From d796c9dd933ab96ec83b9a634feedd5d32e1ba3f Mon Sep 17 00:00:00 2001 From: Timothy Pearson Date: Tue, 8 Nov 2011 12:31:36 -0600 Subject: Test conversion to TQt3 from Qt3 8c6fc1f8e35fd264dd01c582ca5e7549b32ab731 --- doc/html/tutorial1-02.html | 128 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 128 insertions(+) create mode 100644 doc/html/tutorial1-02.html (limited to 'doc/html/tutorial1-02.html') diff --git a/doc/html/tutorial1-02.html b/doc/html/tutorial1-02.html new file mode 100644 index 000000000..125537d4c --- /dev/null +++ b/doc/html/tutorial1-02.html @@ -0,0 +1,128 @@ + + + + + +TQt Tutorial - Chapter 2: Calling it Quits + + + + + + + +

TQt Tutorial - Chapter 2: Calling it Quits

+ + +

Having created a window in Chapter 1, we will +now go on to make the application tquit properly when the user tells it to. +

We will also use a font that is more exciting than the default one. +

/****************************************************************
+**
+** TQt tutorial 2
+**
+****************************************************************/
+
+#include <qapplication.h>
+#include <qpushbutton.h>
+#include <qfont.h>
+
+
+int main( int argc, char **argv )
+{
+    TQApplication a( argc, argv );
+
+    TQPushButton tquit( "Quit", 0 );
+    tquit.resize( 75, 30 );
+    tquit.setFont( TQFont( "Times", 18, TQFont::Bold ) );
+
+    TQObject::connect( &tquit, SIGNAL(clicked()), &a, SLOT(tquit()) );
+
+    a.setMainWidget( &tquit );
+    tquit.show();
+    return a.exec();
+}
+

+ + + +

Line-by-line Walkthrough +

    #include <qfont.h>
+

Since this program uses TQFont, it needs to include qfont.h. TQt's font +abstraction is rather different from the horror provided by X, and +loading and using fonts has been highly optimized. +

        TQPushButton tquit( "Quit", 0 );
+

This time, the button says "Quit" and that's exactly what the program +will do when the user clicks the button. This is not a coincidence. +We still pass 0 as the parent, since the button is a top-level window. +

        tquit.resize( 75, 30 );
+

We've chosen another size for the button since the text is a bit +shorter than "Hello world!". We could also have used TQFontMetrics +to set right size. +

        tquit.setFont( TQFont( "Times", 18, TQFont::Bold ) );
+

Here we choose a new font for the button, an 18-point bold font from +the Times family. Note that we create the font on the spot. +

It is also possible to change the default font (using TQApplication::setFont()) for the whole application. +

        TQObject::connect( &tquit, SIGNAL(clicked()), &a, SLOT(tquit()) );
+

connect() is perhaps the most central feature of TQt. +Note that connect() is a static function in TQObject. Do not confuse it +with the connect() function in the socket library. +

This line establishes a one-way connection between two TQt objects (objects +that inherit TQObject, directly or indirectly). Every TQt object can have +both signals (to send messages) and slots (to receive messages). All +widgets are TQt objects. They inherit TQWidget which in turn inherits +TQObject. +

Here, the clicked() signal of tquit is connected to the tquit() slot of a, so that when the button is clicked, the +application tquits. +

The Signals and Slots documentation +describes this topic in detail. +

Behavior +

When you run this program, you will see an even smaller window than in +Chapter 1, filled with an even smaller button. +

(See Compiling for how to create a +makefile and build the application.) +

Exercises +

Try to resize the window. Press the button. Oops! That connect() +would seem to make some difference. +

Are there any other signals in TQPushButton you can connect to tquit? +Hint: The TQPushButton inherits most of its behavior from TQButton. +

You're now ready for Chapter 3. +

[Previous tutorial] +[Next tutorial] +[Main tutorial page] +

+ +

Trademarks +

TQt 3.3.8

+ -- cgit v1.2.1