Transcript getch

四時讀書樂 (冬)
木落水盡千崖枯，迥然吾亦見真吾。
坐對韋編燈動壁，高歌夜半雪壓廬。
地爐茶鼎烹活火，四壁圖書中有我。
讀書之樂何處尋？數點梅花天地心。
~ 元‧翁森
1
NCURSES Library
- Functions for Screen Handling
2
rand()
#include <iostream>
using std::cout;
using std::endl;
int main()
{
for (int i=0; i<9; i++)
cout << rand() % 6 + 1 << endl;
return 0;
}
3
Sleep( )
#include <iostream>
#include <Windows.h>
#include <Winbase.h>
using std::cout;
using std::endl;
int main()
{
for (int i=0; i<9; i++)
{
cout << rand() % 6 + 1 << endl;
Sleep(2000); // 2000 ms = 2s
}
return 0;
}
4
Screen Handling
5
pdcurses_1.cpp
#include
#include
#include
#include
<iostream>
<Windows.h>
<Winbase.h>
<curses.h>
int main()
{
int i, j;
int a[6] = { 0 };
initscr();
for (i=0; i<6; i++)
printw("%d ( )\n", i);
for (i=0; i<9; i++)
{
j = rand() % 6;
move(10, i*2);
printw("%2d", j);
move(j, 3);
printw("%2d", ++a[j]);
refresh();
Sleep(2000); // 2000 ms = 2s
}
endwin();
return 0;
}
6
Definition of curses on Wikipedia
curses is
a terminal control library for Unixlike systems, enabling the construction
of text user interface (TUI) applications.
 The name is a pun on the term
“cursor optimization”. It is a library of
functions that manage an application's
display on character-cell terminals
(e.g., VT100)

7
Basic Functions

move(y,x)


addch(ch)


Add a string to screen by calling addch()
printw(fmt, arg1, arg2, …)


Add a character to screen
addstr(str)


Move cursor to (y,x) in screen
Formatted print to screen by calling addstr()
refresh()

Update screen
8
Initialize and Terminate Curses

initscr()


endwin()




Initialize curses
End curses.
This function should be called when your
program is finished.
It will release the space allocated to screen
handling in your program.
Remember to #include <curses.h> at
the beginning of your program.
9
Use Curses Library in Visual C++ 2010
Download Public Domain Curses Library
 Uncompress it and save the 4 files under a
local directory, say L:\PDCurses.
 In Visual C++ 2010 Express,


Project – Property (or Alt-F7)

Under Configuration Properties
 Debugging – Environment
 PATH=L:\PDCurses
 C/C++ - Additional Include Directories
 L:\PDCurses
 Expand Linker, choose Input. In Additional
Dependencies, insert “L:\PDCurses\pdcurses.lib;”
10
Exercise

Modify pdcurses_1.cpp so that in addition
to the counting number, in the same row
you also show a bar (e.g. "******") to
show the same number of stars.
11
Homework: 8 Queens

Imagine there are 8 queens attending a race. On
your computer screen each queen is represented
by a character ‘Q’. On each row there is one
queen.


Use a random number generator to determine
which queen will move forward.


If you think a single character is monotonous, you may
modify this program to handle 8 horses ~/-\^
You may use the Sleep() function to slow down the
program.
Suppose the length of each lane is 50. The first
queen who arrives at the destination wins the
race.
12
四時讀書樂 (春)
山光照檻水繞廊，舞雩歸詠春風香。
好鳥枝頭亦朋友，落花水面皆文章。
蹉跎莫遣韶光老，人生惟有讀書好。
讀書之樂樂何如，綠滿窗前草不除。
~ 元‧翁森
13
四時讀書樂 (夏)
新竹壓檐桑四圍，小齋幽敞明朱暉。
晝長吟罷蟬鳴樹，夜深燼落螢入帷。
北窗高臥羲皇侶，只因素稔讀書趣。
讀書之樂樂無窮，瑤琴一曲來薰風。
~ 元‧翁森
14
四時讀書樂 (秋)
昨夜庭前葉有聲，籬豆花開蟋蟀鳴。
不覺商意滿林薄，蕭然萬籟涵虛清。
近床賴有短檠在，趁此讀書功更倍。
讀書之樂樂陶陶，起弄明月霜天高。
~ 元‧翁森
15
四時讀書樂 (冬)
木落水盡千崖枯，迥然吾亦見真吾。
坐對韋編燈動壁，高歌夜半雪壓廬。
地爐茶鼎烹活火，四壁圖書中有我。
讀書之樂何處尋？數點梅花天地心。
~ 元‧翁森
16
Getting Characters from the Terminal

getch()


getstr(str)


Get a character from the terminal
Get a string from the terminal
scanw(fmt, arg1, arg2, …)

Formatted input from the terminal like scanf().
17
pdcurses_3.cpp
#include <curses.h>
int main()
{
char text[10];
int i, j, c;
initscr();
getstr(text);
// input the string "1,2"
addstr(text); addch('\n');
scanw("%d,%d", &i, &j);
printw("%d\t%d\n", i, j);
// input the string "1,2" again
c = getch();
endwin();
return 0;
}
18
noecho()
#include <curses.h>
int main()
{
int c;
initscr();
// noecho();
do {
c = getch();
printw(" %d\n", c);
} while (c != '0');
endwin();
return 0;
}
19
pdcurses_4.cpp
// pdcurses_4.cpp
#include <curses.h>
int main()
{
int y=10, x=10;
char c;
initscr();
noecho();
do {
move(y, x); addch('Q');
c = getch();
move(y, x); addch(' ');
switch (c)
{
case 'h':
x--;
break;
case 'l':
x++;
break;
case 'j':
y++;
break;
case 'k':
y--;
break;
}
} while (c != 'q');
endwin();
return 0;
}
20
curs_set()
curs_set() alters the appearance of the
text cursor.
 int curs_set(int visibility);




A value of 0 for visibility makes the cursor
disappear;
a value of 1 makes the cursor appear "normal"
(usually an underline)
2 makes the cursor "highly visible" (usually a
block).
21
pdcurses_4a.cpp
// pdcurses_4.cpp
#include <curses.h>
int main()
{
int y=10, x=10;
char c;
initscr();
noecho();
curs_set(0); // no cursor
do {
move(y, x); addch('Q');
c = getch();
move(y, x); addch(' ');
switch (c)
{
case 'h':
x--;
break;
case 'l':
x++;
break;
case 'j':
y++;
break;
case 'k':
y--;
break;
}
} while (c != 'q');
endwin();
return 0;
}
22
Function Keys

Call keypad() to enable the handling of Function
keys and arrow keys.



int keypad(WINDOW *win, bool bf);
keypad(stdscr, TRUE);
getch() returns an integer corresponding to the
key pressed.


If it is a normal character, the integer value will be
equivalent to the ASCII code of the character.
Otherwise it returns a number which can be matched
with the constants defined in curses.h.

For example if the user presses F1, the integer returned is
265.
23
Function Keys (cont.)

With keypad() enabled, you can check the
returned value of getch() with the
constants defined in curses.h



KEY_UP, KEY_DOWN, KEY_LEFT, KEY_RIGHT
KEY_HOME, KEY_END,
KEY_F(n)
24
Key Definitions







#define KEY_IC
0x14b
enter ins mode (Insert) */
#define KEY_DC
0x14a
(Delete) */
#define KEY_HOME
0x106
#define KEY_END
0x166
#define KEY_PPAGE
0x153
(PageUp) */
#define KEY_NPAGE
0x152
(PageDown) */
#define PADENTER
0x1cb
/* insert char or
/* delete character
/* home key */
/* end key */
/* previous page
/* next page
/* enter on keypad */
You may check curses.h to see more definitions.
25
Colors

To start using color, you should first call
the function start_color().


To find out whether a terminal has color
capabilities or not, you can use has_colors()
function, which returns FALSE if the terminal
does not support color.
Colors are always used in pairs.


A color-pair consists of a foreground color and
a background color.
Initializes a color-pair with the routine
init_pair(). After it has been initialized,
COLOR_PAIR(n) is used to represent the color 26
attribute.
pdcurses_2.cpp
#include <curses.h>
int main()
{
initscr();
start_color();
init_pair( 1, COLOR_WHITE, COLOR_RED );
attron( COLOR_PAIR(1) );
printw("Background red");
attroff( COLOR_PAIR(1) );
refresh();
getch();
endwin();
return 0;
}
27
Pre-defined Colors on Unix
COLOR_BLACK
 COLOR_RED
 COLOR_GREEN
 COLOR_YELLOW
 COLOR_BLUE
 COLOR_MAGENTA
 COLOR_CYAN
 COLOR_WHITE

=
=
=
=
=
=
=
=
0
1
2
3
4
5
6
7
28
Exercise: Arrow Keys
Modify pdcurses_4a.cpp so that users can
use arrow keys and HJKL to control the
movement of ‘Q’.
 Moreover, try to allow users to use both
uppercase ‘H’ and lowercase ‘h’ to do the
same movement.
 Users can also change the color of ‘Q’ by
pressing ‘0’…’7’.

29
HW: Tetris
30
int timeout(int delay)

The timeout() function affects the
behaviour of getch() when reading a
character from stdscr.


If delay is a positive number, then getch() will
wait for that many milliseconds before
returning
If no character was available, then ERR (-1)
will be returned.
31
pdcurses_6.cpp
#include <curses.h>
switch(c)
{
case 'h':
x--;
break;
case 'l':
x++;
break;
}
move(y, old_x); addch(' ');
int main()
{
int x=10, old_x;
int c;
initscr();
noecho();
curs_set(0);// hide the cursor
timeout(500);
// getch() will only wait 0.5 second
for (int y=1; y<15; y++)
{
move(y, x); addch('Q');
old_x = x;
c = getch();
}
refresh();
endwin();
return 0;
}
32
HW: Tetris
Rotation
Replay
Falling Down
33
Rotate with respect to a fixed point
(x+1
,y-1)
(x,y)
(x+2
,y-1)
(x+1
,y)
x
y
34
Relative Coordinates
(1,-1)
(0,0)
(2,-1)
(1,0)
x
y
35
Rotate 90 Degrees
(-1,-2)
(-1,-1)
(0,-1)
(0,0)
x
y
36
Rotate 180 Degrees
(-1,0)
(-2,1)
(0,0)
(-1,1)
x
y
37
Rotate 270 Degrees
(0,0)
(0,1)
(1,1)
(1,2)
x
y
38
Observe the x and y
(y, -x)
(-x, -y)
(0,0)
x
(x, y)
(-y, x)
y
39
switch(rotate)

case 0:




x = x0 + x;
y = y0 + y;
break;
case 2:




x = x0 - x;
y = y0 - y;
break;
case 1:




x = x0 + y;
y = y0 - x;
break;
case 3:



x = x0 - y;
y = y0 + x;
break;
40
Seven Shapes
41
Represent these objects with struct
struct Shape
{
Cell c[4];
};
struct Cell
{
int dx;
int dy;
}
42
Choose a reference point
(0,-1)
(-1,0)
(1,-1)
(0,0)
43
Shape s[7];
void init_shape()
{
int i, j, x, y;
FILE* fp;
fp = fopen("X:\\WWW\\Course\\CS101\\shape_xy.txt", "r");
for (i=0; i<7; i++)
{
0 0 0 1 -1 0 -1 1
for (j=0; j<4; j++)
0 0 1 0 2 0 -1 0
{
0 0 0 1 -1 0 -1 -1
fscanf(fp, "%d %d", &y, &x);
0 0 0 1 0 -1 -1 0
s[i].c[j].dx = x;
0 0 0 1 0 2 -1 0
s[i].c[j].dy = y;
0 0 0 -1 -1 0 -1 1
}
0 0 0 -1 0 -2 -1 0
}
fclose(fp);
// Initialize the bottom line
for (i=0; i<12; i++)
occupy[11][i] = true;
}
44
plot_shape(shape_id, y0, x0, rotate, character)
for (j=0; j<4; j++)
{
x = x0 + s[id].c[j].dx;
y = y0 + s[id].c[j].dy;
move(y, x);
addch(character);
}
45
Consider Rotations
46
test_rotate()
KEY_LEFT
 KEY_RIGHT
 KEY_UP


tetris-1.cpp
47
history.txt

shape, y, x, r
1
1
1
1
1
1
6
6
6
6
6
6
6
6
6
110
210
320
430
531
10 3 1
120
220
330
440
551
662
773
880
10 8 0
y=1
implies a
new
object
48
replay()
fopen()
while ( fscanf( ) != EOF )
{
if not a new object
erase the old position
plot at the new position
}
fclose()
49
Falling down
Q: When should an object stop falling
down?
 A: When there get supported by some
cells beneath it.

50
bool occupy[][]

We need an array to allow the program
checking which cells (at the bottom) are
occupied by previous objects.
while ( ! beneath( ) )
{
erase
y = y + 1
plot
}
update_occupy();
51
Define Your Own Color

start_color()


initializes eight basic colors (black, red, green,
yellow, blue, magenta, cyan, and white)
Two global variables:



COLORS: maximum number of colors
COLOR_PAIRS: maximum number of color-pairs
bool has_colors(void);

if the terminal can manipulate colors.
NCURSES Programming HOWTO
 Public Domain Curses Library and
its User's Guide

52
has_colors()
#include <curses.h>
int main()
{
initscr();
start_color();
keypad(stdscr, TRUE); noecho();
move(0, 40);
printw("There are %d colors and %d pairs",
COLORS, COLOR_PAIRS);
move(1,0);
printw("This terminal has %scolor; ", has_colors()?"":"no ");
printw("can %schange colors.", can_change_color()?"":"not ");
getch();
endwin();
53
return 0;
}
pdcurses_2.cpp
#include <curses.h>
int main()
{
initscr();
start_color();
init_pair( 1, COLOR_WHITE, COLOR_RED );
attron( COLOR_PAIR(1) );
printw("Background red");
attroff( COLOR_PAIR(1) );
refresh();
getch();
endwin();
return 0;
}
54
Pre-defined Colors in curses.h
# define COLOR_BLUE 1
# define COLOR_GREEN 2
# define COLOR_RED 4
#define COLOR_CYAN (COLOR_BLUE | COLOR_GREEN)
#define COLOR_MAGENTA (COLOR_RED | COLOR_BLUE)
#define COLOR_YELLOW (COLOR_RED | COLOR_GREEN)
#define COLOR_WHITE
7
55
color_content()

int color_content(short color, short *red,
short *green, short *blue);


int pair_content(short pair, short *fg,
short *bg);


Find the intensity of the red, green, and blue
(RGB) components in a color.
Find out how a given color-pair is currently
defined.
Note that the pointer is passed to the
function so that the value of the
arguments can be modified.
56
Global Variable: COLORS
#include <curses.h>
int main()
{
initscr();
start_color();
short color, red, green, blue;
for (color=0; color < COLORS; color++)
{
color_content(color, &red, &green, &blue);
printw("%d -\t%d\t%d\t%d\n", color, red, green, blue);
}
refresh();
getch();
endwin();
return 0;
}
57
pair_content()
#include <curses.h>
int main()
{
initscr();
start_color();
short pair;
short fg, bg;
for (pair=0; pair < 16; pair++)
{
pair_content(pair, &fg, &bg);
printw("%d -\t%d\t%d\n", pair, fg, bg);
}
refresh();
getch();
endwin();
return 0;
}
58
Highlighted Color
#include <curses.h>
int main()
{
char* name[] = { "Black", "Blue", "Green", "Cyan", "Red", "Magenta", "Yellow", "White",
"Grey", "BLUE", "GREEN", "CYAN", "RED", "MAGENTA", "YELLOW", "WHITE" };
initscr();
start_color();
short c;
for (c=0; c < 8; c++)
{
init_pair( c, COLOR_WHITE, c );
attron( COLOR_PAIR(c) );
move(c, 10); printw("%10s", name[c]);
attroff( COLOR_PAIR(c) );
}
for (c=8; c < 16; c++)
{
init_pair( c, COLOR_WHITE, c );
attron( COLOR_PAIR(c) );
move(c-8, 20); printw("%10s", name[c]);
attroff( COLOR_PAIR(c) );
}
refresh();
getch();
endwin();
return 0;
}
59
init_color()

int init_color(short color, short red, short
green, short blue);




Change the RGB values for the colors defined
by curses initially.
The RGB content is scaled from 0 to 1000.
Initially COLOR_RED is defined with content
1000(r), 0(g), 0(b).
However, the color did not change, after I
run the init_color(). Maybe you can try.

Perhaps the dumb terminal only supports 16
colors.
60
Executable File (.EXE)
Under your Project\demo\Debug directory,
there is a “demo.exe”.
 After setting
“PATH=%PATH%;L:\PDCurses”, you can
run the file “demo” directly (just like a
command as “DIR”, “VOL”, “DATE”) from
the Command Window.

61
argc, argv
#include <iostream>
using std::cout;
C:\> demo.exe This is a book.
There are 5 arguments.
0 - demo.exe
1 - This
2 - is
3-a
4 - book.
int main(int argc, char* argv[])
{
int i;
cout << "There are " << argc << "
arguments.\n";
for (i=0; i<argc; i++)
cout << i << " - " << argv[i] << '\n';
return 0;
62
}
red_quotation.cpp

Suppose you have a file “test.txt”, whose
contents is
You know "COLOR_PAIR", so you
can write a program to read a text file,
and highlight the "strings".
This is useful, especially in a "C++"
program.

After you run “demo test.txt”,
63
Specify Arguments in Visual C++


While you are
debugging, you
may want to
specify the
command
arguments in
Visual C++.
Alt-F7 to open
the Property
Page

Configuration
Properties –
Debugging –
Command
Arguments.
64
TODO

There are many ways you can improve
this program:





Check the number of arguments at the
command line.
Show strings in red, comments in green,
keywords (e.g. int, short, while) in blue.
Pause for every 23 lines (one page). Wait for
the user to press <Space> to display the next
page.
If the user press <b>, then back to the
previous page.
If the user press <q>, then quit the program. 65
HW: Matching a string in files

Create an executable file “find.exe” so
that running the command “find string
file1 file2 file3 …” will search the named
files and print out lines containing the
string.


Show the matched string with a highlighted
color to emphasize it.
For example: “find el message.txt book.txt”
message.txt:Well, you are welcome.
book.txt:Hello Hello
66