java - Detecting backspace key press -


is there way detect when backspace key on keyboard has been pressed, using document filter? the following edited code extract here

for example

public class intfilter extends documentfilter {     boolean truefalse = true;     public void insertstring(documentfilter.filterbypass fb, int offset,                              string string, attributeset attr)             throws badlocationexception {          stringbuffer buffer = new stringbuffer(string);         (int = buffer.length() - 1; >= 0; i--) {             char ch = buffer.charat(i);             if (!character.isdigit(ch)) {                 buffer.deletecharat(i);                 truefalse = false;             }             /*             else if (backspace pressed)             {                 truefalse = true;             }             */             else{                 truefalse = true;             }         }         super.insertstring(fb, offset, buffer.tostring(), attr);     }      public void replace(documentfilter.filterbypass fb,                         int offset, int length, string string, attributeset attr) throws badlocationexception {         if (length > 0) fb.remove(offset, length);         insertstring(fb, offset, string, attr);     } }

pressing backspace key won't trigger insertstring() method. should rather trigger remove() method (only when text removed, not case when caret @ beginning of text example).

but can detect keystroke using keylistener (doc). here's how detect backspace key:

public class keyeventdemo implements keylistener {      /** handle key typed event text field. */     public void keytyped(keyevent e) {}      /** handle key-pressed event text field. */     public void keypressed(keyevent e) {}      /** handle key-released event text field. */     public void keyreleased(keyevent e) {         if(e.getkeycode()==keyevent.vk_back_space){              // something...         }     }  }

Comments

Post a Comment

Popular posts from this blog

powershell Start-Process exit code -1073741502 when used with Credential from a windows service environment -

i'm running strange behavior powershell start-process call. here call: $process = start-process ` "c:\somepath\mybinary.exe" ` -passthru ` -credential $defaultcredential ` -wait ` -workingdirectory "c:\somepath" ` -loaduserprofile if ($process.exitcode -ne 0) { #do } this call return exit code - 1073741502 . after quick search, exit code seems related generic error when program not load required dll (aka. status_dll_init_failed ). when run without -credential $credential program runs correctly. in order isolate problem, manually launched some.exe in prompt target credential , runs smoothly. so problem seems come way start-process cmdlet launch process. i found potential solutions problem tried apply no luck : link , link . would have idea of what's going on here ? edit 1: run proc mon monitoring program activities when launched directly or via powershell script. problem seems occur when loading kernelbase
Read more

twig - Using Twigbridge in a Laravel 5.1 Package -

i'm trying create laravel 5.1 package uses twigbridge instead of .php views. can normal .php views display fine, when try make use of .twig templates i'm met error. possible use twigbridge templates when creating views laravel package or pretty stuck blade , php ? edit 1: loading twig template without extending works. it's when start using {% extends 'file' %} error comes out. i error error loading /virtual/laravel/packages/username/mypackage/src/views/sample.twig: template "templates.master" not defined () in "/virtual/laravel/packages/username/mypackage/src/views/sample.twig" @ line 1. my folders username |_ mypackage |_ src |_ controllers - samplecontroller.php |_ views |_ templates - master.twig - sample.twig twig template sample.twig {% extends 'templates.master' %} {% block content %} {{ parent()
Read more

c# - LINQ join Entities from HashSet's, Join vs Dictionary vs HashSet performance -

i have hashset's each stores t, have written test application compares different relation algorithms can think of, i'm not pleased results getting. does there exist more efficient ways of achieving object relations, once testing? using system; using system.collections.generic; using system.linq; using system.text; using system.threading.tasks; using system.diagnostics; namespace linqtests { class program { static void main(string[] args) { hashset<user> usertable = new hashset<user>(); hashset<userproperty> userpropertytable = new hashset<userproperty>(); #region lets create dummy data. console.writeline("please wait while creating dummy data, can take while..."); console.writeline(""); int rows = 1000000; for(int x = 0; x < rows; x++) { random rnd = new random(); // ad
Read more