How to know width in pixel of a TEXT widget from inside the callback?

mastupristi · February 7, 2018 at 10:56 PM

I need to know the width in pixel of a TEXT widget text from inside the (overridden) callback.
I tried to use GUI_GetStringDistX () but it seems that the font it uses to calculate the width is different from the one user by TEXT widget to render the text.

I have a small slice of code:

C

#include "GUI.h"
#include "TEXT.h"
#include <stdio.h>


static int extent = 0;


void _cbCallback(WM_MESSAGE * pMsg)
{
	switch (pMsg->MsgId)
	{
	case WM_PAINT:
    	{
        	char str[20];
        	TEXT_GetText(pMsg->hWin, str, 20);
        	extent = GUI_GetStringDistX(str);
        	TEXT_Callback(pMsg);
    	}
    	break;
	default:
    	WM_DefaultProc(pMsg);
    	break;
	}
}


void MainTask(void)
{
  GUI_Init();


  GUI_SetBkColor(GUI_WHITE);
  GUI_Clear();
  GUI_SetColor(GUI_BLACK);


  GUI_DispStringAt("DONE", 10, 10);


  WM_HWIN hWin;


  hWin = TEXT_CreateEx(10, 17, 50, 20, WM_HBKWIN, WM_CF_SHOW, TEXT_CF_LEFT|TEXT_CF_TOP, GUI_ID_TEXT0, "");


  WM_SetCallback(hWin, _cbCallback);


  TEXT_SetText(hWin, "DONE");
  GUI_Delay(100);
  char str[3];
  sprintf(str, "%d", extent);
  GUI_DispStringAt(str, 10, 30);
  while(1)
  {
   	GUI_Delay(100);
  }
}

Display More

the result is:
[Blocked Image: https://s17.postimg.org/6fhzza3v3/string_Dim.png]

As you can see 24 is the whidth of the text rendered by GUI_DispStringAt () and not by TEXT widget.

best regards
Max

SEGGER - Schoenen · February 8, 2018 at 12:02 PM

Hi,

While calling GUI_GetStringDistX() within WM_PAINT the default font is still set and you will receive the string length in pixel in combination with the default font.

To get the string length of from the TEXT widget you have to set the font used by the text widget before calling GUI_GetStringDistX().

Try this:

C

#include "GUI.h"
#include "TEXT.h"
#include <stdio.h>


static int extent = 0;


void _cbCallback(WM_MESSAGE * pMsg) {
  char str[20];
  const GUI_FONT * pFont;


  switch (pMsg->MsgId) {
  case WM_PAINT:
	TEXT_GetText(pMsg->hWin, str, 20);
	pFont = GUI_SetFont(TEXT_GetFont(pMsg->hWin));
	extent = GUI_GetStringDistX(str);
	TEXT_Callback(pMsg);
	GUI_SetFont(pFont);
	break;
  default:
	WM_DefaultProc(pMsg);
	break;
  }
}


void MainTask(void) {
  WM_HWIN hWin;
  char str[3];
  GUI_Init();


  GUI_SetBkColor(GUI_WHITE);
  GUI_Clear();
  GUI_SetColor(GUI_BLACK);


  GUI_DispStringAt("DONE", 10, 10);
  
  hWin = TEXT_CreateEx(10, 17, 50, 20, WM_HBKWIN, WM_CF_SHOW, TEXT_CF_LEFT|TEXT_CF_TOP, GUI_ID_TEXT0, "");


  WM_SetCallback(hWin, _cbCallback);


  TEXT_SetText(hWin, "DONE");
  GUI_Delay(100);
  sprintf(str, "%d", extent);
  GUI_DispStringAt(str, 10, 30);
  while(1) {
	GUI_Delay(100);
  }
}

Display More

Regards
Sven

How to know width in pixel of a TEXT widget from inside the callback?

Participate now!

Users Viewing This Thread