keyPressed() combos - How can I check if ctrl and other key are pressed?

Processing Coding Questions
1

Hello, I want to run some code and then quit the program from running when I press ctrl+x. I tried the next code:

boolean ctrl;
boolean x;

void setup() {
  //Some code
}

void draw(){
  //More code
}


void keyPressed() {
  if (key == CODED) {
    if (keyCode == CONTROL){
      ctrl = true; //When ctrl is pressed, I set its variable as true.
      println("ctrl pressed");
    }  
  }
  if (key == 'x' || key == 'X') {
    x = true; //The same as ctrl with x.
    println("x pressed");
  }
  if (ctrl && x) {
    println("Exiting...\n\n"); //If both keys are pressed, it should print this message and quit.
    exit();
  }
}



void keyReleased() {
  if (key == CODED) {
    if (keyCode == CONTROL) {
      ctrl = false; 
      println("ctrl released");
    }
  }
  if (key == 'x' || key == 'X') {
    x = false;
    println("x released");
  }
}

When I run this, if I press x and then ctrl (in that order), it works. But if I do the opposite thing (ctrl first, and then x), it doesn’t do anything. I don’t know why do this happen or how to solve this, can any of you help me?

Thank you so much.

2

Hi,

it’s quite likely ctrl+x is not handled as two independant keyEvent ‘ctrl’ then ‘x’

to try this, you can print what value is key on event:

...
void keyPressed() {
        println("and the winner is: ", int(key) );
...

int(key) will give you the ascii decimal value handled corresponding to https://www.ascii-code.com/

for this kind of combo, i guess it is Os dependant (i don t know)
for eg: ctrl+x on macos give ascii code 24, ascii code for “Cancel”

so i will try:
if(key==24) exit();

2 Likes
3

Hi,
it worked in Windows 10, too.

In case someone is interested, I found a different way to solve it (which is quite more complex than th75’s one, and probably less optimized). Instead of checking if the key is the ASCII code for CAN. I worked with Java keyCodes. Checking if both ctrl and the keyCode 88 (Java code for ‘x’) are pressed:

void keyPressed() {
  if (key == CODED) {
    if (keyCode == CONTROL){
      ctrlPressed = true;
      println("ctrl pressed");
    }  
  }
  if (ctrlPressed && keyCode == 88) {
    //Code
  }
}


void keyReleased() {
  if (key == CODED) {
    if (keyCode == CONTROL) {
      ctrlPressed = false;
      println("ctrl released");
    }
  }
}

Java keyCodes (gotten from this StackOverflow post):

3 -- Cancel
8 -- Backspace
9 -- Tab
10 -- Enter
12 -- Clear
16 -- Shift
17 -- Ctrl
18 -- Alt
19 -- Pause
20 -- Caps Lock
21 -- Kana
24 -- Final
25 -- Kanji
27 -- Escape
28 -- Convert
29 -- No Convert
30 -- Accept
31 -- Mode Change
32 -- Space
33 -- Page Up
34 -- Page Down
35 -- End
36 -- Home
37 -- Left
38 -- Up
39 -- Right
40 -- Down
44 -- Comma
45 -- Minus
46 -- Period
47 -- Slash
48 -- 0
49 -- 1
50 -- 2
51 -- 3
52 -- 4
53 -- 5
54 -- 6
55 -- 7
56 -- 8
57 -- 9
59 -- Semicolon
61 -- Equals
65 -- A
66 -- B
67 -- C
68 -- D
69 -- E
70 -- F
71 -- G
72 -- H
73 -- I
74 -- J
75 -- K
76 -- L
77 -- M
78 -- N
79 -- O
80 -- P
81 -- Q
82 -- R
83 -- S
84 -- T
85 -- U
86 -- V
87 -- W
88 -- X
89 -- Y
90 -- Z
91 -- Open Bracket
92 -- Back Slash
93 -- Close Bracket
96 -- NumPad-0
97 -- NumPad-1
98 -- NumPad-2
99 -- NumPad-3
100 -- NumPad-4
101 -- NumPad-5
102 -- NumPad-6
103 -- NumPad-7
104 -- NumPad-8
105 -- NumPad-9
106 -- NumPad *
107 -- NumPad +
108 -- NumPad ,
109 -- NumPad -
110 -- NumPad .
111 -- NumPad /
112 -- F1
113 -- F2
114 -- F3
115 -- F4
116 -- F5
117 -- F6
118 -- F7
119 -- F8
120 -- F9
121 -- F10
122 -- F11
123 -- F12
127 -- Delete
128 -- Dead Grave
129 -- Dead Acute
130 -- Dead Circumflex
131 -- Dead Tilde
132 -- Dead Macron
133 -- Dead Breve
134 -- Dead Above Dot
135 -- Dead Diaeresis
136 -- Dead Above Ring
137 -- Dead Double Acute
138 -- Dead Caron
139 -- Dead Cedilla
140 -- Dead Ogonek
141 -- Dead Iota
142 -- Dead Voiced Sound
143 -- Dead Semivoiced Sound
144 -- Num Lock
145 -- Scroll Lock
150 -- Ampersand
151 -- Asterisk
152 -- Double Quote
153 -- Less
154 -- Print Screen
155 -- Insert
156 -- Help
157 -- Meta
160 -- Greater
161 -- Left Brace
162 -- Right Brace
192 -- Back Quote
222 -- Quote
224 -- Up
225 -- Down
226 -- Left
227 -- Right
240 -- Alphanumeric
241 -- Katakana
242 -- Hiragana
243 -- Full-Width
244 -- Half-Width
245 -- Roman Characters
256 -- All Candidates
257 -- Previous Candidate
258 -- Code Input
259 -- Japanese Katakana
260 -- Japanese Hiragana
261 -- Japanese Roman
262 -- Kana Lock
263 -- Input Method On/Off
512 -- At
513 -- Colon
514 -- Circumflex
515 -- Dollar
516 -- Euro
517 -- Exclamation Mark
518 -- Inverted Exclamation Mark
519 -- Left Parenthesis
520 -- Number Sign
521 -- Plus
522 -- Right Parenthesis
523 -- Underscore
524 -- Windows
525 -- Context Menu
61440 -- F13
61441 -- F14
61442 -- F15
61443 -- F16
61444 -- F17
61445 -- F18
61446 -- F19
61447 -- F20
61448 -- F21
61449 -- F22
61450 -- F23
61451 -- F24
65312 -- Compose
65368 -- Begin
65406 -- Alt Graph
65480 -- Stop
65481 -- Again
65482 -- Props
65483 -- Undo
65485 -- Copy
65487 -- Paste
65488 -- Find
65489 -- Cut

Anyway I think working with ASCII codes will work better and make the code more universal and readable.
Thank you so much for your help, th75!!

1 Like