EE495K Slides by Avi Kak: OO for GUI Design (contd.)

Transcription

1 EE495K Slides by Avi Kak: OO for GUI Design (contd.) 1

2 Date: Tue, 18 Feb :42:33 CST To: From: Newton Matthew-W18732 Subject: RE: Visit to Purdue! Return-Path: Prof. Kak, Great to hear back from you too! We have several JAVA teams and our global standard in 2003 is to use a Linux OS with JAVA on all cell phones to take advantage of open source! Its amazing how much UML is also used (I did not expect). There is a lot of discussion on use-cases and object modeling before any code is written! Matt Newton Systems Developer PCS Engineering Quality Motorola, Inc. Phone: Pager (2-way): or @skytel.com matt.newton@motorola.com 2

3 1. What are the four different categories of classes in the Java AWT/Swing packages? Also, what s the purpose of each category? 3

4 2. All of the top-level Swing containers are heavyweight. What does that mean? 4

5 3. Given a choice between a lightweight component and a heavyweight component in Java AWT/Swing, you should use the former. Why? 5

6 4. In simulated OO in C, how do we cause type X to become the parent of type Y? 6

7 typedef struct { //... } X; typedef struct { X x_parent; //... } Y; 7

8 5 Suppose X is the parent of Y in simulated OO in C, what s the common way to access the fields of X? 8

9 Y* yobj; ( (X*) yobj )->x_field; get_x_field_1( (X*) yobj ); 9

10 6. How how do we achieve polymorphic effects in simulated OO in C? 10

11 X is the parent of Y. int function_for_x( X* xobj ) { //... } Y* yobj;... function_for_x( (X*) yobj ); Y* yobj; X* xobj = (X*) yobj; Y* yp = (Y*) xobj; 11

12 Overview of GNOME/GTK+ Widgets GNOME stands for GNU Object Modeling Environment. GNOME is designed for creating desktop environments. GNOME is an extension of the GTK+ package. The GTK+ package contains two libraries: GTK and GDK. 12

13 GTK stands for the GIMP Tool Kit. GIMP stands for the GNU Image Manipulation Program. GIMP, available free from the Open Source movement, is to Unix-like platforms what Photoshop is to Windows-based systems. GTK consists of a large collection of widgets for constructing windows and for layout control. The GDK library GDK stands for GIMP Drawing Kit provides numerous drawing functions and facilities for managing color, font, etc. 13

14 The fundamental data types used in GNOME, GTK+, GDK, GIMP, etc., are defined in the glib library of low-level C functions, macros, and structures. The glib library was created as a part of GIMP development for the purpose of standardization and portability. For example, anint in C may be represented by 16 bits in some machines and 32 in others. Similarly, a char may be signed in some and unsigned in others. By contrast, glib defines a type called gint for representing integers; a gint is always 32 bits. If your GNOME/GTK+ code needs a shorter integer, you can use gint8 for an 8-bit integer, or a gint16 for a 16-bit integer. Similarly, a gchar will always be signed. If you need an unsigned char, you can use guchar. 14

15 The glib library also comes with utility functions for memory management, string manipulation, and the formatting of textual output. GNOME/GTK+ programs will, for example, use g print() instead of printf(), g malloc() instead of malloc(), etc. 15

16 GtkObject ^ GnomeClient GnomeCanvasItem GnomeEntryEdit.. GnomeMDI GnomeMDIChild GnomeDockLayout GtkWidget GtkData GtkItemFactory GtkXmHTMLParser GnomeCanvasLine GnomeCanvasGroup GnomeCanvasPolygon GnomeCanvasRE GnomeCanvasImage GnomeCanvasRect GnomeCanvasText GnomeCanvasWidget GnomeCanvasEllipse GtkContainer GtkMisc GtkCalendar GtkRuler GnomeAnimator GnomePixmap GtkDial GtkEditable GtkRange GtkSeparator GtkProgress GtkDrawingArea GtkLabel GtkArrow GtkImage GtkPixmap GtkAccelLabel GtkClock GtkTipsQuery GtkBin GtkList GtkCList GtkFixed GtkNotebook GtkXmHTML GtkTRee GtkPacker GtkSocket GtkTable GtkPaned 16

17 GtkToolbar GtkMenuShell GnomeDock GnomeDockBand GtkBox GtkLayout GnomeCanvas GtkWindow GtkFrame GtkItem GtkInvisible GtkViewPort GtkDockItem GtkEventBox GtkHandleBox GtkButton GtkAspectFrame GtkScrolledWindow GtkMenuItem GtkListItem GtkTreeItem GtkCheckMenuItem GtkTearofMenuItem GtkPixmapMenuItem GnomeColorPicker GnomeHRef GtkToggleButton GtkOptionMenu GtkHBox GtkVBox GtkButtonbox GnomeProcBar GnomeAppBar GnomeFileEntry GtkStatusbar GtkCombo GnomeNumberEntry GnomeDialog GnomeApp GtkPlug GtkHButtonBox GtkVButtonbox GtkColorSlectionDialog GtkFileSlection GtkFontSelectionDialog 17

18 GnomeAbout GnomeMessageBox GnomePropertyBox GnomeScores 18

19 The GNOME/GTK+ widget types can be categorized in the same way that was shown earlier for AWT/Swing and for Qt. There are the top-level containers like GtkWindow that get displayed as windows on a terminal. There are intermediate level containers like GtkTable, GtkHBox, and so on, for creating different kinds of groupings of the more atomic widgets. There are atomic widgets like GtkButton, GtkEditable, GtkLabel, and so on, that actually get displayed in a window. And, finally, there are utility widgets like GtkLayout, GtkSeparator, and so on. 19

20 Many of the non-widget classes that hang from the root class GtkObject are meant for displaying graphics that can consist of shapes, images, text, etc. 20

21 Some Minimalist GUI Programs in Java AWT/Swing //FirstWindow.java import javax.swing.*; class FirstWindow { } public static void main(string[] args) { JFrame f = new JFrame( "FirstWindow" ); f.setsize( 300, 200 ); f.setlocation( 200, 300 ); f.setvisible( true ); } 21

22 A top-level container (JFrame, JApplet, JDialog, etc.) root pane (JRootPane) layered pane (JLayeredPane) MenuBar content pane (can be any Component) (the variable contentpane in JRootClass corresponds to this pane) glass pane (can be any Component) (the variable glasspane in JRootClass corresponds to this pane)

23 rootpane.getcontentpane().add( mywidget ); rootpane.getcontentpane().setlayout( mylayoutmanager ); 23

24 //FirstWindowWithButton.java import javax.swing.*; import java.awt.*; import java.awt.event.*; // for FlowLayout // for ActionListener class FirstWindowWithButton { public static void main(string[] args) { JFrame f = new JFrame( "FirstWindowWithButton" ); f.addwindowlistener(new WindowAdapter() { public void windowclosing(windowevent e) { System.exit(0); } }); JButton b = new JButton("Click Here for a Message"); b.setverticaltextposition( AbstractButton.CENTER ); b.sethorizontaltextposition( AbstractButton.CENTER ); b.addactionlistener( new ActionListener() { public void actionperformed( ActionEvent evt ) { System.out.println( "Have a Good Day!" ); } }); } } f.getcontentpane().setlayout( new FlowLayout() ); f.getcontentpane().add( b ); f.setlocation( 100, 50); f.pack(); f.setvisible( true ); 24

25 f.getcontentpane().setlayout( new FlowLayout() ); 25

26 Some Minimalist GUI Programs in C++ Qt Every GUI program in Qt must have the following two features: It must consist of exactly one object of type QApplication. Every GUI program in Qt must also specify one main widget. 26

27 #include <qapplication.h> #include <qmainwindow.h> int main( int argc, char **argv ) { QApplication myapp( argc, argv ); // (A) QMainWindow* mywin = new QMainWindow( 0, 0, 0 ); // (B) mywin->resize( 500, 300 ); // (C) mywin->move( 200, 100 ); // (D) } myapp.setmainwidget(mywin ); mywin->show(); return myapp.exec(); // (E) // (F) // (G) 27

28 QMainWindow::QMainWindow( QWidget* parent = 0, const char* name = 0, WFlags f = WType_TopLevel ); g++ -o firstwindow firstwindow.cc -I$QTDIR/include -L$QTDIR/lib -lqt 28

29 #include <qapplication.h> #include <qmainwindow.h> #include <qpushbutton.h> #include <qfont.h> int main( int argc, char **argv ) { QApplication myapp( argc, argv ); QMainWindow* mywin = new QMainWindow( 0, 0, 0 ); mywin->resize( 500, 300 ); mywin->move( 200, 100 ); // (A) // (B) // (C) // (D) QPushButton* quitbutton = new QPushButton( "Quit", mywin );// (E) quitbutton->resize( 60, 30 ); // (F) quitbutton->move( 220, 135 ); // (G) quitbutton->setfont( QFont( "Times", 18, QFont::Bold ) ); // (H) } QObject::connect( quitbutton, SIGNAL(clicked()), &myapp, SLOT(quit()) ); myapp.setmainwidget( mywin ); mywin->show(); return myapp.exec(); // (I) // (J) // (L) // (M) 29

30 Some Minimalist GUI Programs in GNOME/GTK+ #include <gnome.h> int main( int argc, char* argv[] ) { GtkWidget* toplevelwindow; // (A) // (B) } gnome_init( "gnomewin", "1.0", argc, argv ); // (C) toplevelwindow = gnome_app_new( "gnomewin", "Gnome Window" ); // (D) gtk_container_set_border_width( GTK_CONTAINER( toplevelwindow ), 200 ); // (E) gtk_widget_show( toplevelwindow ); // (F) gtk_main(); // (G) exit( 0 ); // (H) 30

31 gnome-config --cflags gnomeui -I/usr/include -DNEED_GNOMESUPPORT_H -I/usr/lib/gnome-libs/include -I/usr/lib/glib/include -I/usr/X11R6/include 31

32 CC=gcc LDLIBS= gnome-config --libs gnomeui CFLAGS=-Wall -g gnome-config --cflags gnomeui gnomewin: gnomewin.o Makefile_gnomewin $(CC) $(LDLIBS) gnomewin.o -o gnomewin gnomewin.o: gnomewin.c $(CC) $(CFLAGS) -c gnomewin.c clean: rm -f gnomewin rm -f gnomewin.o 32

33 #include <gnome.h> gint eventdestroy( GtkWidget* widget, GdkEvent* event, gpointer data ); // (A) int main( int argc, char* argv[] ) { GtkWidget* toplevelwindow; GtkWidget* mybutton; // (B) // (C) // (D) gnome_init( "buttonwin", "1.0", argc, argv ); // (E) toplevelwindow = gnome_app_new( "buttonwin", "My Window" );// (F) gtk_container_set_border_width( GTK_CONTAINER( toplevelwindow ), 100 ); // (G) mybutton = gtk_button_new_with_label( "Quit" ); // (H) gtk_signal_connect( GTK_OBJECT( mybutton ), "clicked", GTK_SIGNAL_FUNC( eventdestroy ), NULL ); gnome_app_set_contents( GNOME_APP( toplevelwindow ), mybutton ); // (I) } gtk_widget_show( toplevelwindow ); gtk_main(); exit( 0 ); // (J) // (K) // (L) gint eventdestroy( GtkWidget* widget, GdkEvent* event, gpointer data ) { // (M) gtk_main_quit(); // (N) return( 0 ); // (O) } 33