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diff --git a/tests/manual/findfiles/findfiles.qdoc b/tests/manual/findfiles/findfiles.qdoc new file mode 100644 index 0000000000..ec00698703 --- /dev/null +++ b/tests/manual/findfiles/findfiles.qdoc @@ -0,0 +1,269 @@ +// Copyright (C) 2016 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only + +/*! + \example dialogs/findfiles + \title Find Files Example + \ingroup examples-dialogs + + \brief A dialog for finding files in a specified folder. + + The Find Files application allows the user to search for files in a + specified directory, matching a given file name or wildcard, + and containing a specified string (if filled in). The search + result is displayed in a table containing the names of the files + and their sizes. The application also shows the number of files found. + + The Find Files example illustrates the use of several classes: + + \table + \row + \li QProgressDialog + \li Provide feedback on the progress of a search operation + \row + \li QFileDialog + \li Browse through a file list + \row + \li QTextStream + \li Use stream operators to read a file + \row + \li QTableWidget + \li Browse through the search results in a table + \row + \li QDesktopServices + \li Open files in the result list in a suitable application + \endtable + + \image findfiles-example.png Screenshot of the Find Files example + + + \section1 Window Class Definition + + The \c Window class inherits QWidget, and is the main application + widget. It shows the search options and displays the search + results. + + \snippet dialogs/findfiles/window.h 0 + + The application has two private slots: + \table + \row + \li The \c browse() slot + \li Called whenever the user wants to browse for a directory to search in + \row + \li The \c find() slot + \li Called whenever the user launches a search with the \uicontrol Find button + \endtable + + In addition we declare several private functions: + + \table + \row + \li findFiles() + \li Search for files matching the search parameters + \row + \li showFiles() + \li Display the search result + \row + \li ceateButton() + \li Construct the widget + \row + \li createComboBox() + \li Construct the widget + \row + \li createFilesTable() + \li Construct the widget + \endtable + + \section1 Window Class Implementation + + In the constructor we first create the application's widgets. + + \snippet dialogs/findfiles/window.cpp 0 + + We create the widgets to build up the UI, and we add them to a main layout + using QGridLayout. We have, however, put the \c Find and \c Quit buttons + and a stretchable space in a separate \l QHBoxLayout first, to make the + buttons appear in the \c Window widget's bottom right corner. + + Alternatively, we could have used \QD to construct a UI file, + and \l {uic} to generate this code. + + \snippet dialogs/findfiles/window.cpp 1 + + We did not create a \l QMenuBar with a \uicontrol Quit menu item; but we + would still like to have a keyboard shortcut for quitting. Since we + construct a \l QShortcut with \l QKeySequence::Quit, and connect it to + \l QApplication::quit(), on most platforms it will be possible to press + Control-Q to quit (or whichever standard Quit key is configured on that platform). + (On \macos, this is redundant, because every application gets a + \uicontrol Quit menu item automatically; but it helps to make the application portable.) + + \snippet dialogs/findfiles/window.cpp 2 + + The \c browse() slot presents a file dialog to the user, using the + QFileDialog class. QFileDialog enables a user to traverse the file + system in order to select one or many files or a directory. The + easiest way to create a QFileDialog is to use the convenience + static functions. + + Here we use the static QFileDialog::getExistingDirectory() + function which returns an existing directory selected by the + user. Then we display the directory in the directory combobox + using the QComboBox::addItem() function and update the current + index. + + QComboBox::addItem() adds an item to the combobox with the given + text (if not already present in the list), and containing + the specified userData. The item is appended to the list of + existing items. + + \snippet dialogs/findfiles/window.cpp 3 + + The \c find() slot is called whenever the user requests a new + search by pressing the \uicontrol Find button. + + First we eliminate any previous search results by setting the + table widgets row count to zero. Then we retrieve the + specified file name, text, and directory path from the respective + comboboxes. + + \snippet dialogs/findfiles/window.cpp 4 + + We use the directory's path to create a QDir; the QDir class + provides access to the directory structure and its contents. + + We use QDirIterator to iterate over the files that match the + specified file name and build a QStringList of paths. + + Then we search through all the files in the list, using the private + \c findFiles() function, eliminating the ones that don't contain the + specified text. We sort them (because QDirIterator did not). And finally, + we display the results using the private \c showFiles() function. + + If the user didn't specify any text, there is no reason to search + through the files, so we sort and display the results immediately. + + \image findfiles_progress_dialog.png Screenshot of the Progress Dialog + + \snippet dialogs/findfiles/window.cpp 5 + + In the private \c findFiles() function we search through a list of + files, looking for the ones that contain a specified text. This + can be a very slow operation depending on the number of files as + well as their sizes. QProgressDialog displays a progress dialog + if the application has to search through a large number of files, + or if some of the files have a large size. QProgressDialog can + also allow the user to abort the operation if it takes too much + time. + + \snippet dialogs/findfiles/window.cpp 6 + + We run through the files, one at a time, and for each file we + update the QProgressDialog value. This property holds the current + amount of progress made. We also update the progress dialog's + label. + + Then we call the QCoreApplication::processEvents() function using + the QApplication object. In this way we interleave the display of + the progress made with the process of searching through the files + so the application doesn't appear to be frozen. + + The QApplication class manages the GUI application's control flow + and main settings. It contains the main event loop, where all + events from the window system and other sources are processed and + dispatched. QApplication inherits QCoreApplication. The + QCoreApplication::processEvents() function processes all pending + events according to the specified QEventLoop::ProcessEventFlags + until there are no more events to process. The default flags are + QEventLoop::AllEvents. + + \snippet dialogs/findfiles/window.cpp 7 + + After updating the QProgressDialog, we open the file in read-only + mode, and read one line at a time using QTextStream. + + The QTextStream class provides a convenient interface for reading + and writing text. Using QTextStream's streaming operators, you can + conveniently read and write words, lines and numbers. + + For each line we read we check if the QProgressDialog has been + canceled. If it has, we abort the operation, otherwise we check if + the line contains the specified text. When we find the text within + one of the files, we add the file's name to a list of found files + that contain the specified text, and start searching a new file. + + Finally, we return the list of the files found. + + \snippet dialogs/findfiles/window.cpp 8 + + Both the \c findFiles() and \c showFiles() functions are called from + the \c find() slot. In the \c showFiles() function we run through + the provided list of file names, adding each relative file name to the + first column in the table widget and retrieving the file's size using + QFileInfo for the second column. We use \l QLocale::formattedDataSize() + to format the file size in a human-readable form. For later use, we set + the absolute path as a data on the QTableWidget using the + the role absoluteFileNameRole defined to be Qt::UserRole + 1. + + \snippet dialogs/findfiles/window.cpp 17 + + This allows for retrieving the name of an item using a + convenience function: + + \snippet dialogs/findfiles/window.cpp 18 + + We also update the total number of files found. + + \snippet dialogs/findfiles/window.cpp 10 + + The private \c createComboBox() function is also called from the + constructor. We create a QComboBox with the given text, and make it + editable. + + When the user enters a new string in an editable combobox, the + widget may or may not insert it, and it can insert it in several + locations, depending on the QComboBox::InsertPolicy. The default + policy is is QComboBox::InsertAtBottom. + + Then we add the provided text to the combobox, and specify the + widget's size policies, before we return a pointer to the + combobox. + + \snippet dialogs/findfiles/window.cpp 11 + + The private \c createFilesTable() function is called from the + constructor. In this function we create the QTableWidget that + will display the search results. We set its horizontal headers and + their resize mode. + + QTableWidget inherits QTableView which provides a default + model/view implementation of a table view. The + QTableView::horizontalHeader() function returns the table view's + horizontal header as a QHeaderView. The QHeaderView class provides + a header row or header column for item views, and the + QHeaderView::setResizeMode() function sets the constraints on how + the section in the header can be resized. + + Finally, we hide the QTableWidget's vertical headers using the + QWidget::hide() function, and remove the default grid drawn for + the table using the QTableView::setShowGrid() function. + + \snippet dialogs/findfiles/window.cpp 12 + + \snippet dialogs/findfiles/window.cpp 14 + + The \c openFileOfItem() slot is invoked when the user double + clicks on a cell in the table. The QDesktopServices::openUrl() + knows how to open a file given the file name. + + \snippet dialogs/findfiles/window.cpp 15 + \snippet dialogs/findfiles/window.cpp 16 + + We set the context menu policy to of the table view to Qt::CustomContextMenu + and connect a slot contextMenu() to its signal + customContextMenuRequested(). We retrieve the absolute file name + from the data of the QTableWidgetItem and populate the context menu + with actions offering to copy the file name and to open the file. +*/ + |