On-The-Spot Conversion in DBCS PM

Generally, the on-the-spot conversion is preferred to the fixed-position conversion. To support it, your program should properly handle WM_QUERYCONVERTPOS, which is sent by the system to the application when the user tries to enter the conversion mode. The first message parameter contains pointer to cursorpos (RECTL) and the second message parameter is reserved. The application can specify its intention on DBCS input method by replying to this message as follows:

• If you accept entering the conversion mode, return value QCP_CONVERT (USHORT) with ;

  a.

  If you prefer the on-the-spot conversion, update xLeft and yBottom of cursorpos to the bottom-left corner of the text cursor position in window coordinate.
  b.
  If you prefer the fixed-position conversion, update xLeft and yBottom of cursorpos to (-1,-1).
  2.
  If you want to inhibit to enter the conversion mode, return value QCP_NOCONVERT.

  The above process 1.a. is for the on-the-spot conversion and 1.b. is for the fixed-position conversion. The single line, multi-line, and prompted entry field control (WC_ENTRYFIELD, WC_MLE and WC_COMBOBOX) support the on-the-spot conversion.

  The next code fragment is a sample AVIO application supporting the on-the-spot conversion.

  case WM_QUERYCONVERTPOS:    VioGetCurPos( &cpQuery.y, &cpQuery.x, hpsVio );
      VioGetOrg( &Origin.y, &Origin.x, hpsVio);
      WinQueryWindowRect( hwnd, &rcl );
      ((PRECTL)mp1)->xLeft   = (cpQuery.x - Origin.x) * DevCell.cx;
      ((PRECTL)mp1)->yBottom =
              rcl.yTop-((cpQuery.y-Origin.y+1)*DevCell.cy);
      ((PRECTL)mp1)->xRight  = ((PRECTL)mp1)->xLeft + DevCell.cx;
      ((PRECTL)mp1)->yTop    = ((PRECTL)mp1)->yBottom + DevCell.cy;
      return (MPARAM)QCP_CONVERT;
      break;
  

  Note:

  • If the user chooses the fixed-position conversion (using PM Control Panel), his/her choice takes higher priority even when your program chooses the on-the-spot conversion.

  • For "entry field","combo box" and "multiple line entry field", application programs does not need to handle WM_QUERYCONVERTPOS. These controls handle WM_QUERYCONVERTPOS as default behavior.

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