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Diffstat (limited to 'doc/src/tutorials/widgets-tutorial.qdoc')
-rw-r--r-- | doc/src/tutorials/widgets-tutorial.qdoc | 132 |
1 files changed, 121 insertions, 11 deletions
diff --git a/doc/src/tutorials/widgets-tutorial.qdoc b/doc/src/tutorials/widgets-tutorial.qdoc index ead44af..1e89431 100644 --- a/doc/src/tutorials/widgets-tutorial.qdoc +++ b/doc/src/tutorials/widgets-tutorial.qdoc @@ -41,11 +41,14 @@ /*! \page widgets-tutorial.html + \startpage {index.html}{Qt Reference Documentation} + \nextpage {tutorials/widgets/toplevel}{Creating a Window} \title Widgets Tutorial \ingroup tutorials - \brief This tutorial covers basic usage of widgets and layouts, showing how they are used to build GUI applications. + \brief This tutorial covers basic usage of widgets and layouts, showing how + they are used to build GUI applications. \section1 Introduction @@ -68,7 +71,60 @@ occupied by its parent. This means that, when a window is deleted, all the widgets it contains are automatically deleted. - \section1 Creating a Window + \section1 Writing a main Function + + Many of the GUI examples in Qt follow the pattern of having a \c{main.cpp} + file containing code to initialize the application, and a number of other + source and header files containing the application logic and custom GUI + components. + + A typical \c main() function, written in \c{main.cpp}, looks like this: + + \quotefile doc/src/snippets/widgets-tutorial/template.cpp + + We first construct a QApplication object which is configured using any + arguments passed in from the command line. After any widgets have been + created and shown, we call QApplication::exec() to start Qt's event loop. + Control passes to Qt until this function returns, at which point we return + the value we obtain from this function. + + In each part of this tutorial, we provide an example that is written + entirely within a \c main() function. In more sophisticated examples, the + code to set up widgets and layouts is written in other parts of the + example. For example, the GUI for a main window may be set up in the + constructor of a QMainWindow subclass. + + The \l{Qt Examples#Widgets}{Widgets examples} are a good place to look for + more complex and complete examples and applications. + + \section1 Building Examples and Tutorials + + If you obtained a binary package of Qt or compiled it yourself, the + examples described in this tutorial should already be ready to run. + However, if you may wish to modify them and recompile them, you need to + perform the following steps: + + \list 1 + \o At the command line, enter the directory containing the example you + wish to recompile. + \o Type \c qmake and press \key{Return}. If this doesn't work, make sure + that the executable is on your path, or enter its full location. + \o On Linux/Unix and Mac OS X, type \c make and press \key{Return}; + on Windows with Visual Studio, type \c nmake and press \key{Return}. + \endlist + + An executable file should have been created within the current directory. + On Windows, this file may be located within a \c debug or \c release + subdirectory. You can run this file to see the example code at work. +*/ + +/*! + \page widgets-tutorial-toplevel.html + \contentspage {Widgets Tutorial}{Contents} + \previouspage {Widgets Tutorial} + \nextpage {Widgets Tutorial - Child Widgets} + \example tutorials/widgets/toplevel + \title Widgets Tutorial - Creating a Window If a widget is created without a parent, it is treated as a window, or \e{top-level widget}, when it is shown. Since it has no parent object to @@ -82,7 +138,7 @@ <table align="left" width="100%"> <tr class="qt-code"><td> \endraw - \snippet snippets/widgets-tutorial/toplevel/main.cpp create, resize and show + \snippet tutorials/widgets/toplevel/main.cpp main program \raw HTML </td><td align="right"> \endraw @@ -92,15 +148,28 @@ </table> \endraw - We can add a child widget to this window by passing \c window as the - parent to its constructor. In this case, we add a button to the window - and place it in a specific location: + To create a real GUI, we need to place widgets inside the window. To do + this, we pass a QWidget instance to a widget's constructor, as we will + demonstrate in the next part of this tutorial. +*/ + +/*! + \page widgets-tutorial-childwidget.html + \contentspage {Widgets Tutorial}{Contents} + \previouspage {Widgets Tutorial - Creating a Window} + \nextpage {Widgets Tutorial - Using Layouts} + \example tutorials/widgets/childwidget + \title Widgets Tutorial - Child Widgets + + We can add a child widget to the window created in the previous example by + passing \c window as the parent to its constructor. In this case, we add a + button to the window and place it in a specific location: \raw HTML <table align="left" width="100%"> <tr class="qt-code"><td> \endraw - \snippet snippets/widgets-tutorial/childwidget/main.cpp create, position and show + \snippet tutorials/widgets/childwidget/main.cpp main program \raw HTML </td><td align="right"> \endraw @@ -112,9 +181,16 @@ The button is now a child of the window and will be deleted when the window is destroyed. Note that hiding or closing the window does not - automatically destroy it. + automatically destroy it. It will be destroyed when the example exits. +*/ - \section1 Using Layouts +/*! + \page widgets-tutorial-windowlayout.html + \contentspage {Widgets Tutorial}{Contents} + \previouspage {Widgets Tutorial - Child Widgets} + \nextpage {Widgets Tutorial - Nested Layouts} + \example tutorials/widgets/windowlayout + \title Widgets Tutorial - Using Layouts Usually, child widgets are arranged inside a window using layout objects rather than by specifying positions and sizes explicitly. Here, we @@ -125,7 +201,7 @@ <table align="left" width="100%"> <tr class="qt-code"><td> \endraw - \snippet snippets/widgets-tutorial/windowlayout/main.cpp create, lay out widgets and show + \snippet tutorials/widgets/windowlayout/main.cpp main program \raw HTML </td><td align="right"> \endraw @@ -149,17 +225,31 @@ manage the label and line edit and set the layout on the window, both the widgets and the layout itself are ''reparented'' to become children of the window. +*/ + +/*! + \page widgets-tutorial-nestedlayouts.html + \contentspage {Widgets Tutorial}{Contents} + \previouspage {Widgets Tutorial - Using Layouts} + \example tutorials/widgets/nestedlayouts + \title Widgets Tutorial - Nested Layouts Just as widgets can contain other widgets, layouts can be used to provide different levels of grouping for widgets. Here, we want to display a label alongside a line edit at the top of a window, above a table view showing the results of a query. + We achieve this by creating two layouts: \c{queryLayout} is a QHBoxLayout + that contains QLabel and QLineEdit widgets placed side-by-side; + \c{mainLayout} is a QVBoxLayout that contains \c{queryLayout} and a + QTableView arranged vertically. + \raw HTML <table align="left" width="100%"> <tr class="qt-code"><td> \endraw - \snippet snippets/widgets-tutorial/nestedlayouts/main.cpp create, lay out widgets and show + \snippet tutorials/widgets/nestedlayouts/main.cpp first part + \snippet tutorials/widgets/nestedlayouts/main.cpp last part \raw HTML </td><td align="right"> \endraw @@ -169,6 +259,26 @@ </table> \endraw + Note that we call the \c{mainLayout}'s \l{QBoxLayout::}{addLayout()} + function to insert the \c{queryLayout} above the \c{resultView} table. + + We have omitted the code that sets up the model containing the data shown + by the QTableView widget, \c resultView. For completeness, we show this below. + As well as QHBoxLayout and QVBoxLayout, Qt also provides QGridLayout and QFormLayout classes to help with more complex user interfaces. + These can be seen if you run \l{Qt Designer}. + + \section1 Setting up the Model + + In the code above, we did not show where the table's data came from + because we wanted to concentrate on the use of layouts. Here, we see + that the model holds a number of items corresponding to rows, each of + which is set up to contain data for two columns. + + \snippet tutorials/widgets/nestedlayouts/main.cpp set up the model + + The use of models and views is covered in the + \l{Qt Examples#Item Views}{item view examples} and in the + \l{Model/View Programming} overview. */ |