ATSUDrawText

OSStatus ATSUDrawText (
                     ATSUTextLayout iTextLayout,
                     UniCharArrayOffset iLineOffset,
                     UniCharCount iLineLength,
                     ATSUTextMeasurement iLocationX,
                     ATSUTextMeasurement iLocationY);

iTextLayout

A reference of type ATSUTextLayout. Pass a reference to an initialized text layout object. You cannot pass NULL for this parameter.

iLineOffset

A value of type UniCharArrayOffset. Pass the edge offset that corresponds to the beginning of the range of text that you want to render. If the range of text spans multiple lines, you should call ATSUDrawText for each line and pass the offset of the beginning of the new line to draw. To indicate the beginning of the text buffer, pass the constant kATSUFromTextBeginning, described in Text Offset Constant. To indicate the entire text buffer, pass kATSUFromTextBeginning in this parameter and the constant kATSUToTextEnd in the iLineLength parameter. If the offset is outside the text buffer, ATSUDrawText returns the result code kATSUInvalidTextRangeErr.

iLineLength

A value of type UniCharCount. Pass the length of the range of text that you want to render. To indicate the end of the text buffer, pass the constant kATSUToTextEnd, described in Text Length Constant. To indicate the entire text buffer, pass kATSUToTextEnd in this parameter and the constant kATSUFromTextBeginning in the iLineOffset parameter. If the range of text is outside the text buffer, ATSUDrawText returns the result code kATSUInvalidTextRangeErr.

iLocationX

A value of type ATSUTextMeasurement. Pass the x-coordinate of the origin of the line (in the current graphics port) containing the range of text you want to draw. Pass the constant kATSUUseGrafPortPenLoc, described in Current Pen Location Constant, if you want to draw relative to the current pen location in the current graphics port.

iLocationY

A value of type ATSUTextMeasurement. Pass the y-coordinate of the origin of the line (in the current graphics port) containing the range of text you want to draw. Pass the constant kATSUUseGrafPortPenLoc, described in Current Pen Location Constant, if you want to draw relative to the current pen location in the current graphics port.

function result

A result code. The result code kATSUInvalidCacheErr indicates that an attempt was made to read in style data from an invalid cache. This may be because the format of the cached data does not match that used by ATSUI or the cached data is corrupt. The result code kATSUQuickDrawTextErr indicates that the QuickDraw function DrawText encountered an error while rendering a line of text. For a list of other ATSUI-specific result codes, see Result Codes.

DISCUSSION

The ATSUDrawText function renders a range of text at a specified screen location. It uses the same transfer mode and resolution as those set in the graphics port. Text color is taken from the style object and the value in the graphics port is ignored. If the text color was not previously set in the style object, you will get black text, regardless of what was set in the graphics port.

Before drawing the line, ATSUDrawText turns off any previously set line justification, rotation, width alignment, descent, and ascent values and treats the text as a single line. It then examines the text layout object to make sure that the style runs cover the entire range of text. If there are gaps between style runs, ATSUDrawText assigns the characters in the gap to the style run following the gap. If there is no style run at the beginning of the range of text, ATSUDrawText assigns these characters to the first style run it can find. If there no style run at the end of the range of text, ATSUDrawText assigns the remaining characters to the last style run it can find.

If you want to draw a range of text that spans multiple lines, you should call ATSUDrawText for each line of text that is being drawn, even if all the lines are in the same text layout object. You should adjust the iLineOffset parameter to reflect the beginning of each line to be drawn.

SPECIAL CONSIDERATIONS

ATSUDrawText may allocate memory in your application heap, unless you designate a different heap by calling the function ATSUCreateMemorySetting.

VERSION NOTES

Available beginning with ATSUI 1.0.