Text input.

Text input.

julian_boolean

Member #8,201

January 2007

Just wondering how everyone here deals with inputting text to the screen when your using graphics.

I was trying to use gstream but it didn't seem to work very well.. Whenever I tried normal output the characters would just flash as if they weren't being buffered properly, then when I tried input, it would just be a black screen until I mashed a bunch of keys then my graphics would show. The characters always went over my mouse too no matter where I put the functions.

Before gstream, I was looking at this: http://www.gamedev.net/reference/articles/article2130.asp

It seemed to work pretty good, but I was just curious to see other ideas.

Steve Terry

Member #1,989

March 2002

I don't see any better way of handling text input other than using keypressed and the scancode/ascii code of the key pressed. The methods in the article are correct, if you are seeing text written over your cursor than that is a problem with how you are drawing things to the screen, draw text, then cursor, not the other way around.

___________________________________
[ Facebook ]
Microsoft is not the Borg collective. The Borg collective has got proper networking. - planetspace.de
Bill Gates is in fact Shawn Hargreaves' ßî+çh. - Gideon Weems

julian_boolean

Member #8,201

January 2007

This guy's example is a little difficult for me to use. What I was trying to do with it was make it into a class, then use it in my game state classes like this:

1titlescreen::logic(BITMAP *textbuffer);
2{
3     cText name;
4 
5     name.key_input(textBuffer);
6     name.set_coords(100,100); // <-- hopefully
7 
8     cText pass;
9 
10     pass.key_input(textBuffer);
11     pass.set_coords(100,100); // <-- hopefully
12}
13 
14titlescreen::draw(BITMAP *buffer);
15{
16     // various graphics
17}

But I think the buffers are kinda conflicting and it's making the entire screen flash.. Even if I could get this to work I have no idea how I'd be able to choose and input text between "name" and "pass" with the mouse.

Steve Terry

Member #1,989

March 2002

Why would you create a new cText object each time you called logic that makes no sense. Just make a name and pass object in your constructor, then in your logic you can do an if(needs_login){ name.set_coords(100, 100); pass.set_coords(100, 150); } Your class should get input only when needed so I'm guessing set_coords would activate the input box or you could have a separate activate object. When the user clicks OK or whatever then you call name.get_text() and pass.get_text() which will return the buffers in those classes.

julian_boolean

Member #8,201

January 2007

Not really sure what you mean.. I had always created different instances of interface stuff if I wanted them to have different properties and do different things.

I also managed to sorta get the text to stop flashing by putting it in with my draw function.. Which kinda annoys me because basically everything has to be in the draw function since its the only one thats blitting the buffer. If i try to blit the buffer in a different function then try to run it through the game loop it'll flicker again, ugh.

Steve Terry

Member #1,989

March 2002

What I am trying to say is that you should not have your text input functions stop the program and loop within, instead your functions should simply check for a keypress, if so then add or subtract a character and blit to the buffer, otherwise blit to the buffer the text and return.

julian_boolean

Member #8,201

January 2007

I think I know what your trying to get at now, goina try it out. Also, does anyone know how I could go about setting the capacity or coordinates of the text? Was looking at some Allegro functions for text, but I'm 95% sure this ISN'T how they're suppose to be used, because it's not working.

void text::set_coords(int w, int h)
{
  w = text_length(font, edittext.c_str());
  h = text_height(font);
}

No idea how I make a function for capacity though.

Steve Terry

Member #1,989

March 2002

void text::set_coords(int &w, int &h)

{
  w = text_length(font, edittext.c_str());
  h = text_height(font);
}

Hmm that would be a get_coords function anyway and it's not coords but bounds.

Johan Halmén

Member #1,550

September 2001

Allegro GUI. d_edit_proc() to be more specific. You define the max length, placement of the text box, font colours etc. You have the backspace functionality, and delete, I think. And you can customise it. I made a customised thing that works with non-even coloured fonts. My Christmashack entry uses it for name input in the score list. Check there how it works.

Does it echo here? Feels like a dejavu.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Years of thorough research have revealed that the red "x" that closes a window, really isn't red, but white on red background.

Years of thorough research have revealed that what people find beautiful about the Mandelbrot set is not the set itself, but all the rest.

julian_boolean

Member #8,201

January 2007

Thanks for the help guys. NOW I'm trying to combine a button class and the text code into one class on its own. I have the text code in a seperate function (and the code for drawing the text inside the draw function for the button/textfield.)

1#define SELECTED 0
2#define NOT_SELECTED 1
3 
4  ...
5 
6  selection status;
7 
8----------------------------------
9 
10text::init( ... )
11{
12  ...
13 
14  selection_status = NOT_SELECTED;
15}
16 
17text::text_logic()
18{
19  if(selection_status == SELECTED)
20  {
21      while(keypressed())
22    {
23      int  newkey   = readkey();
24      char ASCII    = newkey & 0xff;
25      char scancode = newkey >> 8;
26  ...
27}

So! Inside the logic function for the new/converted button class called text, I had it set selection_status to SELECTED only if the textfield is pressed. For some reason, if I mash a bunch of keys THEN press the textfield, even though it's set to NOT_SELECTED (yet), all the keys that I pressed will appear.

Jeff Bernard

Member #6,698

December 2005

Sounds like you just need to clear the keyboard buffer.

clear_keybuf() before readkey() and prossibly before keypressed() too.

--
I thought I was wrong once, but I was mistaken.

julian_boolean

Member #8,201

January 2007

I went with "else if(selection_status == NOT_SELECTED) { clear_keybuf(); }" and it seems to work sorta okay. Now I want it so, when you click the text field it sets the status to selected and keeps it that way until I say otherwise! Because right now I have to hold in the text field with my mouse to type, then when I let go it stops me from polling the text. For the record I'm using the code for the Loomsoft Button (which can be found here: http://www.loomsoft.net/util_lsbutton.shtml)

Here's what I'm working with now:

#SelectExpand
   1#include "text.h"
   2#define WHITE makecol(255, 255, 255)
   3#include <allegro.h>
   4#include <string>
   5using namespace std;
   6
   7string edittext;
   8string::iterator iter = edittext.begin();
   9int caret  = 0;
  10bool insert = true;    
  11
  12void text::initialize(BITMAP *bitmap_on, BITMAP *bitmap_down, BITMAP *bitmap_off, int MOUSE_DETECTION_MODE, int MOUSE_CLICK_MODE)
  13{
  // Set the bitmap pointers
  on_bitmap = bitmap_on;
  down_bitmap = bitmap_down;
  off_bitmap = bitmap_off;
  18
  // Set all the modes that were passed.
  mouse_detection_mode = MOUSE_DETECTION_MODE;
  mouse_status = BUTTON_NOT_ON_FOCUS;
  mouse_click_mode = MOUSE_CLICK_MODE;
  23
  // Set the bounding box to be the dimensions of the off_bitmap.
  bound_left = 0;
  bound_top = 0;
  bound_right = off_bitmap->w;
  bound_bottom = off_bitmap->h;
  29
  // Set the x/y position to 0,0
  x_position = 0;
  y_position = 0;
  33
  // Set the masking color to the default "magic pink".
  masking_color = makecol(255,0,255);
  36
  // Turn off the bounding box display feature
  show_bbox = FALSE;
  39
  // Set the original frame to draw the button to off_bitmap
  draw_frame = BUTTON_DRAW_FRAME_OFF;
  42
  // Set the button to an active state.
  is_active = TRUE;
  
  selection_status = BUTTON_NOT_SELECTED;
  47}
  48
  49void text::set_bounds(int left_bound, int right_bound, int top_bound, int bottom_bound)
  50{
if(mouse_detection_mode == BUTTON_BOUNDING_BOX)
{
  bound_left = left_bound;
  bound_right = right_bound;
  bound_top = top_bound;
  bound_bottom = bottom_bound;
}
  58}
  59
  60void text::set_masking_color(int red, int blue, int green)
  61{
if(red < 0)
  red = 0;
else if(red > 255)
  red = 255;
  66
if(blue < 0)
  blue = 0;
else if(blue > 255)
  blue = 255;
  71
if(green < 0)
  green = 0;
else if(green > 255)
  green = 255;
  76
masking_color = makecol(red,blue,green);
  78}
  79
  80//Sets if the drawing function should show the bounding box.
  81void text::set_show_bounding_box(int value)
  82{
show_bbox = value;
  84}
  85
  86//Sets the active state for the button
  87void text::set_active(int value)
  88{
is_active = value;
  90}
  91
  92void text::set_coords(int x, int y)
  93{
x_position = x;
y_position = y;
  96}
  97
  98void text::poll()
  99{
if(mouse_x > bound_left+x_position && mouse_x < bound_right+x_position &&
   mouse_y > bound_top+y_position && mouse_y < bound_bottom+y_position)
{
  if(is_active && selection_status == BUTTON_SELECTED)
  {    
    while(keypressed())
    {
      int  newkey   = readkey();
      char ASCII    = newkey & 0xff;
      char scancode = newkey >> 8;
 110
      if(ASCII >= 32 && ASCII <= 126)
      {
        if(insert || iter == edittext.end())
          iter = edittext.insert(iter, ASCII);
      
        else
          edittext.replace(caret, 1, 1, ASCII);
          caret++;
          iter++;
      }
 121
      else
        switch(scancode)
        {
          case KEY_DEL:
          if(iter != edittext.end()) iter = edittext.erase(iter);
          break;
 128
          case KEY_BACKSPACE:
          if(iter != edittext.begin())
          {
            caret--;
            iter--;
            iter = edittext.erase(iter);
          }break;
          
          case KEY_RIGHT:
          if(iter != edittext.end())   caret++, iter++;
          break;
          
          case KEY_LEFT:
          if(iter != edittext.begin()) caret--, iter--;
          break;
          
          case KEY_INSERT:
          insert = !insert;
          break;
 148
          default:
          break;
        }
    }
  }

  else if(selection_status == BUTTON_NOT_SELECTED) { clear_keybuf(); }
 156
  if(mouse_detection_mode == BUTTON_PIXEL_PERFECT)
  {
          
    if(getpixel(off_bitmap, mouse_x-x_position,mouse_y-y_position) != makecol(255,0,255))
    {
      if(mouse_b & 1)
      {
        selection_status = BUTTON_SELECTED;      
                  draw_frame = BUTTON_DRAW_FRAME_DOWN;
      }
      
      else
      {
                  selection_status = BUTTON_NOT_SELECTED;
                  draw_frame = BUTTON_DRAW_FRAME_ON;
      }
    }
    
    else
    {                
              selection_status = BUTTON_NOT_SELECTED;
              draw_frame = BUTTON_DRAW_FRAME_OFF;
                
      if(mouse_status != BUTTON_MOUSE_STATUS_DOWN)
      {
                  mouse_status = BUTTON_NOT_ON_FOCUS;
      }
    }    
  }
  
  else
  {
    if(mouse_b & 1)
    {
      draw_frame = BUTTON_DRAW_FRAME_DOWN;
    }
    
    else
    {
      draw_frame = BUTTON_DRAW_FRAME_ON;
    }
  }
}

else
{
  draw_frame = BUTTON_DRAW_FRAME_OFF;
  
  if(mouse_status != BUTTON_MOUSE_STATUS_DOWN)
  {
    mouse_status = BUTTON_NOT_ON_FOCUS;
  }
}
 210}
 211
 212int text::is_clicked()
 213{
if(mouse_x > (bound_left+x_position) && mouse_x < (bound_right+x_position) &&
   mouse_y > (bound_top+y_position) && mouse_y < (bound_bottom+y_position))
{
  if(!(mouse_b & 1) && mouse_status == BUTTON_NOT_ON_FOCUS)
  {
    mouse_status = BUTTON_MOUSE_STATUS_UP;
  }
  
  if(mouse_b & 1 && mouse_click_mode == BUTTON_CLICK_MODE_CONSTANT)
  {
    return TRUE;
  }
 226
  if(mouse_b & 1 && mouse_status != BUTTON_NOT_ON_FOCUS)
  {
    mouse_status = BUTTON_MOUSE_STATUS_DOWN;        
  }
  
  else if(!(mouse_b & 1) && mouse_status == BUTTON_MOUSE_STATUS_DOWN)
  {
    mouse_status = BUTTON_MOUSE_STATUS_UP;
      
    if(mouse_detection_mode == BUTTON_PIXEL_PERFECT)
      {
      if(getpixel(off_bitmap, mouse_x-x_position,mouse_y-y_position) != masking_color)
      {
        return TRUE;
      }
    }
    
    else 
    {
      return TRUE;
    }
  }
}
  
else if(!(mouse_b & 1))
{
   mouse_status = BUTTON_NOT_ON_FOCUS;
}
 255
return FALSE;
 257}
 258
 259void text::draw_button(BITMAP *bitmap_buffer)
 260{
if(draw_frame == BUTTON_DRAW_FRAME_DOWN)
{
  if(down_bitmap != NULL)
  {
    acquire_screen();
    draw_sprite(bitmap_buffer, down_bitmap, x_position, y_position);
    release_screen();
    vline(bitmap_buffer, caret* 8, 8, 18, WHITE);
  }
}
  
else if(draw_frame == BUTTON_DRAW_FRAME_ON)
{
  if(on_bitmap != NULL)
  {
    acquire_screen();
    draw_sprite(bitmap_buffer, on_bitmap, x_position, y_position);
    release_screen();
  }
}
  
else if(draw_frame == BUTTON_DRAW_FRAME_OFF)
{
  if(off_bitmap != NULL)
  {
    acquire_screen();
    draw_sprite(bitmap_buffer, off_bitmap, x_position, y_position);
    release_screen();
  }
}
        
if(show_bbox)
{
  rect(bitmap_buffer, bound_left+x_position, bound_top+y_position, bound_right+x_position, bound_bottom+y_position, makecol(255,0,0));
}
  
textout_ex(bitmap_buffer, font, edittext.c_str(), 0, 10, WHITE, -1);
 298}

The string edittext stuff is put right under where I include allegro, the header, etc. I tried to put it somewhere else though it doesn't seem to like it when I do that. Which is sorta a problem because it's always storing the information in the same things.

Steve Terry

Member #1,989

March 2002

Nice globals

You just need an active flag which simply is turned on when you move the mouse inside the bounds of the box and click. The only way it will not be active is if you loose focus to that edit box and into another. For that purpose you can have a text manager which stores a list of all edit boxes you have active at any given time so that when one gains focus you can deactivate the other one. You can even capture TAB as a key to toggle through your list of text objects.

if(green < 0)
    green = 0;
  else if(green > 255)
    green = 255;

You can use MID for this purpose, MID(0, green, 255)

23yrold3yrold

Member #1,134

March 2001

Quote:

Just wondering how everyone here deals with inputting text to the screen when your using graphics.

Probably past this point for you, but I wrote this a long time ago and maybe it's worth something ...

Clickies.

--
Software Development == Church Development
Step 1. Build it.
Step 2. Pray.

julian_boolean

Member #8,201

January 2007

Steve:

I thought that's what I already have. I was planning on having somewhere in my logic function for the game states that if a text field is clicked, it'll stop polling any of the other ones on the screen. Actually I did try to do that but the program would just crash.. It was something simple like:

if(firstName.is_clicked())
{
  lastName.is_active(false)
}

23yrold3yrold:

I'm already using your code works nicely, but I'd still like to put the iter/caret/edittext stuff inside a function if I could find a way how.