I'm studing now and I got this homework / tasks to do:
1) If you press the CTRL + L key, all numeric symbols should change the color.
2) If you press the CTRL + S key, you will get the length of the word, left from the cursor.
I found this function int bioskey(int cmd);
So now I can check if the key is pressed, but how to change the color only of numeric symbols, or read words from console to get their length ?
Some of us still remember the MS-DOS (let it rest in peace or pieces...)
if you are really in MS-DOS then you can not expect that the content of the console would be changed in colors for only specific areas. You need to do that your self. The problem is we do not know anything about your project background so we do not know what and how yours stuff is represented,rendered/outputed/inputed etc...
I assume EGA/VGA BIOS text mode is used so you can exploit direct access to the VRAM. So you need to set pointer to the address B800:0000 and handle it as array where each character on screen has 2 BYTEs. one is color attribute and the other is ASCII code (not sure in which order anymore)...
So for already rendered stuff you just:
loop through whole screen
usually 80x25x2 Bytes
test each ASCII for alpha numeric value
so ASCII code >= '0' and code<='9' for numbers or add all the stuff you are considering as alphanumeric like code>' ' and code<='9'.
change colors for selected characters
just by changing the attribute byte.
When you put it together for numbers it will look like this:
char far *scr=(char far*)0x0B0000000;
int x,y,a;
for (a=0,y=0;y<25;y++)
for (x=0;x<80;x++,a+=2)
if ((scr[a+0]>='0')&&((scr[a+0]<='9'))
{
scr[a+1]=7; //attribute with the different color here
}
if it does not work than try swap scr[a+0] and scr[a+1]. If an exception occur then you are not in MS-DOS and you do not have access to VRAM. In that case use DOS-BOX or driver that allows access to memory like dllportio ...
For more info see some more or less related QA's:
Display an array of color in C
What is the best way to move an object on the screen?
If you got problem with the CTRL+Key detection not sure if in-build function in TC++ allows CTRL (was too long ago) then you can exploit BIOS or even hook up the keyboard ISR. See the second link where ISR for keyboard handler is there present... You can port it to C++ or google there must be a lot of examples out there especially TP7.0 (which is pascal but easily portable to TC++)
Related
I'm currently designing a CLI interface for linux, and for various reasons I am not able to use ncurses. I am using exclusively C++ and the Qt framework.
Therefore, in order to have a user-friendly interface, I have to run this getch loop in a separate thread:
https://stackoverflow.com/a/912796/3605689
Which basically means I have to implement all basic functionalities (such as backspace) by myself. I have already implemented command completion and command history(like when you press tab or uparrow/downarrow in linux), but I can't figure out how to implement leftarrow/rightarrow (aka seeking through the typeahead).
Normally, I implement it like this: upon every gech which is not equal to -1, I check whether the user has pressed a special key (one that modifies the typeahead somehow). I then clear the stdout using the following function:
void inputobject::clear_line(int nletters)
{
QTextStream(stdout) << "\033[2K";
for(int i = 0; i < nletters;i++){
QTextStream(stdout) << "\b";
}
rewind(stdout);
}
And replace it with something else, effectively simulating the typeahead. For example, in the case of backspace, I would save the command call clear_line, and print the command out again, just with one less letter, behaving exactly as a normal console application would.
My real problem is with the cursor, in the case of left/rightarrow, I need to move the cursor visual in order to be able to indicate where in the text is the user seeking:
Because of the nature of how I rewrite the given stdout line to simulate the typeahead, it does not really matter where the cursor REALLY is, as long as it stays on the same line - it is just the visual that matters. How can I achieve moving the cursor visual on linux?
The answer was provided in the comment by Evilruff:
Cursor Movement
ANSI escape sequences allow you to move the cursor around the screen at will. This is more useful for full screen user interfaces generated by shell scripts, but can also be used in prompts. The movement escape sequences are as follows:
Position the Cursor:
\033[;H
Or
\033[L;Cf
puts the cursor at line L and column C.
Move the cursor up N lines:
\033[NA
Move the cursor down N lines:
\033[NB
Move the cursor forward N columns:
\033[NC
Move the cursor backward N columns:
\033[ND
Clear the screen, move to (0,0):
\033[2J
Erase to end of line:
\033[K
Save cursor position:
\033[s
Restore cursor position:
\033[u
Not using ncurses and co is a serious limitation.
It is hell to make correct input/output on shell for displaying anything.
The only others real solutions (I can't think as a solution to reimplement a ncurse-like library) I think of are:
making call to dialog (for some example www.linuxjournal.com/article/2807 and for the doc: http://linux.die.net/man/1/dialog)
using the framebuffer mecanism with Qt4 (here)
If I put an int into Visual Studio's watch window, I can use various format additions to display it in different ways. So if I have "int myVariable = 10;" in the code, I can put "myVariable,x" into the watch window to have it display as hex. Likewise, "myVariable,c" makes it take the low byte and display it as a character. All the format tricks are documented here.
Now, with an int, I can do this:
(char*)(&myVariable),4
The ",4" says to display 4 values of the array. That will let me see the integer as a string of 4 characters -- this is some old software I'm working with that has a bunch of 4-character encodings. But I can't do that trick with a value returned from a function:
(char*)(&foo()),4
because I cannot take the address of the returned function. Watch window reports an error.
Does anyone know a trick where I can put a function into the watch window and format its integer return value as a string of characters?
I am writing an interactive terminal program using Python curses. I'd like to write unit tests for its functionalities such as drawing custom pads, controlling font colors, scrolling, and resizing responses. But after some tries and searches, I couldn't find a way to write such unit tests without actually invoking the terminal; I couldn't find a function in curses to read the content of the screen, either.
Is there a mock terminal for Python curses that serves these unit testing needs?
You can ask curses what it thinks is on the screen:
inch, winch, mvinch, mvwinch - get a character and
attributes from a curses window
inchstr, inchnstr, winchstr, winchnstr, mvinchstr,
mvinchnstr, mvwinchstr, mvwinchnstr - get a string of
characters (and attributes) from a curses window
instr, innstr, winstr, winnstr, mvinstr, mvinnstr, mvwin-
str, mvwinnstr - get a string of characters from a curses
window
The Python binding provides a way to use those functions (not complete, but sufficient):
window.inch([y, x])
Return the character at the given position in the window. The bottom 8 bits are the character proper, and upper bits are the attributes.
window.instr([n]) window.instr(y, x[, n])
Return a string of characters, extracted from the window starting at the current cursor position, or at y, x if specified. Attributes are stripped from the characters. If n is specified, instr() returns a string at most n characters long (exclusive of the trailing NUL).
I'm currently designing a CLI interface for linux, and for various reasons I am not able to use ncurses. I am using exclusively C++ and the Qt framework.
Therefore, in order to have a user-friendly interface, I have to run this getch loop in a separate thread:
https://stackoverflow.com/a/912796/3605689
Which basically means I have to implement all basic functionalities (such as backspace) by myself. I have already implemented command completion and command history(like when you press tab or uparrow/downarrow in linux), but I can't figure out how to implement leftarrow/rightarrow (aka seeking through the typeahead).
Normally, I implement it like this: upon every gech which is not equal to -1, I check whether the user has pressed a special key (one that modifies the typeahead somehow). I then clear the stdout using the following function:
void inputobject::clear_line(int nletters)
{
QTextStream(stdout) << "\033[2K";
for(int i = 0; i < nletters;i++){
QTextStream(stdout) << "\b";
}
rewind(stdout);
}
And replace it with something else, effectively simulating the typeahead. For example, in the case of backspace, I would save the command call clear_line, and print the command out again, just with one less letter, behaving exactly as a normal console application would.
My real problem is with the cursor, in the case of left/rightarrow, I need to move the cursor visual in order to be able to indicate where in the text is the user seeking:
Because of the nature of how I rewrite the given stdout line to simulate the typeahead, it does not really matter where the cursor REALLY is, as long as it stays on the same line - it is just the visual that matters. How can I achieve moving the cursor visual on linux?
The answer was provided in the comment by Evilruff:
Cursor Movement
ANSI escape sequences allow you to move the cursor around the screen at will. This is more useful for full screen user interfaces generated by shell scripts, but can also be used in prompts. The movement escape sequences are as follows:
Position the Cursor:
\033[;H
Or
\033[L;Cf
puts the cursor at line L and column C.
Move the cursor up N lines:
\033[NA
Move the cursor down N lines:
\033[NB
Move the cursor forward N columns:
\033[NC
Move the cursor backward N columns:
\033[ND
Clear the screen, move to (0,0):
\033[2J
Erase to end of line:
\033[K
Save cursor position:
\033[s
Restore cursor position:
\033[u
Not using ncurses and co is a serious limitation.
It is hell to make correct input/output on shell for displaying anything.
The only others real solutions (I can't think as a solution to reimplement a ncurse-like library) I think of are:
making call to dialog (for some example www.linuxjournal.com/article/2807 and for the doc: http://linux.die.net/man/1/dialog)
using the framebuffer mecanism with Qt4 (here)
I don't know how to write a good question here, but, basically, does anyone know where I can possibly find some C++ source code using these to actually set keyboard state? For some reason using it the way MSDN does on Windows 7 doesn't do...anything at all.
Basic code:
PBYTE keyState;
GetKeyboardState(keyState);
...
// Later on when I need to set the keyboard state (key pressed etc) back to original:
SetKeyboardState(keyState);
and ... nothing happens :(
From:
http://www.gamedev.net/community/forums/topic.asp?topic_id=43463
First off, GetKeyboardState() would be the wrong function to use because as Windows has a chance to process keyboard messages (whether you want it too or not) it updates the results of the keyboard's state for the next call to GetKeyboardState().
Here's a little function that I use to get the status of the keyboard's keys. Be carefull though, depending on how fast your main loop is, it may cause problems if you aren't expecting it.
You need to keep track of whether or not a specific key was pressed the last time you called the ReadKeyboard() function. If your loop polls the keyboard 30 times a second, then pressing a key once probably causes the key to be flagged 3 or 4 calls in a row. Rather confusing sometimes. Just thought I'd mention it.
void ReadKeyboard( char* keys )
{
for (int x = 0; x < 256; x++)
keys[x] = (char) (GetAsyncKeyState(x) >> 8);
}