we use |
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109 \l{QCompleter}'s default implementation, otherwise we use the |
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110 \l{QStringList::prepend()}{prepend()} function to navigate upwards and |
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111 accumulate the data. The function then returns a QStringList, \c dataList, |
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112 using a separator to join objects of different levels. |
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113 |
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114 \snippet examples/tools/treemodelcompleter/treemodelcompleter.cpp 4 |
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115 |
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116 \section1 MainWindow Class Definition |
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117 |
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118 The \c MainWindow class is a subclass of QMainWindow and implements five |
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119 custom slots: \c about(), \c changeCase(), \c changeMode(), |
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120 \c highlight(), and \c updateContentsLabel(). |
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121 |
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122 \snippet examples/tools/treemodelcompleter/mainwindow.h 0 |
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123 |
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124 In addition, the class has two private functions, \c createMenu() and |
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125 \c modelFromFile(), as well as private instances of QTreeView, QComboBox, |
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126 QLabel, \c TreeModelCompleter and QLineEdit. |
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127 |
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128 \snippet examples/tools/treemodelcompleter/mainwindow.h 1 |
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129 |
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130 \section1 MainWindow Class Implementation |
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131 |
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132 The \c{MainWindow}'s constructor creates a \c MainWindow object with a |
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133 parent and initializes the \c completer and \c lineEdit. The |
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134 \c createMenu() function is invoked to set up the "File" menu and "Help" |
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135 menu. The \c{completer}'s model is set to the QAbstractItemModel obtained |
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136 from \c modelFromFile(), and the \l{QCompleter::highlighted()} |
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137 {highlighted()} signal is connected to \c{MainWindow}'s \c highlight() |
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138 slot. |
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139 |
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140 \snippet examples/tools/treemodelcompleter/mainwindow.cpp 0 |
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141 |
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142 The QLabel objects \c modelLabel, \c modeLabel and \c caseLabel are |
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143 instantiated. Also, the QComboBox objects, \c modeCombo and \c caseCombo, |
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144 are instantiated and populated. By default, the \c{completer}'s mode is |
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145 "Filtered Popup" and the case is insensitive. |
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146 |
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147 \snippet examples/tools/treemodelcompleter/mainwindow.cpp 1 |
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148 \codeline |
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149 \snippet examples/tools/treemodelcompleter/mainwindow.cpp 2 |
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150 |
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151 We use a QGridLayout to place all the objects in the \c MainWindow. |
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152 |
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153 \snippet examples/tools/treemodelcompleter/mainwindow.cpp 3 |
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154 |
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155 The \c createMenu() function sets up the QAction objects required and |
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156 adds them to the "File" menu and "Help" menu. The |
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157 \l{QAction::triggered()}{triggered()} signals from these actions are |
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158 connected to their respective slots. |
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159 |
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160 \snippet examples/tools/treemodelcompleter/mainwindow.cpp 4 |
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161 |
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162 The \c changeMode() function accepts an \a index corresponding to the |
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163 user's choice of completion mode and changes the \c{completer}'s mode |
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164 accordingly. |
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165 |
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166 \snippet examples/tools/treemodelcompleter/mainwindow.cpp 5 |
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167 |
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168 The \c about() function provides a brief description on the Tree Model |
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169 Completer example. |
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170 |
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171 \snippet examples/tools/treemodelcompleter/mainwindow.cpp 6 |
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172 |
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173 The \c changeCase() function alternates between \l{Qt::CaseSensitive} |
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174 {Case Sensitive} and \l{Qt::CaseInsensitive}{Case Insensitive} modes, |
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175 depending on the value of \a cs. |
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176 |
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177 \snippet examples/tools/treemodelcompleter/mainwindow.cpp 7 |
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178 |
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179 \section1 \c main() Function |
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180 |
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181 The \c main() function instantiates \c MainWindow and invokes the |
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182 \l{QWidget::show()}{show()} function to display it. |
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183 |
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184 \snippet examples/tools/treemodelcompleter/main.cpp 0 |
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185 */ |